Effects of smoking and age on serum levels of immune-reactive proteins altered in cancer patients.

In patients with solid malignancies, such as those associated with chronic smoking, levels of immunosuppressive acute-phase proteins (haptoglobin, alpha 1-acid glycoprotein, alpha 1-antitrypsin) are increased and correlate directly with extent of tumor and inversely with immune reactivity. Other serum proteins with immunorestorative properties (alpha 2HS-glycoprotein, prealbumin) are decreased and correlate directly with immune reactivity. Serum levels of these glycoproteins and albumin were measured in normal volunteers (132 cigarette smoking and 140 nonsmoking) to determine the effects of smoking history, age, and sex on protein levels. The alpha 1-acid glycoprotein increased, whereas albumin decreased with age in both groups, and haptoglobin increased with age in smokers. The alpha 1-acid glycoprotein, haptoglobin, and albumin levels also correlated with the extent of smoking (pack-years). In a comparison of age- and sex-matched smokers and nonsmokers, alpha 1-antitrypsin uniquely and significantly increased (P less than 0.001) in smokers but was not related to age or extent of smoking. The diagnostic and immunological implications of smoking and age-related changes in serum protein levels are discussed.