支气管哮喘患儿血浆类胰蛋白酶与类糜蛋白酶活性测定及其临床意义

Measurement of tryptase and chymasr activity in plasma of asthmatic children and its clinical significance

目的探讨哮喘患儿外周血血浆类胰蛋白酶(Trytase)与类糜蛋白酶(Chymase)的活性变化及其在哮喘发病机制中的作用。方法分别取健康儿童、哮喘急性期中度和重度患儿各45例,静脉抽取抗凝血,在Uip-CAP100全自动体外变应原检测仪上进行Trytase测定。Chymase活性测定:使用琥珀酰—丙氨酸—丙氨酸—脯氨酸—苯丙氨酸—酰苯氨(SAAPP)做为底物,采用酶标仪在410nm连续监测吸光度的变化。结果急性期哮喘患儿血浆Trytase(2.65μg/L)值与对照组(1.24μg/L)比较明显升高(P<0.05);26.6%的哮喘患者血浆Chymase活性[(109.9±132.0)nkat]高于对照组(0 nkat);缓解期哮喘患儿血浆Trytase(1.75μg/L)值与急性期(2.65μg/L)比较明显降低(P<0.05)。结论Trytase与Chymase等细胞因子参与儿童哮喘发病的病理生理过程,动态检测其血浆中的活性水平,可能为将来的临床诊断和治疗提供有意义的参考指标,并可作为病情变化的监测指标。

Objective： To evaluate the changes of tryptase and chymase in peripheral blood of asthmatic children and their effect on pathogenesis of asthma. Methods： A total of 45 children with asthma at acute attack stage （ 15 severe and 30 moderate） and 45 healthy children were recruited into the study. Tryptase levels were measured by the use of antibody against tryptase with UniCAP system. The chymase activity was determined spetrophotometrically （410nm） by the rate of hydrolysis of N-succingl-L-Ala-L-Ala-L-Pro-L-Phe-P-nitronilide（SAAPP） 0.7 mmol/L in Nacl 1.5 mol/L and Tris 0.3 mol/L. The actions of proteast inhibitors on chymase activities were examined with enzyme assay. Results： At acute attack stage, the plasma levels of tryptase （ 2.65μg/L} were higher than those of heahhy subjects （ 1.24μg/L）. At paracme stage, the plasma levels of tryptase （1.75μg/L） were obviously cut down compared to those with severe and moderate asthma. The specific chymase activities of 26.6 % of children with asthma [ （ 109.9 ± 132.0 ） nkat] were higher than those of controls （0 nkat）. Conclusion： Tryptase and chymase is likely to participate in the pathogenesis of allergic inflammation. The serum levels of tryptase and chymase can be the criteria for the changes in patient conditions.