Increased serum levels of alpha-2-macroglobulin in severe chronic airflow obstruction

Serum levels of alpha-2-macroglobulin, the major proteinase inhibitor besides alpha-1-antitrypsin, were investigated in 20 patients with severe Chronic Airflow Obstruction (CAO), as compared to 20 age- and sex-matched controls. Alpha-2-macroglobulin was assessed by rocket immuno-electrophoresis, and alpha-1-antitrypsin by a laser-nephelometric method. All patients had spirometric values determined, including diffusing capacity. The reversibility test for isoprenalin was performed. Alpha-2-macroglobulin levels were found to be significantly elevated in patients with CAO, even when two patients with alpha-1-antitrypsin deficiency were omitted from the statistical evaluation. Except for these two patients, there was no difference in alpha-1-antitrypsin level between the patients and the control group. It is concluded that elevated levels of alpha-2-macroglobulin are associated with the development of severe CAO and emphysematous lesions, also in the absence of alpha-1-antitrypsin deficiency.