Experimental study for the mechanism of gastroesophageal-reflux-associated asthma.

Epidemiologic studies have shown a strong association between gastroesophageal reflux (GER) and asthma, especially in children. Diagnosing GER can be difficult in some patients when GER presents solely with asthma. The aim of this study was to explore the relationship between GER and asthma with animal model. Sixty rats were randomly divided into six equal groups, GER group, GER-associated-asthma group, allergic asthma group, and their control groups. The cytokine levels and concentration of inflammatory cells in bronchoalveolar lavage (BAL) were determined. The BAL of the rats with allergic asthma contained higher concentration of Interleukin-5 (IL-5) and more eosinophils than those of rats with GER-associated-asthma. This demonstrates that assaying the concentrations of IL-5 and inflammatory cells in BAL may be an effective method of distinguishing GER-associated asthma from allergic asthma.