Prevalence of hepatitis C virus infection in lymphoproliferative diseases other than B-cell non-Hodgkin's lymphoma, and in myeloproliferative diseases: an Italian Multi-Center case-control study.

BACKGROUND AND OBJECTIVES: Infection with hepatitis C virus (HCV) is associated with type II mixed cryoglobulinemia (MC), a lymphoproliferative disorder which, in some patients, evolves into overt B-cell non-Hodgkin's lymphoma (B-NHL). Recently, also the association between HCV infection and B-NHL, which had long been controversial, was confirmed in a large case-control study. Little knowledge is, however, available on possible associations between HCV infection and other lymphoid or myeloid malignancies. The present study was set up in order to investigate this aspect.

DESIGN AND METHODS: The study was conducted in hematology departments of ten hospitals in different Italian cities. The cases consisted of consecutive patients with a new diagnosis of T-NHL, Hodgkin's disease (HD), chronic lymphocytic leukemia (CLL), acute lymphoblastic leukemia (ALL), multiple myeloma (MM), acute myeloid leukemia (AML), and chronic myeloid leukemia (CML). The controls were patients in other departments of the same hospitals. HCV infection was investigated by testing for HCV antibodies and HCV-RNA in serum samples.

RESULTS: The prevalence of HCV infection was not higher in patients with HD (3.2%, 5 out of 157 cases) or MM (4.7%, 5 out of 107) than in controls. On the other hand, it was consistently higher in T-NHL (13.8%, 4 out of 30), CLL (9.0%, 9 out of 100), ALL (7.6%, 5 out of 54), AML (7.9%, 11 out of 140), and CML (12.2%, 6 out of 49) patients. These patient groups were not, however, large enough to render statistically significant results.

INTERPRETATION AND CONCLUSIONS: Our data suggest that HCV infection may be associated not only with B-NHL but also with some other lymphoid and myeloid malignancies.