Correlation between cell content of bronchoalveolar lavage (BAL) and histologic findings in asthma

We have recently examined the relationship between cell content of bronchoalveolar lavage (BAL) fluid and lung histology in a group of 13 asthmatic subjects during clinical remission. Inflammatory cells in BAL appeared to reflect the severity of the overall inflammatory process of the bronchial mucosa. In the present report we examined whether in asthma the presence of a thickened basement membrane is associated with inflammation of the bronchial mucosa. There was a significantly higher number of inflammatory cells (p less than 0.01) and eosinophils (p less than 0.005) in the submucosa of subjects showing a thickened basement membrane (greater than 7 microns) compared to those having normal basement membrane (less than or equal to 7 microns). These findings seem to support the hypothesis that the degree of thickening of basement membrane in asthma is related to mucosal inflammation.