Serum acute-phase glycoproteins and immune complexes in relation to smoking and respiratory symptoms: an epidemiological study.

A nephelometric assay of concanavalin A binding was used to measure serum acute-phase glycoproteins in young conscripts, in middle-aged males, and in adults with persistent respiratory symptoms. The findings in conscripts, irrespective of the smoking status, did not differ from those in blood donors, whereas, a strikingly higher portion (38%) of the middle-aged heavy smokers exhibited elevated values. In subjects with persistent respiratory symptoms the corresponding figure was even higher (52%), but no difference was recorded between smokers and non-smokers. Elevated amounts of circulating immune complexes, as measured by conglutinin-binding assay, were detected in 6% of the middle-aged males and in 20% of the subjects with persistent respiratory symptoms.