Differential diagnosis of hepatitis E virus, cytomegalovirus and Epstein-Barr virus infection in patients with suspected hepatitis E

Background: The accuracy of the diagnosis of hepatitis E in the clinical setting relies mainly on the performance of assays for hepatitis E virus (HEV)-specific IgM (anti-HEV IgM) testing in serum. Objectives: Identification of factors influencing the specificity of the results obtained with these assays is an important issue in regard to the accuracy of the diagnosis. Study design: Anti-HEV IgM and HEV RNA were studied in samples from 153 patients with acute hepatitis of unknown aetiology received during a two-year period. Fifteen patients were positive for anti-HEV IgM, and eight of them were also positive for HEV RNA. Investigation of CMV and Epstein-Barr virus (EBV) infection markers among the remaining seven patients, and of HEV infection markers among 18 patients with infectious mononucleosis, was performed. Results: The results obtained showed that acute infection by CMV or EBV may cause false reactivity for anti-HEV IgM, likely because of polyclonal B-cell stimulation. Conclusions: Since infection by these herpesviruses may produce acute hepatitis, such event can cause diagnostic mistakes and should be investigated in patients positive for anti-HEV IgM and negative for HEV RNA. (C) 2009 Elsevier B.V. All rights reserved.