Increased expression of CXCR3 on B cells from patients with HCV infection. (A) PBMCs from a healthy donor were stained for CD3, CD20, and CXCR3. T and B cells identified by staining for CD3 or for CD20, respectively, were analyzed for expression of CXCR3. Numbers in dot plots represent the percentage of gated cells within the region indicated. (B) PBMCs from a patient with HCV were stained for CD3, CD20, and CXCR3. T and B cells identified by staining for CD3 or CD20, respectively, were analyzed for expression of CXCR3. (C) Frequency of T lymphocytes and B lymphocytes expressing CXCR3 among healthy donors and patients with HCV. Patient samples came from chronically infected patients who had not received antiviral therapy for at least 6 months. Lines across each column represent the median value for each group. Values of P were calculated by the Mann-Whitney test. (D) Frequency of CD20⁺ B lymphocytes expressing CXCR3 plotted against the frequency of PBMCs expressing CD20 in the same sample for the 29 patients listed in Table 2. Samples were obtained 1 week before the start of antiviral therapy. The symbols used indicate the outcome of therapy (▪, no response; ▵, SVR; ×, transient response followed by breakthrough or relapse). The values are correlated for the patients as a group (Spearman r = –0.6407, P = .001) and for nonresponders to antiviral therapy (Spearman r = –0.8788, P = .001).