Clinical study of cryoglobulinaemia in Chinese patients with chronic hepatitis C

Cryoglobulinaemia is the most common immunological disorders seen in patients with chronic hepatitis C virus (HCV) infection. We evaluated the incidence and clinical significance of cryoglobulinaemia in 122 Chinese patients with chronic hepatitis C. The pathogenic roles of HCV genotypes and viraemia in this phenomenon were also evaluated. Fifty-four (44%) of the 122 patients with chronic hepatitis C had cryoglobulinaemia. Eleven (20%) of the patients with cryoglobulinaemia had symptoms and signs of cutaneous vasculitis, arthralgia, neuropathy and renal involvement. The patients with cryoglobulinaemia were predominantly female and had a significantly higher mean serum level of rheumatoid factor and a lower mean serum C4 level compared with patients without cryoglobulinaemia (50 vs 29%, 23 vs 15 IU/mL, 25 vs 31 mg/dL, respectively, P < 0.05). The mean serum HCV RNA level, HCV genotype, the presence of serum auto-antibodies, and the rate of cirrhosis were not significantly different between the two groups. Univariate logistic regression analysis showed female serum levels of alanine aminotransferase (> 90 U/L), rheumatoid factor (> 15 IU/mL), C3c (< 100 mg/dL) and C4 (< 20 mg/dL) to be significant predictors of cryoglobulinaemia in chronic hepatitis C patients. However, multivariate analysis showed only serum C4 levels (< 20 mg/dL) as a significantly independent predictor. We concluded that 44% of Chinese patients with chronic hepatitis C had cryoglobulinaemia. Serum C4 levels were significantly lower in chronic hepatitis C patients with cryoglobulinaemia and the serum C4 level was the only clinical independent predictor associated with this phenomenon. Hepatitis C virus genotype and serum viral load were not clinical independent predictors.