Study on polymorphonucleocytal elastase-alpha 1-protease inhibitor complex in bronchoalveolar lavage fluid (BALF)

The purpose of the present study is to determine polymorphonucleocytal elastase-alpha 1-protease inhibitor complex in bronchoalveolar lavage fluid (BALF) in order to investigate the clinical significance of the increased complex in BALF. BALF was collected by the usual method using a bronchial fiberscope and concentrated 5-10 folds by Amicon UM-2 ultrafiltration. Determination of the complex in BALF and plasma was made in accordance with the method of Neumann et al. The level of complex (microgram/mg albumin, mean value) in BALF was 0.38 in healthy non-smokers (n = 5), 3.14 in healthy smokers (n = 6), 5.61 in the patients with chronic obstructive pulmonary disease (COPD) (n = 9) and 1.78 in the patients with idiopathic pulmonary fibrosis (IPF) (n = 15), that is, higher in healthy smokers and COPD and IPF patients. The ratio of the complex in BALF vs plasma was higher in healthy smokers and in COPD patients than in healthy non-smokers. Furthermore, there was a positive correlation between the level of this complex in BALF and the number of PMN in BLAF (r = 0.68, p less than 0.01). From the above it was assumed that the release of elastase from PMN is progressed in the lower airway of smokers and COPD patients.