Antileukoprotease in sputum during bronchial infections.

Production of sputum and concentrations of antileukoprotease (ALP) in sputum were serially measured in hypersecreting patients with recurrent or chronic bronchial infections. Patients with stable continuous mucoid (n = 4) or purulent (n = 5) secretions had constant sputum concentrations of ALP and a calculated daily production of 1.4 and 1.9 mg of ALP per 24 hours, respectively. In patients with overt recurrent bronchial infections, production of sputum and the ALP concentration were found to be negatively correlated during treatment with antibiotics (n = 14) and during the coming (n = 5) of an exacerbation. Daily production of ALP was rather constant in these groups (2.4 and 4.8 mg, respectively, per 24 hours). While ALP was not behaving like an acute-phase protein, bronchial infection appeared to be a determinant for production of ALP; however, between individual patients with comparable severity of disease, total production of ALP varied over tenfold. Therefore, bronchial infection is not the only factor in determining production of ALP.