乙型肝炎表面抗原酶联免疫吸附试验试剂在血液筛查中的临界值设置

Cut-off value setting of enzyme-linked immunosorbent assay reagents for detection of hepatitis B surface antigen in blood screening

目的探讨乙型肝炎表面抗原(HBsAg)酶联免疫吸附试验(ELISA)试剂设置灰区的范围及必要性。方法使用国产试剂和进口试剂平行检测HBsAg阳性血清样本(423份)和HBsAg阴性献血者样本(2996份),计算2种试剂不同吸光度值/临界值(S/CO值)下的灵敏度及特异度,并通过约登指数分析2种试剂设置灰区的合理范围。结果S/CO值为0.4时,国产试剂的约登指数(0.957)最大;S/CO值为0.7时,进口试剂的约登指数(0.971)最大。结论若对献血者HBsAg实施1遍ELISA试剂检测策略,本实验室使用的2种试剂均有必要设置灰区,其中国产试剂的反应性判定值宜设置为S/CO值≥0.4,进口试剂宜设置为S/CO值≥0.7。

Objective To explore the necessity and range of grey area of enzyme-linked immunosorbent assay(ELISA)reagents for detection of hepatitis B surface antigen(HBsAg).Methods HBsAg positive sero-panels(423 copies)and HBsAg negative blood donors(2996 copies)were detected by domestic reagent and imported reagent in parallel,and the sensitivity,specificity of the reagents under different absorbance value/threshold value(S/CO)ratio were calculated,and Yoden index was used to analyze the rationale range of grey area of two reagents.Results When the S/CO ratio was 0.4,the domestic reagent had the largest index(0.957),and the imported reagent had the largest index(0.971)when the S/CO ratio was 0.7.Conclusion If HBsAg of the blood donor is tested for 1 time by ELISA reagents,it is necessary to set the gray zone for reagents in our laboratory.The cut-off value should be 0.4 and above for domestic ELISA kits,while≥0.7 for imported kits.