Background: Increased serum and intrahepatic interferon γ inducible protein 10 (IP-10) levels in patients with chronic hepatitis C (CHC) have been described.

Aim: To analyse the possible association of serum IP-10 levels with different outcomes to antiviral therapy.

Patients: A total of 137 CHC patients treated with peginterferon plus ribavirin.

Methods: Serum IP-10 levels were determined by enzyme linked immunosorbent assay before therapy, after 12 weeks of treatment, and 24 weeks after cessation of therapy. Variables significantly associated with a sustained virological response (SVR) on univariate analysis were included in a multivariate logistic regression model.

Results: Pretreatment serum IP-10 levels in patients with SVR were significantly lower than in non-responders (NR) (332.4 (222.1) v 476.8 (305.3) pg/ml, respectively; p = 0.004). Serum IP-10 concentrations significantly decreased in patients with SVR (pretreatment: 332.4 (222.1) pg/ml; post-treatment: 170.2 (140.1) pg/ml; p<0.001) but not in NR (pretreatment: 476.8 (305.3) pg/ml; post treatment: 387.3 (268.1) pg/ml; p = 0.06). By multivariate analysis, non-1 genotype (odds ratio (OR) 3.5 (95% confidence interval (CI) 1.1–10.4); p = 0.003) and low viral load at baseline (OR 0.34 (95% CI 0.14–0.79); p = 0.01) were independent predictors of SVR in all patients. When multivariate analysis was restricted to patients with genotype 1, only baseline viral load (OR 0.38 (95% CI 0.155–0.96); p = 0.04) and pretreatment serum IP-10 levels (OR 0.99 (95% CI 0.996–0.999); p = 0.03) were identified as predictive factors of SVR.

Conclusion: Pretreatment serum IP-10 behaves as a predictive factor of SVR to peginterferon plus ribavirin therapy in genotype 1 infected patients.