哮喘联盟

   摘要
   背景：过敏性咳嗽可能与上呼吸道咳嗽综合症(UACS)的发病机制有关。本研究旨在研究UACS患者过敏性咳嗽中，辣椒素敏感的咳嗽受体在咽喉和下呼吸道的作用。
   材料和方法：研究入组了59例UACS患者，33例鼻炎/鼻窦炎不伴咳嗽患者，39例健康志愿者。对所有人员检测基线以及利多卡因咽喉麻醉后的咳嗽阈值C5（咳嗽阈值C5定义为在辣椒素暴露下，导致³5次咳嗽的所需最低辣椒素浓度）。诱导痰细胞学检测后，采用ELISA法检测诱导痰液中的组胺、前列腺素E-2(PGE2)和降钙素基因相关肽(CGPR)。15例UACS患者成功治疗后，再次检测痰细胞学和以上介质。
   结果：UACS组的辣椒素C5值显著低于鼻炎/鼻窦炎组和健康对照组[3.9 (0.98, 7.8) µmol/L vs. 7.8 (3.9, 93.75) µmol/L vs. 31.2 (15.6, 62.5) µmol/L, H=40.12, P=0.000]。在3组研究对象中，利多卡因咽喉麻醉可显著增加辣椒素C5值且增加程度相似，但UACS组的增加值仍为最低且诱导痰组胺、PGE2和CGRP水平增加。当西替利嗪单药或联合红霉素治好咳嗽后，15例UACS患者诱导痰中CGRP和组胺水平显著降低、细胞分类计数或诱导痰PGE2水平无明显变化。
   结论：喉部TRPV1在过敏性咳嗽中其重要作用，但是下呼吸道辣椒素敏感咳嗽受体致敏可能对UACS患者过敏性咳嗽更为重要。
 

（刘国梁 审校）
Med Sci Monit. 2013 Dec 3;19:1095-101. doi: 10.12659/MSM.889118.

Capsaicin-sensitive cough receptors in lower airway are responsible for cough hypersensitivity in patients with upper airway cough syndrome.

Yu L, Xu X, Wang L, Yang Z, Lü H, Qiu Z.

ABSTRACT
BACKGROUND：Cough hypersensitivity may be related to the pathogenesis of upper airway cough syndrome (UACS). The purpose of the study was to investigate the role of capsaicin-sensitive cough receptors on the laryngopharynx and lower airway in the cough hypersensitivity of patients with UACS.
MATERIAL AND METHODS：59 patients with UACS, 33 patients with rhinitis/sinusitis without cough, and 39 healthy volunteers were recruited for the study. Cough threshold C5, defined as the lowest concentration of capsaicin required for the induction of ³5 coughs upon esposure to capsaicin, were determined at baseline and after laryngopharngeal anesthesia with lidocaine in all the subjects. After induced sputum cytology, the concentrations of histamine, prostaglandin E2 (PGE2), and calcitonin-gene-related peptide (CGPR) in the induced sputum were measured by ELISA. In 15 patients with UACS, sputum cytology and measurement of the above mediators were repeated after successful therapy.
RESULTS： C5 response to capsaicin was significantly lower in the UACS group than in the rhinitis/sinusitis group and healthy control groups [3.9 (0.98, 7.8) µmol/L vs. 7.8 (3.9, 93.75) µmol/L vs. 31.2 (15.6, 62.5) µmol/L, H=40.12, P=0.000]. Laryngopharngeal anesthesia with lidocaine dramatically increased C5 to capsaicin in the subjects of all 3 groups by a similar degree, but the increase in the UACS group was still the lowest, with an increased level of histamine, PGE2, and CGRP in the induced sputum. When cough resolved with the treatment of cetirizine alone or in combination with erythromycin, the levels of CGRP and histamine in the induced sputum decreased significantly in 15 patients with UACS, with no obvious change in cell differential or concentration of PGE2 in the induced sputum.
CONCLUSIONS：Laryngeal TRPV1 plays an important role in cough sensitivity, but sensitization of capsaicin-sensitive cough receptors in the lower airway may be more responsible for the cough hypersensitivity in patients with UACS.
 

Med Sci Monit. 2013 Dec 3;19:1095-101. doi: 10.12659/MSM.889118.