Comparison of antigen-induced leukotriene and histamine release from nasal scrapings in allergic rhinitis.
BACKGROUND: In the early phase response of allergic rhinitis, the nasal mucosa produces important mediators including histamine and leukotrienes. OBJECTIVE: To investigate the relationship between antigen-induced leukotriene release and histamine secretion in nasal scrapings. METHODS: Using nasal mucosal scrapings from patients sensitized to only house dust mite, we studied the time course of antigen-induced leukotriene release and its relationship to histamine release. RESULTS: Cumulative peptydyl leukotriene (LT) production from nasal scrapings increased from 10 min to approximately 90 min following exposure to mite antigen. The rate of LT release was small (<5 pg/10 min) until 10 min following antigen exposure, increased to approximately 250 to 350 pg LT/10 min from 10 to 45 min post exposure, was reduced to <100 pg/10 min by 60 to 150 min, and by 180 min LT production was negligible. By contrast, histamine secretion began 30 sec after antigen exposure and was complete within approximately 10 min. Net antigen-induced LT secretion strongly correlated (R=0.72) with net antigen induced histamine secretion with a ratio of 1:8.7. In addition, net LT/ng histamine and total LT secretion correlated well with antigen-specific IgE in serum, and with the patients' symptoms. CONCLUSION: There is a close relationship between amounts of histamine and LT secretion from antigen challenged nasal mucosa, although the time course of LT release is delayed. In the early phase response, LT are likely to be generated from mucosal mast cells, and thus, mast cell activation will provide an important therapeutic target.