Bronchial-associated lymphoid tissue (BALT) response to airway challenge with cigarette smoke,bovine antigen and anti-pulmonary serum

Abstract

The bronchial-associated lymphoid tissue (BALT) is a lymphoepithelial organ, related to the immune defence of the lung and to alveolar clearance, which changes size in certain states of disease. Changes in the size of BALT were quantified and compared, and Spearman's test was used to test the relation with the bronchial epithelium. A total of 180 rats were used, divided into 6 groups of 30 as follows: 1) untreated controls; 2) exposed to cigarette smoke for two months; 3) treated with antipulmonary serum three doses daily over five days; 4) exposed to cigarette smoke and treated with antipulmonary serum; 5) sensitized with bovine albumin and exposed to an environment containing this antigen for two months; 6) exposed to cigarette smoke and bovine albumin. The lungs were processed for histological study, and were stained with the PAS-Alcian blue method. The main left bronchi BALT was studied, and the following were quantified: Lymphatic area (LA), as a percentage of the lung surface occupied by BALT; the flat epithelium (FEp), as the length of bronchial epithelium anatomically related to LA, whose cells tend to adopt a flat shape; the Contact epithelium (Cep), as the length of bronchial epithelium which is in direct contact with the LA. A percentage count of bronchial cells was made in the following classifications: globet cells; globet cells stained with the PAS-Alcian blue method; flat cells; lymphoepithelium cells; columnar cells; and bronchial epithelium cells excluding the above two cell types. The most outstanding findings were that, in comparison with the controls, the FEp and CEp had increased in al1 the treated animals, and the CEp of the group treated with bovine albumin + cigarette smoke was the only one in which the difference was Offprint requests to: Dr. D. Juan de Dios Escolar Castellón, Facultad de Medicina, C./ Domingo Miral s/n, 50009 Zaragoza, Spain not significant (p > 0.05). The lymphatic area increased significantly (p < 0.001) in the groups treated with cigarette smoke, anti-pulmonary serum and cigarette smoke + anti-pulmonary serum, and decreased (p > 0.05) in the one treated with bovine albumin. Regression analysis gave good indices in general (Rho > 0.06), the exception being the group treated with cigarette smoke + ALS, in the relations CEpJFEp and CEpILA (Rho < 0.06). The globet ceiis decreased significantly in al1 the treated animals; however, the correlation between globet cells and the other variables did not give good indices (Rho > 0.06). Therefore, it is deduced that BALT can change shape in different conditions, FEp being the variable which increases most. The fa11 in globet ceiis is associated exclusively with the substances which were administered, since no relation was found between these cells and the morphological changes in the BALT.