CD4 and tuberculosis: Other host immune correlates have been associated with MDR- and XDR-TB patients when compared to both drug-susceptible TB and uninfected individuals: decreased levels of CD4, CD3/HLA-DR+ and Fas+ T cells, and increased levels of NKT and γδ T cells (Kiran et al., 2010); altered CD4/CD8 ratio and higher TNF levels in serum (Song et al., 2018); and low plasma concentrations of human neutrophil peptides (HNP1-3) (Zhu et al., 2011).