Changes in serum IgD in cigarette smokers.

Serum IgD levels in 83 healthy adults were measured by a radioimmunoassay technique and analysed according to each subject's smoking habit. The IgD geometric mean in cigarette smokers was twice as high as in non-smokers (408.6 vs 202.0 μg/dl). Serum IgD levels of 1,000 μg/dl or greater were noted in 22% of smokers but in none of the rare smokers or non-smokers. In the smokers group, the highest mean IgD level was found in those who did not actively inhale the smoke (7626 μg/dl), followed by that in moderate smokers (5638 μg/dl), and was lowest in heavy smokers who inhaled the smoke (2830 μg/dl). The number of years a person smoked did not appear to have a significant effect on IgD levels. In exsmokers, the mean IgD level (199.8 μg/dl) was similar to that in non-smokers, suggesting reversibility of the IgD changes following cessation of smoking. It seems prudent that the smoking habit should be taken into consideration in the interpretation of serum IgD levels. [ABSTRACT FROM AUTHOR]