Immune-complex mediated colitis in rabbits. An experimental model

Abstract

An experimental colitis in rabbits is described, following the intravenous injection of preformed immune complexes of human serum albumin (HSA) and anti-HSA into non-sensitised rabbits. Tissue damage was localised to the colon by the Auer technique of inducing local non-specific inflammation, by the rectal instillation of dilute formalin. Formalin alone gave transient changes that reverted to normal within 24 hours. In rabbits given intravenous immune complexes formed in antigen-excess, a severe colitis was initiated, with histological features including mucosal ulceration, mixed inflammatory cell infiltration in the lamina propria, and crypt abscess formation. It is possible that immune-complex damage may be one of the pathogenic mechanisms involved in human ulcerative colitis.