Alopecia areata (AA) is regarded as an organ-specific and cell-mediated autoimmune disorder. In cytokine balance of AA, several reports have suggested AA as Th1 disease. For example, Murine IFN-γ-injected C3H/HeJ mice showed AA like hair loss with infiltration of CD4+ and CD8+ T cells Th1 cytokine. In human, IFN-γ-producing cells were detected in the perifollicular infiltrate, and serum Th1 cytokines were increased in AA patients. On the other hand, AA often complicates atopic dermatitis (AD). However, the immunological aspects of AA with AD are still poorly understood. Recently AD is categorized into the extrinsic and intrinsic types. Extrinsic AD shows high total serum IgE levels and the presence of specific IgE for environmental and food allergens, whereas intrinsic AD exhibits normal total IgE values. Therefore, the objective of this study is to clarify the cytokine balances in AA with extrinsic AD/intrinsic AD. In this study, the expression of intracytoplasmic cytokine, chemokine receptor, IgE were analyzed in healthy control, and patients with AA and AA+AD. Flowcytometric analysis revealed the frequency of IFN-γ-producing CD8+ T cells were significantly lower in extrinsic AA with AD compared with AA. In addtion, IFN-γ-producing CD4+ T cells, extrinsic AA with AD were significantly lower than controls and AA. Furthermore, the ratio of IFN-γ-producing CD4+ T cells/IL-4-producing CD4+ T cells was lower in AA with extrinsic AD compared with AA. In AA, IFN-γ-producing CD8+ T cells were inversely correlated to IgE level. Interesitngly, anti-IL-4R recepter antibody “dupilumab” showed efficacy not only extrinsic AD but also AA in patients with AA+extrinsic AD. However, dupilumab showed no remarkable effect on AA in the patient with AA+intrinsic AD. In conclution, AA is basically classfied to Th1 disease. However, AA can be regarded as Th2-shifted disease in AA with extrinsic AD. The cytokine balance of AA should be considered in the selection of treatment such as contact immunotherapy.

New concept of cytokine balance in alopecia areata with atopic dermatitis