巨细胞病毒IgG抗体亲合力分析与IgM抗体检测的评价

目的评估IgM抗体检测及IgG抗体亲合力分析对于巨细胞病毒(CMV)原发性感染诊断的意义。方法 80例标本经间接免疫荧光法检测CMV IgG抗体,免疫捕获法检测CMV-IgM抗体,ELISA法进行CMV IgG抗体亲合力分析,计算亲合力指数(AI)。结果 40例标本的抗CMV IgG抗体阳性、IgM抗体阴性,AI在56%～97%之间,平均为79%。40例标本的抗CMV IgG、IgM抗体均阳性,AI为5%～99.3%,平均61.72%,其中9例(22.5%)标本的AI值低于30%,为低亲合力抗体;4例(10%)AI值介于30%～60%之间,为中等亲合力抗体;其他27例(67.5%)标本的AI值均高于60%,为高亲合力抗体。两组数据的AI均值有显著性差异。结论大部分CMV IgM抗体阳性的患者不是近期原发感染,单纯一项血清学检测不能进行诊断,结合IgM抗体检测及IgG抗体亲合力分析可以大大提高检测效率。

Evaluation of the Cytomegalovirus Immunoglobulin M and Immunoglobulin G Avidity Assay

ObjectiveTo evaluate the IgM and IgG avidity assay for the infection of primary Cytomeglovirus (CMV). MethodsCMV IgG of 80 samples was measured by indirect immunofluorescence. Enzyme-linked immunosorbent assay(ELISA) was used for measuring CMV IgG avidity. Avidity index(AI) was then determined. IgM was examined by capture ELISA.ResultsThere were 40 CMV IgG positive,IgM negtive specimens. AI values were between 56%~97%, with an average of 79%. CMV IgG and IgM were detected positive in the other 40 specimens, AI values were between 5%~99.3%, with an average of 61.7%,in which 9(22.5%) were low, 4(10%) were moderate,and 27(67.5%) were hign-avidity IgG respectively. A significant difference was observed in mean AI between the two groups. ConclusionThe majority of CMV IgM-positve patients were unrelated with the recent primary CMV infection. Diagnosis could not be done only by one item of serology. The use of the CMV IgM assay, followed by an avidity test,should result in a more accurate diagnosis of CMV infection.