Comparative clinical study on diagnostic detection of hepatitis E virus between nested polymerase chain reaction (PCR) and serological tests

This study was carried out to evaluate the diagnostic value of nested reverse transcriptase-polymerase chain reaction (RT-PCR) for HEV (hepatitis E virus) RNA detection relative to anti-HEV immunoglobulin G (IgG) and IgM enzyme-linked immunosorbent assays. One hundred and twenty six (126) patients with sporadic acute hepatitis E were included in this study. We focused on the popular genotype I and IV of HEV-positive patients in China, and selected the conserved region located in ORF2 for designing a set of nested RT-PCR primers. HEV RNA was detected in 53.2% (67/126) of patients, while all control subjects were negative for HEV RNA. The total agreement between IgM and nested RT-PCR detection was 80.9%, showing a fine coincidence. The results further suggested that there was a significant difference between nested RT-PCR detection and IgM ELISA: 3 cases with positive results for HEV RNA showed negative anti-HEV IgM at the early phrase, and presented positive IgM reaction in succession after the trail of detection. HEV RNA was detected in serum samples from sporadic acute hepatitis patient usually by day 1 to 12 after the onset of symptoms, but showed a decreasing sensitivity with the increasing disease course. From these experiments, we can conclude that HEV RNA detection is of great clinical significance, which has an obvious advantage in diagnosis of early infection of HEV.