Bhargava Mudita, Kumar Varsha, Pandey Himansha, Singh Vasudha, Misra Vatsala, Gupta Poonam
Department of Pathology, M.L.N. Medical College, George Town, Prayagraj, 211002 India.
Department of Pathology, VMMC and Safdarjung Hospital, New Delhi, India.
Indian J Hematol Blood Transfus. 2020 Oct;36(4):719-724. doi: 10.1007/s12288-020-01282-z. Epub 2020 May 2.
A large majority of microcytic hypochromic anemia have defects in cellular hemoglobin synthesis due to either iron deficiency or thalassemia trait; both differing in management and prognosis. HPLC and serum iron profile as confirmatory tests are unavailable at health care centers. Blanket therapy of iron supplements is therefore given in all such cases which may cause iron overload in thalassemia cases. Easy to use and cost effective screening methods are desirable. The present study was undertaken to evaluate the diagnostic accuracy of twelve indices to effectively screen cases of thalassemia trait and differentiate them from iron deficiency anemia. Routine samples from the hematology lab with Hb < 13 gm/dl, MCV < 80 fl and MCH < 27 pg were screened. Taking HPLC and serum ferritin as gold standard, out of total 1353 cases, 98 cases of thalassemia trait (HbA2 > 3.5 on HPLC) and 1102 cases of iron deficiency anemia (serum ferritin < 12 g/ml) were evaluated using discrimination indices. Diagnostic accuracy for each index was calculated. While few indices showed a sensitivity of 100%, their specificity was low which meant more number of false positive cases. Based on Youden's Index, which measures the diagnostic tests ability to balance sensitivity and specificity, the best three indices in the decreasing order of their efficacy in our study were Ricerca Index (RI), Green and King Index (GKI) and Mentzer Index (MI). MI is considered a reliable index by many clinicians since a long time, however RI and GKI were found to have a better diagnostic accuracy based on our study.
绝大多数小细胞低色素性贫血是由于缺铁或地中海贫血特质导致细胞血红蛋白合成缺陷；两者在治疗和预后方面有所不同。医疗保健中心无法进行作为确诊试验的高效液相色谱法（HPLC）和血清铁谱分析。因此，在所有此类病例中都给予铁补充剂的全面治疗，这可能会导致地中海贫血病例出现铁过载。需要易于使用且具有成本效益的筛查方法。本研究旨在评估十二项指标的诊断准确性，以有效筛查地中海贫血特质病例并将其与缺铁性贫血区分开来。对血液学实验室中血红蛋白（Hb）<13 gm/dl、平均红细胞体积（MCV）<80 fl和平均红细胞血红蛋白含量（MCH）<27 pg的常规样本进行筛查。以HPLC和血清铁蛋白作为金标准，在总共1353例病例中，使用鉴别指标对98例地中海贫血特质病例（HPLC上HbA2>3.5）和1102例缺铁性贫血病例（血清铁蛋白<12 g/ml）进行了评估。计算每个指标的诊断准确性。虽然少数指标显示出100%的敏感性，但其特异性较低，这意味着假阳性病例数量较多。基于约登指数（Youden's Index），该指数衡量诊断测试平衡敏感性和特异性的能力，在我们的研究中，按功效递减顺序排列的最佳三项指标是里塞尔卡指数（Ricerca Index，RI）、格林和金指数（Green and King Index，GKI）和门泽指数（Mentzer Index，MI）。长期以来，许多临床医生都认为MI是一个可靠的指标，然而根据我们的研究，RI和GKI具有更好的诊断准确性。
