ABSTRACT
BACKGROUND: Although regulatory T cells (Tregs) are affected in several autoimmune skin diseases, only two studies have been performed in patients with bullous pemphigoid (BP) with contrasting results. OBJECTIVE: To characterize Tregs and to determine the serum levels of regulatory cytokines in patients with BP. METHODS: In BP lesional skin, immunohistochemistry and confocal microscopy were performed for CD4(+) , CD25(+) , forkhead/winged helix transcription factor (FOXP3)(+) , transforming growth factor (TGF)-ß(+) and interleukin (IL)-10(+) cells. In addition, the number of CD4(+) CD25(++) FOXP3(+) Tregs in peripheral blood was assessed by flow cytometry, and the levels of TGF-ß and IL-10 were determined in serum samples by enzyme-linked immunosorbent assay before and after steroid therapy. Controls included patients with psoriasis, atopic dermatitis (AD) and healthy donors. RESULTS: The frequency of FOXP3(+) cells was significantly reduced in skin lesions from patients with BP (P < 0.001) compared with psoriasis and AD. Moreover, the number of IL-10(+) cells was lower in BP than in psoriasis (P < 0.001) and AD (P = 0.002), while no differences were observed in the number of TGF-ß(+) cells. CD4(+) CD25(++) FOXP3(+) Treg in the peripheral blood of patients with BP was significantly reduced compared with healthy controls (P < 0.001), and augmented significantly after steroid therapy (P = 0.001). Finally, TGF-ß and IL-10 serum levels were similar in patients with BP compared with healthy controls. However, after therapy, BP patients showed significantly higher IL-10 serum levels than before therapy (P = 0.01). CONCLUSIONS: These data suggest that the depletion of Tregs and of IL-10 in patients with BP may be an important factor in the pathogenesis of the disease.
