Gautrin D, Boulet L P, Boutet M, Dugas M, Bhérer L, L'Archevêque J, Laviolette M, Côté J, Malo J L
Department of Chest Medicine, Sacré-Coeur Hospital, Montreal, Quebec, Canada.
J Allergy Clin Immunol. 1994 Jan;93(1 Pt 1):12-22. doi: 10.1016/0091-6749(94)90228-3.
Reactive airways dysfunction syndrome (RADS) or irritant-induced asthma is a syndrome that leaves subjects with asthma-like symptoms after one or more exposures to a high concentration of an irritant substance. The degree of reversibility of airway obstruction in subjects with RADS is nevertheless unknown, as is the degree of associated lesions at the airway level.
We compared the acute reversibility of forced expiratory volume in 1 second (FEV1) after inhalation of albuterol (200 micrograms) in 15 subjects with RADS (12 cases caused by chlorine inhalation) with that of 30 subjects with occupational asthma (OA) caused by various agents. They were paired according to baseline airway obstruction (61% and 63% of predicted value in the RADS and OA groups), requirement for medication (bronchodilator only--7 of 15 subjects with RADS and 14 of 30 subjects with OA--as compared with bronchodilator + inhaled steroids in 8 of 15 subjects with RADS and 16 of 30 subjects with OA, respectively), and interval since removal from exposure (means of 30 and 24 months in the RADS and OA groups). In addition, five nonsmokers with RADS who had not received inhaled steroids underwent bronchoscopy with lavage and bronchial biopsies less than 2 years after the exposure.
The percentage increase in FEV1 over baseline after inhalation of albuterol was 10% +/- 9% in the RADS group and 19% +/- 16% in the OA group (p = 0.005). Only 2 of 15 subjects (13%) with RADS and 12 of 30 subjects (40%) with OA showed an improvement in FEV1 of 20% or greater after inhalation of albuterol. Bronchoalveolar lavage showed an increased number of cells with a predominance of lymphocytes, and biopsy specimens showed increased basement membrane thickness in the five subjects with RADS who underwent bronchoscopy.
Subjects with RADS are generally left with less airway reversibility than those with OA. We suggest that this difference is secondary to distinct pathologic changes.
反应性气道功能障碍综合征(RADS)或刺激性诱导哮喘是一种在一次或多次暴露于高浓度刺激性物质后使患者出现哮喘样症状的综合征。然而,RADS患者气道阻塞的可逆程度以及气道水平相关病变的程度尚不清楚。
我们比较了15例RADS患者(12例因吸入氯气所致)吸入沙丁胺醇(200微克)后1秒用力呼气容积(FEV1)的急性可逆性,以及30例由各种因素引起的职业性哮喘(OA)患者的FEV1急性可逆性。根据基线气道阻塞情况(RADS组和OA组分别为预测值的61%和63%)、用药需求(仅使用支气管扩张剂——15例RADS患者中的7例和30例OA患者中的14例——相比之下,15例RADS患者中的8例和30例OA患者中的16例分别同时使用支气管扩张剂和吸入性类固醇)以及脱离暴露后的时间间隔(RADS组和OA组分别平均为30个月和24个月)对他们进行配对。此外,5例未接受吸入性类固醇治疗的RADS非吸烟患者在暴露后不到2年接受了支气管镜灌洗和支气管活检。
RADS组吸入沙丁胺醇后FEV1较基线增加的百分比为10%±9%,OA组为19%±16%(p = 0.005)。15例RADS患者中只有2例(13%)和30例OA患者中有12例(40%)在吸入沙丁胺醇后FEV1改善20%或更多。支气管肺泡灌洗显示细胞数量增加,以淋巴细胞为主,接受支气管镜检查的5例RADS患者的活检标本显示基底膜厚度增加。
RADS患者的气道可逆性通常比OA患者小。我们认为这种差异继发于不同的病理变化。