Madan N, Sikka M, Sharma S, Rusia U, Kela K
Department of Pathology, UCMS & GTB Hospital, Shahdara, Delhi.
Indian J Pathol Microbiol. 1999 Jan;42(1):55-61.
Red cell indices and discriminant functions were studied in 463 heterozygous beta-thalassaemics (337 without iron deficiency, 126 with iron deficiency) and 195 patients of iron deficiency anaemia (IDA) to ascertain their utility in the detection of betathalassaemia trait (BTT). Majority of traits in both groups had an elevated RBC count (> or = 5.0 x 10(12)/L). The counts were significantly higher than of patients with IDA, only 4.6% of whom had this degree of erythrocytosis. Mean Hb concentration was significantly higher in traits as compared to iron deficient subjects (p < 0.0001). Mean MCV and MCH were significantly (p < 0.0001) lower in traits more so in those with ID as compared to patients of IDA. MCV < 80 fl and MCH < 27 pg were found to be sensitive markers in the detection of traits even in the presence of ID. Of the four discriminant functions studied MCSQ was found to be most sensitive in detection of BTT and it identified 97.9% traits. DF of England and Fraser was most specific for BTT being < 8.4 in only 6.2% patients with IDA. Detection of erythrocytosis especially in the presence of mild anaemia and calculation of discriminant functions derived from red cell indices were found to play an important role in screening for BTT even in the presence of ID and helped identify those patients who required further laboratory evaluation.
对463例杂合子β地中海贫血患者（337例无缺铁，126例缺铁）和195例缺铁性贫血（IDA）患者的红细胞指数和判别函数进行了研究，以确定它们在检测β地中海贫血特征（BTT）中的效用。两组中的大多数特征均有红细胞计数升高（≥5.0×10¹²/L）。这些计数显著高于IDA患者，IDA患者中只有4.6%有这种程度的红细胞增多。与缺铁受试者相比，特征患者的平均血红蛋白浓度显著更高（p<0.0001）。与IDA患者相比，特征患者的平均MCV和MCH显著更低（p<0.0001），在缺铁患者中更是如此。即使在存在缺铁的情况下，MCV<80 fl和MCH<27 pg被发现是检测特征的敏感标志物。在所研究的四个判别函数中，MCSQ在检测BTT方面最敏感，它识别出97.9%的特征。英格兰和弗雷泽判别函数对BTT最具特异性，仅6.2%的IDA患者<8.4。发现红细胞增多症的检测，尤其是在存在轻度贫血的情况下，以及计算从红细胞指数得出的判别函数，在筛查BTT中起着重要作用，即使在存在缺铁的情况下，也有助于识别那些需要进一步实验室评估的患者。
