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Veling, J., F. G. van Zijderveld, A. M. van Zijderveld-van Bemmel, H. W. Barkema e Y. H. Schukken. "Evaluation of Three Newly Developed Enzyme-Linked Immunosorbent Assays and Two Agglutination Tests for Detecting Salmonella enterica subsp. enterica Serovar Dublin Infections in Dairy Cattle". Journal of Clinical Microbiology 38, n. 12 (2000): 4402–7. http://dx.doi.org/10.1128/jcm.38.12.4402-4407.2000.
Testo completoAbstract (sommario):
In this study test characteristics of three newly developed enzyme-linked immunosorbent assays (ELISAs) for Salmonella enterica subsp. enterica serovar Dublin were evaluated and compared with two agglutination tests. The ELISAs involved were an indirect ELISA with serovar Dublin lipopolysaccharide (LPS ELISA), an indirect ELISA with serovar Dublin flagellar antigen (GP ELISA), and a double-antibody sandwich blocking ELISA that uses monoclonal antibodies against S. enterica subsp.enterica serovar Enteritidis flagellin (GM-DAS ELISA). The agglutination tests involved were two routine serum agglutination tests with either somatic (O) or flagellar (H) antigen. Diagnostic specificity of the three ELISAs was determined using 840 serum samples from seven dairy herds without any history of serovar Dublin infection. Cutoff values at a titer of 100, 100, and 10, respectively, for the LPS ELISA, GP ELISA, and GM-DAS blocking ELISA resulted in a specificity of 99.3, 100, and 100%, respectively. Using these cutoff values the LPS ELISA, GP ELISA, and GM-DAS ELISA were able to detect, respectively, 30, 46, and 38% of 50 fecal culture-positive animals from 13 herds with a recent serovar Dublin infection. With the same cutoff values, active carriers (n = 18) were detected for 94.4% with the LPS ELISA and for 100% with the GP and GM-DAS ELISAs. Kappa values determined on the results of all tests from 8 of the 13 serovar Dublin-infected herds and the 7 control herds demonstrated a good correlation between the results of all ELISAs and the H-agglutination test. The results of the O-agglutination test failed to correlate with those of the other tests. Using a set of sera from 170 aborting cows (with 25 abortions due to serovar Dublin), test results of the ELISAs and the H-agglutination test were comparable. The H-agglutination test may be used successfully for single sample testing, especially to diagnose abortion due to serovar Dublin. It is concluded that the ELISAs are useful diagnostic tools in serovar Dublin control programs and that they are preferred to agglutination tests for reasons of automation and costs.
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Tenter, A. M., C. Vietmeyer, A. M. Johnson, K. Janitschke, M. Rommel e W. Lehmacher. "ELISAs based on recombinant antigens for sero-epidemiological studies onToxoplasma gondiiinfections in cats". Parasitology 109, n. 1 (luglio 1994): 29–36. http://dx.doi.org/10.1017/s0031182000077738.
Testo completoAbstract (sommario):
SUMMARYTwo recombinantToxoplasma gondiipolypeptides, H4 and H11, were tested as diagnostic antigens in enzyme-linked immunosorbent assays (ELISAs). The results obtained by ELISAs based on single H4 (H4-ELISA), on single H11 (H11-ELISA) and on a mixture of H4 and H11 (H4/H11-ELISA) were compared with results obtained by an ELISA based on traditional ELISA antigen (TEA-ELISA), an indirect fluorescent antibody test (IFAT), the Sabin-Feldman dye test (SFDT) and a direct agglutination test (DAT). A total of 306 cats from a suburban cat population were tested of which about 45% showed serological evidence ofT. gondiiinfection. Infection rates varied from about 32% for cats kept indoors to about 55% for stray cats. Specificities > 99% were observed for all ELISAs based on the recombinant antigens (H4-ELISA, H11-ELISA and H4/H11-ELISA). The H4/H11-ELISA also reached a sensitivity of 95% which compared very favourably with those observed for the TEA-ELISA (98%) and for the IFAT (94%). Negative and positive predictive values for the H4/H11-ELISA were 96 and < 99%, respectively. Antibody titres measured by the H4/H11-ELISA also correlated well with those measured by the SFDT and the DAT. Hence, the H4/H11-ELISA appears to be a very suitable test for sero-epidemiological studies onT. gondiiinfections in cats.
3
McKenna, S. L. B., D. C. Sockett, G. P. Keefe, J. McClure, J. A. VanLeeuwen e H. W. Barkema. "Comparison of Two Enzyme-Linked Immunosorbent Assays for Diagnosis of Mycobacterium Avium Subsp. Paratuberculosis". Journal of Veterinary Diagnostic Investigation 17, n. 5 (settembre 2005): 463–66. http://dx.doi.org/10.1177/104063870501700510.
Testo completoAbstract (sommario):
Enzyme-linked immunosorbent assays (ELISAs) are used in Johne's disease (JD) control programs as a first screening for presence of the disease in a herd. A high sensitivity of the ELISA is therefore important, yet the commonly used ELISAs have relatively low sensitivity. The inclusion of an absorption phase, although improving specificity, potentially decreases sensitivity. Sera and feces of 383 adult dairy cows in 8 herds were used to compare the test characteristics of an absorbed and a nonabsorbed indirect ELISA for the detection of JD. The absorbed ELISA is based on a protoplasmic antigen, whereas the nonabsorbed uses a lipoarabinomannan-based antigen. The potential advantage of the nonabsorbed ELISA is that it may be less specific and more sensitive. Two herds certified free of JD were used to compare the specificity of the ELISAs. The other herds used to compare sensitivity were either infected with Mycobacterium avium subsp. paratuberculosis or had unknown status. Using fecal culture as a gold standard, the diagnostic specificity for the absorbed and nonabsorbed ELISAs were 98.4% and 87.9%, respectively. The diagnostic sensitivity was 72.4% and 65.5% for the absorbed and the nonabsorbed ELISA, respectively. Furthermore, a comparison using a fecal DNA probe as the comparison standard resulted in both ELISAs having a sensitivity of 61.9%. Agreement between the 2 ELISAs was moderate, with a kappa statistic of 0.58. The nonabsorbed ELISA did not have a higher sensitivity and had a lower specificity than the absorbed ELISA. Therefore, in this population, there was no advantage gained with using the nonabsorbed ELISA.
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Kande, Sylvie. "Elisa". Callaloo 20, n. 3 (1997): 646–50. http://dx.doi.org/10.1353/cal.1998.0076.
Testo completo
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Fereig, Ragab M., Sarah A. Altwaim e Caroline F. Frey. "Evaluation of a Commercial Serum Competitive Enzyme-Linked Immunosorbent Assay for Detection of Neospora caninum-Specific Antibodies in Raw Milk of Ruminants". Parasitologia 4, n. 2 (27 marzo 2024): 91–98. http://dx.doi.org/10.3390/parasitologia4020008.
Testo completoAbstract (sommario):
Bovine neosporosis is an infection caused by the protozoan parasite Neospora caninum and has substantial veterinary hazards. Neosporosis cannot be controlled by vaccination or chemotherapy. Thus, accurate diagnosis followed by isolation and culling of infected animals is regarded as the most efficient method of control. In vivo diagnosis often relies on serologic testing of the animals, and milk represents a non-invasive and easy-to-collect sample matrix. However, indirect enzyme-linked immunosorbent assay (ELISA) specifically designed for antibody detection in milk are sometimes not easily available and it is tempting to use ELISA kits that are originally designed for use in serum in milk samples instead. Herein, we evaluated a widely used commercial ELISA (ID Screen® Neospora caninum competition Multispecies ELISA (ID. Vet, Grabels, France)), developed for detection of N. caninum antibodies in serum samples, for its performance on milk samples. Milk samples from dairy ruminants (cows, buffaloes, sheep, and goats; n = 149) were tested in parallel with the serum ELISA and a commercial milk ELISA as a standard test (Neospora caninum Milk Competitive ELISA, ID. Vet, Grabels, France). The detected prevalence values were 28.2% (42/149), 17.4% (26/149), and 17.4% (26/149) using milk ELISA, serum ELISA, and both ELISAs, respectively. Sensitivity, specificity, positive predictive value, and negative predictive value for the serum ELISA used with milk samples were 61.9%, 100%, 100%, and 87%, respectively. The agreement and kappa value between the two ELISAs were 89.3% and 0.70, respectively, suggesting substantial agreement. High values of Pearson correlation coefficient (0.904, p ≥ 0.0001) and area under the receiver operating characteristic (ROC) curve (0.789, p ≥ 0.0001) demonstrated the high diagnostic performance of the serum ELISA in milk samples. Also, a Bland–Altman Plot and histogram describing the frequency of distribution of ELISA optical densities confirmed the high agreement of both serum and milk ELISAs. The current results revealed the high specificity but moderate sensitivity of the serum ELISA used for milk samples compared with the milk ELISA. However, the excellent positive predictive value of the serum ELISA makes it an alternative option in case of the unavailability of milk ELISAs. With this study, we provided additional evidence that a widely used serum ELISA test kit may also be used for the detection of N. caninum antibodies in milk samples.
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Nielsen, Flemming A. J. "Litterær shamanisme i Kongebøgerne – sagaen om Elias og Elisa". Dansk Teologisk Tidsskrift 78, n. 3 (10 ottobre 2015): 185–201. http://dx.doi.org/10.7146/dtt.v78i3.105812.
Testo completoAbstract (sommario):
The Saga of Elijah and Elisha (1 Kgs 16:29 – 2 Kgs 13:25) deals with the history of the cult of Ba’al in Biblical Israel. Its nucleus is a mosaic of 35 episodes containing several versions of the biographies of Elijah and Elisha who are atypical Old Testament prophets belonging to a select circle of “men of God”. Their saga supplements and comments on the greater story of Biblical Israel, and it is argued that there is an affinity between them and the shamans known in particular from the Arctic world and the aboriginal peoples of the Americas. Definitions of prophets and shamans are briefly discussed, and the kind of shamanism associated with Elijah and Elisha is described and named literary shamanism.
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Morenkov, O. S., Nadja Fodor e I. Fodor. "Indirect Elisas Based on Recombinant and Affinity-Purified Glycoprotein E of Aujeszky's Disease Virus to Differentiate Between Vaccinated and Infected Animals". Acta Veterinaria Hungarica 47, n. 1 (1 gennaio 1999): 137–50. http://dx.doi.org/10.1556/avet.47.1999.1.15.
