Abstract: Chronic obstructive pulmonary disease (COPD) is a treatable and preventable disease state, characterized
by progressive airflow limitation that is not fully reversible. In the present study; 101 COPD patients and 52 agematched
healthy nonsmokers (HNS) control subjects were recruited and their pulmonary functions were assessed.
The frequencies of CD3+ T, CD4+ T, CD8+ T, B, NK, NKT-like cells and CD16+ were determined using
flowcytometry. The potential association of lymphocyte cell subsets with disease severity was further analyzed.
Statistically highly significant reduction in the frequencies of CD4+ T cells, and the CD4+/CD8+ ratio, but increased
frequencies of B cells, CD8+ T cells, CD16, CD3−CD56+ NK and CD3+CD56+ NKT-like cells were observed in
COPD patients compared to controls. There were significant positive correlations between the frequencies of CD4+
T cells and CD8+ T cells and pulmonary functions. A significant positive correlation between CD4+/CD8+ ratio and
FEV1/FVC was observed. While significant negative correlations between the frequency of B cells and pulmonary
functions; and between the frequency of CD16 and FVC% were denoted. There were no significant correlations
between the frequencies of all other cell types tested and pulmonary functions. Our data indicated that COPD
patients have immune dysfunction which may play key roles in the development and progression of COPD. These
findings suggest that modulating immune cells activation may be a new target for the treatment of COPD.