IL-8 and airway neutrophilia in children with gastroesophageal reflux and asthma-like symptoms.

Summary Gastroesophageal reflux (GER) may induce respiratory symptoms (RS) through inhalation of acid gastric contents. To characterize the airway inflammation associated with this condition, 20 children [7.4 (0.9) yr old] with "difficult to treat" RS and a positive 24-h oesophageal pH monitoring (pHm) were studied and bronchoalveolar lavage (BAL) performed. The control group included 10 children [7.3 (1.3) yr], non-atopics, with a respiratory clinical history similar to the cases but no reflux, as demonstrated by a negative 24-h oesophageal pHm. On BAL samples, in addition to inflammatory indexes, the lipid-laden macrophage (LLM) index was determined as index of gastric content inhalation. As compared to controls, GER children had higher neutrophil proportion ( P = 0.0 0 2 ), higher LLM index ( P = 0.0 0 4 ) and higher concentrations of interleukin (IL)-8 ( P = 0.0 0 5 ), myeloperoxidase (MPO) ( P = 0.0 0 1 ) and elastase ( P = 0.0 4 5 ) in BAL fluid. In GER children, but not in controls, neutrophil proportion significantly correlated with LLM index ( r = 0.6 5 , P = 0.0 0 2 ), with IL-8 ( r = 0.6 2 , P = 0.0 0 3 ) and MPO levels ( r = 0.5 4 , P = 0.0 1 4 ) but not with elastase concentrations. These results suggest an active pathogenetic role of IL-8 in the recruitment and activation of neutrophils in the airways of children with GER, respiratory symptoms and BAL findings suggestive of gastric content aspiration.