Sysmex XE-2100中Q-flags阳性报警临界值的调整与验证

The adjustment and validation of the Q-flags positive alarm threshold values in Sysmex XE-2100

目的对Sysmex XE-2100中可疑报警信号(Q-flags)设置合理的临界值,制定适合于本实验室Q-flags的镜检标准,提高工作效率,保证血液分析结果的准确性。方法选择2011年3月至2012年3月期间本院门急诊及住院患者的4 500例标本,上机检测后推片、染色、手工镜检。以查见原始和幼稚细胞≥1%,早幼粒和中幼粒细胞≥1%,晚幼粒细胞>2%,杆状核粒细胞>5%,异型淋巴细胞>5%,有核红细胞≥1%为阳性标准。重新定义仪器Q-flags主要参数的临界值,最后选择1 400份标本验证新确定临界值可信度。结果 (1)修订前/后临界值为:原始细胞:100/130、未成熟粒细胞:100/150、核左移:100/160、异形淋巴细胞:100/180、有核红细胞:100/90、异常/原始淋巴细胞:100/200;(2)修订前/后假阳性率(%)分别为61.05/50.15、56.36/35.60、44.34/14.10、62.12/32.20、36.18/40.61、62.96/26.30;真阴性率(%)分别为38.95/49.85、43.64/64.36、55.66/85.90、37.88/67.80、63.82/59.39、37.04/73.70;总符合率(%)分别47.75/56.42、57.00/71.83、73.44/89.67、45.33/71.33、80.17/79.17、43.33/76.00;报警率下降了14.67%;(3)验证试验显示无初发白血病细胞漏检。结论 (1)Sysmex XE-2100设置合理Q-flags的临界值,保证血液分析结果的准确性,有效地筛选出真正异常样本,有选择性地对复片镜检,提高工作效率;(2)对于自动化血液分析系统Q-flags的临界值应根据各实验室实际情况重新修订,不应直接使用其出厂值。

Objective To improve the work efficiency and ensure the accuracy of the blood test through establishing an appropriate standard of microscopic examination based on setting up reasonable threshold values to suspicious alarm informations（Q-flags） in Sysmex XE-2100 automatic hematology analyzer.Methods A total of 4 500 specimens from the out-patient and emergency departments and the in-patient department during March 2011 to March 2012 underwent the measurement by Sysmex XE-2100 with blood slide,subsequent staining and manual microscopic examination.The positive standard was set up as follows： blast cell ≥ 1%,promyelocyte and myelocyte ≥ 1%,metamyelocyte 2%,stab granulocyte 5%,atypical lymphocyte 5% and nucleated erythrocyte ≥ 1%.According to these positive standards,the threshold valus of the main parameters in the Q-flags were redefined.Finally,1 400 specimens were measured to verify the reliability of the newly established cut-off value.Results（1） Threshold values before/after amendment were： blast cell 100 /130,immature granulocyte 100 /150,left shift 100 /160,atypical lymphocyte 100 /180,nucleated erythrocyte 100 /90 and abnormal/blast lymphocyte 100 /200.（2） False positive rates（%） before/after amendment were： 61.05/50.15,56.36/35.60,44.34/14.10,62.12/32.20,36.18/40.61 and 62.96 /26.30.Real negative rates（%） before/after amendment were： 38.95 /49.85,43.64 /64.36,55.66 /85.90,37.88 /67.80,63.82 /59.39 and 37.04 /73.70.Total coincidence rates（%） before/after amendment were ： 47.75/56.42,57.00 /71.83,73.44 /89.67,45.33 /71.33,80.17 /79.17 and 43.33 /76.00.The alarm rate decreased by 14.67%.（3） There were no initial leukemic cells omitted in the validation test.Conclusions（1） Amending reasonable threshold values of Q-flags in Sysmex XE-2100 can effectively filter out the truly abnormal samples and ensure the accuracy of blood test results.The selected and targeted microscopic examination of the smeared blood specimen can greatly improve work efficiency.（2） The threshold values of the Q-flags in automatic blood cell analysis system should be revised according to the practical situation for each laboratory.Original factory value cannot be directly used.