哮喘患儿体内嗜酸性粒细胞凋亡的研究

Eosinophils apoptosis in asthmatic children

目的 探讨嗜酸性粒细胞 (EOS)凋亡及调控因子在儿童哮喘发病机制中的作用和临床意义。方法 采用末端脱氧核苷酸转移酶介导的缺口末端标记 (TUNEL)技术进行原位活化嗜酸性粒细胞 (EG+ 2 )细胞凋亡的检测 ,以免疫组化标记EG+ 2 细胞和凋亡相关基因BcL 2的表达 ,对 1 1例哮喘缓解期患儿吸入糖皮质激素前后及 7例非哮喘患儿的支气管粘膜、痰液、BAL、外周血液中EG+ 2 细胞及其凋亡、BcL 2的表达进行研究。结果 (1 )治疗前哮喘患儿支气管粘膜、痰液、BAL中的EG+ 2 凋亡细胞分别为 0 (0～ 3)个 /mm2 、(4 51± 2 1 2 ) %、(4 0 1± 1 91 ) % ,均低于对照组的 3(0～ 1 0 )个 /mm2 、(1 2 1 1± 0 41 ) %、(1 3 42± 3 83) % (均P <0 0 1 ) ,而EG+ 2 细胞分别为 62 (2 3～ 1 4 2 )个 /mm2 、(8 2 4±3 1 3) %、(2 0 4± 0 92 ) % ,均高于对照组 (P <0 0 0 1 ) ;吸入糖皮质激素治疗后上述标本中EG+ 2 凋亡细胞较治疗前明显增高 (均P <0 0 1 ) ,并高于对照组 ,分别为 5(1～ 1 1 )个 /mm2 、(2 0 0 1± 8 2 3) %、(2 1 2 3± 1 0 2 4 ) % ;EG+ 2 细胞较治疗前减少 (P <0 0 1 ,<0 0 5) ,分别为 30 (1 2～ 51 )个 /mm2 、(3 83± 1 1 4 ) %、(0 64± 0 1 1 ) % ,但仍高于对照组 ;

Prominent eosinophil airway inflammation is important in the pathogenesis of asthma There is increasing evidence that the disorder of eosinophil apoptosis contributes to the mechanism But most of the studies have been done in vitro or on animal models, very few were done among the adult asthmatics in vivo Objective The aim of this study was to elucidate the relationship between the apoptotic eosinophils and Bcl 2 in asthmatic children in vivo Methods Eleven mild to moderate asthmatic patients were recruited and the range of age was 7 14 years (9 males, 2 females), meanwhile 7 patients with lower respiratory infection were recruited as control and the range of age was 9 14 years (5 males, 2 females) Before and after inhaled glucocorticoid (GC) induced sputum, bronchoalveolar lavage (BAL),bronchial mucosa specimens and peripheral blood were obtained for measuring and comparing the changes of apoptotic EG + 2cell by combining the techniques of TUNEL and immunohistochemistry, meanwhile the expression of Bcl 2 in bronchial mucosa specimens was measured by using the immunohistochemical assay Results Before the inhalation of GC, the apoptotic EG + 2cells in asthmatics were significantly lower than that in control group ( P <0 01) , and the numbers of EG + 2cell in asthmatics group were significantly higher than that in control group ( P <0 001) After the treatment apoptotic EG + 2cells in asthmatics were increased ( P <0 01), and the numbers of EG + 2cell were decreased ( P <0 01, P <0 05 and P <0 05, respectively), FEV 1% was increased ( P <0 05) Before the inhalation of GC, the numbers of Bcl 2 + cell in asthmatic airway submucosa were higher than that in control group ( P <0 05) but after the treatment the number of Bcl 2 +cell did not change significantly (4) Before and after GC treatment the percentages of apoptotic eosinophils of peripheral blood in vivo had no significant changes compared with those of control subjects ( P >0 05) There was a positive correlation between apoptosis of EG + 2 cell in sputum, BAL, airway submucosa and FEV 1%( P <0 05) Conclusion Apoptosis of EG + 2 cell decreased in the airway of asthmatic children and inducing EOS apoptosis is one of the important mechanism of inhaled GC therapy for asthma