Enhanced leukotriene generation adn bronchial hyperresponsiveness in asthmatics with allergic rhinitis

Rhinitis frequently precedes asthma, and treating allergic rhinitis has benefi-cial effects on asthma, suggesting upper airway disease ia a risk factor for asthma. The aim of the present study was to investigate the influence of allergic rhinitis on se-rum IgE level, leukotriene generation by peripheral leukocytes, and bronchial hyperresponsiveness (BHR) to methacholine in patients with atopic asthma. Seventy-one asthmatic subjects (mean age, 59.5±12.5, years ; 37 women, 34 men) were recruited, and 48 asthmatics had allergic rhinitis and 23 asthmatics did not have allergic rhinitis. The log10 (Dmin) was significantly lower for those with allergic rhinitis than those with-out allergic rhinitis (P<0.05), implying that those with allergic rhinitis developed BHR to a greater degree than those without allergic rhinitis. LTC4 generation from periph-eral leukocytes was significantly greater for atopic astmatics with allergic rhinitis than those without allergic rhinitis (p<0.05). In contrast, the amount of LTB4 produced from peripheral leukocytes did not significantly differ between asthmatic patients with and without allergic rhinitis. These results suggest that the presence of allergic rhinitis enhances BHR by enhancing LTC4 production. while the presence of allergic rhinitis did not affect LTB4 production in patients with atopic asthma.

アレルギー鼻炎は気管支喘息のリスクファクターの一つであると考えられている｡しばしば喘息に先行して発症し,その治療を行うことは喘息の治療に有用であることが報告されている｡我々は本検討において,アトピー性瑞息71例(平均年齢59.5±12.5歳,女性37例,男性34例)を対象としアレルギー性鼻炎の有無によって2群に分類し,血清IgE値,末梢白血球のロイコトリエン産生能,メサコリンに対する気道過敏性を測定し,2群間で比較検討した｡対象症例中,48例はアレルギー鼻炎を合併し,23例はアレルギー鼻炎を合併していなかった｡アレルギー性鼻炎非合併例に比較してアレルギー性鼻炎合併例において,気道過敏性は有意に克進していた(p<0.05)｡末梢血白血球のLTC4産生能も同様に,アレルギー性鼻炎非合併例に比較してアレルギー性鼻炎合併例において有意に克進していた(p<0.05)｡しかし,末梢血白血球のLTB4産生能は,両群間で有意の差を認めなかった｡以上より,アレルギー性鼻炎の存在が末梢血白血球のⅠ:TC4産生克進を介して,気道過敏性の克進に関連している可能性が示唆された｡