APOPTOSIS IN PATIENTS WITH POSTERIOR UVEITIS

Background: Apoptosis plays a part in the pathogenesis of autoimmune d iseases.Objective: To investigate the expression of apoptotic markers in the eyes of patients with uveitis. Methods: With the use of immunoh istochemical and in situ apoptotic detection techniques, apoptotic mol ecules (Fas or Fas ligand [FasL]) and nuclear DNA fragmentation were e xamined in 8 enucleated eyes with Behcet's disease (1), sarcoidosis (1 ), subretinal fibrosis and uveitis (1), sympathetic ophthalmia (4), an d the Vogt-Koyanagi-Harada syndrome (1); in 5 chorioretinal biopsy spe cimens with acute retinal necrosis (2), multifocal choroiditis (1), sa rcoidosis (1), and subretinal fibrosis and uveitis (1); and in 3 norma l control eyes. Results: Fas and FasL were constitutively expressed in the normal human retina, but they were expressed much less in the cho roid. Increased expression of Fas and FasL was found in the retina, ch orioretinal scar, and choroidal granulomas in uveitic eyes. However, F as and FasL expression was absent in the biopsy specimens with acute r etinal necrosis, and little Fas or FasL was noted on infiltrating lymp hocytes. DNA fragmentation was also identified in eyes with chorioreti nal scar and gliosis. Conclusions: Apoptosis occurs in uveitic eyes an d may play a regulatory role in limiting ocular inflammation. In uveit ic eyes, a dysregulation of the Fas-FasL apoptotic pathway may lead to gliosis and fibrosis.