Etude de la cinétique de l'antigène ORF2 du virus de l'hépatite E dans des souris au foie humanisé et son impact sur le diagnostic du HEV

International audienceBackground: Hepatitis E virus infection (HEV) is an emerging problem in developed countries. Diagnosis of HEV infection is based on the detection of HEV-specific antibodies, viral RNA and/or antigens (Ag). Humanized mice were previously reported as a model for the study of HEV infection, but published data was focused on the quantification of viral RNA. However, the kinetics of HEV Ag expression during the course of infection remains poorly understood.Methods: Plasma and fecal suspensions from HEV infected and ribavirin-treated humanized mice were analyzed using HEV antigen ELISA, RT-qPCR, density gradient and Western blotting.Result: ORF2 Ag was detected in both plasma and stool of HEV infected mice, and increased overtime. Contrary to HEV RNA, ORF2 Ag levels were higher in mouse plasma than in stool. Interestingly, ORF2 was detected in plasma of mice that were RNA negative in plasma but RNA positive in stool; and after viral clearance by ribavirin. Plasma density gradient analysis revealed the presence of the non-infectious glycosylated form of ORF2.Conclusion: ORF2 Ag can be used as a marker of active HEV infection and the assessment of antiviral therapy, especially when fecal samples are not available or molecular diagnostic tests are not accessible