[A preliminary study on hepatitis E virus antibody IgG and IgM for the diagnosis of acute hepatitis E].
OBJECTIVE
To evaluate the significance of hepatitis E virus antibody (anti-HEV) IgG and IgM for the diagnosis of acute hepatitis E.


METHODS
Acute phase sera from a total of 143 patients with sporadic hepatitis E in 7 cities of China were determined for anti-HEV IgM and IgG by using an enzyme-linked immunosorbent assay (EIA). 359 serial sera of 56 patients with hepatitis E and 68 serial sera of 4 rhesus macaques experimentally infected with hepatitis E virus (HEV) were also detected for anti-HEV IgG and IgM.


RESULTS
In the 143 patients the positive rate of anti-HEV IgG was 100.0%, which was significantly higher than that of anti-HEV IgM (73.4%, 105/143). 97.2% of anti-HEV IgG positive patients had a titer over 1:40. The positive rate of anti-HEV IgM increased with the titer of anti-HEV IgG in sera. It was 0% (0/4), 44.4% (8/18) and 80.2% (97/121), respectively in patients with the anti-HEV IgG titer of 1:20, 1:40 and >or=1:80 (P < 0.001). All the anti-HEV IgM positive patients were also anti-HEV IgG positive. No patients were found to be anti-HEV IgM positive alone. Anti-HEV IgG was detected as early as 2 days after onset of the disease, with a cumulative positive seroconversion rate of 100% by 1 month. The negative seroconversion rate of anti-HEV IgG increased with course of the disease and 43.3% of the patients lost their anti-HEV IgG by 6 months after illness. Though anti-HEV IgM also seroconverted at the same time as anti-HEV IgG, its cumulative positive seroconversion rate was only 71.4% and declined rapidly. Up to 37.5% of anti-HEV IgM positive patients became negative by 1 month after onset. Similar antibody responses were observed in 4 rhesus macaques experimentally infected with HEV.


CONCLUSIONS
It is suggested that as a result of the poor sensitivity of currently available anti-HEV IgM EIA kits, anti-HEV IgG will be a more reliable marker for the diagnosis of acute hepatitis E as compared with anti-HEV IgM.
Li
K
K
Department of Microbiology, Beijing Medical University, Beijing 100083.
Zhuang
H
H
Zhu
W
W
Ruan
B
B
Jiang
J
J
Li
S
S
Zhai
Q
Q
Yao
Z
Z
Tang
R
R
Chen
Y
Y
D000208:Acute Disease; D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay; D006508:Hepatitis Antibodies / Q000097:blood*; D016751:Hepatitis E / Q000175:diagnosis*; D016752:Hepatitis E virus / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood*; D008253:Macaca mulatta; D012680:Sensitivity and Specificity
D006508:Hepatitis Antibodies; D007074:Immunoglobulin G; D007075:Immunoglobulin M