巨细胞病毒特异性IgG抗体亲和力测定及其临床意义

Measurement of specific IgG avidity for verification of recent primary cytomegalovirus infection

目的 区分巨细胞病毒 (CMV)原发性感染、继发性感染的病毒活化或再感染。方法 对 12岁以下儿童CMV感染者中IgG抗体阳性血清在常规ELISA检测过程中再进行尿素变性实验 ,以判别抗体的亲和力指数(AI)。结果 112岁的小儿中 ,A组 (IgG阳性 ,IgM阴性 )和B组 (IgG阳性 ,IgM阳性 )CMV IgG亲和力变化有相同趋势 ,绝大多数AI在 30 %以上 ,其中大部 >5 0 % ,只有B组的 1例患儿血清CMVAI<30 %。而 40例 1岁以内婴儿中 2 1例 (5 3% )AI<30 % ,8例在 30 % 5 0 %间 ,11例 >5 0 % ;其中 13个月和 46个月婴儿抗体亲和力受母体IgG影响 ,712个月的婴儿 80 % (12 / 15 )为低亲和力抗体。结论 CMV感染大都发生在 1岁以内。尿素变性实验是鉴别初次感染和体内病毒活化及再感染的有效方法。

Objective To distinguish primary CMV infection from reactivation or reinfection.Methods A urea denaturation test was included in the washstep of the standard IgG ELISA in 12 patients of age<12 whose serum CMV-IgG were positive,avidity indexes of CMV-IgG were measured.Results Among children aged 1~12 years,the varieties of avidity indexes of CMV-IgG in A group(IgM negative and IgG positive) and B group(IgM positive and IgG positive) had the same trend.There was only one case in B group whose avidity index was under 30%,the other were all above 30%,and most were above 50%.But among 40 children aged 1~12 months,the avidity indexes were under 30% in 21 cases,8 cases were 30~50%,and 11 cases were above 50%.The antibody avidity in 1~6 months children was influenced by their mother's IgG,80%(12/15) of 7~12 months children had low-avidity antibodies.Conclusion CMV infection mostly occurred among 1~12 months children.Urea denaturation test was an efficient method to distinguish primary CMV infection from reactivation or reinfection.