Wickramaratne K A C, Wijewickrama D C
Department of Pathology.
Department of Physiology, Faculty of Medicine, University of Ruhuna, Galle, Sri Lanka.
Int J Health Sci (Qassim). 2021 Jan-Feb;15(1):29-34.
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.
A retrospective study was performed to assess reliability of 11 red cell indices, parameters and formulae in differentiating BTT from non-BTT in a cohort of individuals referred for confirmation of BTT.
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 ± 1.7 pg, respectively. The mean red cell count in BTT group was 5.3 ± 0.8 × 10/L while in non BTT group it was 4.7 ± 0.7 × 10/L. The highest specificity (86.4%) was shown by Sirdah, Sriwastava and England and Fraser indices, but their sensitivities were 61.8%, 57.3%, and 32.6%. The lowest number of false positives ( = 3, 13.6%) was shown by Srivastava, Sirdah and England and Fraser indices. Shine and Lal index showed 100% sensitivity and NPV and 12 false positives. MCV and MCH showed results similar to Shine and Lal index with 16 false positives each.
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.
红细胞指数和参数用于筛查β地中海贫血特征（BTT）。用于区分不同人群中BTT的不同红细胞指数和公式显示出不一致的结果。
进行了一项回顾性研究，以评估11种红细胞指数、参数和公式在一组因BTT确诊而转诊的个体中区分BTT与非BTT的可靠性。
111名个体中，79名女性，32名男性。总共89名通过Hb A2定量确诊为BTT。该组的平均年龄为29.9±19.2岁。BTT组的平均血红蛋白浓度、平均红细胞体积（MCV）和平均红细胞血红蛋白含量（MCH）分别为10.45±1.6 g/dL、62.1±5.4 fl和19.7±1.7 pg。BTT组的平均红细胞计数为5.3±0.8×10/L，而非BTT组为4.7±0.7×10/L。Sirdah、Sriwastava以及England和Fraser指数显示出最高的特异性（86.4%），但它们的敏感性分别为61.8%、57.3%和32.6%。Srivastava、Sirdah以及England和Fraser指数显示出最低的假阳性数（=3，13.6%）。Shine和Lal指数显示出100%的敏感性和阴性预测值以及12例假阳性。MCV和MCH显示出与Shine和Lal指数相似的结果，各有16例假阳性。
在BTT筛查项目中使用Shine和Lal指数优于所有其他指数和公式。为证实本研究结果，建议在斯里兰卡针对不同种族进行进一步研究。
