Chang A B, Hills Y C, Cox N C, Cleghorn G J, Valery P C, Lewindon P J, Ee L C, Withers G D, Beem C, Hills B A
Department of Respiratory Medicine, Royal Children's Hospital, Queensland, Australia.
Intern Med J. 2006 Apr;36(4):226-30. doi: 10.1111/j.1445-5994.2006.01041.x.
Dipalmitoylphosphatidycholine (DPPC) is the characteristic and main constituent of surfactant. Adsorption of surfactant to epithelial surfaces may be important in the masking of receptors. The aims of the study were to (i) compare the quantity of free DPPC in the airways and gastric aspirates of children with gastroesophageal reflux disease (GORD) to those without and (ii) describe the association between free DPPC levels with airway cellular profile and capsaicin cough sensitivity.
Children aged <14 years were defined as 'coughers' if a history of cough in association with their GORD symptoms was elicited before gastric aspirates and nonbronchoscopic bronchoalveolar lavage (BAL) were obtained during elective flexible upper gastrointestinal endoscopy. GORD was defined as histological presence of reflux oesophagitis. Spirometry and capsaicin cough-sensitivity test was carried out in children aged >6 years before the endoscopy.
Median age of the 68 children was 9 years (interquartile range (IQR) 7.2). Median DPPC level in BAL of children with cough (72.7 microg/mL) was similar to noncoughers (88.5). There was also no significant difference in DPPC levels in both BAL and gastric aspirates of children classified according to presence of GORD. There was no correlation between DPPC levels and cellular counts or capsaicin cough-sensitivity outcome measures.
We conclude that free DPPC levels in the airways and gastric aspirate is not influenced by presence of cough or GORD defined by histological presence of reflux oesophagitis. Whether quantification of adsorbed surfactant differs in these groups remain unknown. Free DPPC is unlikely to have a role in masking of airway receptors.
二棕榈酰磷脂酰胆碱（DPPC）是表面活性剂的特征性主要成分。表面活性剂吸附于上皮表面可能在受体掩盖方面具有重要作用。本研究的目的是：（i）比较胃食管反流病（GORD）患儿与非GORD患儿气道和胃吸出物中游离DPPC的量；（ii）描述游离DPPC水平与气道细胞特征及辣椒素咳嗽敏感性之间的关联。
在择期进行的可弯曲上消化道内镜检查期间，在获取胃吸出物和非支气管镜下支气管肺泡灌洗（BAL）之前，如果有与GORD症状相关的咳嗽病史，则将<14岁的儿童定义为“咳嗽者”。GORD定义为反流性食管炎的组织学表现。在>6岁的儿童内镜检查前进行肺功能测定和辣椒素咳嗽敏感性试验。
68名儿童的中位年龄为9岁（四分位间距（IQR）7.2）。咳嗽患儿BAL中的中位DPPC水平（72.7μg/mL）与不咳嗽患儿（88.5）相似。根据是否存在GORD分类的儿童，其BAL和胃吸出物中的DPPC水平也无显著差异。DPPC水平与细胞计数或辣椒素咳嗽敏感性结果指标之间无相关性。
我们得出结论，气道和胃吸出物中的游离DPPC水平不受咳嗽或由反流性食管炎组织学表现定义的GORD的影响。这些组中吸附的表面活性剂定量是否不同仍不清楚。游离DPPC不太可能在气道受体掩盖中起作用。
