测定抗HCMV-IgG抗体亲合力指数鉴别原发感染和再激活感染

Evaluation of cytomegalovirus IgG avidity index in differentiation of primary infection from reactivation

目的通过抗体亲合力指数(AI)鉴别人巨细胞病毒(HCMV)原发感染和再次或再激活感染。方法ELISA测定50例患者血浆(包括8例为系列标本)抗HCMV-IgM和抗HCMV-IgG,温育法测定血浆抗HCMV-IgG抗体AI,同时提取白细胞DNA用巢式PCR检测HCMV DNA。结果高浓度抗HCMV-IgG影响温育法检测AI;4例抗HCMV-IgM强阳性标本中3例AI<30%;DNA和抗HCMV-IgM均阴性组17例标本中15例(88.2%)抗HCMV-IgG为中等或高亲合力;根据8例患者抗HCMV-IgG AI的动态变化,其中2例诊断为原发感染。结论温育法测定血浆抗HCMV-IgG AI能够鉴别HCMV原发感染和再次或再激活感染。

Objective To distinguish primary infection of human cytomegalovirus （HCMV） from reinfection or reactivation by evaluation of IgG avidity indeX. Methods Anti-HCMV IgM and IgG were detected by ELISA and anti-HCMV IgG avidity index （AI） was determined by an incubation assay from plasma of 50 patients （including longitudinal specimens from 8 patients）. HCMV DNA was detected by nested PCR after total DNA was extracted from leukocytes. Results High concentration of anti-HCMV IgG influenced the measurement of AI. Three out of the 4 cases with high IgM titer showed AI 〈 30%, and 15 out of 17 （88.2%） cases negative for HCMV DNA and anti-HCMV IgM showed intermediate or high avidity. Two out of 8 cases were diagnosed to be primary infection based on the AI determined in the serial samples. Conclusions Anti-HCMV IgG AI determined based on the incubation assay can be used to distinguish primary infection of HCMV from reinfection or reactivation.