Proinflammatory mediators in nasal lavage of subjects with occupational rhinitis

We sought to investigate the type and kinetics of late-phase nasal inflammatory response after nasal challenge with occupational allergens. Participants were 10 subjects experiencing work-related rhinitis symptoms who underwent specific inhalation challenge and tested positive for occupational rhinitis. During challenge, we monitored changes in inflammatory cells, eosinophil cationic protein, myeloperoxidase, and interleukin-8 in nasal lavage samples. The challenge with the active agent induced a significant increase in the percentage of eosinophils at 30 minutes as compared with prechallenge values (P = 0.04). A significant increase in eosinophil cationic protein levels after challenge with the control (P = 0.01) and active agent (P = 0.02) was observed in the late phase after challenge. No significant changes in nasal levels of neutrophils, myeloperoxidase, and interleukin-8 were observed on both control and active challenge days. Our results suggest a predominant nasal eosinophilic inflammatory response after occupational allergen challenge.