Extrahepatic disorders of HCV infection: a distinct entity of B-cell neoplasia?

Some infectious agents have been associated with B-cell lymphoma development. In the last decades, it has been demonstrated that patients infected by hepatitis C virus (HCV) are more likely to develop B-cell non-Hodgkin's lymphoma (NHL) than those uninfected. The prevalence of HCV-infection among NHL patients is reported in this review of all Italian studies on NHL and HCV infection, both case-control and case series. From 18 studies, the prevalence of anti-HCV antibodies in 2736 NHL patients was 19.7% (range: 8.3-37.1%). The association of HCV-infection with each NHL histotype in case-control studies is discussed. Molecular mechanisms by which HCV infection promotes B-cell NHL development is also explored and indicate that HCV-associated lymphomas may be a distinct entity. Clarification of these mechanisms may improve diagnosis, classification and therapy of this subset of NHL. Finally, treatment of HCV-positive patients with lymphoproliferative disorders are herein summarized and further support the notion that HCV infection contributes to the development of these pathologic conditions.