B cell malignancy and hepatitis C virus infection.

Italian authors report that hepatitis C virus (HCV) infection may be one of the causes of lymphoid malignancy such as non-Hodgkin's lymphoma (NHL) and Waldenström's macroglobulinemia (WM). To assess the relationship between HCV infection and B cell malignancy (BCM) in Japan, we analyzed HCV-RNA in 50 patients with BCM [25 cases of NHL, 4 of WM and 21 of multiple myeloma (MM)] and determined genotype of infected HCV(Okamoto's classification) using reverse transcription-polymerase chain reaction assay. Eight (16.0%) of 50 patients with BCM were HCV-RNA positive [HCV(+)], while no patients were HCV(+) in control group (18 patients of non-B cell NHL). Numbers of HCV(+) cases in each group examined were as follows; four (16.0%) in B cell NHL (genotype II/III/IV were 3/1/0, respectively), one (25.0%) in WM (genotype III) and three (14.3%) in MM (genotype II/III/IV were 1/1/1, respectively). All patients examined had no symptoms and signs suggesting vasculitis. The incidence of HCV infection in the patients with BCM was markedly higher than that (approximately 1%) of healthy blood donors in Japan. We also experienced four B cell NHL cases with splenic or hepatic origin in the course of chronic hepatitis C. These results implicate the association between persistent HCV infection and the occurrence of BCM.