Cigarette smoking enhances LTB4 generation by leucocytes associated with bronchial hyperresponsiveness in asthma in the elderly

Abstract : Influence of cigarette smoking on leukotriene 84 (LTB4) generation by leucocytes associated with bronchial hyperresponsiveness was examined in 110 patients with asthma. l. The frequency of positive RAST score for inhalant allergens and LTB4 generation by leucocytes were significantly larger in previous and current smokers than in nonsmokers. 2. In nonsmokers, bronchial hyperresponsiveness was significantly higher in asthmatics under the age of 49 years compared with that in patients between 50 and 59 years, between 60 and 69 years, and those over age 70 years. In contrast, no significant differences were present between bronchial hyperresponsiveness and patient age in previous and current smokers. 3. In patients over age 60, bronchial hyperresponsiveness was significantly higher in previous and current smokers than in nonsmokers. In these patients, LTB4 generation was significantly more increased in previous and current smokers than in nonsmokers. 4. A significant correlation was observed in asthmatics of nonsmokers between LTB4 generation and bronchial hyperresponsiveness . 5. LTC4 generation was significantly higher in previous and current smokers than in nonsmokers in patients under age 49 years. These results show that in patients over age 60 years, cigarette smoking induces an increase in the generation of LTB4, leading to an increase in bronchial hyperresponsiveness .

気管支喘息110例を対象に，長期間の喫煙の気道過敏性および白血球のロイコトリエンB4産生に及ぼす影響について検討した。　 1．吸入抗原に対してRAST陽性を示す症例の頻度および白血球のLTB4産生は，喫煙例において非喫煙例に比べ有意に高い値を示した。　 2．非喫煙例においては、その気道過敏性は49才以下の症例において50－59才，60－69才および70才以上の症例に比べ，有意に高い値を示した。しかし，喫煙例においては，年令による気道過敏性の差は見られなかった。　 3．60才以上の症例では，その気道過敏性は非喫煙例に比べ，喫煙例で有意に高い値を示した。このような症例では，LTB4産生能も非喫煙例に比べ喫煙例で有意の亢進が見られた。　 4．非喫煙例では，気道過敏性とLTB4産生との間に有意の相関が見 られた。以上の結果より，60才以上の症例では喫煙がLTB4産生を克進させ，その結果として気道過敏性が亢進してくることが推測された。