CD4 and type 2 diabetes mellitus: Type 2 diabetes is associated with an increased frequency of mycobacterial antigen-specific CD4+ helper T cell type 1 (Th1) and type 17 (Th17), and PTB coexisting with type 2 diabetes is associated with changes in CD8+ T and natural killer (NK) cells that produce cytokines and express cytotoxic molecules, leading to aggressive abnormalities in pathology (15, 16).