Department of Respiratory Medicine, Kyoto University, Kyoto, Japan.
Respiration. 2011;82(5):431-8. doi: 10.1159/000330419. Epub 2011 Aug 12.
Substance P (SP) is involved in the pathogenesis of cough in animal models. However, few studies in humans have been reported and the roles of SP in clinical cough remain obscure.
To clarify the relevance of plasma levels of SP in patients with persistent cough.
We studied 82 patients with cough persisting for at least 3 weeks and 15 healthy controls. Patients were classified as having asthmatic cough (cough-variant asthma and cough-predominant asthma; n = 61) or nonasthmatic cough (n = 21; postinfectious cough, n = 6; gastroesophageal reflux disease, n = 5; idiopathic cough, n = 5, and others, n = 5). Correlations were evaluated between plasma SP levels as measured with ELISA and methacholine airway hyperresponsiveness (airway sensitivity and airway reactivity), capsaicin cough sensitivity, sputum eosinophil and neutrophil counts, and pulmonary function.
Plasma SP levels were significantly elevated in patients with both asthmatic and nonasthmatic cough compared with controls [31.1 pg/ml (range 18.0-52.2) and 30.0 pg/ml (range 15.1-50.3) vs. 15.4 pg/ml (range 11.3-23.7); p = 0.003 and p = 0.038, respectively] but did not differ between the two patient groups (p = 0.90). Plasma SP levels correlated with airway sensitivity (threshold dose of methacholine) in the patients with asthmatic cough (r = -0.37, p = 0.005) but not with airway reactivity, cough sensitivity, FEV1 values, or sputum eosinophil and neutrophil counts in either group.
Increased levels of SP in plasma are associated with persistent cough in humans and might be related to airway sensitivity in asthmatic cough.
P 物质（SP）参与动物模型中的咳嗽发病机制。然而，在人类中报道的研究很少，SP 在临床咳嗽中的作用仍不清楚。
阐明持续性咳嗽患者血浆 SP 水平的相关性。
我们研究了 82 例持续咳嗽至少 3 周的患者和 15 例健康对照者。患者分为哮喘性咳嗽（咳嗽变异性哮喘和以咳嗽为主的哮喘；n=61）或非哮喘性咳嗽（n=21；感染后咳嗽，n=6；胃食管反流病，n=5；特发性咳嗽，n=5 和其他，n=5）。用 ELISA 法测定血浆 SP 水平，并与乙酰甲胆碱气道高反应性（气道敏感性和气道反应性）、辣椒素咳嗽敏感性、痰嗜酸性粒细胞和中性粒细胞计数以及肺功能进行相关性评估。
与对照组相比，哮喘性和非哮喘性咳嗽患者的血浆 SP 水平均显著升高[31.1pg/ml（范围 18.0-52.2）和 30.0pg/ml（范围 15.1-50.3）与 15.4pg/ml（范围 11.3-23.7）；p=0.003 和 p=0.038]，但两组患者之间无差异（p=0.90）。血浆 SP 水平与哮喘性咳嗽患者的气道敏感性（乙酰甲胆碱的阈值剂量）相关（r=-0.37，p=0.005），但与气道反应性、咳嗽敏感性、FEV1 值或两组的痰嗜酸性粒细胞和中性粒细胞计数均无关。
血浆中 SP 水平升高与人类持续性咳嗽有关，可能与哮喘性咳嗽的气道敏感性有关。
