RESUMO
Exercise training has been shown to reduce symptoms and exacerbations in COPD patients; however, the exercise effect on patients' immune response is poorly known. We thus verified if an exercise program (EP) impacted on proliferative T cell response of COPD patients. Fourteen non-O2 dependent COPD patients on standard treatment were studied. EP consisted in 24 sessions of aerobic and muscular training. Peripheral blood mononuclear cells were stimulated with the mitogen phytohemagglutinin and antigens from Haemophilus influenzae and cytomegalovirus, and the lymphocyte proliferative response (LPR) was assessed through the expression of Ki67 before and after the EP. The Quality of life [COPD assessment test (CAT)], dyspnea [(modified Medical Research Council scale (mMRC)], and 6-min walk distance were also assessed. The EP program increased significantly the LPR of TCD4+ lymphocytes to phytohemagglutinin and cytomegalovirus and H. influenzae antigens, but with TCD8+ lymphocytes the increase was less marked. Consistent with this, a higher proportion of TCD8+ than TCD4+ cells did not express the costimulatory molecule CD28. The EP also resulted in improvement of the quality of life, dyspnea, and physical capacity. The improvement in TCD4+ cell function may represent an additional mechanism through which the EP results in less exacerbations and hospitalizations.