[Hepatitis E infections in rheumatology. A previously underestimated infectious disease?]

The detection and estimation of hepatitis E have greatly changed in recent years. An increasing number of hepatitis E virus (HEV) infections, which were acquired in Europe and knowledge on chronic hepatitis E in immunosuppressed patients, give this infectious disease a new significance in industrial nations in contrast to the previous assumption of merely being a tropical disease with an acute course. Rheumatology patients under immunosuppressive therapy generally have an increased risk of infections.

An HEV infection should always be taken into consideration for the differential diagnostics, particularly in cases of increased transaminase levels and/or diarrhea. In contrast to healthy individuals where the course of HEV infections is mostly innocuous, in immunocompromised patients isolated severe and also chronic courses have been described. Testing of these patients should initially also include PCR of HEV-RNA because serological markers are not always reliable. Therapy with ribavirin (cave: off-label) is a possible therapeutic option and should be considered in individual cases in cooperation with a hepatologist and/or specialist for infections. Whether a general screening for HEV before therapy with biologics is recommendable, cannot yet be conclusively assessed. Additionally, an HEV infection should be included in the differential diagnostics of unclear systemic diseases because the disease can have diverse extrahepatic manifestations.

There are serological indications that hepatitis E can act as a trigger for autoimmune diseases, such as autoimmune hepatitis and cryoglobulinemia but this phenomenon and the underlying pathological mechanisms need further clarification.