Fig. 2.

Chronic hepatitis C virus (HCV) patients rapidly catabolize CXCL10 due to higher ex-vivo dipeptidylpeptidase IV (DPP4) activity. (a) Whole blood taken from HCV patients was stimulated with 100 IU/ml interferon (IFN)-α₂ (final concentration) using TruCulture collection tubes. Culture supernatants were analysed using the CXCL10 triplex assay. (b) CXCL10 (1–77) concentration was plotted against CXCL10 (total) concentration. The coefficient of determination, R², and the curve equation are represented. (c) CXCL10 (total), CXCL10 (1–77) and CXCL10 (3–77) concentration in the two patient groups – sustained virological responders (SVR) and those who remained persistently infected after treatment (chronic). (d) DPP activity was measured in SVR and chronic patients. (c,d) A Mann–Whitney U-test was used to compare the two groups and, where significant, P-value is indicated.