AIRWAY ISOCYANATE-ADDUCTS IN ASTHMA INDUCED BY EXPOSURE TO HEXAMETHYLENE DIISOCYANATE

Objectives The clinical features, airway histology, and detection of h examethylene diisocyanate (HDI) protein adducts in endobronchial biops ies from a patient with HDI asthma are described. Methods Isocyanate a sthma was diagnosed by history, methacholine challenge, and workplace HDI challenge. Bronchoscopy was performed 24 h after challenge and imm unohistochemical staining was performed. Results Airway biopsies obtai ned at bronchoscopy demonstrated inflammatory changes typical for asth ma, including increased airway eosinophils and T cells. Immunohistoche mical staining with specific anti-HDI antibodies demonstrated the pres ence and localization of HDI adducts in human bronchial biopsies. Conc lusions These studies confirm epithelial exposure to HDI following wor kplace challenge and demonstrate the feasibility of detecting and loca lizing isocyanate adducts in human lung tissue. identifying and charac terizing the airway macromolecules to which isocyanates bind in vivo a re probably crucial to the understanding of how isocyanates cause sens itization and asthma. The ability to detect isocyanate adducts may als o help characterize isocyanate exposure patterns and exposure-disease relationships.