FIG. 5.

MFI of PD-1 expression on T cells in CSF correlates with status of HIV disease. (Top) Correlations between log₁₀ HIV-1 RNA copies/ml in CSF and MFIs of PD-1 on CD4⁺, CD8⁺, and HIV-specific CD8⁺ T cells in CSF and in blood. (Bottom) Correlations between peripheral blood CD4⁺ T-cell counts and MFIs of PD-1 on CD4⁺, CD8⁺, and HIV-specific CD8⁺ T cells in CSF and in blood. Spearman's rho (r) and P values are indicated. Data for healthy HIV-negative controls (Ctls) are also shown. Markers for CSF are red, and those for blood are black.