Based on this, a TB-DM internal model performance was constructed, and the receiver operating characteristic (ROC) curve was used to evaluate its diagnostic efficacy.<h4>Results</h4>The study demonstrated significantly reduced NK cells (P<sub>TB-DM vs. HC</sub> < 0.0001 and P<sub>TB-DM vs. DM</sub> = 0.0292), total T cells (P<sub>TB-DM vs. HC</sub> = 0.0018 and P<sub>TB-DM vs. DM</sub> < 0.0001), and CD8+ T cells (P<sub>TB-DM vs. HC</sub> = 0.0009 and P<sub>TB-DM vs. DM</sub> = 0.0072) in TB-DM versus HCs and DM groups. This evidence concerns the gene CD8A and diabetes mellitus.