Immunological status of patients of Eales' disease.

To test the hypothesis that altered immune reactivity to an extraneous agent might lead to primary retinal perivasculitis, a study was undertaken to determine the serum immunoglobulin levels, T lymphocyte subsets, antibody responses to BCG and 'S' antigen, and lymphoproliferative response to mitogens. No difference was observed in these parameters between patients and controls. Both Mantoux positive and negative conditions existed in patients with Eales' disease. Mantoux positive patients showed a higher level of lymphoproliferative response in vitro to PPD than Mantoux positive controls, indicating the presence of two populations among Eales' patients.