Testo completoAbstract (sommario):
Two indirect ELISAs for the detection of antibodies against glycoprotein E (gE) of Aujeszky's disease virus (ADV) in sera have been developed. The rec-gE-ELISA is based on theE. coli-expressed recombinant protein containing the N-terminal sequences of gE (aa 1-125) fused with the glutathione S-transferase fromSchistosoma japonicum. The affi-gE-ELISA is based on native gE, which was purified from virions by affinity chromatography. The tests were optimised and compared with each other, as well as with the recently developed blocking gE-ELISA (Morenkov et al., 1997b), with respect to specificity and sensitivity. The rec-gE-ELISA was less sensitive in detecting ADV-infected animals than the affi-gE-ELISA (sensitivity 80% and 97%, respectively), which is probably due to the lack of conformation-dependent immunodominant epitopes on the recombinant protein expressed inE. coli. The specificity of the rec-gE-ELISA and affi-gE-ELISA was rather moderate (90% and 94%, respectively) because it was necessary to set such cut-off values in the tests that provided a maximum level of sensitivity, which obviously increased the incidence of false positive reactions. Though the indirect ELISAs detect antibodies against many epitopes of gE, the blocking gE-ELISA, which detects antibodies against only one immunodominant epitope of gE, showed a better test performance (specificity 99% and sensitivity 98%). This is most probably due to rather high dilutions of the sera used in the indirect gE-ELISAs (1:30) as compared to the serum dilution in the blocking gE-ELISA (1:2). We conclude that the indirect gE-ELISAs are sufficiently specific and sensitive to distinguish ADV-infected swine from those vaccinated with gE-negative vaccine and can be useful, in particularly affi-gE-ELISA, as additional tests for the detection of antibodies to gE.
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Veling, J., F. G. van Zijderveld, A. M. van Zijderveld-van Bemmel, Y. H. Schukken e H. W. Barkema. "Evaluation of Two Enzyme-Linked Immunosorbent Assays for Detecting Salmonella enterica subsp.enterica Serovar Dublin Antibodies in Bulk Milk". Clinical Diagnostic Laboratory Immunology 8, n. 6 (1 novembre 2001): 1049–55. http://dx.doi.org/10.1128/cdli.8.6.1049-1055.2001.
Testo completoAbstract (sommario):
ABSTRACT Two enzyme-linked immunosorbent assays (ELISAs) for the detectingSalmonella enterica subsp. entericaserovar Dublin antibodies in bulk milk were developed and evaluated for potential use in control programs. The ELISAs were based on either lipopolysacharide (LPS ELISA) or flagellar antigen (GP ELISA). Sensitivity was determined with 79 case herds with a wide range of clinical signs. Specificity was determined with 125 Dutch and 200 Swedish control herds. The relation between antibodies in bulk milk, antibodies in serum, and the level of milk production of individual cows was studied with 61 case herds. The optimal optical density (OD) values of the LPS ELISA and the GP ELISA were determined to be 0.2 and 0.5, respectively. The sensitivities of the LPS ELISA and the GP ELISA were 54 and 63%, respectively, with a specificity of 98% for both ELISAs with samples from the Dutch control herds. The specificities for samples from the Swedish herds were 100% for the LPS ELISA and 95% for the GP ELISA. The sensitivity of the combination of tests was 65% when samples were run in parallel, and the specificity was 100% when samples were run in series, irrespective of whether the samples came from Dutch or Swedish control herds. The variance (R 2) in the OD value for bulk milk samples could be explained by the percentage of seropositive lactating cows in a herd with the LPS ELISA for 51% of the samples and with the GP ELISA for 72%. The variance in the OD value was best explained by the combination of the percentage of seropositive lactating cows in the herd and the mean log10 serum antibody titer for that herd (R 2 = 62% for the LPS ELISA andR 2 = 75% for the GP ELISA). Case herds more often tested negative by the ELISA with bulk milk when the percentage of seropositive lactating cows was less than 5%. It is concluded that both ELISAs with bulk milk can be used in control programs to distinguish between infected and noninfected herds. Specificity can be increased by using the two tests in combination. Sensitivity was relatively low for both single tests and both tests combined.
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Prieto, José M., Ana Balseiro, Rosa Casais, Naiara Abendaño, Liam E. Fitzgerald, Joseba M. Garrido, Ramon A. Juste e Marta Alonso-Hearn. "Sensitive and Specific Enzyme-Linked Immunosorbent Assay for Detecting Serum Antibodies against Mycobacterium avium subsp. paratuberculosis in Fallow Deer". Clinical and Vaccine Immunology 21, n. 8 (28 maggio 2014): 1077–85. http://dx.doi.org/10.1128/cvi.00159-14.
Testo completoAbstract (sommario):
ABSTRACTThe enzyme-linked immunosorbent assay (ELISA) is the diagnostic test most commonly used in efforts to control paratuberculosis in domestic ruminants. However, commercial ELISAs have not been validated for detecting antibodies againstMycobacterium aviumsubsp.paratuberculosisin wild animals. In this study, we compared the sensitivities and specificities of five ELISAs using individual serum samples collected from 41 fallow deer with or without histopathological lesions consistent with paratuberculosis. Two target antigenic preparations were selected, an ethanol-treated protoplasmic preparation obtained from a fallow deerM. aviumsubsp.paratuberculosisisolate (ELISAs A and B) and a paratuberculosis protoplasmic antigen (PPA3) (ELISAs C and D). Fallow deer antibodies bound to the immobilized antigens were detected by using a horseradish peroxidase (HRP)-conjugated anti-fallow deer IgG antibody (ELISAs A and C) or HRP-conjugated protein G (ELISAs B and D). A commercially available assay, ELISA-E, which was designed to detectM. aviumsubsp.paratuberculosisantibodies in cattle, sheep, and goats, was also tested. Although ELISAs A, C, and E had the same sensitivity (72%), ELISAs A and C were more specific (100%) for detecting fallow deer with lesions consistent with paratuberculosis at necropsy than was the ELISA-E (87.5%). In addition, the ELISA-A was particularly sensitive for detecting fallow deer in the latent stages of infection (62.5%). The antibody responses detected with the ELISA-A correlated with both the severity of enteric lesions and the presence of acid-fast bacteria in gut tissue samples. In summary, our study shows that the ELISA-A can be a cost-effective diagnostic tool for preventing the spread of paratuberculosis among fallow deer populations.
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van Hoeven, Karen H., Connie Dale, Phil Foster e Barbara Body. "Comparison of Three Enzyme-Linked Immunosorbent Assays for Detection of Immunoglobulin G Antibodies to Tetanus Toxoid with Reference Standards and the Impact on Clinical Practice". Clinical and Vaccine Immunology 15, n. 12 (8 ottobre 2008): 1751–54. http://dx.doi.org/10.1128/cvi.00254-08.
Testo completoAbstract (sommario):
ABSTRACT Accurate determination of the concentrations of immunoglobulin G (IgG) antibody to tetanus toxoid is important in order to evaluate the immunogenicity of tetanus toxoid vaccines, determine immune competence in individual patients, and measure the prevalence of immunity in populations. The performance of three commercially available enzyme-linked immunosorbent assays (ELISAs) for IgG antibodies to tetanus toxoid were evaluated. Serially diluted NIBSC 76/589 and TE-3 human tetanus IgG immunoglobulin international reference standards were analyzed in quadruplicate using ELISAs manufactured by The Binding Site, Inc. (VaccZyme); Scimedx; and Euroimmun. In addition, IgG antibodies to tetanus toxoid were measured in 83 deidentified serum specimens using each manufacturer's ELISA. Each ELISA provided linear results when evaluated with the reference preparations. The Binding Site ELISA provided results that closely corresponded to the reference preparations (y = 1.09x − 0.08), whereas the Scimedx ELISA gave results that were consistently lower (y = 0.21x − 0.07) and the Euroimmun ELISA gave results that were consistently higher (y = 1.5x + 0.30) than the reference preparation concentrations. Using the recommended cutoff for each ELISA (<0.10 IU/ml), the overall agreement of all of the ELISA methods was 78%. Three of eighty-three (3.6%) human serum samples demonstrated inadequate immunity with all three assays. The Binding Site ELISA yielded nonprotective antibody concentrations in only these 3 samples, whereas 19 samples (22.9%) according to the Scimedx ELISA and 6 samples (7.2%) according to the Euroimmun ELISA demonstrated nonprotective concentrations. The performance characteristics of ELISAs for tetanus immunoglobulin titers were manufacturer dependent, and the differences translated into important disparities in reported results.
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Blacksell, Stuart D., Richard G. Jarman, Robert V. Gibbons, Ampai Tanganuchitcharnchai, Mammen P. Mammen, Ananda Nisalak, Siripen Kalayanarooj et al. "Comparison of Seven Commercial Antigen and Antibody Enzyme-Linked Immunosorbent Assays for Detection of Acute Dengue Infection". Clinical and Vaccine Immunology 19, n. 5 (21 marzo 2012): 804–10. http://dx.doi.org/10.1128/cvi.05717-11.
Testo completoAbstract (sommario):
ABSTRACTSeven commercial assays were evaluated to determine their suitability for the diagnosis of acute dengue infection: (i) the Panbio dengue virus Pan-E NS1 early enzyme-linked immunosorbent assay (ELISA), second generation (Alere, Australia); (ii) the Panbio dengue virus IgM capture ELISA (Alere, Australia); (iii) the Panbio dengue virus IgG capture ELISA (Alere, Australia); (iv) the Standard Diagnostics dengue virus NS1 antigen ELISA (Standard Diagnostics, South Korea); (v) the Standard Diagnostics dengue virus IgM ELISA (Standard Diagnostics, South Korea); (vi) the Standard Diagnostics dengue virus IgG ELISA (Standard Diagnostics, South Korea); and (vii) the Platelia NS1 antigen ELISA (Bio-Rad, France). Samples from 239 Thai patients confirmed to be dengue virus positive and 98 Sri Lankan patients negative for dengue virus infection were tested. The sensitivities and specificities of the NS1 antigen ELISAs ranged from 45 to 57% and 93 to 100% and those of the IgM antibody ELISAs ranged from 85 to 89% and 88 to 100%, respectively. Combining the NS1 antigen and IgM antibody results from the Standard Diagnostics ELISAs gave the best compromise between sensitivity and specificity (87 and 96%, respectively), as well as providing the best sensitivity for patients presenting at different times after fever onset. The Panbio IgG capture ELISA correctly classified 67% of secondary dengue infection cases. This study provides strong evidence of the value of combining dengue virus antigen- and antibody-based test results in the ELISA format for the diagnosis of acute dengue infection.
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Elderbrook, Molly J., Brant A. Schumaker, Massaro W. Ueti, Meila Bastos de Almeida, Thallitha S. W. J. Vieira, Rafael F. C. Vieira e Kerry S. Sondgeroth. "Comparison of 2 ELISAs for detecting exposure to Brucella ovis". Journal of Veterinary Diagnostic Investigation 32, n. 5 (4 agosto 2020): 700–705. http://dx.doi.org/10.1177/1040638720943880.
