The effects of spa therapy for asthmatics with a long history of cigarette smoking were studied, compared with the effects for those without smoking history. 1. Of 22 patients with smoking history, 15 (68.2%) had definite efficacy of spa therapy (4 had marked efficacy, and 11 had moderate efficacy), and the residual 7 had slight or no efficacy. In contrast, of 36 patients without smoking history, 29 (80.6%) had definite efficacy. The effects of spa therapy for asthmatics were significantly higher in never-smokers than in ex-smokers.
2. A significant increase in the production of IgE antibodies, bronchial hyperresponsiveness and the generation of leukotrienes B₄ (LTB₄) and C₄ (LTC₄) by leucocytes was observed in ex-smokers compared with never-smokers. 3. The frequency of patients with a positive BAST against inhalant allergens was larger in subjects with slight or no efficacy than in those with marked or moderate efficacy in never-smokers, but not in ex-smokers. 4. Bronchial hyperresponsiveness was significantly increased in patients with slight or no efficacy than in those with marked or moderate efficacy both in ex-smokers and never-smoker. 5. The generation of LTB₄ was more increased in subjects with slight or no efficacy than in those with efficacy both in ex-smokers and never-smokers, however, the differences were not significant. 5. The generation of LTC₄ tended to be more increased in subjects with slight or no efficacy than in those with efficacy in never-smokers, but not in ex-smokers, although these were not significant. The results suggest that an increase in the production of IgE antibodies, bronchial hyperresponsiveness, and the generation of LTB₄ and LTC₄, which might be influenced by cigarette smoking, affect the effects of spa therapy for patients with asthma.