Littérature scientifique sur le sujet « BETA-THALASSEMIA TRAIT »

Objectives: To assess the sensitivity of the various discrimination indicesas screening test in beta-thalassemia trait patients in our population. Study design: Crosssectional descriptive study. Period: 1-Sep 2012 to 31-Jan 2013 (5 months). Settings: PathologyDepartment, District Head Quarters (DHQ) Hospital, Rawalpindi. Materials and Methods: Atotal of 150 diagnosed cases of beta thalassemia trait were included in the study. Study wasdone from 1-Sep 2012 to 31-Jan 2013 in DHQ hospital, Rawalpindi. Four discrimination indicesi.e. Mentzer, Shine & Lal, Srivastava, and Red cell Distribution Width Index were calculated forall the patients. The number of correctly identified cases were determined and sensitivity ofeach discrimination index was calculated accordingly. Results: The sensitivity in diagnosingbeta thalassemia trait patients was highest for Shine and Lal index (95%), followed by Mentzerindex (52% sensitivity), and then Srivasava index (46% sensitivity). Red cell distribution widthindex had poor sensitivity of 2% in our study. None of the discrimination indices showed 100%sensitivity. Conclusion: We concluded that Shine & Lal and Mentzer index are the most sensitiveindices. They can be used for cheap and quick screening of beta-thalassemia trait patients inlaboratories where advanced investigation tools are not available. Patients who give positiveresult for beta thalassemia trait with these indices may then be referred for further workup toconfirm the diagnosis.

Thalassemia beta / hemoglobin E adalah suatu kondisi dengan heterozigot ganda gen pembawa thalassemia beta dan hemoglobin E. Hal ini menyebabkan kondisi dengan gambaran fenotip yang berat dibandingkan trait thalassemia beta dan trait hemoglobin E. Secara logika, nilai mean corpuscular dari thalassemia beta / hemoglobin E seharusnya memburuk. Pada penelitian ini, kami meneliti sebelas kasus dari dua keluarga dengan anggota menderita thalassemia beta / hemoglobin E.Pada keluarga-1 dua anggota dengan trait thalassemia beta memiliki nilai MCV 68 fL dan 65 fL, dan nilai MCH 21 pg dan 20 pg. Pada keluarga-2 anggota dengan trait thalassemia beta memiliki nilai MCV 60,2 fL dan MCH 18,8 pg. Anak perempuan dari kedua keluarga dengan thalassemia beta / hemoglobin E memiliki nilai mean ± SD MCV 70,8 ± 4,9 fL dan MCH 22.8 ± 2.3 pg, nilai ini signifikan lebih tinggi daripada trait thalassemia beta (p<0.05). Terdapat perbedaan yang signifikan antara nilai hemoglobin dan RDW antara thalassemia beta / hemoglobin E (p=0.001).Kami juga menemukan bahwa nilai MC dari keadaan post-transfusi signifikan lebih tinggi daripada pre-transfusi (p<0.001)Kami menyimpulkan bahwa nilai MC dari thalassemia beta / hemoglobin E secara persisten lebih tinggi daripada trait thalassemia beta. Peran transfusi darah pada pasien dengan thalassemia beta / hemoglobin E tampak memainkan peran dalam diskrepansi pada kasus ini.

