[Acute anterior uveitis: para-infectious hypothesis in predisposed individuals]

The etiology and the physiopathology of acute anterior uveitis (AAU) is not well understood yet. However, two major predisposing factors have been identified: a bacterial infection especially with gram negative organisms (functioning as a trigger) and a genetic background, in particular the expression of HLA B-27 tissue antigen. We report the case of a young woman returning from travel to the Far East with her partner. Both presented simultaneously a gastrointestinal infection with fever and diarrhea. Despite extensive investigations, the infectious agent was never identified because of early empirical antibiotic therapy. A few days later, the patient developed AAU of a moderate grade in both eyes. HLA B-27 testing was positive for her, but not for her partner. Experimental research, based on a animal model such as endotoxin-induced uveitis (EIU), gives us some insight into the possible pathogenic mechanisms of AAU. Footpad injection of endotoxin (lipopolysaccharide component of the wall of gram negative), produce an acute anterior uveitis in rats. Extensive histologic analysis of other organs shows that the anterior segment of the eye is the only structure involved. Intensity of inflammation varies in different rat strains, stressing the importance of the genetic background. The similarity of the animal model to AAU will contribute to orient clinical research towards identifying more thoroughly the possible infectious agent at the origin of AAU and possibly to develop a prophylactic therapy.