Unique clinical courses of transfusion‐transmitted hepatitis E in patients with immunosuppression

Abstract

BACKGROUND The high prevalence of specific immunoglobulin G for hepatitis E virus (HEV) in Japanese people raises the possibility of a high incidence of HEV‐viremic blood donors and therefore frequent transfusion‐transmitted HEV (TT‐HEV). STUDY DESIGN AND METHODS TT‐HEV cases established in Japan through hemovigilance and those published in the literature were collected. Infectivity of HEV‐contaminated blood components and disease severity in relation to immunosuppression were investigated. RESULTS Twenty established TT‐HEV cases were recorded over the past 17 years. A lookback study verified that five of 10 patients transfused with known HEV‐contaminated blood components acquired HEV infection. The minimal infectious dose of HEV through transfusion was 3.6 × 10 4 IU. Nine of the 19 TT‐HEV cases analyzed had hematologic diseases. Only two cases showed the maximal alanine aminotransferase level of more than 1000 U/L. Two patients with hematologic malignancy and two liver transplant recipients had chronic liver injury of moderate severity. CONCLUSION The infectivity of HEV‐contaminated components was 50%. Immunosuppression likely causes the moderate illness of TT‐HEV, but it may lead to the establishment of chronic sequelae. Transfusion recipients, a population that is variably immunosuppressed, are more vulnerable to chronic liver injury as a result of TT‐HEV than the general population is as a result of food‐borne infection.