Difference in the onset mechansisms of attacks between atopic and nonatopic asthma. A role of leukotriene C4

Concentrations of main bronchoconstricting chemical mediators, histamine and leukotriene C4 (LTC4), were measured in bronchoalveolar lavage (BAL) fluid, and when cells (peripheral leukocytes and BAL cells) were stimulated by Ca ionophore A23187, in 7 atopic and 7 nonatopic asthma patients. 1. The proportion of basophilic cells was significantly larger in atopic than in nonatopic asthma (p<0.05), however no significant difference was present in the other BAL cells between the two asthma types. 2. Concentration of histamine in BAL fluid was significantly higher in atopic than that in nonatopic asthma, however, difference in that of LTC4 was not found between them. 4. The release of LTC 4 from BAL cells was higher in nonatopic than that in atopic asthma, but this was not significant. In contrast, the release of histamine was significantly higher in atopic compared to that in nonatopic asthma (p<0.001) when the cells were stimulated by Ca ionophore A23187. These results suggest that both histamine and LTC4 participate in the onset mechanism of atopic asthma, and only LTC4 in that of nonatopic asthma.

気管支喘息患者14人(アトピー型,非アトピー型各7人)につき気管支肺胞洗浄(BAL)液及び気管支肺胞洗浄細胞と末梢血白血球をカルシウムイオノファA23187で刺激し,主要な気管支収縮メディエーターであるヒスタミンとロイコトリエンC4(LTC4)の濃度を測定した｡1.BAL中細胞の比率では好塩基球のみ非アトピー型に比べアトピー型で優位に高い値であった｡(p<0.05) 2.BAL液のヒスタミンの濃度はアトピー型で有意に高い値であったが,ロイコトリエンC4はアトピー型,非アトピー型で有意な差を認めなかった｡3.BAL細胞からのカルシウムイオノファA23187刺激によるロイコトリエンC4産生はアトピー型に比べ非アトピー型で高い値であったが,有意差は認めなかった｡一方,同刺激によるヒスタミン遊離は非アトピー型よりアトピー型で有意 に高値であった｡(p<0.001)｡以上の結果よりアトピ-型の気管支喘息の発症機序にはヒスタミン,ロイコトリエンC4の両者が,非アトピー型に於いてはロイコトリエンC4のみが主として関与していること可能性が示唆された｡