Microcytic hypochromic anemia is one of the commonest hematological abnormalities in Bangladeshi population. Iron deficiency anemia and beta thalassemia traits are the most frequent causes of microcytic hypochromic anemia which are sometimes difficult to differentiate clinically and by routine laboratory examinations due to similar blood picture. To differentiate between patients of beta thalassemia trait and iron deficiency anemia, physicians need a group of investigations including peripheral blood film, estimation of HbA2, serum ferritin, serum iron, total iron binding capacity and transferrin saturation. But these tests are relatively expensive, time consuming and need sophisticated techniques. The aim of this study was to evaluate the pattern of red cell count and RDW-CV (%) in beta thalassemia trait in adults and thereby determine the role of these parameters in differentiation between patients of beta thalassemia trait and iron deficiency anaemia. In this study 50 confirmed cases of beta thalassemia trait aged 18 to 60 years, both male and female were included as cases and 50 age- and sex-matched iron deficiency subjects were included as control. RBC count and RDW-CV (%) were measured by an electronic cell counter device. The present study revealed that RBC count was higher in patients with beta thalassemia trait than that in iron deficiency anemia and RDW-CV(%) was significantly higher in patients with iron deficiency anemia than that in beta thalassemia trait.Bangladesh J Med Biochem 2016; 9(1): 31-35

Background and objectives: The identification of carriers of beta- thalassemia depends on the detection of a high level of hemoglobin A2. The hemoglobin A2 level is influenced by some elements including iron. The consequence of concomitant iron deficiency on the hemoglobin A2 level is critical in screening laboratories for hemoglobinopathies, particularly in resource-limited ones where molecular identification of hemoglobin A2 levels is unavailable. The aim of this study is to evaluate the consequence of iron deficiency on hemoglobin A2 level to obtain a definite diagnosis of beta- thalassemia trait. Methods: A total of one hundred forty -five subjects were involved, divided into three groups: (50) healthy controls, (50) beta-thalassemia trait, and (45) coincident iron deficiency with beta-thalassemia trait. Full blood count, Iron status including serum iron with total iron-binding capacity, lastly hemoglobin A2 with hemoglobin F estimation were performed for all enrollees. Results: The age range in the beta-thalassemia trait group was 7-40 years, with mean of (26.6± 5.3) years, while the concomitant group has an age range of 15-36 years, with a mean of (24.4 ±5.1) years. Meanwhile the age of control group ranged from 19-36 years with a mean of (24.6 ±3.8) years. The hematological parameters were significantly reduced in beta- thalassemia trait and concomitant iron deficiency in comparison to the controls with no significant difference in hemoglobin A2 between beta thalassemia trait and concomitant iron deficiency (5.1± 0.9) and beta-thalassemia minor (5.2 ± 0.9). Conclusion: No influence of iron deficiency on the identification of beta-thalassemia minor detected in the screened population.

Beta thalassemia trait is a heterogeneous autosomal recessive form of beta thalassemia. Individual with beta thalassemia are clinically asymptomatic. Here we have described a case that has been incidentally diagnosed as beta thalassemia trait. A 31 year old male form Newar Community came to hospital for routine health checkup was send for hematological investigation. On examination, his red cell morphology was found to be microcytic hypochromic and his hemoglobin concentration was mildly decrease. His other parameters was evaluated and requested for analysis of iron profile and hemoglobin electrophoresis. Iron profile test was normal. Hemoglobin electrophoresis showed prominent band in HbA2 region. Presence of HbA2 band was confirmed by hemoglobin variant HPLC analysis. A diagnosis of heterozygous beta thalassemia trait was made. Prevalence of beta thalassemia gene in Tharu population was reported but its presence in other communities is still unknown so it is recommended to study the prevalence of beta thalassemia gene in Newar community as well.

