Background: Diagnosis of acute hepatitis E has been based in many clinics predominantly on detection of anti-HEV (hepatitis E virus) antibody. Now, new assays have been developed to detect other HEV markers. Our aim was to investigate the relationships among HEV diagnostic markers and liver function markers in acute hepatitis E.
Methods: Seventy serum samples were collected from non-A, non-B, non-C acute hepatitis patients and tested for HEV markers (HEV antigen and RNA and anti-HEV IgM) and markers of liver function [alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total iron binding capacity (TBA), gamma-glutamyl transferase (GGT), total bilirubin (TBIL), and direct bilirubin (DBIL)]. Partial open reading frame (ORF) 2 sequences from HEV RNA-positive samples were cloned and analyzed.
Results: The concordances between HEV antigen and HEV RNA and between HEV antigen and anti-HEV IgM were 77.1% and 72.9%, respectively, with significant correlations, while that between HEV RNA and anti-HEV IgM was 61.4% with no significant correlation. Eleven of 25 samples negative for anti-HEV IgM were positive for HEV antigen. The ALT, AST, ALP, TBA, GGT, TBIL, and DBIL levels did not differ significantly between the anti-HEV IgM-positive and -negative groups. However, the ALT, AST, ALP, TBA, and GGT levels were significantly higher in the HEV antigen-positive group than in the HEV antigennegative group. All of the HEV isolates cloned belonged to genotype 4.
Conclusions: HEV antigen was highly correlated with HEV RNA and elevated ALT, AST, ALP, TBA, and GGT levels. Testing for HEV antigen in combination with anti-HEV IgM is useful for the diagnosis of HEV infection.