Effects of cigarette smoking on the serum concentration of lung surfactant protein A (SP-A)

We have tested the hypothesis that serum surfactant protein A (SP-A) production may be affected by cigarette smoke exposure, and that alterations in serum levels may reflect smoking habits. A total of 52 subjects were divided into the following two groups: active smokers (Group A; n = 23); and nonsmokers (Group B; n = 29). The assessment of smoking habit was determined by self-report, carbon monoxide concentration in expired air, and cotinine concentration in urine. Serum SP-A was compared in both groups and was found to be higher in Group A (active smokers) (p < 0.002). We conclude that surfactant protein A levels are increased in the serum of smokers. However, it was found that this is not a sensitive discriminating factor to separate smokers from nonsmokers.