Abstract Abstract 5303 The state of West Bengal in the eastern part of India has a high prevalence of the carrier states of beta thalassemia and Hb E. Analysis of Hb HPLC screening data from 200 individuals, including adults and children from urban areas around Kolkata in West Bengal, carried out in our institution1, reveals a prevalence 6.5% for beta trait and 5.5% for HbE trait. (unpublished data) It may be possible to reduce births of beta thalassemia major and E beta thalassemia by preventive strategies, including mass screening and awareness campaigns. The best preventive method is debatable, because of the highly variable prevalence of the haemoglobin disorders within defined geographic regions (Weatherall DJ, Blood.2010), the economic factors involved and most importantly the question of acceptance of prevention methods. Because of the social stigma attached to the diagnosis of a genetic disease, families of young men and women diagnosed as thalassemia carriers in community screening programs often suppress this information when marriages are arranged, according to prevalent social practice. Therefore pre-marital screening, in our experience, is unlikely to be effective in reducing the number of beta thalassemia major and E-Beta thalassemia births in eastern India. Antenatal screening on the other hand has the potential for greater acceptability. Concern for the welfare of the unborn child are likely to make prospective parents more amenable to counselling and getting themselves tested for the thalassemia carrier state. We analysed data of 1000 antenatal mothers (Table 1), who had undergone screening for the thalassemia carrier state by red cell indices and Hb HPLC, as part of a government funded screening programme conducted in our institution1 in Kolkata city of West Bengal, India, in order to determine whether red cell indices, which is more economical than Hb HPLC, was an effective screening tool. Results of Hb HPLC screening data of 1000 antenatal women (Table 1) Result Beta Trait (HbA2% 3.6-6.6) Hb E trait (A2+E% 22.8-42.8) E Beta E Disease Sickle trait Sickle Beta D Trait D disease No of cases (%) 58(5.8%) 48(4.8%) 3(0.2%) 2(0.2%) 2(0.2%) 1(0.1%) 1 1 Where both partners were carriers, mutations were confirmed by complementary reverse dot blot hybridisation or DNA sequencing. Red Cell Indices in Thalassemia Carrier States (Table 2) Thalassemia Carrier State (1000 Antenatal Women) MCV (fl) MCH (pg) Mean Range (±95%CI) (±2SD) Mean Range (±95%CI) (±2SD) Beta Trait (n= 58) 68.6±1.70 55.4–81.8 21.80±0.64 16.6–26.8 E Trait(n=48) 78.8±1.42 67.8–89.8 26.4±0.62 22.0–30.8 Most antenatal women received iron and folic acid supplements, therefore iron status was not separately examined. To exclude the possibility of the effect of pregnancy on red cell indices, evaluation of MCV and MCH in 50 HbE trait individuals and 250 beta trait drawn from community screening data, comprising non-pregnant females and males, with normal serum ferritin values, mean MCV was 76.6fl (range 66.3–86.8fl), mean MCH 25.6pg (range 21.5–29.7pg) for E trait. For beta trait mean MCV was 67.0 fl (range 50–84 fl), mean MCH 21 pg (range 15–26 pg). There was no statistically significant difference from antenatal cases (Student's t-test ). MCV of <80fl and MCH < 27pg were previously reported to predict most beta thalassemia in pregnancy (Weatherall and Clegg Eds, The Thalassemia Syndromes, Part 4. UK: Blackwell Science Ltd, 2001 ). We tested whether these values could reliably predict beta trait and E trait taken together, in 1000 antenatal women in the present study (Table 3) Red Cell Indices as Predictor of Beta Trait and HbE Trait (Table 3) Sensitivity (%) Specificity (%) Positive Predictive Value (%) Negative Predictive Value (%) No of Beta Trait Missed on Screening (%) n=58 No of E Trait Missed on Screening (%) n=48 MCV <80fl 88 85 42 98 6 (10.3) 15 (31.3) MCH <27pg 84 82 35.2 98 9 (15.5) 17 (35.4) Conclusion –MCH and MCV tend to be higher in E trait compared to beta trait. We recommend that in high prevalence areas, Hb HPLC should be performed in all antenatal women irrespective of red cell indices, to avoid missing thalassemia carriers and facilities for genetic diagnosis and counselling be made available to couples at risk of beta thalessemia major and E beta thalessemia births. Disclosures: No relevant conflicts of interest to declare.