Testo completoAbstract (sommario):
Control of Brucella ovis infection in sheep flocks in the United States depends on early detection of B. ovis antibodies via serologic testing. We used 2,276 sheep sera and various cutoff values to compare seroprevalence and agreement between 2 ELISAs: the National Veterinary Services Laboratories (NVSL) B. ovis indirect ELISA and the IDEXX B. ovis ELISA kit. A subset of 295 sera was used to compare agreement and evaluate relative sensitivity and specificity of the 2 ELISAs with an agar gel immunodiffusion (AGID) test kit. There was no significant difference in B. ovis seroprevalence between the ELISAs; however, there was poor agreement between them. When the AGID test was used as the reference test, the IDEXX ELISA with a moderate cutoff value (S/P ratio = 45%) had the highest relative sensitivity of 38.1% and specificity of 92.0%. The NVSL ELISA with a lax cutoff value (S/P ratio = 0.75) had relative sensitivity of 19.1% and specificity of 94.6%. Receiver operating characteristic analysis revealed that optimal cutoff values for the NVSL and IDEXX ELISAs were 0.091 and 16.5%, respectively. This results in sensitivity and specificity of 85.7% and 31.8% for the NVSL ELISA, and sensitivity and specificity of 81.0% and 53.6% for the IDEXX ELISA, respectively.
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Anderson, Brian L., Ryan J. Welch e Christine M. Litwin. "Assessment of Three Commercially Available Serologic Assays for Detection of Antibodies to Mycobacterium tuberculosis and Identification of Active Tuberculosis". Clinical and Vaccine Immunology 15, n. 11 (30 settembre 2008): 1644–49. http://dx.doi.org/10.1128/cvi.00271-08.
Testo completoAbstract (sommario):
ABSTRACT Tuberculosis (TB) caused by Mycobacterium tuberculosis remains a major world disease, with approximately 9 million new cases each year. Identification and treatment of active disease are essential for TB control. Serology may offer increased detection of active disease in patients with a positive tuberculin skin test (TST) or QuantiFERON-TB (QFT-G). The InBios Active TbDetect immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA), IBL M. tuberculosis IgG ELISA, and Anda Biologics TB ELISAs were evaluated for the ability to detect M. tuberculosis antibodies in patients with active disease. Agreement, sensitivity, and specificity for each ELISA were determined and compared to those for culture or amplified direct detection and M. tuberculosis low-risk control patients. The InBios Active TbDetect ELISA had an agreement of 96.2%, a sensitivity of 83.3%, and a specificity of 98.9%. The IBL M. tuberculosis ELISA had an agreement of 84.0%, a sensitivity of 5.6%, and a specificity of 100.0%. The agreement, sensitivity, and specificity of the Anda Biologics TB ELISA were 74.2%, 83.3%, and 72.0%, respectively. The sensitivity for detecting M. tuberculosis antibodies in human immunodeficiency virus-associated TB was 50% for both the InBios Active TbDetect ELISA and the Anda Biologics TB ELISA and 0% for the IBL M. tuberculosis ELISA. The positivity rates for InBios Active TbDetect ELISA, IBL M. tuberculosis ELISA, and Anda Biologics TB ELISA in latently infected individuals positive by TST and/or QFT-G were 5.1%, 0.0%, and 30.8%, respectively. It can be concluded that the InBios Active TbDetect IgG ELISA is superior to the other ELISAs in accurately detecting active TB.
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Galula, Jedhan Ucat, Gielenny M. Salem, Raul V. Destura, Roland Remenyi e Day-Yu Chao. "Comparable Accuracies of Nonstructural Protein 1- and Envelope Protein-Based Enzyme-Linked Immunosorbent Assays in Detecting Anti-Dengue Immunoglobulin G Antibodies". Diagnostics 11, n. 5 (21 aprile 2021): 741. http://dx.doi.org/10.3390/diagnostics11050741.
Testo completoAbstract (sommario):
Background: Dengue virus (DENV) infection remains a global public health concern. Enzyme-linked immunosorbent assays (ELISAs), which detect antibodies targeting the envelope (E) protein of DENV, serve as the front-line serological test for presumptive dengue diagnosis. Very few studies have determined the serostatus by detecting antibodies targeting the nonstructural protein 1 (NS1), which can function as diagnostic biomarkers to distinguish natural immunity from vaccine-induced immunity. Methods: We used community-acquired human serum specimens, with the serostatus confirmed by focus reduction microneutralization test (FRμNT), to evaluate the diagnostic performances of two NS1-based ELISA methods, namely, immunoglobulin G antibody-capture ELISA (NS1 GAC–ELISA) and indirect NS1 IgG ELISA, and compared the results with an E-based virus-like particle (VLP) GAC–ELISA. Results: NS1-based methods had comparable accuracies as VLP GAC–ELISA. Although the sensitivity in detecting anti-NS1 IgM was poor, indirect NS1 IgG ELISA showed similar limits of detection (~1–2 ng/mL) as NS1 GAC–ELISA in detecting anti-NS1 IgG. Combining the results from two or more tests as a composite reference standard can determine the DENV serostatus with a specificity reaching 100%. Conclusion: NS1-based ELISAs have comparable accuracies as VLP GAC–ELISA in determining dengue serostatus, which could effectively assist clinicians during assessments of vaccine eligibility.
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Okada, Kohki, e Kano Matsuo. "Development of New Antibodies and an ELISA System to Detect the Potato Alkaloids α-Solanine and α-Chaconine". Foods 12, n. 8 (12 aprile 2023): 1621. http://dx.doi.org/10.3390/foods12081621.
Testo completoAbstract (sommario):
Food poisoning can be caused by the potato alkaloids α-solanine (SO) and α-chaconine (CHA). Therefore, this study aimed to establish new enzyme-linked immunosorbent assays (ELISAs) for detecting these two toxins in biological samples and potato extracts. Two antibodies that bind to solanidine, a chemical compound found in both SO and CHA, were newly developed, and two types of ELISAs (Sold1 ELISA and Sold2 ELISA) were constructed. We measured SO and CHA diluted in phosphate-buffered saline (PBS), serum, and urine. The detection performance of the two ELISAs for SO and CHA in PBS was higher than in serum and urine, and the sensitivity of Sold2 ELISA was lower than that of Sold1 ELISA. Thus, we used these ELISAs to measure SO and CHA in potato part extracts and found that potato sprouts contained approximately 80-fold more SO and CHA than tubers and 8-fold more SO and CHA than peels. Although the detection sensitivity of SO and CHA depends on the sample types, these ELISAs may be effective as future clinical and food testing methods after further improvements.
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Talarmin, Antoine, Bhety Labeau, Josiane Lelarge e Jean-Louis Sarthou. "Immunoglobulin A-Specific Capture Enzyme-Linked Immunosorbent Assay for Diagnosis of Dengue Fever". Journal of Clinical Microbiology 36, n. 5 (1998): 1189–92. http://dx.doi.org/10.1128/jcm.36.5.1189-1192.1998.
Testo completoAbstract (sommario):
Dengue fever (DF) is usually diagnosed by testing for dengue virus immunoglobulin M (IgM) by a capture enzyme-linked immunosorbent assay (ELISA) (MAC-ELISA). However, IgM can last for months, and its presence might reflect a previous infection. We have tested the use of anti-dengue virus IgA capture ELISA (AAC-ELISA) for the diagnosis of DF by comparing the results of MAC-ELISAs and AAC-ELISAs for 178 serum samples taken from patients with confirmed cases of DF. IgM appears more rapidly (mean delay of positivity, 3.8 days after the onset of DF) than IgA (4.6 days) but lasts longer; the peak IgA titer is obtained on day 8. The specificity and the positive predictive value of AAC-ELISA are 100%; its sensitivity and negative predictive value (NPV) are also 100% between days 6 and 25 after the onset of DF, but they decrease drastically when data for tests conducted with specimens from the first days of infection are included, because the IgA titers, like the IgM titers, have not yet risen. AAC-ELISA is a simple method that can be performed together with MAC-ELISA and that can help in interprating DF serology.
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Patel, D., W. Egner, D. Gleeson, G. Wild e A. Ward. "Detection of serum M2 anti-mitochondrial antibodies by enzyme-linked immunosorbent assay is potentially less specific than by immunofluorescence". Annals of Clinical Biochemistry: International Journal of Laboratory Medicine 39, n. 3 (1 maggio 2002): 304–7. http://dx.doi.org/10.1258/0004563021902008.
Testo completoAbstract (sommario):
Aim To compare the predictive values of enzyme-linked immunosorbent assays (ELISAs) and indirect immunofluorescence (IIF) techniques for the detection of M2 anti-mitochondrial antibodies. Methods Commercial ELISAs are widely available for the detection of antimitochondrial antibody subtypes in primary biliary cirrhosis (PBC). We compared the results from two ELISAs (one recombinant, one purified antigen) with those from two IIF methods in a well-defined cohort of PBC patients and in patients with systemic lupus erythematosus, Sjögren's syndrome, sicca syndrome, systemic sclerosis, rheumatoid arthritis and blood donor controls. Results There was good correlation between a rodent substrate IIF and ELISA A ( r = 0·9134), but poor correlation with ELISA B ( r = 0·5999), which produced many false-positive results in the control population. We show that rodent IIF alone or human epithelial cell (HEp-2000®) screening with confirmation by ELISA produce similar predictive values for PBC and require lesser degrees of skilled interpretation of IIF patterns. Conclusions We conclude that the specificities of IIF are greater than the ELISA methods (99% versus 85-97%), although the ELISAs are slightly more sensitive in biopsy-proven PBC. Careful in-house validation of all new ELISA technologies is mandatory for good laboratory practice, but IIF in experienced hands remains an effective and specific assay.
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Sauerbrei, Andreas, Anna Schäfler, Jörg Hofmann, Michael Schacke, Bernd Gruhn e Peter Wutzler. "Evaluation of Three Commercial Varicella-Zoster Virus IgG Enzyme-Linked Immunosorbent Assays in Comparison to the Fluorescent-Antibody-to-Membrane-Antigen Test". Clinical and Vaccine Immunology 19, n. 8 (20 giugno 2012): 1261–68. http://dx.doi.org/10.1128/cvi.00183-12.
