HEV核酸、抗原、抗体对HEV感染的诊断价值

目的探讨HEV核酸(HEV RNA)、HEV抗原(HEV Ag)、HEV抗体(HEV IgM抗体和HEV IgG抗体)在临床诊断HEV感染中的作用。方法收集在北京大学人民医院进行HEV IgM抗体和HEV IgG抗体检测的13992例标本,其中1924例HEV IgM抗体或HEV IgG抗体阳性。分别采用荧光PCR法进行HEV RNA和基因型检测,酶联免疫吸附试验方法进行HEV Ag、HEV IgM抗体和HEV IgG抗体检测,并检测ALT、AST、TBil和DBil水平。计量资料两组间比较采用Mann-Whitney U检验。结果1924例标本中HEV IgM抗体阳性152例(7.9%),HEV IgG抗体阳性1897例(98.6%),HEV RNA阳性62例(3.2%),HEV Ag阳性55例(2.9%)。HEV IgM抗体阳性组中HEV RNA阳性率为40.8%(62/152),HEV Ag阳性率为36.2%(55/152)。HEV RNA阳性组中HEV Ag阳性率为88.7%(55/62)。HEV RNA阳性组(n=62)ALT、AST、TBil、DBil水平高于HEV RNA阴性组(n=90)(Z值分别为-7.609、-6.942、-5.815、-6.130,P值均<0.001),HEV Ag阳性组(n=55)ALT、AST、TBil、DBil水平明显高于HEV Ag阴性组(n=97)(Z值分别为-6.413、-5.786、-5.199、-5.545,P值均<0.001)。巢式PCR扩增测序结果显示58例HEV RNA阳性,4例阴性。HEV IgG抗体阳性高水平明显降低HEV Ag检测的S/CO值,甚至出现阴性结果。结论与HEV抗体相比,HEV Ag可以提高戊型肝炎的诊断水平,具有一定的临床意义;高水平的转氨酶或胆红素可以辅助诊断HEV感染;高水平的HEV IgG抗体会降低HEV Ag检测值,检测时应注意HEV Ag阴性时HEV IgG抗体值。

Value of hepatitis E virus nucleic acid,antigen,and antibodies in the diagnosis of hepatitis E virus infection

Objective To investigate the role of hepatitis E virus nucleic acid(HEV RNA),hepatitis E virus antigen(HEV Ag),hepatitis E virus antibodies(HEV IgM antibody and HEV IgG antibody)in the clinical diagnosis of hepatitis E virus infection.Methods A total of13992 specimens,for which the detection of HEV IgM antibody and HEV IgG antibody were performed in Peking University People’s Hospital,were collected,among which 1924 had positive HEV IgM antibody or HEV IgG antibody.Quantitative real-time PCR was used to determine HEV RNA and HEV genotype,and enzyme-linked immunosorbent assay was used to detect HEV Ag,HEV IgM antibody,and HEV IgG antibody and measure the levels of alanine aminotransferase(ALT),aspartate aminotransferase(AST),total bilirubin(TBil),and direct bilirubin(DBil).The non-parametric rank sum Mann-Whitney U test was used for comparison of continuous data between groups.Results Among the 1924 specimens with positive HEV IgM antibody or HEV IgG antibody,152(7.9%)had positive HEV IgM antibody,1897(98.6%)had positive HEV IgG antibody,62(3.2%)had positive HEV RNA,and 55(2.9%)had positive HEV Ag.Among the 152 specimens with positive HEV IgM antibody,62(40.8%)had positive HEV RNA,and 55(36.2%)had positive HEV Ag,and among the 62 specimens with positive HEV RNA,55(88.7%)had positive HEV Ag.The HEV RNA-positive group with 62 specimens had significantly higher levels of ALT,AST,TBil,and DBil than the HEV RNA-negative group with 90 specimens(Z=-7.609,-6.942,-5.815,and-6.130,all P<0.001),and the HEV Ag-positive group with 55 specimens had significantly higher levels of ALT,AST,TBil,and DBil than the HEV Ag-negative group with 97 specimens(Z=-6.413,-5.786,-5.199,and-5.545,all P<0.001).Nested PCR amplification and sequencing showed that in the HEV RNA-positive group with 62 specimens,58 had positive HEV RNA and 4 had negative HEV RNA.The high level of positive HEV IgG antibody significantly reduced the S/CO value of HEV Ag detection and even yielded a negative result.Conclusion Compared with HEV antibodies,HEV Ag can improve the diagnostic level of hepatitis E and has certain clinical significance.High levels of aminotransferases or bilirubin can help with the diagnosis of hepatitis E.The high level of HEV IgG antibody may reduce the detection value of HEV Ag,and attention should be paid to HEV IgG antibody value when HEV Ag is negative.