血清稀释度对捕捉法ELISA检测抗HAV IgM影响的探讨

Influence of serum dilution on the detection of anti HAV IgM by capture ELISA.

在捕捉法ＥＬＩＳＡ检测抗ＨＡＶＩｇＭ时，分别使用了单克隆和多克隆抗ＨＡＶ－ＨＲＰ以确定血清标本的最适稀释度。发现抗ＨＡＶＩｇＭ阳性血清Ａ值均随稀释度增高而上升，绝大多数在１０－３达高峰。部分阳性血清原倍（１００）的Ａ＜临界值（假阴性）。部分抗ＨＡＶＩｇＭ阴性血清在低稀释度时不论加入ＨＡＡｇ与否，能与两种酶抗体结合物之一或同时反应呈假阳性，Ａ值随稀释度增高而下降。结果表明最适血清稀释度为１０－３，既能防止阳性漏检，也可防止因原倍血清所致的假阳性。本文还提示使用单克隆抗ＨＡＶ－ＨＲＰ能防止ＲＦ等因素对结果的干扰。

In order to investigate the influence of serum dilution on the detection of anti HAV IgM by capture ELISA, a series of ten time dilutions from 10 0 to 10 -5 of 187 patient sera were determined by this kind of ELISA simultaneously using monoclonal anti HAV HRP(MHA HRP) and polyclonal anti HAV HRP(PHA HRP). In 91 original anti HAV IgM positive sera (at 10 -3 dilution using MHA HRP), there were 15 and 16 negative at 10 0 dilution in MHA HRP and PHA HRP groups, respectively. In 86 original anti HAV IgM negative sera (at 10 -3 dilution using MHA HRP), 4 Theumatoid factor (RF) positive sera diluted from 10 0 to 10 -4 in PHA HRP group, 1 (RF negative) from 10 0 to 10 -2 in MHA HRP group and 1 (RF negative) from 10 0 to 10 -2 in both groups above were false positive. The results show that ① for detection of anti HAV IgM by capture ELISA, some false negative and false positive results can be occured at 10 0 serum dilution and the optimal serum dilution is 10 -3 ; ② MHA HRP can eliminate effectively interference of RF in detecting anti HAV IgM.