Objective: To prospectively evaluate the prevalence and clinical spectrum of cryoglobulinemia in a population infected with the hepatitis C virus (HCV).
Methods: Inpatients and outpatients at the Veterans Affairs (VA) Medical Center were recruited for study. Sixty-nine patients with HCV and 68 anti-HCV negative, age and sex matched controls were evaluated for the prevalence of cryoglobulinemia. Clinical and laboratory profiles were obtained in all patients and rheumatologic complaints were sought in 58 anti-HCV positive patients.
Results: Twenty-nine (42%) of 69 anti-HCV positive patients and no controls had cryoglobulinemia (p < 0.001). A history of intravenous drug abuse and excessive alcohol ingestion was more prevalent in the anti-HCV positive group compared to controls, (p < 0.001 and p = 0.02, respectively), but was unrelated to the presence or absence of cryoglobulinemia. Of 58 anti-HCV positive patients evaluated for rheumatologic complaints, 12 (21%) reported symptoms; 9 (41%) of 22 with cryoglobulinemia and 3 (8%) of 36 without cryoglobulinemia (p < 0.01). No patient had vasculitis. Antinuclear antibody (ANA) and rheumatoid factor (RF) were evaluated in 19 anti-HCV positive patients with cryoglobulinemia. About one-half were positive for ANA or RF, fewer than 50% of whom had rheumatologic symptoms. Nineteen of the 29 patients with cryoglobulinemia were available for followup after one year. Ten of 19 revealed only trace (< 5%) cryoglobulinemia; 7 were type III, one type I, and none were type II. The character of the remaining 2 cryoglobulins was unknown. Twenty-five liver biopsy specimens were available for review; there were no histological differences between patients with and without cryoglobulinemia.
Conclusion: The prevalence of HCV related cryoglobulinemia at a VA hospital was 42% and was most often of the type III variety. Although mild rheumatologic symptoms were common in HCV infected patients with cryoglobulinemia, no specific syndrome denoted its presence. The absence of any specific rheumatologic disease in this cohort implies that the pathogenesis of diseases such as essential mixed cryoglobulinemia is multifactorial and that low levels of type III cryoglobulinemia in HCV infected patients are not specific for the diagnosis.