Elderly Patients with Tuberculosis Combined with Diabetes Mellitus: A Comprehensive Analysis of Lymphocyte Subpopulation Dynamics, Clinical Features, Drug Resistance and Disease Regression.

Objective: The aim of this study was to evaluate lymphocyte subsets and clinical outcomes in patients with pulmonary tuberculosis (PTB) combined with type 2 diabetes mellitus (T2DM). Methods: Between January 2022 and March 2024, 320 patients aged > 60 years were included, 95 of whom had comorbid DM. Lymphocyte subsets (T-lymphocytes, B-lymphocytes, and natural killer cells, NK) were assessed in both groups of patients using fluorescence-associated cell sorting. Clinical characteristics, drug resistance, regression and lymphocyte subsets were compared in PTB patients with DM versus PTB patients alone. The correlation between lymphocyte subsets-related indices and the above characteristics in PTB patients with DM was analyzed. Results: Compared with PTB patients alone, PTB patients with comorbid DM had a higher positive rate (81.05% vs 62.67%, Conclusion: Lymphocyte homeostasis is altered in PTB patients with comorbid DM, making them more susceptible to severe clinical manifestations and therapeutic outcomes. Notably, NK cells have been identified as key regulatory cells with a significant impact on prolonged treatment course and drug resistance. This study provides new ideas and methods for individualized treatment of PTB combined with DM in the elderly, which can help to optimize the treatment plan and improve the outcome and quality of life of patients.