Sodium cromoglycate attenuates pulmonary inflammation without influencing bronchial responsiveness in healthy subjects exposed to organic dust

Background Inhalation of organic dust from a pig house induces airway inflammation and increases bronchial responsiveness to methacholine in healthy subjects. Objective To study whether sodium cromoglycate influences the airway inflammatory reaction and the increase in airway responsiveness induced by inhalation of organic dust. Methods Bronchoalveolar and nasal lavages, and bronchial methacholine challanges were performed and blood samples were drawn in 32 healthy subjects before and after exposure to dust in a pig farm. Sodium cromoglycate was inhaled (20 mg, twice a day) and administered intranasally (5.2 mg, twice a day) by 16 and a corresponding placebo was given to the other 16 healthy controls for two weeks prior to exposure. Results Exposure induced a significant increase in inflammatory cells and soluble components (pro-inflammatory cytokines, inflammatory mediators) in bronchoalveolar and nasal lavage fluid in both groups. The increase in neutrophils, interleukin (IL)-6 and tumour necrosis factor (TNF)-alpha as well as myeloperoxidase and soluble intracellular adhesion molecule (ICAM)-1 in bronchoalveolar lavage (BAL) fluid was significantly reduced by treatment with sodium cromoglycate. Although sodium cromoglycate inhalation largely influenced a variety of inflammatory indices in bronchoalveolar lavage fluid it had no effect on the increase in bronchial responsiveness to methacholine. Conclusion Sodium cromoglycate alters the airway inflammatory response to inhaled organic dust without influencing the dust-induced increase in bronchial responsiveness to methacholine.