DIFFERENT ROLES OF HISTAMINE AND LEUKOTRIENE C-4 IN THE AIRWAYS BETWEEN PATIENTS WITH ATOPIC AND NONATOPIC ASTHMA

The release of histamine and leukotriene C-4 (LTC4) from bronchoalveol ar lavage (BAL) cells and peripheral blood stimulated with Ca ionophor e A231 87 was compared between atopic and nonatopic asthma. The propor tion of basophilic cells in BAL fluid was significantly higher in atop ic than in nonatopic asthma (p < 0.01); however, no significant differ ences were present in the other BAL cells between the two asthma types . The concentration of histamine in BAL fluid was significantly higher in younger patients (20-59 years) with atopic than in nonatopic asthm a (p < 0.01). In contrast, the concentration of LTC4 was significantly higher in nonatopic than in younger patients with atopic asthma (p < 0.01). The release of histamine from BAL cells (p < 0.001) and periphe ral blood (p < 0.01) was significantly larger in younger patients with atopic than in nonatopic asthma. The generation of LTC, by BAL cells was significantly larger in nonatopic than in younger (p < 0.01) and o lder patients with atopic asthma (60+ years) (p < 0.05). These results suggest that both histamine and LTC4 participate in the onset mechani sm of atopic asthma, and only LTC4 participates in that of nonatopic a sthma.