摘要目的 探究嗜酸粒细胞性支气管炎(EB)和咳嗽变异性哮喘(CVA)患者气道炎症细胞、细胞因子和炎性介质的特征,阐明两者存在不同气道炎性特征的可能机制.方法检测杭州市第一人民医院门诊收治的15例EB患者(EB组)、15例CVA患者(CVA组)、14例支气管哮喘(简称哮喘)患者(哮喘组)和14名健康体检者(健康对照组)诱导痰中嗜酸粒细胞(EOS)百分比;流式细胞仪检测白细胞介素(IL)-5及干扰素(IFN)-γ刺激的EOS表面CD69的表达;实时荧光定量PCR方法检测各组诱导痰上清液中前列腺素E2(PGE2)、白三烯C4(LTC4)、IL-5、IFN-γ mRNA的表达水平;酶联免疫吸附法(ELISA)检测各组诱导痰上清液中PGE2、LTC4、IFN-γ和IL-5蛋白表达水平.结果 EB组、CVA组、哮喘组诱导痰中EOS百分比分别为(15.8±3.2)%、(13.0±2.7)%和(11.6±4.5)%,均明显高于健康对照组的(1.0±0.4)%(均P<0.05).在IL-5和IFN-γ刺激下,EB组诱导痰中EOS表达CD69分别为1.49±0.42和1.51±0.52、CVA组分别为1.37±0.41和1.42±0.32、哮喘组分别为1.42±0.72和1.37±0.46,3组间差异无统计学意义,但较健康对照组(分别为0.42±0.21和0.39±0.12)差异均有统计学意义(均P<0.05).EB组、CVA组、哮喘组诱导痰中IL-5的mRNA及蛋白表达水平明显高于健康对照组(均P<0.05),但3组间差异无统计学意义;各组诱导痰中IFN-γ的mRNA及蛋白表达水平较健康对照组差异均无统计学意义.EB组诱导痰中PGE2浓度为(839±69)ng/L,明显高于CVA组的(33±8)ng/L、哮喘组的(25±6)ng/L和健康对照组的(24±8)ng/L(均P<0.01),后3组差异无统计学意义;EB组PGE2限速酶前列腺素氧化环化酶2(PTGS2)的mRNA水平表达量显著增加,较CVA组、哮喘组及健康对照组差异均有统计学意义(均P<0.01);CVA、EB和哮喘组诱导痰中LTC4浓度明显高于健康对照组(均P<0.05),CVA、EB及哮喘组中LTC4限速酶白三烯C4合成酶(LTC4S)的mRNA表达水平明显高于健康对照组(均P<0.05),EB组LTC4的mRNA及蛋白表达水平与CVA组和哮喘组比较,差异也有统计学意义(均P<0.05).CVA组、哮喘组诱导痰中LTC4/PGE2比值明显高于EB组(t值分别为8.67和13.12,均P<0.05).结论 EB患者诱导痰中PGE2高表达以及CVA组LTC4/PGE2比值较EB组显著增高,这两者可能是EB缺乏气道高反应性的炎症基础.

abstractsObjective To explore the characteristics of airway inflammatory cells, cytokines and inflammatory mediators in eosinophilic bronchitis (EB) and cough variant asthma (CVA) patients and to elucidate the underlying mechanism of distinct airway inflammation between EB and CVA. Methods This study included 15 patients with EB (EB group), 15 patients with cough variant asthma (CVA, CVA group), 14 patients with bronchial asthma (asthma group) and 14 healthy controls (healthy group). Percentage of eosinophils (EOS) in sputum induced by hypertonic saline was detected by FACS. The percentage of CD+69 EOS stimulated by interleukin-5 (IL-5) and interferon γ (IFN-γ) was also detected by FACS. The expression of leukotriene C4 synthase (LTC4S) and prostaglandin-endoperoxide synthase-2 (PTGS2) mRNA in sputum was measured by real-time PCR and the concentration of leukotriene C4 (LTC4) and prostaglandin E2(PGE2) in sputum was measured by ELISA. Results The percentage of EOS in induced sputum was 15.8±3.2 (EB group), 13.0±2.7 (CVA group) and 11.6±4.5 (asthma group), respectively, which were significantly higher than 1.0±0.4 in the healthy group. The difference was significant and the t value was 16.31, 15.23 and 14.21 respectively (P<0.05). After stimulated by IL-5 and IFN-γ, the percentage of CD+69 EOS in induced sputum was 1.5±0.4 and 1.5±0.5 (EB group), 1.4±0.4 and 1.4±0.3 (CVA group) and 1.42±0.72 and 1.37±0.46 (asthma group) respectively. There was no statistical significance between these 3 groups, but when compared with 0.4±0.2 and 0.4±0.1 in healthy group, the difference was significant(P<0.05). The expression of IL-5 mRNA and protein in induced sputum of EB group, CVA group and asthma group were higher than the healthy group and the difference was all statistically different (P<0.05), but there was no statistical significance between EB group, CVA group and asthma group. The expression of IFN-γ mRNA and protein in induced sputum of each group was not different when compared with healthy group (P＞0.05). The concentration of PGE2 in induced sputum of EB group was(839±69)ng/L, which was higher than (33±8) ng/L of CVA group, (25±6) ng/L of asthma group and (24±8) ng/L of healthy group (all P<0.01). There was no statistical difference between CVA group, asthma group and healthy group. The expression of PTGS2 in induced sputum of EB group increased significantly; when compared with CVA group, asthma group and healthy group, the difference was significant (all P<0.01). The concentration of LTC4 in induced sputum of EB group, CVA group and asthma group was all higher than the healthy group (all P<0.05). The expression of LTC4S mRNA of EB group, CVA group and asthma group was also higher than the healthy group (all P<0.05). The expression of LTC4S mRNA and LTC4 in the EB group was higher than that in the CVA group and the asthma group (P<0.05). The value of LTC4/PGE2 in the CVA group and the asthma group was higher than that in the EB group (t=8.7 and 13.1, P<0.05). Conclusion These data suggest that the difference in airway function observed in subjects with eosinophilic bronchitis and CVA (or asthma) may be due to the results of differences in PGE2 production and an imbalance between the production of bronchoconstrictor LTC4 and bronchoprotective PGE2 lipid mediators.