献血者HEV感染后VP13抗体的免疫应答研究

Study on the antibody immune responses against HEV VP13 in blood donors

目的调查南京地区献血者的HEV感染情况,对感染者的VP13抗体免疫水平进行分析研究;利用VP13抗体的型特异性,进行毒株分型。方法采用ELISA法,检测献血者标本的HEV-IgM、HEV-IgG;对筛选到的HEVIgM阳性标本进行HEV RNA核酸检测;使用Ⅰ-Ⅳ型HEV-VP13抗原包被ELISA板,检测患者血清中VP13抗体型别;对VP13抗体阳性的标本进行western blot验证,确证标本中VP13抗体的特异性。结果 ELISA检测献血者合格标本5 256份,其中HEV-IgM阳性为99份(1.88%),HEV-IgG阳性为1 624份(30.9%),HEV-IgM和HEV-IgG合并阳性为72份(1.37%)。HEV-IgM阳性标本中,检测到HEV RNA阳性标本1份(0.019%);HEV-VP13抗体阳性42份,占HEV-IgM阳性比42.4%。全部为基因Ⅰ型和Ⅳ型,Ⅰ型13例(30.9%),Ⅳ型37例(88.1%),Ⅰ型、Ⅳ型合并感染者8份(19%)。结论南京地区献血人群的合格血液中,能检测到HEV的多项标志物,存在HEV的传染风险。基于Ⅰ-Ⅳ型VP13抗体的免疫学检测,可用于区分HEV毒株的型别,对HEV感染确认具有重要意义。

Objective To explore the HEV infection in blood donors in Nanjing, to investigate the immune response of VP13 antibody, and to define the HEV genotype by the specific response to the VP13 antibody.Methods The collected samples from blood donors were detected for HEV-IgM, HEV-IgG by ELISA. If HEV-IgM was positive, the HEV-RNA was detected by nucleic acid test. The typing of HEV was tested by ELISA which were coated with different VP13 antigens from I to IV. After the detection of VP13 antibody, the Western Blot would be carried out to confirm the specificity of antibody.Re- suits 99 （1.88%） HEV-lgM positive samples and 1 624 （30. 9%） HEV-IgG positive samples were detected in 5 256 qualified samples by ELISA. 72 （ 1.37% ） samples were both HEV-IgM and HEV-IgG positive. The prevalence is 1.37%. 1 （0. 019%） HEV-RNA positive sample was detected in all HEV-IgM positive samples. By the testing of anti-VPl3, 42 （42.4%） positive samples were detected in HEV-IgM positive samples. The genotypes of anti-VPl3 were genotype I and genotype IV. 13 （30. 9%） samples were genotype I, 37 （88. 1%） samples were genotype IV, and 8 （19%） samples were infected by both genotype I and genotype IV. Conclusion In the qualified samples from health blood donors in Nanjing, HEV markers can be detected. The HEV infection risk exists in healthy blood donors. With further detection, the genotype of HEV can be defined by the immune response of different VP13 antigens from I to IV, and carries important significance in defining HEV infection.