Imbalance of peripheral blood T h17 and T reg responses in patients with chronic obstructive pulmonary disease

Background Autoimmune responses mediated by cluster of differentiation 4 + T cells may contribute to the development of chronic obstructive pulmonary disease ( COPD ). However, little is known about the frequency of peripheral blood T h17 cells and of regulatory T cells ( T regs) in C hinese patients with COPD . This study is aimed at determining the frequency of circulating T h17 and T regs in patients with moderate and severe COPD , heavy smokers and healthy controls ( HC ). Method The percentages of circulating T ‐helper type ( T h)17 cells and T regs were determined by flow cytometry in 32 patients with moderate COPD , 33 patients with severe COPD , 35 smokers, and 31 HC . The concentrations of serum T h17‐ and T reg‐related cytokines were measured by enzyme‐linked immunosorbent assay ( ELISA ). The levels of retinoic acid orphan receptor ( ROR )‐γt and F orkhead box p3 ( F oxp3) m RNA transcripts in peripheral blood mononuclear cells were determined by real‐time polymerase chain reaction. The potential correlation between the percentages of T h17 T regs, serum cytokines and lung function was evaluated. Results In comparison with that in the smokers and HC , significantly higher frequencies of T h17 cells and higher levels of ROR ‐γt m RNA transcripts and serum interleukin ( IL )‐17 A , IL ‐6, IL ‐21, IL ‐22 and IL ‐23, but lower frequency of T regs and lower levels of F oxp3 and serum IL ‐10 were detected in patients with moderate and severe COPD . The increased ratios of T h17 to T regs were negatively correlated with the values of forced vital capacity ( FVC ), forced expiratory volume in 1 s ( FEV 1) and FEV 1/ FVC . Conclusions An imbalance of circulating T h17 cells and T regs is associated with the deterioration of pulmonary function in patients with moderate and severe COPD .