The role of fibronectin in bronchoalveolar lavage fluid of asthmatic patients

Allergic and chronic inflammation of the airway is regarded as the main pat hogenesis of bronchial asthma, in which adhesion of inflammatory cells requ ires the expression of adhesion molecules. Thus, to clarify the role of fib ronectin (FN) in the airway inflammation of bronchial asthma, FN levels in plasma and bronchoalveolar lavage fluid (BALF) from bronchial asthmatics we re determined. FN concentrations in plasma and BALF were measured by enzyme -linked immunosorvent assay (ELISA) in 17 asthmatic patients and 10 healthy controls to elucidate the role of FN in allergic inflammation, The mean FN /albumin (Alb) level in the BALF of asthmatic patients was 2.973 mug/mg, wh ich was significantly higher than that of healthy controls (0.727 mug/mg). Non-atopic asthmatics showed a significantly higher level of FN in their BA LF in comparison with atopic asthmatics, although the ratio of FN to albumi n showed no significant difference. FN levels in BALF correlated significan tly with total cell density (r = 0.71, P < 0.05) and alveolar macrophage de nsity (r = 0.64, P < 0.05), FN levels in plasma did not correlate with thos e in BALF, In conclusion, increased FN in BALF, which was produced locally in the airways of asthmatic patients, is actively involved in the regulatio n of allergic inflammation.