不同控制水平的支气管哮喘患者气道炎症与外周气道功能状态的研究

目的 了解不同临床控制水平的支气管哮喘(简称哮喘)患者的气道炎症状况及外周气道功能,观察哮喘患者诱导痰中的炎症指标能否反映外周气道功能的改变.方法 收集在北京朝阳医院就诊的哮喘患者66例,分为控制组(21例)、部分控制组(28例)、未控制组(17例)以及健康对照组(20名).所有受试者第1天进行哮喘控制测试(ACT)评分,行脉冲振荡肺功能检测气道阻力及肺功能基础值、诱导痰细胞计数和分类以及嗜酸粒细胞阳离子蛋白(ECP)浓度测定;第2天测定呼出气一氧化氮浓度(FE_(NO)),若所测得的FEV_1≥70%预测值则行乙酰甲胆碱激发试验,当气道阻力升高至基础阻力2倍或乙酰甲胆碱达到最大浓度时终止试验,3 min后行气道阻力及通气功能检测;然后嘱受试者行5次深吸气后再复测气道阻力及通气功能.比较4组受试者诱导痰细胞计数和分类、诱导痰中ECP浓度、FE_(NO)水平与ACT评分间的相关性;观察激发后以及深吸气后外周气道阻力的变化与ACT评分、诱导痰中嗜酸粒细胞(EOS)计数、痰ECP水平及FE_(NO)间的关系.结果 (1)哮喘患者诱导痰EOS计数、ECP浓度以及FE_(NO)随着控制水平的下降逐渐增高,且诱导痰EOS计数、ECP浓度均与ACT评分呈负相关(r值分别为-0.43和-0.56,均P<0.01).(2)在健康对照组,乙酰甲胆碱激发后中心气道阻力(R_(20))、外周气道阻力(R_5-R_(20))增高程度间比较差异无统计学意义(F=3.472,P>0.05),而在控制组及部分控制组激发试验后外周气道的反应强于中心气道(F值分别为18.09和14.14,均P<0.01),但激发后R_5-R_(20)的变化与ACT评分、诱导痰EOS计数、ECP、FE_(NO)水平间无相关性.(3)深吸气后,健康对照组R_5-R_(20)由(0.13±0.14)kPa·L~(-1)·s~(-1)降至(0.08±0.09)kPa·L~(-1)·s~(-1)(t=2.84,P<0.05),而控制组、部分控制组R_5-R_(20)分别由(0.24±0.15)、(0.31±0.18)kPa·L~(-1)·s~(-1)>增至(0.30±0.16)、(0.39±0.17)kPa·L~(-1)·s~(-1)(t值分别为3.90、4.68,均P<0.01),但相关分析显示,深吸气后R_5-R_(20)的变化与ACT评分、诱导痰EOS计数、ECP、FE_(NO)水平无相关性.结论 即使在控制水平的哮喘患者,仍存在气道嗜酸粒细胞炎症,且该炎症状态随着疾病控制水平的降低而逐渐加重;哮喘患者深吸气所致的外周气道舒张作用消失;检测诱导痰中的炎症指标并不能反映外周气道功能的改变.

Airway inflammation and peripheral airway function in asthmatic patients with different control levels

Objective To observe the airway inflammation and peripheral airway function in asthmatic patients with different control levels, and to investigate whether the airway inflammation profile detected by induced sputum reflects the peripheral airway dysfunction. Methods The recruited asthmatic subjects (n=66) were divided into 3 groups: asthma controlled (8 male and 13 female), asthma partly controlled (12 male and 16 female), asthma uncontrolled (6 male and 11 female). Twenty healthy subjects served as the control group (9 male and 11 female). On the 1st day, all the subjects were required to take asthma control test (ACT), and to receive measurement of lung function by osciilometry and spirometry as well as inflammatory cell profile of induced sputum and the concentration of eosinophil cationic protein (ECP). Exhaled nitric oxide (Feso) was measured on the 2nd day, and oscillometry methacholine provocation was conducted for patients whose baseline FEV_1 was ≥70% predicted. The provocation process was terminated when airway resistance was increased by twice of the basic value, or when the mcthacholine reached the highest concentration. Then airway resistance and lung function were examined after 3 minutes. Finally, airway resistance and lung function were measured again after the subjects had 5 consecutive deep inspirations (DI). Correlation analysis was conducted between ACT scores and inflammatory cells count, ECP concentrations of induced sputum and FE_(NO) among different groups. The correlations were also made between the change of peripheral airway resistance triggered by provocation or DI and ACT scores, total eosinophil, ECP level of induced sputum, FE_(NO) respectively. Results The total eosinophil count and ECP level in induced sputum and FE_(NO) in asthmatic patients increased with the decline of control level. Negative correlations between ACT scores and total eosinophil count as well as the ECP level were observed (r = -0.43, -0.56, P < 0.01). In the healthy control group, the percentage of increase in peripheral airway resistance (R_5-R_(20)) and central airway resistance (R_(20)) did not show significant difference (F = 3.472, P > 0.05) with methacholine provocation, while the percentage of increase in R_5-R_(20) was greater than in R_(20) in both controlled and partly controlled asthmatic patients with provocation (F=18.09 and 14.14, P< 0.01), though the change of R_5-R_(20) showed no correlations with ACT scores, eosinophil count of induced sputum, ECP level and FE_(NO). After DI, R_5-R_(20), decreased from (0. 13 ±0. 14) kPa · L~(-1) · s~(-1) to (0. 08 ± 0. 09) kPa · L~(-1) · s~(-1) (t = 2. 84, P < 0. 05) in the healthy control group, while R_5-R_(20), increased from (0. 24 ±0. 15) kPa · L~(-1) · s~(-1) to (0.30 ±0. 16) kPa · L~(-1) · s~(-1) in the controlled asthma group, from (0.31 ±0. 18) kPa · L~(-1) · s~(-1) to (0. 39 ±0. 17) kPa · L~(-1) · s~(-1) in the partly controlled asthma group (t =3.90 and 4. 68, P <0. 01, respectively). No correlations were observed between the change of R_5-R_(20) after DI and ACT scores, total eosinophil counts, ECP level as well as FE_(NO)(r= -0. 07, 0. 28, -0. 14, 0. 14, P >0. 05). Conclusions Even in asthma patients with controlled disease, eosinophilic inflammation in the airway was still present, and the eosinophilic inflammation became more severe with the decline of control level. Bronchodilatory effect caused by DI disappeared in asthmatic patients. The inflammation profile detected by induced sputum did not reflect the dysfunction of peripheral airways.