<unk>  is a rare form of posterior uveitis and accounts for 1-3% of uveitis cases in general.<unk>  is thought to be an autoimmune disease. The disease has strong association with the Human leukocyte antigen haplotype (HLA)-A29, which is the strongest association between a disease and HLA class I documented (>99% of patients are HLA-A29 positive by molecular testing and HLA-A29-negative cases are controversial). This indicates a role for T-lymphocytes in the pathogenesis.<unk>  is associated with IL-17, a hallmark cytokine of TH17 cells that play an important role in autoimmunity. The disease affects typically middle-aged or elderly caucasians. HLA-A29 is less prevalent in Asia and no<unk>  cases have been reported in Asia. When<unk>  is suspected, a person is usually tested to determine if they are HLA-A29 positive. Although previously HLA-A29 testing was not considered necessary for definitive diagnosis, because HLA-A29 is also common in the general healthy population (7%). An increasing number of specialists consider the presence of HLA-A29 critical for diagnosis. Additional (genetic or environmental) or unknown factors may be associated with HLA-A29 in the pathogenesis. In 2014, Kuiper et al. conducted a genome-wide association study in<unk>  and studied the entire genome of Dutch, Spanish and English patients. This large genetic study ascertained HLA-A29:02 as the primary risk factor and identified the endoplasmic reticulum aminopeptidase (ERAP) 2 gene strongly associated with<unk> . Genetic variants near ERAP2 on chromosome 5 resulted in high mRNA and protein expression of this aminopeptidase in BSCR patients. ERAP2 is an aminopeptidase that, together with the closely related ERAP1, trims peptides in the endoplasmic reticulum and loads these peptides on HLA molecules for presentation to T cells of the immune system. ERAP-HLA associations have also been reported in Ankylosing spondylitis and Behcet's disease, suggesting shared pathogenic pathways among these diseases. The combined<unk>  risk polymorphisms at 5q15 linked to ERAP1 and ERAP2 genes (T-rs10044354-C-rs2287987) are only observed in HLA-A29-positive individuals in populations in which BU is “endemic”, explaining why BU is reported merely in populations of Western European Ancestry (Spain, France, The Netherlands, Great Britain, but also non-european countries such as Puerto Rico). Functional analysis of patient-derived immune cells revealed that ERAP2 increases the abundance of peptides that specifically bind to HLA-A29 and further supports that the antigen presentation pathway drives the etiology of BSCR.
Birdshot chorioretinopathy
Retinal vasculitis
Toxoplasmic chorioretinitis
Vitreoretinopathy
Central serous chorioretinopathy
Iridocorneal endothelial syndrome
Proliferative vitreoretinopathy
Serpiginous choroiditis