A case of severe acute hepatitis C and delayed antibody production due to rituximab therapy.

A 59-year-old male patient underwent surgical treatment for non-Hodgkin's lymphoma of the right scrotum in October 2007. He received a total of 4 courses of two different adjuvant chemotherapy regimens including rituximab from January to April 2008. In June 2008 he was hospitalized due to severe liver dysfunction with an alanine aminotransferase of 2039 IU/l and a prothrombin time of 23.3%. He was diagnosed with acute hepatitis C by the detection of hepatitis C virus (HCV) RNA and negative anti-HCV antibody, and his hepatic function improved with bed rest during hospitalization; however, the production of anti-HCV antibodies was not detected until January 2009. Severe liver dysfunction is uncommon among patients with acute hepatitis C, and the long window (8 months) between HCV infection and the development of anti-HCV antibodies observed in the present case may have been due, at least in part, to a B cell disorder caused by rituximab therapy. In addition to the well-known risk of reactivation of hepatitis B virus infection in patients undergoing chemotherapy, physicians should be aware of the potential effects of chemotherapy on the clinical course of HCV infection.