Distribution of two CD4⁺FOXP3⁺ T cell subpopulations reflects disease phenotypes and prognosis in COPD

Chronic obstructive pulmonary disease (COPD) is a heterogeneous condition, with varying clinical phenotypes and prognoses. Regulatory T cells (Tregs), particularly CD4⁺FOXP3⁺ T cell subpopulations, are crucial in modulating immune responses. This study investigates the distribution of two CD4⁺FOXP3⁺ T cell subpopulations in bronchoalveolar lavage fluid (BALF) from COPD patients and their association with disease phenotypes and prognosis. Patients were classified into Type A (lower frequencies of inflammatory FOXP3^lo T cells) and Type B (higher frequencies of inflammatory FOXP3^lo T cells). Type B COPD patients, who demonstrated more severe emphysema, heightened inflammatory responses, faster lung function decline, and more pronounced osteoporosis, showed a significant increase in FOXP3^lo non-suppressive T cells. In contrast, Type A patients exhibited a higher proportion of FOXP3^hi Treg cells, which correlated with milder disease phenotypes. The distinct distribution of CD4⁺FOXP3⁺ T cell subpopulations provides insights into the progression of COPD and suggests that these cells could serve as potential biomarkers for disease severity and prognosis. Further research may offer new therapeutic avenues by targeting these Treg subpopulations in COPD management.