Objective: To explore the role of eosinophil cationic protein (ECP) and T lymphocytes in exercise-induced asthma (EIA).
Methods: In 32 patients with asthma (13 patients with EIA) and 8 normal subjects, peripheral blood ECP, CD(25)(+)%, and IL-5 mRNA were measured before, 10 min and 60 min after exercise testing.
Results: (1) There was a linear relationship between ECP, CD(25)(+)% and the forced expiratory volume in one second (FEV(1)) before exercise (r = -0.79, -0.61, P < 0.01). (2) In patients with EIA, FEV(1) and PEF decreased remarkably after exercise test, but in patients without EIA, FEV(1) and PEF did not change. The difference between the two groups was significant. (3) There was no significant difference between the two groups in terms of ECP, CD(25)(+)%, and IL-5 mRNA.
Conclusion: T lymphocyte activation and ECP secreted by eosinophils do not seem to play a major role in EIA.