Testo completoAbstract (sommario):
ABSTRACTCommercial serologic assays for varicella-zoster virus (VZV), which enable reliable determination of VZV immune status and are amenable to automation, are needed. The present study compares the automated performance of the VZV whole-cell enzyme-linked immunosorbent assay (ELISA) Enzygnost anti-VZV/IgG, the Euroimmun anti-VZV ELISA (IgG) based on highly purified viral proteins, and the VZV glycoprotein (gp)-based Serion ELISA Classic VZV IgG. The fluorescent-antibody-to-membrane-antibody (FAMA) test was used as a reference. A total of 638 serum samples from VZV-negative children, blood donors, varicella vaccinees, and bone marrow transplant recipients were included. The Enzygnost anti-VZV/IgG and the Serion ELISA Classic VZV IgG showed sensitivities of 99.6% and 99.2%, respectively, and the Euroimmun anti-VZV ELISA (IgG) had a significantly lower sensitivity of 90.5%. Specificity was calculated as 100% for both the Euroimmun anti-VZV ELISA (IgG) and for the Enzygnost anti-VZV/IgG, and the Serion ELISA Classic VZV IgG had a significantly lower specificity of 89.4%. Quantitative results of all ELISAs correlated well, but there was a poor quantitative correlation between the ELISAs and FAMA. In conclusion, this study does not show any superiority of a gp- and a protein-based ELISA compared to a whole-cell ELISA for the automated detection of VZV-specific IgG. The automated performance of the Enzygnost anti-VZV/IgG assay correlated best with the FAMA reference assay.
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Suttisunhakul, Vichaya, Vanaporn Wuthiekanun, Paul J. Brett, Srisin Khusmith, Nicholas P. J. Day, Mary N. Burtnick, Direk Limmathurotsakul e Narisara Chantratita. "Development of Rapid Enzyme-Linked Immunosorbent Assays for Detection of Antibodies to Burkholderia pseudomallei". Journal of Clinical Microbiology 54, n. 5 (24 febbraio 2016): 1259–68. http://dx.doi.org/10.1128/jcm.02856-15.
Testo completoAbstract (sommario):
Burkholderia pseudomallei, the causative agent of melioidosis, is an environmental bacillus found in northeast Thailand. The mortality rate of melioidosis is ∼40%. An indirect hemagglutination assay (IHA) is used as a reference serodiagnostic test; however, it has low specificity in areas where the background seropositivity of healthy people is high. To improve assay specificity and reduce the time for diagnosis, four rapid enzyme-linked immunosorbent assays (ELISAs) were developed using two purified polysaccharide antigens (O-polysaccharide [OPS] and 6-deoxyheptan capsular polysaccharide [CPS]) and two crude antigens (whole-cell [WC] antigen and culture filtrate [CF] antigen) ofB. pseudomallei. The ELISAs were evaluated using serum samples from 141 culture-confirmed melioidosis patients from Thailand along with 188 healthy donors from Thailand and 90 healthy donors from the United States as controls. The areas under receiver operator characteristic curves (AUROCC) using Thai controls were high for the OPS-ELISA (0.91), CF-ELISA (0.91), and WC-ELISA (0.90), while those of CPS-ELISA (0.84) and IHA (0.72) were lower. AUROCC values using U.S. controls were comparable to those of the Thai controls for all ELISAs except IHA (0.93). Using a cutoff optical density (OD) of 0.87, the OPS-ELISA had a sensitivity of 71.6% and a specificity of 95.7% for Thai controls; for U.S. controls, specificity was 96.7%. An additional 120 serum samples from tuberculosis, scrub typhus, or leptospirosis patients were evaluated in all ELISAs and resulted in comparable or higher specificities than using Thai healthy donors. Our findings suggest that antigen-specific ELISAs, particularly the OPS-ELISA, may be useful for serodiagnosis of melioidosis in areas where it is endemic and nonendemic.
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Van de gaer, Otto, Petra de Haes e Xavier Bossuyt. "Detection of circulating anti-skin antibodies by indirect immunofluorescence and by ELISA: a comparative systematic review and meta-analysis". Clinical Chemistry and Laboratory Medicine (CCLM) 58, n. 10 (25 settembre 2020): 1623–33. http://dx.doi.org/10.1515/cclm-2019-1031.
Testo completoAbstract (sommario):
AbstractBackgroundBoth enzyme-linked immunosorbent assays (ELISAs) and indirect immunofluorescence (IIF) are available for the diagnosis of autoimmune bullous diseases (AIBD). Many studies have reported on the performance of ELISAs and concluded that ELISAs could replace IIF. This study compares the diagnostic accuracy of ELISA and IIF for the detection of autoantibodies to desmoglein 1 (DSG1), desmoglein 3 (DSG3), bullous pemphigoid antigen 2 (BP180) and bullous pemphigoid antigen 1 (BP230) to support the diagnosis of pemphigus vulgaris (PV), pemphigus foliaceus (PF) and bullous pemphigoid (BP).MethodsA literature search was performed in the PubMed database. The meta-analysis was performed using summary values and a bivariate random effect model.ResultsThe five included studies on PV did not demonstrate significant differences between IIF and DSG3-ELISA (sensitivity 82.3% vs. 81.6%, p = 0.9284; specificity 95.6% vs. 93.9%, p = 0.5318; diagnostic odds ratio [DOR] 101.60 vs. 67.760, p = 0.6206). The three included studies on PF did not demonstrate significant differences between IIF and DSG1-ELISA (sensitivity 80.6% vs. 83.1%, p = 0.8501; specificity 97.5% vs. 93.9%, p = 0.3614; DOR 160.72 vs. 75.615, p = 0.5381). The eight included studies on BP showed that BP230-ELISA differed significantly from both IIF on monkey esophagus (MO) and BP180-ELISA with regard to DOR (11.384 vs. 68.349, p = 0.0008; 11.384 vs. 41.699, p = 0.0125, respectively)ConclusionsOur meta-analysis shows that ELISA performs as well as IIF for diagnosing PV, PF and BP.
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Poolman, Jan T., Carl E. Frasch, Helena Käyhty, Pascal Lestrate, Shabir A. Madhi e Isabelle Henckaerts. "Evaluation of Pneumococcal Polysaccharide Immunoassays Using a 22F Adsorption Step with Serum Samples from Infants Vaccinated with Conjugate Vaccines". Clinical and Vaccine Immunology 17, n. 1 (4 novembre 2009): 134–42. http://dx.doi.org/10.1128/cvi.00289-09.
Testo completoAbstract (sommario):
ABSTRACT The history of the pneumococcal polysaccharide enzyme-linked immunosorbent assay (ELISA) is characterized by a continuous search for increased specificity. A third-generation ELISA that uses 22F polysaccharide inhibition has increased the specificity of the assay, particularly at low antibody concentrations. The present work compared various 22F ELISAs and non-22F ELISAs. The comparisons involved three different laboratories, including a WHO reference laboratory, and included sera from subjects from different geographic areas immunized with different pneumococcal conjugate vaccines, including the licensed 7-valent Prevenar vaccine and the 10-valent Synflorix vaccine. All comparisons led to the same conclusion that the threshold defined as 0.35 μg/ml for the WHO non-22F ELISA is lower when any 22F ELISA is used. The use of highly purified polysaccharides for coating further improved the specificity of the assay. In conclusion, we confirm that the 22F ELISA can be recommended as a reference method for the determination of antibodies against pneumococcal polysaccharides.
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Persson, Anders, Charlotte Becker, Ida Hansson, Anita Nilsson e Carina Törn. "Comparison of Measurements of Autoantibodies to Glutamic Acid Decarboxylase and Islet Antigen-2 in Whole Blood Eluates from Dried Blood Spots Using the RSR-Enzyme Linked Immunosorbent Assay Kits and In-House Radioimmunoassays". Experimental Diabetes Research 2010 (2010): 1–6. http://dx.doi.org/10.1155/2010/173652.
Testo completoAbstract (sommario):
To evaluate the performance of dried blood spots (DBSs) with subsequent analyses of glutamic acid decarboxylase (GADA) and islet antigen-2 (IA-2A) with the RSR-ELISAs, we selected 80 children newly diagnosed with type 1 diabetes and 120 healthy women. DBSs from patients and controls were used for RSR-ELISAs while patients samples were analysed also with in-house RIAs. The RSR-ELISA-GADA performed well with a specificity of 100%, albeit sensitivity (46%) was lower compared to in RIA (56%;P=.008). No prozone effect was observed after dilution of discrepant samples. RSR-ELISA-IA-2A achieved specificity of 69% and sensitivity was lower (59%) compared with RIA (66%;P<.001). Negative or low positive patients and control samples in the RSR-ELISA-IA-2A increased after dilution. Eluates from DBS can readily be used to analyse GADA with the RSR-ELISA, even if low levels of autoantibodies were not detected. Some factor could disturb RSR-ELISA-IA-2A analyses.
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Hortin, G. L., A. L. Summerfield, T. R. Wilhite, C. H. Smith, E. L. Branum, J. F. O'Brien e M. Landt. "Detection of autoantibodies to amylase by ELISA: comparison of detection of macroamylase and free autoantibody". Clinical Chemistry 40, n. 12 (1 dicembre 1994): 2254–59. http://dx.doi.org/10.1093/clinchem/40.12.2254.
Testo completoAbstract (sommario):
Abstract New ELISAs for detecting macroamylase or free autoantibodies to amylase were tested with 48 samples that had been characterized by gel chromatography and electrophoresis. The macroamylase ELISA, with anti-IgG or anti-IgA for detection, detected macroamylase in 28 of 33 samples known to contain macroamylase (85% sensitivity), whereas the ELISA for free autoantibody to amylase was positive for only 11 samples. Specificities of both ELISAs were 93%. Among 28 true positives detected with the macroamylase ELISA, 22 contained IgA, 3 contained IgG, and 3 contained both immunoglobulins. Detection of IgM added no true positives. ELISA responses (y) were proportional to log [macroamylase concentration by chromatography (x)] from 0 to 1200 U/L: y = 5.15 x + 1.66; r = 0.72; Sy x = 1.65. As new tools for detecting macroenzymes consisting of enzyme-autoantibody complexes, the ELISAs show that some autoantibodies are detected more sensitively as antibody-antigen complexes than as free antibody.
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Xu, Shun-Qing, Min He, Hong-Ping Yu, Xiao-Yang Wang, Xiang-Lin Tan, Bin Lu, Xi Sun et al. "Bioluminescent Method for Detecting Telomerase Activity". Clinical Chemistry 48, n. 7 (1 luglio 2002): 1016–20. http://dx.doi.org/10.1093/clinchem/48.7.1016.
Testo completoAbstract (sommario):
Abstract Background: Telomerase is a promising biomarker in cancer diagnosis and therapy. The elongation of telomeric repeats catalyzed by telomerase is accompanied by release of six PPi for each TTAGGG repeat (1 pmol PPi/310 pg telomeric repeats). We developed a novel method to measure telomerase activity by use of an enzymatic luminometric PPi assay (ELIPA). Methods: Extracts of cell lines and tissues were incubated with primer at 30 °C for 30 min. Released PPi was converted to ATP by sulfurylase, and ATP was detected by a luciferase bioluminescence system. The ELIPA results were compared with results obtained with the conventional telomeric repeat amplification (TRAP)-ELISA in 42 lung carcinoma tissues and 27 control tissues without malignancy. Results: The lower detection limits of ELIPA and TRAP-ELISA were 5 and 10 cells, respectively. The within-run imprecision (CV) of ELIPA was ≤12%. When compared with TRAP-ELISA, the correlation coefficient (r) was 0.79. When we used the cutoff value from ROC analysis to distinguish malignant and nonmalignant tissues, the sensitivity and specificity of ELIPA were 83% and 96%, respectively, whereas the sensitivity and specificity of TRAP-ELISA were 71% and 96%, respectively. Conclusion: ELIPA is a simple and sensitive homogeneous method to quantify telomerase activity.
