Consecutive evaluation of immunoglobulin M and G antibodies against hepatitis E virus

Hepatitis E virus (HEV) infection is sporadic in the Guangzhou city southern China. However, the evaluation of antibodies to HEV during consecutive time periods after infection has not been reported. We utilized enzyme immunosorbent assay (ELISA) to defect IgM and IgG anti-HEV in consecutive serum specimens from patients with acute hepatitis E and compared that data with detection rates of IgM and IgG anti-HAV in patients with acute hepatitis A. IgM anti-HEV can be detected as early as 4 days after onset of disease symptoms in some patients. The detection rate of IgM anti-HEV is significantly higher in specimens collected within 4 weeks (95%) of onset than in those specimens collected 4 to 18 weeks after onset (67.6%) (P < 0.005). IgM anti-HEV had a similar pattern to IgM anti-HAV and can be used as a marker of acute HEV infection. In contrast with IgG anti-HAV, 56.8% of the specimens did not contain detectable levels of IgG anti-HEV (P < 0.005). One should be cautioned against making a diagnosis of HEV infection solely by the currently available assays for IgG anti-HEV. In conclusion, IgM anti-HEV can be used as a reliable and sensitive marker for recent HEV infection, but serum specimens should be collected within 4 weeks after onset of symptoms to avoid false-negative results. In contrast, we should be aware of the failure to develop IgG anti-HEV in some patients. These patients carry the risk of reinfection.