CD4 ⁺foxp3 ⁺ T-regulatory cells in noninfectious uveitis

Objective: To evaluate CD4 ⁺Foxp3 ⁺ (forkhead box P3) T-regulatory cell populations in patients with uveitis and to determine if T-regulatory cell populations are associated with disease features. Methods: Patients with uveitis were evaluated for CD4 ⁺Foxp3 ⁺T-regulatory cells by flow cytometry. Systemic and ocular diagnoses, disease activity, and the resence of cystoid macular edema were reviewed. Percentages of CD4 ⁺Foxp3 ⁺lymphocytes were compared for patients with inactive vs active disease, systemic vs ocular diagnoses, and the presence or absence of cys-toid macular edema. Real-time polymerase chain reaction testing was performed on 2 patients with extremely low CD4 ⁺oxp3 ⁺cell populations to assess Foxp3 mRNA. Results: A total of 20 patients with intermediate uveitis, posterior uveitis, and panuveitis were evaluated. The mean age was 40.6 years and the mean visual acuity was 20/57. Percentages of CD4 ⁺Foxp3 ⁺ cells were lower in patients with active compared with inactive uveitis (P< 5). No differences in T-regulatory cells were observed between the other subgroups. Two patients with recalcitrant uveitis who demonstrated less than 1% CD4 ⁺Foxp3 ⁺ lymphocytes showed extremely low or absent Foxp3 mRNA. Conclusion: T-regulatory cells are reduced in patients with active compared with inactive disease. Severe depletion of CD4 ⁺Foxp3 ⁺ T cells and Foxp3 mRNA in 2 patients with severe uveitis suggests that loss of the T-regulatory cells of uveitis may be a salient feature in certain patients.