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Rizzini, Irma, Camilla Estevam Dantas Gomes e Alessandra Frota Martinez de Schueler. "Elisa Scheid". Revista HISTEDBR On-line 20 (8 ottobre 2020): e020050. http://dx.doi.org/10.20396/rho.v20i0.8656567.
Testo completoAbstract (sommario):
A proposta do artigo é analisar a trajetória de uma professora primária municipal do Rio de Janeiro e militante no movimento operário, Elisa Scheid, a partir de seus escritos e indícios de suas ações, pesquisados nos jornais de grande circulação da cidade e nos impressos vinculados aos movimentos de trabalhadores. O estudo se insere em pesquisa mais ampla sobre a trajetória de mulheres, com destaque para as professoras, e sua participação nas lutas por direitos civis, políticos e no mundo do trabalho, entre os séculos XIX e XX. A análise realizada sugere que Elisa Scheid constituiu ampla rede de sociabilidade, baseada nas suas experiências familiares e de formação educacional, na prática do magistério primário nos subúrbios cariocas e na sua inserção em associações, publicações e organizações políticas formais. Participou da criação e da direção da União Operária do Engenho de Dentro e do Partido Operário Independente. A despeito das interdições e desigualdades históricas de gênero, classe e raça, nossa hipótese é a de que a professora representou liderança proeminente na defesa dos direitos dos/as trabalhadores\as e da educação, atuando na propaganda político-partidária e na formação de agremiações trabalhistas. Os indícios de sua trajetória retratada neste artigo evidenciam a ocupação de espaços públicos possíveis a algumas mulheres, ao menos àquelas pertencentes aos meios letrados. Suas lutas políticas relativizam a representação corrente sobre o suposto predomínio do mundo doméstico como limite para as experiências femininas naquele contexto histórico.
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Evans, George, e Jessica Morgan. "Elisa Kneeling". Grand Street, n. 63 (1998): 124. http://dx.doi.org/10.2307/25008266.
Testo completo
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Malinen, Erja, Jaana Mättö, Merja Salmitie, Minna Alander, Maria Saarela e Airi Palva. "PCR-ELISA". Systematic and Applied Microbiology 25, n. 2 (gennaio 2002): 249–58. http://dx.doi.org/10.1078/0723-2020-00117.
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Laitinen, Reija, Erja Malinen e Airi Palva. "PCR-ELISA". Systematic and Applied Microbiology 25, n. 2 (gennaio 2002): 241–48. http://dx.doi.org/10.1078/0723-2020-00118.
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Malinen, Erja, Jaana Mättö, Merja Salmitie, Minna Alander, Maria Saarela e Airi Palva. "PCR-ELISA". Systematic and Applied Microbiology 26, n. 1 (2003): 154–55. http://dx.doi.org/10.1078/072320203322337452.
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Bouche, Fabienne B., Nicolaas H. C. Brons, Sophie Houard, Francois Schneider e Claude P. Muller. "Evaluation of Hemagglutinin Protein-Specific Immunoglobulin M for Diagnosis of Measles by an Enzyme-Linked Immunosorbent Assay Based on Recombinant Protein Produced in a High-Efficiency Mammalian Expression System". Journal of Clinical Microbiology 36, n. 12 (1998): 3509–13. http://dx.doi.org/10.1128/jcm.36.12.3509-3513.1998.
Testo completoAbstract (sommario):
Recombinant hemagglutinin (H) of the measles virus (MV) expressed in a mammalian high-expression system based on the Semliki Forest virus replicon was used in an enzyme-linked immunosorbent assay (ELISA) for the detection of specific immunoglobulin M (IgM) and IgG in patients with acute-phase measles. One hundred twelve serum specimens from 70 patients with measles were analyzed. Case definition was based on a commercial IgM ELISA that utilizes MV-infected cells (MV-ELISA) (Enzygnost; Behring Diagnostics); the clinical criteria of the Centers for Disease Control and Prevention (Atlanta, Ga.); and/or the increase in hemagglutinin test titers, neutralization test titers, and levels of MV-specific IgG whenever paired sera were available. The initial time courses of the IgM signal after the onset of rash are similar in the H- and MV-ELISAs. On days 0 to 19, both ELISAs detected IgM in 67 of 68 (98.5%) sera. Average maximal levels of IgM seem to persist, however, about 10 days longer in the MV-ELISA (up to day 25) than in the H-ELISA (day 15). From days 20 to 29 and 30 to 59, the H-ELISA detected only 64.3 (9 of 14) and 19.2% (5 of 26), respectively, of sera that were IgM positive by MV-ELISA. At least up to day 30, the performance of the H-ELISA seemed to be similar to that reported for commercial ELISAs based on whole MV. Our results demonstrate that MV H-specific IgM can be used to diagnose most measles cases from a single serum specimen collected within 19 days after the onset of rash and that the recombinant protein used in this study is suitable for this purpose.
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Zhang, Mengran, Xinyu Wei, Jing Qian, Zhengyu Yu, Xin Liu, Yan Luo, Haitao Zhang, Youfang Gu e Yin Li. "Establishment and Application of Indirect ELISAs for Detecting Antibodies against Goose Astrovirus Genotype 1 and 2". Vaccines 11, n. 3 (15 marzo 2023): 664. http://dx.doi.org/10.3390/vaccines11030664.
Testo completoAbstract (sommario):
Goose astrovirus (GAstV) was classified into GAstV-1 and GAstV-2, and both caused gosling viral gout. Recently, there has been no effective commercial vaccine to control the infection. It is important to establish serological methods to distinguish between the two genotypes. In this study, we reported the development and application of two indirect enzyme-linked immunosorbent assays (ELISAs) using the GAstV-1 virus and a recombinant GAstV-2 capsid protein as specific antigens to detect antibodies against GAstV-1 and GAstV-2, respectively. The optimal coating antigen concentration of indirect GAstV-1-ELISA and GAstV-2-Cap-ELISA was 1.2 µg/well and 125 ng/well, respectively. In addition, the antigen coating temperature and time, sera dilution and reaction time, and the dilution and reaction time of HRP-conjugated secondary antibody were optimized. The cut-off values were 0.315 and 0.305, and the analytical sensitivity was 1:6400 and 1:3200 for indirect GAstV-1-ELISA and GAstV-2-Cap-ELISA, respectively. The assays were able to differentiate specific sera against GAstVs, TUMV, GPV, and H9N2-AIV. The intra- and inter-plate variabilities of indirect ELISAs were less than 10%. The coincidence rate of positive sera was higher than 90%. The indirect ELISAs were further applied to test 595 goose serum samples. The results showed that the detection rates were 33.3% and 71.4% in GAstV-1-ELISA and GAstV-2-Cap-ELISA, respectively, and the co-detection rate was 31.1%, which indicates that the seroprevalence rate of GAstv-2 was higher than that of GastV-1, and the co-infection existed between GAstV-1 and GAstV-2. In summary, the developed GAstV-1-ELISA and GAstV-2-Cap-ELISA have high specificity, sensitivity, and reproducibility and can be used in the clinical detection of the antibody against GAstV-1 and GAstV-2.
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Ruiz Moreno, Yorleydy, Silvia Tavares Donato, Fátima Nogueira e Marcelo Sousa Silva. "Comparative Analysis of the Serological Reactivity of Individuals with Clinical History of Malaria using Two Different ELISA Tests". Diagnostics 9, n. 4 (30 ottobre 2019): 168. http://dx.doi.org/10.3390/diagnostics9040168.
Testo completoAbstract (sommario):
Early diagnosis of malaria reduces disease, prevents deaths, and contributes to decreased malaria transmission. The use of specific and sensitive antigens in the execution of serological diagnostics may have an impact on the transmission of the disease. However, many individuals cannot be easily diagnosed by serological tests due to low levels of antibodies in the serum. Using two different Enzyme-Linked Immunosorbent Assay (ELISA) tests (a commercial and an in-house ELISA), a total of 365 serum samples from individuals with a clinical history of malaria were analyzed. From the serum samples analyzed, 192 (53%) samples from the commercial ELISA and 219 (60%) samples from the in-house ELISA presented positive serological reactivity to malaria. The concordance of the samples tested (n = 365) between both ELISAs was of 67% (n = 242), and with the negative control was 100% (n = 17). We demonstrated that the in-house ELISA showed high antigenic reactivity to Plasmodium falciparum antigens when compared with the commercial ELISA. The degree of concordance of both ELISAs suggested the possibility of existence of other P. falciparum antigens present in the crude extract of P. falciparum that are important in the serological response during malaria infection.
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Czopowicz, Michał, Olga Szaluś-Jordanow, Agata Moroz, Marcin Mickiewicz, Lucjan Witkowski, Iwona Markowska-Daniel, Emilia Bagnicka e Jarosław Kaba. "Use of two commercial caprine arthritis-encephalitis immunoenzymatic assays for screening of arthritic goats". Journal of Veterinary Diagnostic Investigation 30, n. 1 (4 settembre 2017): 36–41. http://dx.doi.org/10.1177/1040638717729397.
Testo completoAbstract (sommario):
Roughly one-fourth of goats infected with small ruminant lentivirus (SRLV) develop caprine arthritis-encephalitis (CAE). We compared the profile of antibody response to surface glycoprotein (SU), and combined transmembrane glycoprotein and capsid protein (TM/CA) in SRLV-infected arthritic and asymptomatic goats, and determined the ability of 2 commercial ELISAs to distinguish between arthritic and asymptomatic goats. We used sera from 312 SRLV-seropositive dairy goats in a whole-virus ELISA; 222 were collected from arthritic goats and 90 from apparently healthy goats. Sera were screened with a competitive inhibition ELISA based on SU antigen (SU-ELISA) and an indirect ELISA based on TM and CA antigens (TM/CA-ELISA). Receiver operating characteristic (ROC) curves were prepared for both ELISAs, and areas under the ROC curves (AUC) were compared. The proportion of goats with antibody response stronger to SU antigen than to TM/CA antigen was significantly higher among arthritic than asymptomatic goats (58.1% vs. 28.9%; p < 0.001). Antibody response to SU antigen was a good predictor of the arthritic form of CAE: AUC for SU-ELISA was 89.7% (95% CI: 85.2%, 94.2%), compared to 59.3% (95% CI: 51.9%, 66.8%) for TM/CA-ELISA ( p < 0.001). With the cutoff set at percentage of inhibition of 56%, SU-ELISA had sensitivity of 86.9% (95% CI: 81.9%, 90.7%) and specificity of 84.4% (95% CI: 75.6%, 90.5%) in discriminating between arthritic and asymptomatic goats.
