Loss of antibodies to hepatitis E virus in organ transplant patients with hepatitis E

Aim Studies regarding changes in antibodies to hepatitis E virus (HEV) after HEV infection in organ transplant patients are limited. This study aimed to clarify HEV infection trends in organ transplant patients who contracted HEV using data from a previous Japanese nationwide survey. Methods This study was undertaken from 2012 to 2019. Among 4518 liver, heart, and kidney transplant patients, anti‐HEV immunoglobulin G (IgG) antibodies were positive in 164; data were collected from 106 of these patients, who consented to participate in the study. In total, 32 liver transplant patients, seven heart transplant patients, and 67 kidney transplant patients from 16 institutions in Japan were examined for IgG, IgM, and IgM antibodies to HEV and the presence of HEV RNA in the serum. The χ2‐test was used to determine the relationship between the early and late postinfection groups in patients with anti‐HEV IgG positive‐to‐negative conversion rates. The Mann–Whitney U‐test was used to compare clinical factors. Results Anti‐HEV IgG positive‐to‐negative conversion occurred in 25 (23.6%) of 106 organ transplant patients. Of eight patients with hepatitis E who tested positive for HEV RNA, one (14.0%) had anti‐HEV IgG positive‐to‐negative conversion. Twenty‐four (24.5%) of 98 patients negative for HEV RNA had anti‐HEV IgG positive‐to‐negative conversion. Conclusions This study revealed, for the first time, the changes in HEV antibodies in organ transplant patients. Loss of anti‐HEV IgG could often occur unexpectedly in organ transplant patients with previous HEV infection.