Chronic Hepatitis E in Liver Transplant Recipients: a Significant Clinical Problem?

Hepatitis E is an inflammatory liver disease caused by infection with the hepatitis E virus (HEV). Five different HEV genotypes have been described. While HEV genotypes 1 and 2 primarily infect man, genotypes 3 and 4 have been detected both in humans and several animal species including pigs. HEV genotype 1 and 2 infections are frequent in Southern Asia and Africa. However, Hepatitis E is more and more considered as an re-emerging zoonotic disease also in industrialized countries as HEV genotype 3 infections seem to increase in Western Europe and North America. Acute hepatitis E usually takes an acute self limited course but may take a fulminant course in particular in pregnant women and patients with pre-existing chronic liver disease. Several cases of persistent HEV-infection have been reported in immunosuppressed patients during the last three years being associated with progressive liver disease in some patients. Thus, screening for HEV RNA should be part of the diagnostic work-up of elevated liver transaminases in organ transplantation recipients or HIV-infected individuals. In this review we summarize the recent data on hepatitis E with a particular focus on the importance of persistent HEV infections in liver transplant recipients.