Uveitis in Behçet's disease (BD) is an important cause of vision loss through recurrent ocular inflammatory attacks. CD4 T cells that react to various self-antigens play a central role in the pathogenesis of this disease, and the activation or inactivation of the CD4 T cells is controlled by costimulatory molecules. In Behçet's disease patients with active uveitis, among the various costimulatory molecules, the inducible co-stimulator (ICOS), an active form of stimulatory molecule, is most strongly expressed, and is associated with cytokine production by Th1 and Th17 cells. It is suggested that ICOS could be a potential marker of disease activity and a candidate therapeutic target. Inhibition of the ICOS/B7RP-1 costimulatory pathway has demonstrated favorable therapeutic effects in various autoimmune diseases. Targeting the ICOS/B7RP-1 costimulatory pathway may be a useful future treatment strategy for uveitis in Behçet's disease.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 116: 1037-1045, 2012.