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Weissbach, Fabian H., e Hans H. Hirsch. "Comparison of Two Commercial Tick-Borne Encephalitis Virus IgG Enzyme-Linked Immunosorbent Assays". Clinical and Vaccine Immunology 22, n. 7 (29 aprile 2015): 754–60. http://dx.doi.org/10.1128/cvi.00096-15.
Testo completoAbstract (sommario):
ABSTRACTDespite the availability of protective vaccines, tick-borne encephalitis virus (TBEV) infections have been increasingly reported to the European Centre for Disease Prevention and Control in the past 2 decades. Since the diagnosis of TBEV exposure relies on serological testing, we compared two commercial enzyme-linked immunosorbent assays (ELISAs), i.e., Immunozym FSME IgG assay (ELISA-1) and Euroimmun FSME Vienna IgG assay (ELISA-2). Both assays use whole TBEV antigens, but they differ in viral strains (Neudoerfl for ELISA-1 and K23 for ELISA-2) and cutoff values. In testing of samples from 398 healthy blood donors, ELISA-1 showed higher reactivity levels than ELISA-2 (P< 0.001), suggesting different assay properties. This finding was supported by Bland-Altman analysis of the optical density at 450 nm (OD450) (mean bias, +0.32 [95% limits of agreement, −0.31 to +0.95]) and persisted after transformation into Vienna units. Concordant results were observed for 276 sera (69%) (44 positive and 232 negative results). Discordant results were observed for 122 sera (31%); 15 were fully discordant, all being ELISA-1 positive and ELISA-2 negative, and 107 were partially discordant (101 being ELISA-1 indeterminate and ELISA-2 negative and 6 having positive or indeterminate reactivity in both ELISAs). Neutralization testing at a 1:10 dilution yielded positive results for 33 of 44 concordant positive sera, 1 of 15 fully discordant sera, and 1 of 33 partially discordant sera. Indirect immunofluorescence testing revealed high antibody titers of ≥100 for yellow fever virus in 18 cases and for dengue virus in one case, suggesting that cross-reactivity contributed to the ELISA-1 results. We conclude that (i) cross-reactivity among flaviviruses remains a limitation of TBEV serological testing, (ii) ELISA-2 revealed reasonable sensitivity and specificity for anti-TBEV IgG population screening of human sera, and (iii) neutralization testing is most specific and should be reserved for selective questions.
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DAVISON, H. C., M. V. THRUSFIELD, A. HUSEIN, S. MUHARSINI, S. PARTOUTOMO, P. RAE e A. G. LUCKINS. "The occurrence of Trypanosoma evansi in buffaloes in Indonesia, estimated using various diagnostic tests". Epidemiology and Infection 124, n. 1 (febbraio 2000): 163–72. http://dx.doi.org/10.1017/s0950268899003271.
Testo completoAbstract (sommario):
The prevalence and incidence of Trypanosoma evansi infections in village buffaloes in Central Java were estimated using parasitological tests, two antigen-detection ELISAs (2G6 Ag-ELISA and Tr7 Ag-ELISA), an antibody-detection ELISA (IgG ELISA) and a card agglutination test (CATT). Of 2387 village buffaloes tested in five districts, 4% (95% confidence interval [CI]: 3%, 5%) were positive with the microhaematocrit test (MHCT), 58% (95% CI: 56%, 60%) were positive with the 2G6 Ag-ELISA and 70% (95% CI: 68%, 72%) were positive with the Tr7 Ag-ELISA. An increasing prevalence with age was found and the proportion of positive buffaloes was highest in the over 84 months-old age-group (68%) with the 2G6 Ag-ELISA and in the 37–60 months-old age-group (78%) with the Tr7 Ag-ELISA. Parasitaemic buffaloes were found in more than half of the villages visited. Corrected village-specific prevalence values obtained with the two Ag-ELISAs ranged from 0% to over 100%, and prevalence differed significantly (P[les ]0·0001) between villages in four of the five districts. Overall, 10% of buffaloes tested in markets were found to be parasitaemic and 39, 56 and 47% were found positive with the 2G6 Ag-ELISA, IgG ELISA and CATT, respectively. Incidence rates varied according to the test used and ranged from 0·22 (95% CI: 0·09, 0·44) to 0·44 (95% CI: 0·24, 0·76), per animal-year at risk, in two villages. The results highlight the importance of using validated diagnostic tests to obtain accurate estimates of prevalence and incidence. These parameters are needed, for example in mathematical models, for the development and evaluation of different control strategies for T. evansi infections in buffaloes.
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Kai, Junhai, Nelson Santiago, Aniruddha Puntambekar, Se Hwan Lee, David Sehy, Randy Durnell, Ron Schultheis, Jungyoup Han e Chong Ahn. "Optimiser™ microplate and OptiMax™ reagent systems enable femtogram/ml level sensitivity employing standard ELISA equipment and protocols (65.32)". Journal of Immunology 186, n. 1_Supplement (1 aprile 2011): 65.32. http://dx.doi.org/10.4049/jimmunol.186.supp.65.32.
Testo completoAbstract (sommario):
Abstract Optimiser™ Microfluidic ELISA Plates dramatically enhance ELISA sensitivity through the incorporation of microfluidic channels into a standard ELISA plate configuration. Validation studies with Optimiser™ microfluidic ELISA plates demonstrate the Optimiser™’s ability to utilize available sandwich ELISA reagents, equipment, and protocols to attain unparalleled levels of sensitivity. Limits of Detection and Limits of Quantification are demonstrated for a variety of assays in the range of 30-100 fg/ml, representing a 20-1000 fold improvement over the same assays run in conventional ELISA plates. OptiMax™ ELISA Reagent protocols on Optimiser™ Microfluidic ELISA Plates employ the similar reagents, but abbreviated assay steps because, unlike conventional sandwich ELISAs, no traditional plate washing is required. Optimiser™ Microfluidic ELISA Plates are compatible with existing pipetting systems (manual or automated) and ELISA plate readers. Furthermore, the surface area to volume ratio of each microfluidic reaction chamber represents a 50-fold increase when compared to the well of a conventional 96-well immunoassay plate. The improvement in surface to volume ratio increases binding kinetics dramatically, enabling assays to be run in less than half the time of traditional ELISA assays and providing researchers with the flexibility to use dramatically smaller sample and reagent volumes (e.g., 5 ul).
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Arnout, J., E. Huybrechts, M. Vanrusselt, C. Falcon e J. Vermylen. "Detection of Lupus-Like Anticoagulants by an Enzyme-Linked Immunosorbent Assay Using a Partial Thromboplastin as Antigen; A Comparative Study". Thrombosis and Haemostasis 64, n. 01 (1990): 026–31. http://dx.doi.org/10.1055/s-0038-1647148.
Testo completoAbstract (sommario):
SummaryClotting assays allow qualitative rather than quantitative detection of the lupus anticoagulant. We have therefore studied the usefulness of an ELISA using a commercial partial thromboplastin, Thrombofax, oS antigen; the results obtained on 146 selected patient plasmas were compared to the results of coagulation tests (kaolin clotting time, tissue thromboplastin inhibition test, activated partial thromboplastin time) and of ELISAs using cardiolipin or phosphatidylserine as antigen. While satisfactory agreement was found within the group of coagulation tests or that of ELISAs, only a moderate agreement was obtained between clotting tests and ELISAs, the best being with the partial thromboplastin ELISA using low plasma dilutions. The study further indicates that ELISA techniques cannot entirely replace coagulation tests for the detection of a lupus anticoagulant, even when a partial thromboplastin is used as antigen. On the other hand, coagulation tests are less sensitive than ELISAs for the detection of antiphospholipid antibodies.
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Emmerich, Petra, Ronald von Possel, Christina Deschermeier, Salih Ahmeti, Lindita Berisha, Bahrije Halili, Xhevat Jakupi, Kurtesh Sherifi, Claudia Messing e Viola Borchardt-Lohölter. "Comparison of diagnostic performances of ten different immunoassays detecting anti-CCHFV IgM and IgG antibodies from acute to subsided phases of Crimean-Congo hemorrhagic fever". PLOS Neglected Tropical Diseases 15, n. 3 (15 marzo 2021): e0009280. http://dx.doi.org/10.1371/journal.pntd.0009280.
Testo completoAbstract (sommario):
Crimean-Congo Hemorrhagic Fever Virus (CCHFV) is a geographically widespread tick-borne arbovirus that has been recognized by the WHO as an emerging pathogen needing urgent attention to ensure preparedness for potential outbreaks. Therefore, availability of accurate diagnostic tools for identification of acute cases is necessary. A panel comprising 121 sequential serum samples collected during acute, convalescent and subsided phase of PCR-proven CCHFV infection from 16 Kosovar patients was used to assess sensitivity. Serum samples from 60 healthy Kosovar blood donors were used to assess specificity. All samples were tested with two IgM/IgG immunofluorescence assays (IFA) from BNITM, the CCHFV Mosaic 2 IgG and IgM indirect immunofluorescence tests (IIFT) from EUROIMMUN, two BlackBox ELISAs for the detection of CCHFV-specific IgM and IgG antibodies (BNITM), two Anti-CCHFV ELISAs IgM and IgG from EUROIMMUN using recombinant structural proteins of CCHFV antigens, and two ELISAs from Vector-Best (IgM: μ-capture ELISA, IgG: indirect ELISA using immobilized CCHFV antigen). Diagnostic performances were compared between methods using sensitivity, specificity, concordance and degree of agreement with particular focus on the phase of the infection. In early and convalescent phases of infection, the sensitivities for detecting specific IgG antibodies differed for the ELISA test. The BlackBox IgG ELISA yielded the highest, followed by the EUROIMMUN IgG ELISA and finally the VectorBest IgG ELISA with the lowest sensitivities. In the subsided phase, the VectorBest IgM ELISA detected a high rate of samples that were positive for anti-CCHFV IgM antibodies. Both test systems based on immunofluorescence showed an identical sensitivity for detection of anti-CCHFV IgM antibodies in acute and convalescent phases of infection. Available serological test systems detect anti-CCHFV IgM and IgG antibodies accurately, but their diagnostic performances vary with respect to the phase of the infection.
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Backhouse, J. L., H. F. Gidding, P. B. McIntyre e G. L. Gilbert. "Evaluation of Two Enzyme Immunoassays for Detection of Immunoglobulin G Antibodies to Mumps Virus". Clinical and Vaccine Immunology 13, n. 7 (luglio 2006): 764–67. http://dx.doi.org/10.1128/cvi.00199-05.
