Acute Hepatitis E Infection Accounts for Some Cases of Suspected Drug-Induced Liver Injury

Abstract

Background & Aims The diagnosis of drug-induced liver injury relies upon exclusion of other causes, including viral hepatitis A, B, and C. Hepatitis E virus (HEV) infection has been proposed as another cause of suspected drug-induced liver disease. We assessed the frequency of HEV infection among patients with drug-induced liver injury in the United States. Methods The drug-induced liver injury network (DILIN) is a prospective study of patients with suspected drug-induced liver injury; clinical information and biological samples are collected to investigate pathogenesis and disease progression. We analyzed serum samples, collected from patients enrolled in DILIN, for immunoglobulin (Ig)G and IgM against HEV; selected samples were tested for HEV RNA. Results Among 318 patients with suspected drug-induced liver injury, 50 (16%) tested positive for anti-HEV IgG and 9 (3%) for anti-HEV IgM. The samples that contained anti-HEV IgM (collected 2 to 24 weeks after onset of symptoms) included 4 that tested positive for HEV RNA, genotype 3. Samples from the 6-month follow-up visit were available from 4 patients; they were negative for anti-HEV IgM, but levels of anti-HEV IgG increased with time. Patients that had anti-HEV IgM were mostly from older men (89%; mean age, 67 years) and 2 were HIV positive. Clinical reassessment of the 9 patients with anti-HEV IgM indicated that acute hepatitis E was the most likely diagnosis for 7 and might be the primary diagnosis for 2. Conclusion HEV infection contributes to a small but important proportion of cases of acute liver injury that are suspected of being drug induced. Serologic testing for HEV infection should be performed—particularly if clinical features are compatible with acute viral hepatitis.