Correlations Between The Chymase Activity, Levels Of Tryptase And Eotaxin In Patients With COPD

Objective To investigate correlations between the sputum chymase activity, levels of tryptase,IL-8, eotaxin, neutrophil and eosinophil numbers in the sputum and plasma of elderly patients with COPD their clinical implications.Methods A total of 73 elderly patients with COPD (21 severe, 21 moderate and 31 mild) were recruited into the study. IL-8 and eotaxin levels were detected with Sandwich ELISA procedures and tryptase levels were measured with antibody against tryptase with UniCAP system. Chymase activity was determined spectro-photometrically (410nm) by the rate of hydrolysis of 0.7 mmol/L N-succinyl-L-Ala-L-Ala-L-Pro-L-Phe-p-nitroanilide (SAAPP) in NaCl 1.5 mol/L and Tris 0.3 mol/ L. The specific activity of chymase was expressed as mU/mL. Actions of protease inhibitorson chymase activities were also examined with enzyme assay. Results 1. At acute attack stage of patients with COPD, the plasma levels of tryptase were greater than that for healthy controls, The tryptase levels in the plasma of severe patients were significantly decreased following treatment. At severe and moderate acute attack stage of the patients with COPD, the sputum levels of tryptase were greater than that of the patients at mild acute stages. The tryptase levels in the sputum of all patients were significantly decreased following treatment. 2. The specific chymase activities of severe and moderate patients were higher than mild patients. Native protease inhibitors a1-antitrypsin(a1-AT) and soy bean trypsin inhibitor (SBTI) inhibited 83% and 89% enzymatic chymase activity, respectively. 3. At acute attack stage of patients with COPD, the plasma levels of IL-8 were greater than that for healthy controls. The IL-8 levels in the plasma of severe and moderate patients were significantly decreased following treatment. At severe and moderate acute attack stage of the patients with COPD, the sputum levels of IL-8 were greater than that of the patients at mildacute stages. At both acute attack and remission stages of patients with COPD, the plasma levels of eotaxin were greater than that for healthy controls. The eotaxin levels in the plasma of all patients were significantly decreased following treatment. The sputum levels of eotaxin were signifinificantly elevated in the patients with COPD at the acute stage compared with the mild convalescent stage. 4. At acute attack stage of patients with COPD, the numbers of neutrophils and eosinophils in blood were increased in comparison with the numbers for healthy controls. Following treatment, the elevated numbers of cells were significantly reduced. The numbers of neutrophils and eosinophils in sputum were increased in the patients with COPD at the acute stage compared with the mild convalescent stage. At all remission stages, the elevated numbers of cells were significantly reduced. 5. At acute attack stage of patients with COPD, there were correlations between the blood and sputum levels of tryptase, IL-8, eotaxin, neutrophils and eosinophils, there were correlations between the and sputum levels of tryptase, chymase, neutrophils.Conclusion Mast cell degranulation was observed by our study, mast cells and their released mediators also likelihood contribute to the airway inflammation of COPD.