Xia Y, Pan X H, Zhang J F, He L, Luo M Y, Jiang J, Yao J M, Wang H
Department of AIDS/STD Prevention and Control, Zhejiang Provinicial Center for Disease Control and Prevention, Hangzhou 310051, China.
Zhonghua Yu Fang Yi Xue Za Zhi. 2020 Nov 6;54(11):1232-1236. doi: 10.3760/cma.j.cn112150-20200606-00837.
To evaluate the applicability of limiting antigen avidity enzyme immunoassay (LAg-Avidity EIA, LAg for short) in determining the new HIV-1 infection status of MSM population with seroconversion and make correlation analysis of other biological indicators. The 15 cases with HIV seroconversion were found in a MSM observation cohort for calculating the HIV prevalence in Zhejiang.The subjects were conducted epidemiological investigation and sampled.The interval of infection time was estimated according to the exposure history and the time of HIV-positive confirmation.LAg, immunoblotting, CD4 cell counting and viral load test were applied in the testing of the related blood samples. McNermar test was conducted for consistency of the two methods. Of 15 cases, the average age was (31.5±8.0) years old, ranging from 24 to 57 years old. The interval of infection time ranged from 40 days to 366 days, and the median was 134 days, with inter-quartile range from 89 to 180 days. A total of 7 cases were classified as new HIV-1 infection by LAg, and 8 cases were classified as chronic infection.The consistent rate was high to 86.67%, and kappa value was 0.73.The samples lacking at least two bands in p31, p51, p66 and gp120 by immunoblotting were determined as recent infection, of which the new infection proportion was significantly higher than that of other samples (=0.029).There was no statistical difference in the distribution of CD4 counts (=0.533) and viral loads (=0.467) between the new infection and chronic infection groups that divided by LAg. By combining with exposure history, the limiting antigen avidity enzyme immunoassay can be used to estimate the new HIV-1 infection.The other biological indicators such as immunoblotting bands, CD4 cell counts and viral loads, can be used as accessory indicators in evaluating the status of new HIV-1 infection.
评估限量抗原亲和力酶免疫测定法（LAg-Avidity EIA，简称LAg）在确定血清学转换的男男性行为人群中新发HIV-1感染状态中的适用性，并对其他生物学指标进行相关性分析。在浙江省一个男男性行为观察队列中发现15例HIV血清学转换病例，用于计算HIV流行率。对研究对象进行流行病学调查并采样。根据暴露史和HIV阳性确认时间估算感染时间间隔。对相关血液样本进行LAg检测、免疫印迹检测、CD4细胞计数和病毒载量检测。采用McNemar检验分析两种方法的一致性。15例患者平均年龄为（31.5±8.0）岁，年龄范围为24至57岁。感染时间间隔为40天至366天，中位数为134天，四分位间距为89至180天。LAg检测共判定7例为新发HIV-1感染，8例为慢性感染。符合率高达86.67%，kappa值为0.73。免疫印迹法检测p31、p51、p66和gp120中至少缺少两条带的样本判定为近期感染，其中新发感染比例显著高于其他样本（P = 0.029）。LAg法划分的新发感染组和慢性感染组在CD4细胞计数分布（P = 0.533）和病毒载量分布（P = 0.467）上无统计学差异。结合暴露史，限量抗原亲和力酶免疫测定法可用于估算新发HIV-1感染。免疫印迹条带、CD4细胞计数和病毒载量等其他生物学指标可作为评估新发HIV-1感染状态的辅助指标。
