Organization of the Bronchial Associated Lymphoid Tissue (BALT) of the Dromedary Camel (camelus Dromedarius)

The BALT is an organized lymphoid tissue in the mucosa of the bronchi and bronchioles that samples antigens leading to lymphocytes stimulation. This vital structure was studied in different species but not in the camel. Therefore this work studied the bronchi and bronchioles of 14 healthy camels of different ages (10 months - 12 years) using light and transmission electron microscope. BALT was regularly present in all specimens studied. It was variable in locations and structures. BALT was found in the form of patches across the circumference of the bronchial tree in the form of loose lymphocytic aggregations to a well organized lymphoid tissue with secondary lymphoid follicles. It was localized in the lamina propria and sub mucosa or even the adventitia. At the margin of BALT, several high endothelial venules and lymphatics were localized. The BALT associated epithelium was formed from ordinary pseudo-stratified columnar ciliated epithelium with goblet cells in the bronchi and simple columnar in the bronchioles. Interepithelial lymphocytic infiltration of variable number was observed.