HLA and uveitis.

The association between HLA-A29 and birdshot chorioretinopathy is the strongest of all associations between HLA and disease. Determination of HLA-A29 is even of diagnostic significance. The association between HLA-B27 and acute anterior uveitis (AAU) is much weaker, but B27 positive AAU may be considered as a distinct clinical entity. B27 positive patients with AAU should be referred to a rheumatologist, because half of these patients have ankylosing spondylitis or Reiter's syndrome. The determination of HLA-Bw51 is of limited but significant diagnostic value for the diagnosis of Behçet's disease. The present article shows how HLA determinations can serve as diagnostic tests. It is explained how the sensitivity and specificity of such tests can be used to calculate the influence of positive or negative results on the probability of the diagnosis. The structure and function of HLA class I molecules is now known to a great extent. This may lead to a better understanding of the pathogenic role of HLA-A29, HLA-B27, HLA-Bw51 and other HLA molecules which are associated with uveitis.