CD4 and pneumocystosis: The results, as shown in Figure 2, indicate that PCP did not caused significant increases or decreases in CD4+ T-cell percentages or CD8+ T-cell percentages in blood relative to percentages in non-PCP (P < 0.0001), as were CD4+/CD8+ T-cell ratios (P < 0.0001, Figure 2A-C).