Screening for beta-thalassemia trait; applicability of red cell indices and parameters – A study in Sri Lanka
Abstract
Objective: Red cell indices and parameters are used to screen beta thalassemia trait (BTT). Different red cell indices and formulae used to discriminate BTT in different populations show inconsistent results.
Methods: A retrospective study was performed to assess reliability of eleven red cell indices, parameters and formulae in differentiating BTT from non BTT in a cohort of individuals referred for confirmation of BTT.
Results: Of 111 individuals, 79 were females and 32 were males. Of the total, 89 were confirmed to have BTT by Hb A2 quantification. The mean age of the group was 29.9±19.2 years. The mean Hb concentration, MCV and MCH in BTT group were 10.45±1.6 g/dL, 62.1±5.4 fl and 19.7±1.7pg respectively. The mean red cell count in BTT group was 5.3±0.8 x109/L while in non BTT group it was 4.7±0.7 x109/L. The highest specificity (86.4%) was shown by Sirdah, Sriwastava and England & Fraser indices, but their sensitivities were 61.8%, 57.3% and 32.6%. The lowest number of false positives (n=3, 13.6%) was shown by Srivastava, Sirdah and England and Fraser indices. Shine & Lal index showed 100% sensitivity and NPV and 12 false positives. MCV and MCH showed results similar to Shine & Lal index with 16 false positives each.
Conclusion: Use of Shine and Lal index in screening programs of BTT is superior to all the other indices and formulae. To confirm the findings of this study, further studies are recommended to be carried out in Sri Lanka on different ethnicities.
Keywords:
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).