Figure 2.

Decline in anti–hepatitis C virus (HCV) envelope binding antibody titers after incident human immunodeficiency virus (HIV) infection occurs in subjects with CD4⁺ T-cell loss. A–C, Anti-HCV envelope titers were stable after incident HIV infection in subjects with CD4⁺ T-cell counts >350/mm³ but declined significantly in subjects with CD4⁺ T-cell counts of 200–350/mm³ or <200/mm³. Gray line represent titers for individual subjects measured at 2 time points; black lines, medians. Enzyme-linked immunosorbent assay (ELISA) titers below the level of detection were assigned a titer of 1:25, and serum samples still ELISA positive at a 1:51 200 dilution were assigned that value for comparison analysis. Wilcoxon signed rank test was used to calculate significance of changes; when normality was satisfied, paired t tests were used. D, Comparison of the change in binding antibody titers over time in HCV-monoinfected controls and HIV/HCV-coinfected subjects stratified by post-HIV CD4⁺ T-cell count. Symbols represent changes for individual subjects; black lines, medians. Rank sum tests were used to calculate significance; when normality was satisfied, t tests were used.