Hepatitis C virus infection is an independent prognostic factor in follicular lymphoma

Hepatitis C virus (HCV) is a single-stranded RNA virus that not only affects hepatocytes, by B cells as well. It is thought that HCV is involved in the onset of B-cell lymphoma. The clinicopathological characteristics of HCV-positive diffuse large B-cell lymphoma (DLBCL) and HCV-positive splenic marginal zone lymphoma (SMZL) are known, but there has been no report on HCV-positive follicular lymphoma (FL). In this study, the clinicopathological characteristics of HCV-positive FL were examined in 263 patients with FL who were classified into a HCV-positive group with HCV antibody and negative groups without one. The number of patients with HCV-positive FL and HCV-negative FL was 10 (3.8%) and 253 (96.2%), respectively. The patients with HCV-positive FL commonly had more than one region of lymphadenopathy, Ann Arbor stage III/IV, hemoglobin < 120 g/l, elevated lactate dehydrogenase level, and highrisk categorization of Follicular Lymphoma International Prognostic Index (FLIPI) than in patients with HCV-negative FL. Overall survival and progression-free survival were poorer in patients with HCV-positive FL than in those with HCV-negative FL (p < 0.0001 and 0.006, respectively). Also, multivariate analysis revealed that positive HCV antibody was a poor prognostic factor of OS. In conclusion, HCV-positive FL has unique clinical features and may have a great impact on the overall survival of affected patients.