División Hematología Clínica, Departamento de Medicina, Hospital Nacional Alejandro Posadas, Buenos Aires, Argentina.
Ann Hematol. 2011 Jun;90(6):625-34. doi: 10.1007/s00277-010-1112-0. Epub 2010 Nov 16.
This prospective study was carried out to assess the usefulness of five laboratory tests in the diagnosis of hereditary spherocytosis (HS), based on the correlation of erythrocyte membrane protein defects with clinical and laboratory features, and also to determine the membrane protein deficiencies detected in Argentina. Of 116 patients and their family members tested, 62 of them were diagnosed to have HS. The specificity of cryohemolysis (CH) test was 95.2%, and its cut-off value to distinguish HS from normal was 2.8%. For flow cytometry, cut-off points of 17% for mean channel fluorescence (MCF) decrease and 14% coefficient of variation (CV) increase showed 95.9% and 92.2% specificity, respectively. Both tests showed the highest percentages of positive results for diagnosis. Either CH or flow cytometry was positive in 93.5% of patients. In eight patients, flow cytometry was positive only through CV increase. Protein defects were detected in 72.3% of patients; ankyrin and spectrin were the most frequently found deficiencies. The CV of the fluorescence showed significantly higher increases in moderate and severe anemia than in mild anemia (p = 0.003). Severity of anemia showed no other correlation with tests results, type of deficient protein, inheritance pattern, or neonatal jaundice. CH and flow cytometry are easy methods with the highest diagnostic accuracy. Simultaneous reading of mean channel fluorescence (MCF) decrease and CV increase improve diagnostic usefulness of flow cytometry. This test seems to be a reliable predictor of severity. The type of detected protein deficiency has no predictive value for outcome. Predominant ankyrin and spectrin deficiencies agree with reports from other Latin American countries.
本前瞻性研究旨在评估五种实验室检测在遗传性球形红细胞增多症（HS）诊断中的作用，依据红细胞膜蛋白缺陷与临床和实验室特征的相关性，并确定在阿根廷检测到的膜蛋白缺陷。在接受测试的 116 名患者及其家庭成员中，有 62 名被诊断为 HS。冷冻溶血（CH）试验的特异性为 95.2%，其区分 HS 与正常的截断值为 2.8%。对于流式细胞术，平均通道荧光（MCF）降低的截断值为 17%，变异系数（CV）增加的截断值为 14%，其特异性分别为 95.9%和 92.2%。这两项检测的阳性结果诊断率最高。CH 或流式细胞术在 93.5%的患者中均为阳性。在 8 名患者中，仅通过 CV 增加，流式细胞术呈阳性。在 72.3%的患者中检测到蛋白缺陷；锚蛋白和血影蛋白是最常见的缺陷。与轻度贫血相比，中重度贫血的荧光 CV 增加明显更高（p=0.003）。贫血严重程度与检测结果、缺陷蛋白类型、遗传模式或新生儿黄疸均无相关性。CH 和流式细胞术是具有最高诊断准确性的简便方法。同时读取 MCF 降低和 CV 增加可提高流式细胞术的诊断效果。该检测似乎是严重程度的可靠预测指标。检测到的蛋白缺陷类型对结果无预测价值。主要的锚蛋白和血影蛋白缺陷与来自其他拉丁美洲国家的报告一致。
