We identified 1189 patients from the Swiss Hepatitis C Cohort database with at least one biopsy prior to antiviral treatment and assessable date of infection. Stage-constant fibrosis progression rate was assessed using the ratio of fibrosis Metavir score to duration of infection. Stage-specific fibrosis progression rates were obtained using a Markov model. Risk factors were assessed by univariate and multivariate regression models.
Independent risk factors for accelerated stage-constant fibrosis progression (>0.083 fibrosis units / year) included male sex (OR = 1.60, [95 % CI 1.21–2.12], P < 0.001), age at infection (OR = 1.08, [1.06–1.09], P < 0.001), histological activity (OR = 2.03, [1.54–2.68], P < 0.001) and genotype 3 (OR = 1.89, [1.37–2.61], P < 0.001). Slower progression rates were observed in patients infected by blood transfusion (P = 0.02) and invasive procedures or needle stick (P = 0.03), compared to those infected by intravenous drug use. Maximum likelihood estimates (95 % CI) of stage-specific progression rates (fibrosis units / year) for genotype 3 versus the other genotypes were: F0 → F1: 0.126 (0.106–0.145) versus 0.091 (0.083–0.100), F1 → F2: 0.099 (0.080–0.117) versus 0.065 (0.058–0.073), F2 → F3: 0.077 (0.058–0.096) versus 0.068 (0.057–0.080) and F3 → F4: 0.171 (0.106–0.236) versus 0.112 (0.083–0.142, overall P < 0.001).
This study shows a significant association of genotype 3 with accelerated fibrosis using both stage-constant and stage-specific estimates of fibrosis progression rates. This observation may have important consequences for the management of patients infected with this genotype.