Plasma CXCL10 levels measured before start of therapy correlate with early responses to therapy. (A) CXCL10 levels measured 7 days before the start of therapy were lower in those whose serum viral load declined by > 2 log₁₀ during the first 29 days of therapy than in those whose serum viral load declined by < 1 log₁₀ during the first 29 days of therapy. (B) CXCL10 levels measured 7 days before the start of therapy were lower in patients in whom serum HCV RNA had declined by > 2 log₁₀ by 12 weeks of therapy than in those whose serum viral load declined by < 1 log₁₀ after 12 weeks of antiviral therapy. Measurements from all 29 patients are shown. Lines across each column represent the median for each set of measurements. Value of P was calculated by the Mann-Whitney test.