Mixed cryoglobulinaemia and chronic hepatitis C virus infection: the rheumatic manifestations.

The prevalence of rheumatologic symptoms in patients with mixed cryoglobulinaemia associated to chronic hepatitis C virus (HCV) infection was investigated. One hundred fourteen patients (96 female, mean age 63.5 years) with chronic HCV infection and cryoglobulinaemia were recruited. The presence, concentration, and type of cryoglobulins were tested by immunofixation. Rheumatoid factor (RF) and antinuclear antibody (ANA) were also measured. Rheumatological related symptoms were investigated by anamnesis and clinical evaluation. HCV genotype was determined by polymerase chain reaction (PCR) with genotype specific primer. Type II cryoglobulinaemia was identified in 39 cases and it was of type III in 58. HCV-RNA genotype was determined in 62 patients: 47 (76%) were infected by genotype1b, 8 (13%) by genotype 2a, while other genotypes were less common. RF and ANA were, respectively, present in 36 (31.5 %) and 4 (3.5 %) patients at low titre (RF < 50 UI/ml, ANA < 1:80). Of the 114 patients, 51 (44.7%) complained for rheumatological symptoms. The mean cryocrit value in these patients was 2,6 %, while in patients with HCV infection, liver disease, and cryoglobulinaemia without rheumatological symptoms the cryocrit value was lower than 0.5% in 50% of cases. It is concluded that patients with chronic HCV infection reported a wide variety of rheumatological manifestations, impairing their quality of life, with discrete frequency. These results suggest that HCV infection should be considered in the differential diagnosis of rheumatological symptoms of unknown origin.