Role of T helper 17 cells and T regulatory cells in alopecia areata: comparison of lesion and serum cytokine between controls and patients.

BACKGROUND: Alopecia areata (AA) is an organ-specific autoimmune disease with T-cell-mediated attack of hair follicle autoantigens. As T helper 17 (Th17) cells and T regulatory (Treg) cells are crucially involved in the pathogenesis, the role of Th17 and Treg cytokines has not been studied yet.

OBJECTIVE: To determine whether AA is associated with alterations in lesional and serum Th17 and Treg cytokines and studied whether they were associated with clinical type.

METHODS: Scalp skin samples from 45 patients and eight normal controls were obtained for PCR specific for IFN-γ, TNF-α, TGF-β, IL-1, IL-2, IL-4, IL-10, IL-12A, IL-13, IL-17, IL-22 and IL-23. Serum cytokines were measured from 55 patients and 15 normal controls using ELISA.

RESULTS: Lesional IL-17 and IL-22 were significantly increased in patient group. Moreover, positive correlations were shown between lesional IL-17, IL-22 and disease severity. Serum IL-1, IL-17, TNF-α and TGF-β were significantly increased, and positive correlation was shown between serum IL-17 and disease severity.

CONCLUSION: These results showed significantly high Th17 cytokines in both lesion and serum in AA patients, which may highlight a functional role of these cytokines in the pathogenesis of AA.