Enumeration of autoreactive helper T lymphocytes in uveitis

In a one-stage, interleukin-2 (IL-2), limiting-dilution analysis, peripheral blood mononuclear cells from patients with uveitis and normal control subjects were assayed for S-antigen specific, tetanus-specific, and in vivo activated helper T cells. Controls subjects consistently demonstrated tetanus-specific responses, but neither in vivo activation nor S-antigen specific helper T cell responses were seen. Patients with active forms of diffuse, posterior, and anterior uveitis were found to have significant frequencies of both in vivo activated and S-antigen specific helper T cells in their peripheral blood. These data show that patients with certain forms of uveitis have a measurable frequency of lymphocytes in the peripheral immunologic compartment capable of secreting IL-2 in response to autologous presentation of ocular autoantigen (S-antigen). Limiting-dilution analysis techniques, generating minimal responder cell frequency estimates and distinct IL secretion patterns, may provide an index of disease activity and critical information about the mechanism(s) of ocular inflammation.