The role of the immune system in uveitis induced in animals.

The etiological diagnosis in many cases of uveitis is hampered by the lack of insight into the pathogenesis of the disease. Animal models might provide clues for the understanding of the ocular and systemic processes leading to this invalidating disease. The immune system seems to play an important role in the pathogenesis of uveitis. Four main topics i.e. autoimmune phenomena, circulating immune complexes, effects of systemic endotoxin and bacterial or viral uveitis are reviewed. Autoimmune phenomena might cause the recurrence of uveitis after presentation of slightly altered self-antigens to the immune system. The endotoxin induced uveitis might be the initial event of recurrent episodes of uveitis caused by the deposition of immune complexes. Endotoxin might play a role in the so called HLA-B27 positive uveitis, mediated through tumour necrosis factor and interleukin-1. In this paper the characteristics of these animal models are described. Attention has been paid to those situations where several of these mechanisms combine in the pathogenesis of ocular diseases.