Israel Medical Association Journal

Serum rheumatoid factors are autoantibodies of different isotypes directed against the Fc fraction of immunoglobulin G (IgG) and represent paradigmatic autoantibodies that have been largely used in clinical practice for decades. Traditionally IgG has been associated with rheumatoid arthritis and more recently included also in the classification criteria for Sjӧgren’s syndrome. Researchers have established that rheumatoid factors are positive in a variety of infectious, autoimmune, and neoplastic disorders, thus requiring a comprehensive evaluation of seropositive patients. Of note, hepatitis B and C viruses represent a crossroad that includes the high rheumatoid factor seroprevalence and chronic inflammatory disease, as well as progression to non-Hodgkin's lymphomas. Chronic antigen stimulation is the likely common ground of these processes and rheumatoid factors may represent mere bystanders or drivers of pathology. Mixed cryoglobulinemia and lymphoproliferative disease are prime examples of the deleterious effects of rheumatoid factor-B cell activity, possibly associated with hepatitis B and C. More importantly, they show a clear association in a physiological host response to infection, chronic inflammation, and the slide toward autoimmunity and malignancy. The association between hepatitis B and C infections and the appearance of serum rheumatoid factors is further supported by prevalence data, which support a coexistence of these markers in a significant proportion of cases, with viral infections being frequent causes of rheumatoid factors in patients without a rheumatic condition. We provide a comprehensive overview of the known connections between hepatitis B and C infections and rheumatoid factors.

Background: Epidemiological studies in different parts of the world have revealed controversial results on the association between hepatitis C virus infection and non-Hodgkin’s lymphoma. This discrepancy suggests that HCV[1] lymphotropism or its effect on host lymphocytes may be influenced by regional and racial factors, as well as by genomic variations.

Objective: To determine the prevalence of HCV infection in patients with lymphoproliferative disorders diagnosed and treated in our institute in Israel.

Methods: A total of 212 consecutive patients (95 males and 117 females) treated in our hematology outpatient clinic between August 1997 and September 1999 was screened for anti-HCV antibodies and hepatitis B surface antigen. HCV infection was confirmed by the presence of HCV RNA in the serum. The prevalence of HCV in patients with lymphoproliferative disorders was compared to a control group of patients with myeloproliferative disorders and myelodysplastic syndromes.

Results: HCV infection was more prevalent in the group of LPD[2] patients than in the control group, but this finding was not statistically significant. The prevalence of HCV among LPD patients was 7.8%, while that in the group with myeloproliferative and myelodysplastic disorders was 1.19% and in the general population 0.64%. Among the different classes of LPD, a significant association with HCV infection was established only in patients with diffuse large B cell lymphoma. Furthermore, HCV infection was significantly more prevalent than HBV infection in the LPD group, but not in the myeloproliferative and myelodysplastic disorders group.

Conclusions: Our finding of a significant association between HCV infection and diffuse large B cell lymphoma leads us to suggest that anti-HCV antibodies be performed routinely in such subjects.  

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 [1]LPD = lymphoproliferative disorders

[2] HCV = hepatitis C virus