Lymph node histopathological studies in a combined adjuvant–collagen induced arthritis model in albino rat Rattus rattus

There are at least 16 types of collagen. Antibodies, to collagens, in particular to types I and II have been reported in a number of autoimmune diseases. In this study, we used rat and bovine collagens to study the effects of anti-collagen antibodies on the lymphoid organs of rats Histological examination of the lymph node sections showed that immunization with different collagen types combined with the adjuvant used in this study induced arthritis and immune reaction in lymph nodes. The degrees of the disease symptoms and immune reaction depended on the foreignness of the stimulating collagen and on whether it was accompanied with adjuvant. Anti-collagen antibodies led to a decrease in the thickness of the lymph node cortex and atrophy, with medullary hyperplasia, small granulomas appeared in the section. Immunizing with either bovine collagen or BSA has shown a remarkable distortion in architecture appeared, follicular hyperplasia and reactive inflammatory hyperplasia of the LN. Passive transfer of rat anti-rat collagen antibodies either accompanied with Freund’s adjuvant or not with a lesser degree of severity, resulted in epithelioid cells forming granuloma surrounded by collar of lymphocytes, scattered apoptotic bodies, lymphatic sinus ectasia accompanied with lymphoid follicles atrophy. The results of our study present a reliable model for collagen induced arthritis which is suitable for the investigation of the mechanism of disease induction and treatment approaches.