AIRWAYS INFLAMMATION IN SUBJECTS WITH CHRONIC-BRONCHITIS WHO HAVE NEVER SMOKED

Background - Smoking is the single most common cause of chronic bronch itis but the disease can also occur in non-smokers. Alterations in the lung responsible for the disease, such as oxidant/antioxidant and pro tease/antiprotease imbalance, have been investigated in smokers. The a im of our study was to evaluate local cellular and soluble factors (al bumin, immunoglobulins, proteases, alpha(1)-antitrypsin, and transferr in) that may be involved in the development of chronic bronchitis in s ubjects who have never smoked. Methods - Sixteen clinically stable pat ients with chronic bronchitis who had never been smokers were studied and 17 healthy non-smokers served as controls. All subjects underwent bronchoalveolar lavage (BAL). Total and differential cell counts and c oncentrations of the main proteins (albumin, immunoglobulins, compleme nt fractions, alpha(1)-antitrypsin, and transferrin) were measured, El astase-like activity was assessed in cells and supernatants. To estima te the oxidant burden the release of superoxide anion (O-2(-)) from na tive cell populations was evaluated. Results - Recovery of BAL fluid w as reduced in older individuals in both the chronic bronchitis and con trol groups. There was no difference in total cell count, but neutroph il percentage count was higher in those with chronic bronchitis (media n (range) 3.5 (1.6-14.2)) than in controls (1.3 (0.5-3.7)). These diff erences were most pronounced in the first recovery, representative of the bronchial lavage. There was no difference in bronchial epithelial cells. Total proteins and albumin levels were comparable and IgG, IgA, IgM, C3, C4, transferrin and alpha(1)-antitrypsin values standardised to albumin did not show any significant differences. No differences i n elastase-like levels in supernatants were detected. In cell lysates elastase-like activity x 10(7) cells (macrophages + neutrophils) was i ncreased in patients with chronic bronchitis (0.25 (0.06-4.3) compared with controls 0.08 (0.03-0.9) mu g PPEeq). The release of O-2(-) both at base-Line and after opsonised zymosan phagocytosis did not show an y differences. Correlation analysis between FEV(1) and BAL fluid data showed a negative correlation only with neutrophils/ml. Conclusions - Clinically stable nonsmokers with chronic bronchitis show no alteratio ns of local immune components, oxidant burden, and free elastase-like activity in BAL fluids, while the content of elastase-like activity in phagocytic cells is increased. As in smokers, bronchial neutrophilia is the most significant cellular modification which correlates with th e degree of airflow obstruction.