HBcAb阳性伴HBsAb阴性的人群HBsAg合适临界值的研究

Appropriate critical value of HBsAg for the HBcAb positive and HBsAb negative groups

目的:HBcAb阳性伴HBsAb阴性的人群HBsAg合适临界值的研究。方法:收集并检测HBcAb阳性伴HBsAb阴性组HBsAg阴性及HBcAb阴性伴HBsAb阴性组HBsAg阴性的样本各1 522例,比较两组HBsAg结果的差异。采用ROC曲线对ELISA定性HBsAg结果诊断HBcAb阳性伴HBsAb阴性的人群的阳性判断值的再确定,寻找更好的的诊断性能。结果:i2000SR检测HBsAg的结果具有良好的重复性,符合临床检测要求。HBcAb阴性组复检前与复检后相比明显降低,复检后HBcAb阳性组的结果相比阴性组明显降低,差异具有统计学意义(P<0.05);利用ROC曲线对HBcAb阳性伴HBsAb阴性的人群HBsAg建立合适临界值为0.415后的准确度、敏感度、特异度、阳性预测值、阴性预测值、曲线下面积、Youden指数显示具有更好的诊断性能。HBcAb阳性伴HBsAb阴性人群的HBsAg结果与HBcAb阴性伴HBsAb阴性人群HBsAg的相比明显升高,差异具有统计学意义(P<0.05)。结论:实验室建立HBcAb阳性伴HBsAb阴性人群的ELISA法定性HBsAg结果合适的的阳性判值具有更好的诊断性能。

Objective： To find an appropriate threshold of HBsAg for HBcAb positive and HBsAb negative group. Methods： A total of 1 522 eases of HBcAb positive, HBsAb negative and HBsAg negative （group 1）, HBeAb negative, HB- sAb negative and HBsAg negative （group 2） were collected. HBsAg was compared between the two groups. ROC curve was applied to redefine cases that were diagnosed as positive HBcAb and negative HBsAg according to ELISA test. Results： The HBsAg level is detected by i2000SR with good repeatability. HBcAb positive results were significantly decreased according to i2000SR than the detected results of ELISA （P〈0.05）. ROC curve showed critical values of 0. 415 with better accuracy, sen- sitivity, specificity, positive predicting value, negative predicting value, larger size of area under the curve as well as better Youden index. Comparing with those with HBcAb negative and HBsAb negative, the HBsAg in those with HBcAb positive and HBsAb negative was significantly increased （P〈0.05）. Conclusion： ELISA test had better diagnostic performance in detecting positive values of HBsAg.