Lee M H, Lee J H, Park C H, Ahn Y M, Koh Y Y
Department of Pediatrics, Seoul National University Children's Hospital, Korea.
Ann Allergy Asthma Immunol. 1997 Oct;79(4):363-9. doi: 10.1016/S1081-1206(10)63029-3.
Serum levels of eosinophil cationic protein are an indirect measure of airway inflammation in asthma. It is proposed that the extent to which broncho-constriction or airway inflammation contributes to airflow obstruction in acute asthma may determine responsiveness to bronchodilator therapy.
To test the hypothesis that subjects with acute asthma exacerbations who respond poorly to inhaled bronchodilator treatment may have more marked airway inflammation than those who respond well to identical therapy.
Forty-eight asthmatic children who visited the emergency room due to acute exacerbations were studied. Serum levels of eosinophil cationic protein were measured at the time of acute exacerbations and of clinical remissions. At acute exacerbation, FEV1 was assessed before and after the administration of aerosolized salbutamol.
The mean serum level of eosinophil cationic protein at acute exacerbation (41.1 +/- 12.8 micrograms/L) was significantly higher (P < .01) than that at clinical remission (30.0 +/- 8.5 micrograms/L) in the study population. The level at acute exacerbation was even higher in group A (n = 18: postbronchodilator FEV1 < 75% predicted) than in group B (n = 30: postbronchodilator FEV1 > or = 75% predicted), whereas both groups showed similar levels at clinical remission. The level at acute exacerbation correlated positively with severity of exacerbation (r = .47, P < .01) and negatively with bronchodilator responses (r = -.56, P < .01). This negative correlation was valid among subjects with a similar degree of exacerbation.
A higher level of eosinophil cationic protein at acute asthma exacerbation was associated not only with more severe exacerbation but also with a lower degree of bronchodilator responsiveness. This suggests that degree of airway inflammation may be one determinant of degree of responsiveness to initial bronchodilator therapy at acute asthma exacerbation.
血清嗜酸性粒细胞阳离子蛋白水平是哮喘气道炎症的一项间接指标。有人提出，在急性哮喘中，支气管收缩或气道炎症导致气流阻塞的程度可能决定对支气管扩张剂治疗的反应性。
检验这样一个假设，即对吸入性支气管扩张剂治疗反应不佳的急性哮喘加重患者，其气道炎症可能比反应良好的患者更为明显。
对48名因急性加重而到急诊室就诊的哮喘儿童进行了研究。在急性加重期和临床缓解期测量血清嗜酸性粒细胞阳离子蛋白水平。在急性加重期，在雾化吸入沙丁胺醇前后评估第一秒用力呼气容积（FEV1）。
在研究人群中，急性加重期嗜酸性粒细胞阳离子蛋白的平均血清水平（41.1±12.8微克/升）显著高于临床缓解期（30.0±8.5微克/升）（P<.01）。A组（n = 18：支气管扩张剂治疗后FEV1<预测值的75%）急性加重期的水平甚至高于B组（n = 30：支气管扩张剂治疗后FEV1≥预测值的75%），而两组在临床缓解期的水平相似。急性加重期的水平与加重的严重程度呈正相关（r = .47，P<.01），与支气管扩张剂反应呈负相关（r = -.56，P<.01）。这种负相关在加重程度相似的受试者中是有效的。
急性哮喘加重期较高水平的嗜酸性粒细胞阳离子蛋白不仅与更严重的加重有关，还与较低程度的支气管扩张剂反应性有关。这表明气道炎症程度可能是急性哮喘加重期对初始支气管扩张剂治疗反应程度的一个决定因素。
