Prevalence of hepatitis E virus infection in liver transplant recipients.

Hepatitis E virus (HEV) infection is known to run a self-limited course. Recently, chronic hepatitis E has been described in several immunosuppressed patients after solid organ transplantation. The prevalence of HEV infection after transplantation, however, is unknown. We studied HEV parameters [HEV RNA, HEV immunoglobulin M (IgM), and HEV immunoglobulin G (IgG) by enzyme-linked immunosorbent assay and confirmatory immunoblotting] in a cohort of 285 adult liver transplant recipients. The most recent freeze-stored sera were investigated, and if they were positive, a retrospective analysis was performed. Samples from 274 patients (96.1%) tested negative for all HEV parameters. This included a patient described earlier as having experienced an episode of chronic HEV hepatitis in the past. One patient was found positive for HEV RNA without HEV antibodies. She presently suffers from chronic HEV hepatitis and has also been described before. Sera from 9 patients tested positive for HEV IgG without HEV IgM or HEV RNA. Six of these 9 patients (2.1% of the total) were found to have HEV IgG antibodies in retrospect related to an HEV infection at some time pre-transplant as they also tested positive in a pretransplant serum sample. One of these 9 patients suffered in retrospect from a chronic HEV infection with mild hepatitis between 2 and 5 years after liver transplantation on the basis of the course of HEV RNA, IgM, and IgG, aminotransferases, and liver histology. Overall, the prevalence of acquired HEV hepatitis after liver transplantation was 1% in this cohort. We conclude that liver transplant recipients have a risk for chronic HEV infection, but the prevalence is low.