Lalloo U G, Lim S, DuBois R, Barnes P J, Chung K F
Respiratory Unit, University of Natal, Durban, South Africa.
Eur Respir J. 1998 Mar;11(3):702-5.
Cough is a common presenting symptom of interstitial lung disease (ILD). The aim of this study was to examine the cough reflex in patients with progressive systemic sclerosis (PSS), with and without associated ILD. The cough reflex to inhalation of chloride deficient solutions and capsaicin was determined in patients with PSS with associated ILD (n=12), compared to patients with PSS without ILD (n=12). In addition, patients with a chronic dry cough (n=12) and healthy subjects (n=10) without cough were studied. Cough responses to inhalation of isotonic solutions containing 150, 75, 37.5 and 0 mM Cl- ions and of capsaicin (0.9-500 mM) were measured. PSS patients with ILD reported a significantly higher cough score than PSS patients without ILD (p<0.03). ILD patients coughed more than those without ILD to Cl- of 37.5 and 0 mM (19.1+/-5.0 vs 6.2+/-1.9 coughs x min(-1) (p<0.03), and 29.2+/-5.0 vs 14.1/-4.1 coughs x min(-1) (p<0.04), respectively). The log concentration of capsaicin causing two or five coughs was lower in PSS with ILD compared to PSS without ILD (0.74+/-0.15 mM vs 2.12+/-0.26 mM; p<0.002). Patients with chronic dry cough had a similar degree of response to low-chloride and capsaicin solutions as patients with PSS and ILD, whilst healthy controls had a similar degrees of response to PSS patients. There is an increased cough reflex in patients with interstitial lung disease, which may represent sensitization of airway sensory nerves. This may be the basis for the chronic dry cough in patients with interstitial lung disease.
咳嗽是间质性肺疾病（ILD）常见的就诊症状。本研究旨在检查进行性系统性硬化症（PSS）患者（伴有或不伴有相关ILD）的咳嗽反射。测定了伴有ILD的PSS患者（n = 12）吸入缺氯溶液和辣椒素后的咳嗽反射，并与不伴有ILD的PSS患者（n = 12）进行比较。此外，还研究了慢性干咳患者（n = 12）和无咳嗽的健康受试者（n = 10）。测量了吸入含150、75、37.5和0 mM Cl-离子的等渗溶液以及辣椒素（0.9 - 500 mM）后的咳嗽反应。伴有ILD的PSS患者报告的咳嗽评分显著高于不伴有ILD的PSS患者（p < 0.03）。ILD患者对37.5 mM和0 mM Cl-的咳嗽次数多于无ILD患者（分别为19.1±5.0次/分钟 vs 6.2±1.9次/分钟（p < 0.03），以及29.2±5.0次/分钟 vs 14.1±4.1次/分钟（p < 0.04））。与不伴有ILD的PSS相比，伴有ILD的PSS中引起两次或五次咳嗽的辣椒素对数浓度更低（0.74±0.15 mM vs 2.12±0.26 mM；p < 0.002）。慢性干咳患者对低氯和辣椒素溶液的反应程度与伴有ILD的PSS患者相似，而健康对照与PSS患者的反应程度相似。间质性肺疾病患者的咳嗽反射增强，这可能代表气道感觉神经的致敏。这可能是间质性肺疾病患者慢性干咳的基础。
