Detection and correlation of tryptase, IL-8, eotaxin and chymase activity in plasma of patients with asthma

    XIE Hua, HE Shaoª²Heng, CHI Xiuª²Li, CHEN Ping

    1Institute of Allergy & Inflammation Research, Shantou University Medical College, Shantou 515031, China, 2Department of Respiratory Medicine, General Hospital, Shenyang Command, Shenyang 110015, China

    ¡¾Abstract¡¿ AIM: To investigate the correlaitons and levels of tryptase, ILª²8, eotaxin and chymase activity in the plasma of patients with asthma. METHODS: A total of 60 patients with asthma at acute attack stage (30 severe and 30 moderate) were recruited into the study. ILª²8 and eotaxin levels were detected by sandwich ELISA procedures and tryptase levels were measured using antibody against tryptase with UniCAP system. The chymase activity was determined spectrophotometrically (410 nm) by the rate of hydrolysis of Nª²succinylª²Lª²Alaª²Lª²Alaª²Lª²Proª²Lª²Pheª²pª²nitroanilide (SAAPP) 0.7 mmol/L in NaCl 1.5 mol/L and Tris 0.3 mol/L. The actions of protease inhibitors on chymase activities were examined with enzyme assay. RESULTS: At acute attack stage, the plasma levels of tryptase (2.8 ¦Ìg/L) were higher than those of healthy subjects(1.2 ¦Ìg/L). The plasma levels of ILª²8 (141.5 ¦Ìg/L) and eotaxin (154.9 ¦Ìg/L)were significantly elevated in patients with asthma than those of healthy subjects(6.5 ¦Ìg/L and 49.9 ¦Ìg/L, respectively, P<0.05). The specific chymase activities of 18.3 % of patients with asthma[(109.9¡À132.0)nkat] were higher than those of controls (0 nkat). The native protease inhibitors ¦Á1ª²antitrypsin (¦Á1ª²AT) and soy bean trypsin inhibitor (SBTI) inhibited 87.0% and 88.2% chymase enzymatic activity, respectively. There were correlations between the levels of ILª²8 and eotaxin (r=0.4, P=0.046). There were no correlations between tryptase, ILª²8, eotaxin, neutrophils, lymphocytes, monocytes and eosinophils. CONCLUSION: Mast cells, neutrophils, eosinophils and cytokines participate in the pathogenesis of allergic inflammation. Among these cells, mast cells may play a key role as they can release mediators such as tryptase, chymase, ILª²8 or eotaxin which in turn recruit other inflammation cells including neutrophils and eosinophils to the involved areas. ......