Immunological features of HLA-B27 anterior uveitis.

Analysis of the immunological features of anterior uveitis (AU) revealed a dichotomy of abnormalities defined in terms of the HLA-B27 status of the patient. HLA-B27-positive AU was characterised by the occurrence of iris autoantibodies and an absolute T cell lymphopenia during active disease which returned to normal with recovery. This phenomenon was not observed in HLA-B27-negative AU or in controls and could not be attributed to antilymphocyte antibodies as these were not detected. Furthermore, there were no changes in T-cell subsets (helper and suppressor T lymphocytes). Compared with HLA-B27-positive AU patients, the HLA-B27-negative group demonstrated elevated IgE levels and increased prevalence of smooth muscle autoantibodies.