Histocompatibility antigens (HLA) and uveitis.

The studies of histocompatibility (HLA) antigens have contributed to the understanding of the pathogenesis of uveitis. Acute anterior uveitis is associated with rheumatic disorders such as ankylosing spondylitis. HLA-B 27 antigen is present in 98% of these cases. There are genetic and environmental factors influencing the activity of the disease. HLA-B 27 was found to be associated with 43% of cases of acute anterior uveitis without systemic disease. In juvenile chronic polyarthritis with acute anterior uveitis HLA-B 27 helps in differentiating between ankylosing spondylitis and Still's disease. Specific HLA antigens were also found in other forms of uveitis such as Reiter's disease (HLA-B 27), Behcet's syndrome (HLA-B 5), VKH syndrome (HLA-Bw 22J) and ocular histoplasmosis (HLA-B 7). Despite these new findings, there are still many obscure factors and further studies are required to elucidate the pathogenesis of uveitis and to achieve its prevention.