Hepatitis E virus infection after haploidentical haematopoietic stem cell transplantation: incidence and clinical course.

Hepatitis E virus (HEV) is increasingly found to cause hepatitis in allogeneic haematopoietic stem cell transplantation (HSCT) patients. However, little is known about HEV infection in patients receiving haploidentical HSCT (haplo-HSCT). Here, we retrospectively evaluate the incidence and clinical course of HEV infection in haplo-HSCT patients. From January 2014 to July 2017, 177 patients with unexplained elevated transaminases after receiving haplo-HSCT at Peking University Institute of Haematology were screened for HEV using HEV serology. HEV RNA was assessed in blood samples when HEV-IgG and/or IgM antibodies were positive. Acute HEV infection was identified in 7 patients (3·9%), 1 of whom had developed a chronic HEV infection. The median time from haplo-HSCT to HEV infection was 17·5 (range, 6-55) months. HEV infection was confirmed by the presentation of anti-HEV IgM + anti-HEV IgG (rising) (n = 5) or HEV-RNA + anti-HEV IgM + anti-HEV IgG (n = 2). None of the patients died of HEV infection directly: 2 patients with HEV infection died showing signs of ongoing hepatitis, and 5 patients cleared HEV with a median duration of HEV infection of 1·5 (range, 1·0-5·7) months. In conclusion, HEV infection is a rare but serious complication after haplo-HSCT. We recommend screening of HEV in haplo-HSCT.