Redeveloping antigen detection kits for the diagnosis of rat hepatitis E virus

The emergence of [species HEV ( HEV)] as a causative agent of hepatitis E in humans presents a new potential threat to global public health. The genotype 1 ( -1 HEV) variant only shares 50%-60% genomic identity with [species HEV ( HEV)] variants, which are the main causes of hepatitis E infection in humans. Here, we report antigen diagnoses for -1 HEV and HEV using an enzymatic immunoassay (EIA) method. We detected recombinant virus-like particles protein (HEV 239) of HEV and HEV using a collection of hepatitis E virus (HEV)-specific monoclonal antibodies. Two optimal candidates, the capture antibody P#1-H4 and the detection antibodies C145 (P#1-H4*/C145 ) and C158 (P#1-H4*/C158 ), were selected to detect antigen in infected rat samples and -1 HEV- or HEV-infected human clinical samples. The two candidates showed similar diagnostic efficacy to the Wantai HEV antigen kit in HEV-infected clinical samples. Genomic divergence resulted in low diagnostic efficacy of the Wantai HEV antigen kit (0%, 0 of 10) for detecting -1 HEV infection. Compared with the P#1-H4*/C145 candidate (80%, 8 of 10), the P#1-H4*/C158 candidate had excellent diagnostic efficacy in -1 HEV-infected clinical samples (100%, 10 of 10). The two candidates bind to a discrete antigenic site that is highly conserved across HEV and HEV. P#1-H4*/C145 and P#1-H4*/C158 are efficacious candidate antibody combinations for rat HEV antigen detection.