抗-HIV ELISA检测结果分析及灰区设置研究

Analysis of anti-HIV detection result with enzyme-linked immunosorbent method and the setting of grey area

目的评价与验证本实验室人类免疫缺陷病毒试验设置0.5临界值(CO)的合理性方法首先对检测方法的灵敏性与特异度进行评估,然后参照美国临床和实验室标准协会发布的EP12-A2指南,通过实验确定抗-HIV试验的C5~C95区间,通过实验室既往数据分析,反应性标本包括灰区标本(0.5CO)进行免疫蛋白印迹方法确认结果,绘制抗-HIV的受试者工作特征曲线(ROC曲线)进行分析。结果检测方法的灵敏度和特异度均为100%。C50±20%浓度标本检测结果为100%阳性和100%阴性,灰区临界值应该在0.74倍~1.22倍CO值区间。当S/CO在0.5~9.99区间时,49例标本WB确认结果全部为阴性。WB检测结果 ROC曲线下面积为0.995,最适CO值为2.79,远高于厂家提供的CO值。结论本实验室现在对抗-HIV试验设置0.5CO灰区临界值过于严苛,试验结果支持重新设定或者取消灰区设置。

Objective To evaluate and verify the rationality of setting the cut-off as 0. 5 in the test of anti-human immunodeficiency virus（ HIV） by enzyme-linked immunosorbent method（ ELISA） in our laboratory. Methods To verify the sensitivity and specificity of this method. According to CLIS EP12-A2 guide,the rang of C5-C95 in the anti-HIV ELISA test was determined. Through laboratory data analysis,reactive samples including gray zone specimens（ 0. 5 CO） were confirmed by Western blot（ WB）,and the working characteristic curve（ ROC curve） of anti-HIV patients was drawn for analysis. Results Sensitivity and specificity of the detection methods were both 100%. The test results of the samples with the concentration of C50 ±20% were 100% positive and 100% negative,and the gray zone threshold should be 0. 74 times to 1. 22 times of the CO value interval. When the S/CO value was within 0. 5-9. 99,the results of WB in 49 specimens were all negative. The area under the ROC curve of WB test result was 0. 995,and the optimum CO value was 2. 79,much higher than the CO value provided by the manufacturer. Conclusion The setting of grey area（ 0. 5 CO） is too strict for our laboratory. Experimental data suggests to reset or cancel the grey area.