Background: Sickle cell trait (SCT) is the heterozygous form of sickle cell disease and expectedly should be a benign state with no complications ascribed to it. There are numerous reports challenging its being a benign condition, though this is controversial. Methods and Results: A review of the results of the accompanying investigations done on some of the patients show that beta thalassemia may be responsible for many of the ascribed symptoms and complications. These patients may therefore have sickle cell beta thalassemia, a compound heterozygous form of sickle cell disease. Conclusion: It is important to screen for beta thalassemia using red cell indices and quantitation of the different hemoglobin fractions before attributing any symptoms to SCT. DNA analysis, though useful in ascertaining the presence of the sickle cell gene, is not sufficient. There is the need to exclude the presence of mutations for beta thalassemia, which often is geographical region-specific.

Objective: To assist in the differential diagnosis of beta thalassemia trait and iron deficiency anaemia, many alternative red blood cell index-based formulae were examined. Methods: The Rawalpindi PEMH performed this study from June 2021 to March 2022. For individuals with beta- thalassemia trait and iron deficient anaemia, age and gender were not considered. More than five millilitres of blood were drawn from each patient in order to determine the haemoglobin content, the number of red blood cells, how they were distributed, and the average cell volume. Five alternative formulas may be used to differentiate these two circumstances. Shine and Lal index, Mentzer index, Srivastava index and Green & King index are among the most well- known ones. Youden's index was included in the calculation of sensitivity, specificity, and positive and negative predictive values (PPVs). Results: The iron deficiency anaemia rate was 70%, and the beta thalassemia phenotype was 30% among the 1500 participants. This indicator has a sensitivity of 100% and specificity of 93.3% when it comes to discriminating between beta-thalassemia trait and iron deficiency anaemia. Conclusion: The red cell distribution width index may be used to differentiate between beta thalassemia trait and iron deficiency anaemia. If a haemoglobin electrophoresis is not available, a diagnosis of beta thalassemia may still be made. Keywords: Srivastava index, beta-thalassemia, Anemia, Cell redness, Hb electrophoresis

A certain degree of iron overload (IO) is sometimes seen in subjects with β-thalassemia trait (βTT), a mild form of non-transfusion-dependent β-thalassemia. The pathogenesis is unclear, but recently a population study in Sri Lankan children has showed that βTT is characterized by mild hepcidin suppression due to increased erythropoietic activity. This data is in accordance with previous other studies suggesting that erythropoietic drive can regulate hepcidin production, potentially acting via an erythroid-derived hormone, such as the recently identified erythroferrone (ERFE). Hepcidin is the master regulator of iron homeostasis which acts by inhibiting dietary iron absorption and iron release from macrophages, thus its suppression leads to an increased of iron availability in the body. In βTT patients, hepcidin defect may be further aggravated by genetic (i.e. mutations in hemochromatosis genes) or acquired factors (e.g. alcohol abuse or non-alcoholic liver diseases). Treatment of IO in βTT is problematic, since “standard” large-volume phlebotomies are not feasible in mildly anaemic subjects, as well as the lack of approval of oral iron chelators and of specific guidelines. Deferoxamine is the only approved therapy, but it is poorly applicable because of parenteral administration and side effects. Sporadic case reports have suggested the use of phlebotomies in βTT patients with IO, but feasibility and efficacy of such approach has not been evaluated in patients’ series. This study has been designed to better characterize factors involved in the development of IO in βTT patients, and to evaluate feasibility and efficacy of “mini-phlebotomies” in this condition. In our population, a substantial alcohol consumption (>100 g/day) appears a common acquired cofactor in βTT patients with IO, while biomolecular analysis did not reveal potentially pathogenic variants out of the known H63D and C282Y in HFE. Mean hepcidin levels were higher than those observed in the general population, suggesting that the hepcidin response to IO is conserved, while the hepcidin:ferritin ratio was lower than in age- and sex-matched normal individuals, in agreement with a relative hepcidin defect in βTT. Fifteen patients started treatment with “mini-phlebotomies”, eleven of them have reached the iron depletion and no one experienced a worsening of anaemia during the treatment, suggesting mini-phlebotomies as a valuable approach for this peculiar category of patients.