CD4 and pneumocystosis: The serum concentrations of IgG, IgA, IL-2, IFN-γ, the number of CD4+ T cells, and the CD4+-to-CD8+ T-cell ratio (CD4+/CD8+) were increased, while the levels of IL-6 and TNF-α were decreased in the PCP supplementation groups compared with those in the control group.