Response to: 'Chronic genotype 1 hepatitis E infection from immunosuppression for ileo-colonic Crohn's disease'

Hepatitis E Virus and rheumatic diseases: what do rheumatologists need to know?

BACKGROUND

Hepatitis E virus (HEV) represents the most common cause of acute hepatitis and jaundice in the world. About 2 million of infection cases occur each year in Europe, mainly as autochthonous anthropozoonosis, and HEV can be transmitted through undercooked pork meat. This infection has been linked to various extra-hepatic manifestations, while chronic infections with a rapid development of liver failure have been described in heavily immunosuppressed patients undergoing solid organ transplantations (SOTs), in patients with hematological diseases or with immunodeficiency virus infection.

MAIN BODY OF ABSTRACT

The purpose of this review article is to describe rheumatic manifestations related to HEV infection and their implications for rheumatologists in the daily clinical practice. Despite recent accumulating literature in this field, little is known about the course of the infection in patients with rheumatic diseases (RDs) and about the impact of immunosuppressive drugs. Moreover, HEV infection can mimic RDs' manifestations or drugs toxicity. Specific guidelines on management are lacking and the majority of data are referred to SOTs receivers.

CONCLUSIONS

More studies are needed to better understand the real impact of HEV infection in patients with RDs, regarding both clinical outcomes and their management.

Clinical Manifestations, Pathogenesis and Treatment of Hepatitis E Virus Infections

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis throughout the world. Most infections are acute but they can become chronic in immunocompromised patients, such as solid organ transplant patients, patients with hematologic malignancy undergoing chemotherapy and those with a human immunodeficiency virus (HIV) infection. Extra-hepatic manifestations, especially neurological and renal diseases, have also been described. To date, four main genotypes of HEV (HEV1-4) were described. HEV1 and HEV2 only infect humans, while HEV3 and HEV4 can infect both humans and animals, like pigs, wild boar, deer and rabbits. The real epidemiology of HEV has been underestimated because most infections are asymptomatic. This review focuses on the recent advances in our understanding of the pathophysiology of acute HEV infections, including severe hepatitis in patients with pre-existing liver disease and pregnant women. It also examines the mechanisms leading to chronic infection in immunocompromised patients and extra-hepatic manifestations. Acute infections are usually self-limiting and do not require antiviral treatment. Conversely, a chronic HEV infection can be cleared by decreasing the dose of immunosuppressive drugs or by treating with ribavirin for 3 months. Nevertheless, new drugs are needed for those cases in which ribavirin treatment fails.

The Clinical Perspective on Hepatitis E

Every year, there are an estimated 20 million hepatitis E virus (HEV) infections worldwide, leading to an estimated 3.3 million symptomatic cases of hepatitis E. HEV is largely circulating in the west and is associated with several hepatic and extrahepatic diseases. HEV Genotype 1 and 2 infections are waterborne and causative for epidemics in the tropics, while genotype 3 and 4 infections are zoonotic diseases and are mainly transmitted by ingestion of undercooked pork in industrialized nations. The clinical course of these infections differs: genotype 1 and 2 infection can cause acute illness and can lead to acute liver failure (ALF) or acute on chronic liver failure (ACLF) with a high mortality rate of 20% in pregnant women. In contrast, the majority of HEV GT-3 and -4 infections have a clinically asymptomatic course and only rarely lead to acute on chronic liver failure in elderly or patients with underlying liver disease. Immunosuppressed individuals infected with genotype 3 or 4 may develop chronic hepatitis E, which then can lead to life-threatening cirrhosis. Furthermore, several extra-hepatic manifestations affecting various organs have been associated with ongoing or previous HEV infections but the causal link for many of them still needs to be proven. There is no approved specific therapy for the treatment of acute or chronic HEV GT-3 or -4 infections but off-label use of ribavirin has been demonstrated to be safe and effective in the majority of patients. However, in approximately 15% of chronically HEV infected patients, cure is not possible.