Dosing ribavirin in hepatitis E-infected solid organ transplant recipients.

Hepatitis E virus (HEV) is the most common cause of viral hepatitis worldwide. Genotypes 1 and 2 (GT1 and GT2) are mainly present in developing countries, while GT3 and GT4 are prevalent in developed and high-income countries. In the majority of cases, HEV causes a self-limiting hepatitis. GT3 and GT4 can be responsible for a chronic hepatitis that can lead to cirrhosis in immunocompromized patients, i.e. solid-organ- and stem-cell-transplant-patients, human immunodeficiency virus-infected patients, and patients receiving chemotherapy or immunotherapy. HEV has also been associated with extra-hepatic manifestations such as neurologic disorders (Guillain-Barré Syndrome and neuralgic amyotrophy) and kidney disease. In patients with chronic hepatitis, reduction of immunosuppression, when possible, is the first therapeutic option. In the remaining patients, ribavirin therapy has been shown to very efficient for treating HEV infection leading to a sustained virological response in nearly 80-85% of patients. However, the mechanism of action of ribavirin in this setting is still unknown, as is the impact of HEV RNA polymerase mutations. There are unmet needs with regard to the treatment of chronic HEV with ribavirin. These include the optimal dosing and duration of treatment, and the potential beneficial effects of therapeutic drug monitoring on the virological response and the incidence of side effects. In the present review, we will provide an overview of HEV epidemiology, its mode of transmission and clinical manifestations, as well as its treatment by ribavirin with a focus on the drug's pharmacokinetics and dosing.