title: Serum and sputum alpha 2 macroglobulin in patients with chronic obstructive airways disease.
abstract: Serum alpha 2 macroglobulin concentrations were measured in patients with chronic obstructive airways disease and an age-matched group of control subjects. The mean serum level of alpha 2 macroglobulin was significantly lower in bronchitic subjects with acute chest infections than the mean value of the controls. No significant differences were observed between serum alpha 2 macroglobulin values in controls, subjects with "emphysema", and bronchitic patients who did not have chest infections. Sputum alpha 2 macroglobulin concentrations were compared in sputum samples from bronchitic patients with and without acute chest infections. The protein was detected (greater than 0.2 mg/l) in 94% of sputum samples from infected subjects but only 60% of non-infected sputum samples. Concentrations of alpha 2 macroglobulin in infected samples were significantly higher than the non-infected samples. Sputum/serum concentration ratios of alpha 2 macroglobulin were also significantly higher in infected samples but this difference was eliminated by "correcting" the values with the albumin sputum/serum ratios of the same samples. The results suggest that alpha 2 macroglobulin concentrations are higher in bronchial secretions during chest infection because of increased transudation from the blood rather than the presence of significant local secretion.
mesh_terms: D000368:Aged; D001991:Bronchitis / Q000097:blood / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011656:Pulmonary Emphysema / Q000097:blood / Q000378:metabolism*; D013183:Sputum / Q000032:analysis*; D000511:alpha-Macroglobulins / Q000032:analysis*
chemical_list: D000511:alpha-Macroglobulins