Testo completoAbstract (sommario):
ABSTRACT To determine suitability for national serosurveys, we compared two commercial enzyme-linked immunosorbent assays (ELISAs) for mumps antibody, Enzygnost Anti-Parotitis-Virus/IgG (which uses a whole-virus antigen) and Microimmune Mumps IgG Screen ELISA (which uses a recombinant nucleoprotein antigen), by testing 1,915 opportunistically collected sera submitted to diagnostic laboratories across Australia in 1997 to 1998. The proportion of positive results increased with age in both ELISAs but was significantly higher with the Microimmune than with the Enzygnost ELISA overall (88% versus 63%; P < 0.01) and in all age groups. However, the proportion of equivocal results was significantly higher with the Enzygnost than with the Microimmune ELISA (9% versus 4%; P < 0.01). Of the 572 sera with discrepant or equivocal results, 508 had sufficient sample remaining to perform the neutralization test (NT). A proportion with concordant results in both ELISAs were also tested by the NT. For sera with discrepant results, there was significantly better agreement between the NT and Microimmune than between the NT and Enzygnost (310/444 [70%] versus 135/348 [39%]; P < 0.01). Of 64 sera with equivocal Microimmune results, 45 (70%) were positive in the NT compared with 140 of 160 (88%) equivocal Enzygnost results (P < 0.01). Compared with the NT, the Microimmune ELISA is more sensitive (96% versus 80%) but apparently less specific (36% versus 85%) than the Enzygnost ELISA. However, this is likely to be due to the generally lower sensitivity of the NT, since the Microimmune results reflect expected seroprevalence, based on vaccine uptake in the age groups studied. We conclude that the Microimmune ELISA is a more appropriate assay than the Enzygnost ELISA for estimation of mumps seroprevalence.
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Yilmaz, Aysun, Nuri Turan, Bekir Sami Kocazeybek, Harika Oyku Dinc, Hasan Emre Tali, Ozge Aydin, Hamid Besim Tali et al. "Development of in House ELISAs to Detect Antibodies to SARS-CoV-2 in Infected and Vaccinated Humans by Using Recombinant S, S1 and RBD Proteins". Diagnostics 12, n. 12 (7 dicembre 2022): 3085. http://dx.doi.org/10.3390/diagnostics12123085.
Testo completoAbstract (sommario):
(1) Background: The aim of this study was to produce in-house ELISAs which can be used to determine SARS-CoV-2-specific antibody levels directed against the spike protein (S), the S1 subunit of S and the receptor binding domain (RBD) of S in SARS-CoV-2 vaccinated and infected humans. (2) Methods: Three in-house ELISAs were developed by using recombinant proteins of SARS-CoV-2, namely the S, S1 and RBD proteins. Specificity and sensitivity evaluations of these tests were performed using sera from SARS-CoV-2-infected (n = 70) and SARS-CoV-2-vaccinated (n = 222; CoronaVac vaccine) humans in Istanbul, Turkey. The analyses for the presence of SARS-CoV-2-specific antibodies were performed using the in-house ELISAs, a commercial ELISA (Abbott) and a commercial surrogate virus neutralization test (sVNT). We also analyzed archival human sera (n = 50) collected before the emergence of COVID-19 cases in Turkey. (3) Results: The sensitivity of the in-house S, S1 and RBD ELISAs was found to be 88.44, 90.17 and 95.38%, while the specificity was 72.27, 89.08 and 89.92%, respectively, when compared to the commercial SARS-CoV-2 antibody test kit. The area under curve (AUC) values were 0.777 for the in-house S ELISA, 0.926 for the S1 ELISA, and 0.959 for the RBD ELISA. The kappa values were 0.62, 0.79 and 0.86 for the S, S1 and RBD ELISAs, respectively. (4) Conclusions: The in-house S1 and RBD ELISAs developed in this study have acceptable performance characteristics in terms of sensitivity, specificity, AUC and kappa values. In particular, the RBD ELISA seems viable to determine SARS-CoV-2-specific antibody levels, both in infected and vaccinated people, and help mitigate SARS-CoV-2 outbreaks and spread.
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Wang, Xiaohong, Martin Sapp, Neil D. Christensen e Joakim Dillner. "Heparin-based ELISA reduces background reactivity in virus-like particle-based papillomavirus serology". Journal of General Virology 86, n. 1 (1 gennaio 2005): 65–73. http://dx.doi.org/10.1099/vir.0.80472-0.
Testo completoAbstract (sommario):
The interaction between human papillomavirus (HPV) particles and cell surface heparan sulfate requires intact conformation of the HPV particles. Type-specific HPV serology is currently based on virus-like particles (VLPs) with intact conformation. Presence of incorrectly folded VLPs in VLP preparations is recognized as an important cause of cross-reactivity in HPV serology. Heparin-coated microtitre plates were evaluated for capturing conformationally correct VLPs and improving the type specificity of HPV serology. Hybrid VLPs between HPV16 and HPV11, which had been found to have significant reactivity with children's sera and a batch of HPV18 VLPs that had failed the quality control because of significant reactivity with sera from virginal women, were tested in parallel with heparin ELISA, ordinary ELISA and type-specific mAb capture ELISA. Control sera from children that had detectable reactivity with HPV16/11 hybrid VLPs in ordinary ELISA did not react in heparin-based ELISA, but some hybrid VLPs also had background reactivity in capture ELISAs. Control sera from virginal women that had some reactivity with a poor quality HPV18 VLP preparation in ordinary ELISA had no reactivity in heparin or capture ELISA, suggesting that certain VLP preparations expose cross-reactive epitopes that are not exposed on VLPs with heparin-binding ability. As the sensitivity was similar or only marginally affected by the use of heparin plates, use of heparin-coated plates may improve the type specificity of VLP-based ELISAs and reduce interassay variability attributable to variable quality of different VLP batches.
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Villa-Mancera, Abel, Pedro Molina-Mendoza, Karina Hernández-Guzmán, Jaime Olivares-Pérez, Jorge Sarracent-Pérez e José Zumaquero-Ríos. "Comparative Diagnosis of Serum IgG1 and Coproantigen ELISA for Fasciolosis Detection of Goats in Mexico". BioMed Research International 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/3860928.
Testo completoAbstract (sommario):
The objective of present study was to determine the prevalence of natural caprine fasciolosis in the Mixteca region of Mexico using coproantigen and serum IgG1 ELISA tests for comparative purposes. A total of 1070 serum and faecal samples were analyzed for IgG1 antibodies and coproantigens, using ELISA with E/S products as antigen and a monoclonal antibody-based sandwich ELISA. Prevalence of 73.46% was found using the serological ELISA and a percentage of 77.20 was found for coproantigen ELISA. The diagnostic sensitivity and specificity for serum ELISA were 86.7% and 96.4%, and for the coproantigen ELISA they were 93.1% and 97.8%, respectively. The seropositive samples were further categorized as low, medium, or high positivity. Results show a great proportion of low and medium positive goats when the serum ELISA test was used. Correlation coefficients between coproantigens and seropositivity were statistically significant (P<0.01) for low seropositivity (r=0.93) and medium seropositivity (r=0.84). The accuracy of faecal antigen ELISA was higher compared to indirect ELISA serological test. Two ELISAs were shown to be useful for demonstrating the current status ofF. hepaticainfection in the endemic areas and can be employed in studies on epidemiology as well as anthelmintics treatment for preventing economic loss and the risk of transmission to humans.
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Fledelius, C., I. Kolding, M. Bonde, P. Cloos, S. Christgau, P. Qviat, I. Byrjalsen e C. Christiansen. "Specificity of the crosslapsTM ELISA and the MAbA7 ELISA". Osteoporosis International 6, S1 (gennaio 1996): 193. http://dx.doi.org/10.1007/bf02500310.
Testo completo
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Aubert, D., G. T. Maine, I. Villena, J. C. Hunt, L. Howard, M. Sheu, S. Brojanac, L. E. Chovan, S. F. Nowlan e J. M. Pinon. "Recombinant Antigens To Detect Toxoplasma gondii-Specific Immunoglobulin G and Immunoglobulin M in Human Sera by Enzyme Immunoassay". Journal of Clinical Microbiology 38, n. 3 (2000): 1144–50. http://dx.doi.org/10.1128/jcm.38.3.1144-1150.2000.
Testo completoAbstract (sommario):
We have evaluated the diagnostic utility of eleven Toxoplasma gondii recombinant antigens (P22 [SAG2], P24 [GRA1], P25, P28 [GRA2], P29 [GRA7], P30 [SAG1], P35, P41 [GRA4], P54 [ROP2], P66 [ROP1], and P68) in immunoglobulin G (IgG) and IgM recombinant enzyme-linked immunosorbent assays (Rec-ELISAs). Following an initial evaluation, six recombinant antigens (P29, P30, P35, P54, P66, and P68) were tested in the IgG and IgM Rec-ELISAs with four groups of samples which span the toxoplasmosis disease spectrum (negative, chronic infection, acute infection, and recent seroconversion). Our results suggest that the combination of P29, P30, and P35 in an IgG Rec-ELISA and the combination of P29, P35, and P66 in an IgM Rec-ELISA can replace the tachyzoite antigen in IgG and IgM serologic tests, respectively. The relative sensitivity, specificity, and agreement for the IgG P29-P30-P35 Rec-ELISA were 98.4, 95.7, and 97.2%, respectively. The resolved sensitivity, specificity, and agreement for the IgM P29-P35-P66 Rec-ELISA were 93.1, 95.0, and 94.5%, respectively. Relative to the tachyzoite-based immunocapture IgM assay, the IgM P29-P35-P66 Rec-ELISA detects fewer samples that contain IgG antibodies with elevated avidity from individuals with an acute toxoplasmosis.
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Malan, Annette K., Erick Avelar, Sheldon E. Litwin, Harry R. Hill e Christine M. Litwin. "Serological diagnosis of Trypanosoma cruzi: evaluation of three enzyme immunoassays and an indirect immunofluorescent assay". Journal of Medical Microbiology 55, n. 2 (1 febbraio 2006): 171–78. http://dx.doi.org/10.1099/jmm.0.46149-0.
Testo completoAbstract (sommario):
Chagas' disease is an important cause of heart failure in Latin America, but is rare in the United States. The immigration of persons from endemic countries increases the potential of encountering patients with the disease. Concerns have also been raised about the introduction of Trypanosoma cruzi, the parasite that causes the disease, into the blood supply and during organ transplantation. To compare Chagas' antibody tests that are available in the United States, we evaluated three IgG ELISAs, CeLLabs T. cruzi ELISA, Hemagen Chagas' kit and IVD Research Chagas' Serum Microwell ELISA, and MarDx indirect immunofluorescent assays. The CeLLabs and Hemagen IgG ELISAs had 100 % agreement, sensitivity and specificity. The IVD Research IgG ELISA had 94·6 % agreement, 100 % sensitivity and 93 % specificity.
