Tregs and HLA-DR Expression in Sputum Cells of COPD Patients Treated with Tiotropium and Formoterol

Immune cells expressing the activation markers HLA-DR and regulatory T cells (Tregs) may be involved in the regulation of chronic inflammation in chronic obstructive pulmonary disease (COPD). In this study we analyzed native and activated cell profiles in sputum of 22 stable COPD patients receiving formoterol (F) or formoterol + tiotropium (F + T) for 3 months. Cells were isolated from induced sputum and were examined on Coulter flow cytometer using fluorescent antibodies specific for CD3, CD4, CD8, CD14, CD19, CD25, CD127, and HLA-DR antigens. Cell profiles and cell activation were assessed by analysis of HLA-DR, CD25, and CD127 co-expression in double-stained samples. Tregs were defined as CD4+CD25high CD127low cells. We found that the combined therapy significantly decreased the CD8+ cell number (p