Hematology Laboratory, Hospital Galdakao-Usansolo, Galdakao, Vizcaya, Spain.
Int J Lab Hematol. 2011 Feb;33(1):30-6. doi: 10.1111/j.1751-553X.2010.01237.x.
Cell counter-based formulae have been used in the differential diagnosis of microcytic anemia. The measurement of new red cell parameters is now available on the Sysmex XE 5000 analyzer. Derived from the percentages of microcytic and hypochromic red cells, the authors describe the new formula %microcytic-%hypochromic, M-H index. The aim of this study was to assess the discriminant value of this new index in the differential diagnosis of microcytic anemia and thalassemia screening compared to the published indices. Receiver operating characteristic curves, sensitivity, specificity and Youden index were calculated for a set of 170 iron-deficiency anemia patients and 200 β thalassemia carriers. % microcytic-% hypochromic index showed the best area under the curve (area under curve AUC, 0.994) and Youden index (93.9%), among considered indices; 98% sensitivity, 95.9% specificity, at a cutoff value >11.5; Green and King index ranked second (AUC 0.99, Youden index 90.8%). Because of high sensitivity and specificity, the new index %microcytic-%hypochromic was the most reliable index evaluated. M-H index could be a useful tool in the differential diagnosis of microcytic anemia, and samples with M-H>11.5 can be chosen for further analysis to confirm the diagnosis of thalassemia.
基于细胞计数器的公式已被用于小细胞性贫血的鉴别诊断。新型红细胞参数的测量现在可在 Sysmex XE 5000 分析仪上进行。作者根据小红细胞和低色素红细胞的百分比描述了新的公式 %microcytic-%hypochromic，即 M-H 指数。本研究旨在评估该新指数在小细胞性贫血的鉴别诊断和地中海贫血筛查中的鉴别价值，并与已发表的指数进行比较。为一组 170 例缺铁性贫血患者和 200 例β地中海贫血携带者计算了接受者操作特征曲线、灵敏度、特异性和 Youden 指数。在所考虑的指数中，%microcytic-%hypochromic 指数显示出最佳曲线下面积（AUC，0.994）和 Youden 指数（93.9%）；截断值>11.5 时，灵敏度为 98%，特异性为 95.9%；Green 和 King 指数排名第二（AUC 0.99，Youden 指数 90.8%）。由于具有较高的灵敏度和特异性，新的 %microcytic-%hypochromic 指数是评估的最可靠指数。M-H 指数可以成为小细胞性贫血鉴别诊断的有用工具，M-H>11.5 的样本可选择进行进一步分析以确认地中海贫血的诊断。
