SERUM IGE IN NONATOPIC SMOKERS, NONSMOKERS, AND RECENT EXSMOKERS - RELATION TO LUNG-FUNCTION, AIRWAY SYMPTOMS, AND ATOPIC PREDISPOSITION

The influence of smoking on serum IgE (s-IgE) was studied in a selected nonatopic population. The variation in s-IgE was followed during 1 year of smoking abstinence. The study included 287 smokers and 137 never smokers. IgE was higher in smokers compared with IgE in never smokers (p < 0.005). Male smokers had higher s-IgE than female smokers (p < 0.01). S-IgE was independent of age and claims of atopy among first-degree relatives. Weighted pack-years consumption was defined for cigarette smokers by modifying pack-years consumption by nicotine content of the brand smoked. Weighted pack-years consumption was associated with level of s-IgE (p < 0.05). S-IgE was higher in smokers with airway symptoms compared with that in smokers without symptoms (p < 0.01). In smokers older than 50 years of age, there tended to be decreased FEV1 residuals (0.05 < p < 0.06), and presence of airway symptoms was (p < 0.03) associated with high levels of s-IgE independent of each other. In 92 quitters, s-IgE increased during the first 26 weeks of abstinence (p < 0.05), and after 1 year, s-IgE had returned to baseline. The increase was only observed in smokers younger than 40 years and had no relation to variations in FEV1 during the 1-year follow-up. The increase in s-IgE after smoking cessation was transient, of minor clinical importance, and probably caused by a relief from an immunosuppressive influence.