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Werre, Stephen R., Richard H. Jacobson, Dwight D. Bowman, Jitender P. Dubey e Hussni O. Mohammed. "Evaluation of Kinetics and Single-Read Enzyme-Linked Immunoassays for Detection of Toxoplasma Gondii Antibodies in Sheep". Journal of Veterinary Diagnostic Investigation 14, n. 3 (maggio 2002): 225–30. http://dx.doi.org/10.1177/104063870201400306.
Testo completoAbstract (sommario):
A kinetics enzyme-linked immunosorbent assay (ELISA) and a single-read ELISA for the detection of ovine anti- Toxoplasma gondii IgG were developed and optimized. During the kinetics assay, 3 optical densities were obtained for each serum sample at intervals of 45 seconds, and the results were presented as average slopes (replicates of 2) of the reaction rate between bound enzyme and substrate solution. The kinetics ELISA was stopped 5 minutes after dispensing the substrate to constitute the single-read ELISA, and the results were presented as average optical densities for duplicates of each sample. Performance of the assays was evaluated using the modified agglutination test (MAT) as the “gold standard.” There was a high level of agreement between both ELISAs and the MAT, as measured by Pearson correlation coefficients, kappa statistics, and the area under the receiver operating characteristics curves. The single-read ELISA was as accurate as the kinetics ELISA, with a sensitivity of 89% and a specificity of 96%.
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Chang, Le, Junpeng Zhao, Fei Guo, Huimin Ji, Lu Zhang, Xinyi Jiang e Lunan Wang. "Comparative Evaluation and Measure of Accuracy of ELISAs, CLIAs, and ECLIAs for the Detection of HIV Infection among Blood Donors in China". Canadian Journal of Infectious Diseases and Medical Microbiology 2020 (14 agosto 2020): 1–9. http://dx.doi.org/10.1155/2020/2164685.
Testo completoAbstract (sommario):
Background. Enzyme-linked immunosorbent assay (ELISA) is the only serological method approved for blood screening in China. Automated chemiluminescence immunoassay (CLIA) and electrochemiluminescence immunoassay (ECLIA) had been used in clinical laboratories but not applied to screen HIV among blood donors. This study aimed to evaluate the performance of ELISA, CLIA, and ECLIA, focusing on the feasibility of CLIA/ECLIA for blood screening. Method. 1029 blood donations from 14 blood centers screened by ELISA were enrolled in the study. All plasma samples were tested by eight ELISA assays in 16 blood centers, followed by the detection of CLIA and ECLIA methods in the National Center for Clinical Laboratories (NCCL), further confirmed by nucleic acid testing (NAT) and Western blot (WB). Results. Of 1029 samples, 136 were confirmed as HIV positive. CLIA and ECLIA assay had similar sensitivities with ELISAs but showed higher specificity (CLIA: 99.1%, 885/893; ECLIA: 99.0%, 884/893), concordance rate (CLIA: 99.2%, 1021/1029; ECLIA: 99.1%, 1020/1029), and positive predictive value (PPV) (CLIA: 94.4%, 136/144; ECLIA: 93.8%, 136/145) than most of ELISA kits (>5 ELISAs) (P<0.05). Kappa values of CLIA (0.967) and ECLIA (0.963) were the highest among all the serologic assays. Among 451 samples with initial ELISA reactivity, 315 were negatives, of which 307 (97.5%) and 306 (97.1%) were detected as nonreactive by CLIA (8 nonspecific reactions) and ECLIA (9 nonspecific reactions), respectively. Conclusion. Compared with ELISA, CLIA and ECLIA are more specific and accurate in detecting HIV antibody/antigen and can keep more nonspecifically reactive donors detected by ELISA. CLIA and ECLIA can be used for the improvement of serological blood screening strategy to avoid the unnecessary loss of blood donors.
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Liu, Dan, Tibor Schuster, Marcus Baumann, Marcel Roos, Daniel Sollinger, Jens Lutz, Uwe Heemann e Maximilian von Eynatten. "Comparison of Immunoassays for the Selective Measurement of Human High–Molecular Weight Adiponectin". Clinical Chemistry 55, n. 3 (1 marzo 2009): 568–72. http://dx.doi.org/10.1373/clinchem.2008.112425.
Testo completoAbstract (sommario):
Abstract Background: Adiponectin is an adipocyte-derived hormone circulating in different multimer complexes. The high–molecular-weight (HMW) complex is likely the active form of this protein and has been recognized as a risk marker for type 2 diabetes and coronary artery disease (CAD). Because quantification of HMW adiponectin by Western blot analysis is time-consuming, novel ELISAs have been developed to simplify measurements in clinical research. However, these enzyme immunoassays have not been cross-validated in larger patient groups. We evaluated 2 individual ELISA systems by comparison to Western blotting for measurement of the distribution of HMW adiponectin in healthy individuals and patients with CAD and type 2 diabetes. Methods: We measured HMW adiponectin in 204 individuals (83 CAD patients, 81 type 2 diabetes patients, and 40 healthy controls). Correlations, range of agreement, and imprecision of HMW concentrations obtained using 2 commercial ELISAs (#1, ALPCO Diagnostics; #2, Millipore) were evaluated by comparison with quantitative Western blotting. Result: Adiponectin results of the ELISAs were significantly correlated with those obtained by Western blotting (both r > 0.75, P < 0.001). Deming regression and Bland-Altman analyses indicated high agreement among the 3 immunoassays. The median difference between HMW adiponectin concentrations measured by ELISA and by Western blot was +0.4 mg/L for ELISA #1 and −0.4 mg/L for ELISA #2 with 95% of value differences <3 mg/L. Conclusions: Selective measurement of HMW adiponectin by ELISA is feasible; however, individual differences among immunoassays must be considered. The evaluated ELISAs exhibit analytical characteristics that allow their use as equivalent for Western blot analysis in larger clinical and epidemiological groups.
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Kiechle, Frederick, Ronald Carlton, Angelica Freddo e Henry Quezada. "1779. Comparison of Two Zika IgM Antibody Capture Enzyme-linked Immunosorbent Assays (MAC-ELISA) in Symptomatic Patients from Dominican Republic, 2016". Open Forum Infectious Diseases 6, Supplement_2 (ottobre 2019): S655. http://dx.doi.org/10.1093/ofid/ofz360.1642.
Testo completoAbstract (sommario):
Abstract Background Zika virus (ZIKV) is a Flavivirus transmitted to humans by Aedes mosquitos. To assess the clinical presentation in 434 symptomatic patients (64 men, 370 women [65 pregnant; 305 nonpregnant]) during a ZIKV outbreak in the Dominican Republic (DR) in 2016, we evaluated clinical symptoms, ZIKV by qualitative detection of ZIKV RNA and ZIKV IgM by two MAC-ELISA assays, one from CDC and performed by the Florida Department of Health, Jacksonville, FL and one from InBios International Inc., Seattle, WA (Zika Virus Detect). Methods The Aptima ZIKV assay (Hologic, San Diego, CA) was used to detect ZIKV by transcription-mediated amplification RT–PCR in serum, plasma, or urine. Corresponding clinical symptomology reports were reviewed for all 434 patients. The results from the two MAC-ELISA assays were evaluated by linear regression analysis. The two MAC-ELISA assays were reported as optical density (OD) ratios from a sample with three different antigens (P/N ratio for CDC Zika MAC-ELISA and Zika Immune Status Ratio or ISR for InBios Zika Virus Detect MAC-ELISA). Results There was a biphasic increase in ZIKV detection in April and late May/June 2016 in the 434 symptomatic patients. All 434 had one or more of four symptoms including rash, fever, conjunctivitis, and arthralgia. Linear regression analysis (log scale) of results from subject samples tested on the two MAC-ELISAs (282 total) revealed a slope of 1.172, y-intercept of 0.1584 and R2 of 0.587. In 88 RT–PCR-negative patients, 48 (54.5%) were positive by both MAC-ELISAs; 27 (30.7%) were negative by both MAC-ELISAs and 13 (14.7%) had discrepant results with a sensitivity of 85% for the InBios MAC-ELISA. The InBios also detected IgM in 54.4% of samples that were positive for ZIKV by RT–PCR attributable to errors in determining the days post symptom onset. Conclusion In 2016 there was a biphasic spike of ZIKV-positive infections in 434 symptomatic men and women tested in DR. Both linear regression analysis and our comparative analysis in the ZIKV RT–PCR-positive and negative cohorts demonstrate that the InBios Zika Virus Detect MAC-ELISA provides diagnostic results comparable to the CDC Zika MAC-ELISA. Disclosures All authors: No reported disclosures.
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Collins, Michael T., Scott J. Wells, Kristine R. Petrini, James E. Collins, Ronald D. Schultz e Robert H. Whitlock. "Evaluation of Five Antibody Detection Tests for Diagnosis of Bovine Paratuberculosis". Clinical Diagnostic Laboratory Immunology 12, n. 6 (giugno 2005): 685–92. http://dx.doi.org/10.1128/cdli.12.6.685-692.2005.
Testo completoAbstract (sommario):
ABSTRACT Five diagnostic tests based on enzyme-linked immunosorbent assay (ELISA) technology for bovine paratuberculosis were evaluated by using individual serum or milk samples from 359 dairy cattle in seven paratuberculosis-free herds and 2,094 dairy cattle in seven Mycobacterium paratuberculosis-infected dairy herds. Three independent laboratories using three different culture procedures completed fecal cultures for M. paratuberculosis on these cattle and found 417 cows to be shedding M. paratuberculosis in their feces. An animal that was fecal culture positive for M. paratuberculosis by any of the three laboratories was considered a confirmed case of infection. The specificity of three ELISAs (two on serum and one on milk) was ≥99.8%. The specificity of the remaining two ELISAs, both done on serum, was 94.9 and 84.7%. Four of the five ELISAs evaluated produced similar sensitivity in detecting fecal culture-positive cattle (27.8 to 28.9%). Serum ELISA “D” had the lowest specificity (84.7%) and the highest sensitivity (44.5%), but if the cutoff value defining a positive test was changed from 125 to 250% (of the positive control) the sensitivity and specificity, 31.8 and 97.5%, respectively, were comparable to those of the other four assays. If the case definition for M. paratuberculosis infection was based on the culture results of a single laboratory instead of the combined results of three laboratories, ELISA sensitivity estimates were 45.7 to 50.0%. With the exception of ELISA D, assay agreement was high (kappa 0.66 to 0.85) for categorical assay interpretations (positive or negative), but linear regression of quantitative results showed low correlation coefficients (r 2 = 0.40 to 0.68) due to the fact that ELISA results for some cows were high in one assay but low in another assay. Likelihood ratio analysis showed a direct relationship between the magnitude of ELISA result and the odds of a cow shedding M. paratuberculosis in its feces. If used judiciously and interpreted quantitatively, these ELISAs are useful tools in support of paratuberculosis control programs in dairy herds.