Background: The precise pathogenesis of alopecia areata remains unknown, although this disease seems to be triggered by helper T cell infiltration in hair follicles. Recent studies of psoriasis and vitiligo have demonstrated the involvement of Th17 cells. Psoriasis and vitiligo occasionally develop concomitantly or inversely in patients with alopecia areata. Objective: The aim of this study was to determine whether Th17 cells are present in the affected lesions of alopecia areata. Methods: We performed immunofluorescent staining of representative immunocompetent cells that had infiltrated into the skin of the scalp in 4 individuals with alopecia areata (single patchy alopecia areata, multiple patchy alopecia areata, alopecia totalis and alopecia universalis). Results: We found the infiltration of CD4+IL-17A+ Th17 cells in the dermis, particularly around hair follicles, in all 4 cases. Conclusions: These findings suggest the possibility that alopecia areata is induced by a Th17 cell-associated autoimmune mechanism.

Safavi KH, Muller SA, Suman VJ, Moshell AN, Melton LJ 3rd: Incidence of alopecia areata in Olmsted County, Minnesota, 1975 through 1989. Mayo Clin Proc 1995;70:628-633.
Alkhalifah A, Alsantali A, Wang E, McElwee KJ, Shapiro J: Alopecia areata update. Part I. Clinical picture, histopathology, and pathogenesis. J Am Acad Dermatol 2010;62:177-188.
Barahmani N, Schabath MB, Duvic M: National Alopecia Areata Registry. History of atopy or autoimmunity increases risk of alopecia areata. J Am Acad Dermatol 2009;61:581-591.
Friedmann PS: Decreased lymphocytic reactivity and auto-immunity in alopecia areata. Br J Dermatol 1981;105:145-151.
Yamamoto T, Watanabe K, Katayama I, Nishioka K: Alopecia universalis in a patient with psoriasis vulgaris. J Dermatol 1995;22:623-624.
Miyazaki Y, Yamamoto T, Watanabe K, Katayama I, Nishioka K: Alopecia universalis associated with Zumbusch-type generalized pustular psoriasis. Dermatology 2002;204:308-309.
Narita T, Oiso N, Fukai K, Kabashima K, Kawada A, Suzuki T: Generalized vitiligo and associated autoimmune diseases in Japanese patients and their families. Allergol Int 2011;60:505-508.
Oiso N, Kawada A: Renbök phenomenon in a patient with alopecia areata universalis and psoriasis. J Dermatol 2012;39:288-289.
Asarch A, Barak O, Loo DS, Gottlieb AB: Th17 cells: a new paradigm for cutaneous inflammation. J Dermatolog Treat 2008;19:259-266.
Fitch EL, Rizzo HL, Kurtz SE, Wegmann KW, Gao W, Benson JM, Hinrichs DJ, Blauvelt A: Inflammatory skin disease in K5.hTGF-β1 transgenic mice is not dependent on the IL-23/Th17 inflammatory pathway. J Invest Dermatol 2009;129:2443-2450.
Kotobuki Y, Tanemura A, Yang L, Itoi S, Wataya-Kaneda M, Murota H, Fujimoto M, Serada S, Naka T, Katayama I: Dysregulation of melanocyte function by Th17-related cytokines: significance of Th17 cell infiltration in autoimmune vitiligo vulgaris. Pigment Cell Melanoma Res 2012;25:219-230.
Tanemura A, Kotobuki Y, Itoi S, Takata T, Sano S, Katayama I: Positive link between STAT3 activation and Th17 cell infiltration to the lesional skin in vitiligo vulgaris. J Dermatol Sci 2012;67:207-209.
Ghoreschi K, Laurence A, Yang XP, Hirahara K, O'Shea JJ: T helper 17 cell heterogeneity and pathogenicity in autoimmune disease. Trends Immunol 2011;32:395-401.
Quaglino P, Bergallo M, Ponti R, Barberio E, Cicchelli S, Buffa E, Comessatti A, Costa C, Terlizzi ME, Astegiano S, Novelli M, Cavallo R, Bernengo MG: Th1, Th2, Th17 and regulatory T cell pattern in psoriatic patients: modulation of cytokines and gene targets induced by etanercept treatment and correlation with clinical response. Dermatology 2011;223:57-67.
McElwee KJ, Freyschmidt-Paul P, Hoffmann R, Kissling S, Hummel S, Vitacolonna M, Zöller M: Transfer of CD8+ cells induces localized hair loss whereas CD4+/CD25- cells promote systemic alopecia areata and CD4+/CD25+ cells blockade disease onset in the C3H/HeJ mouse model. J Invest Dermatol 2005;124:947-957.
Ito T, Ito N, Saatoff M, Hashizume H, Fukamizu H, Nickoloff BJ, Takigawa M, Paus R: Maintenance of hair follicle immune privilege is linked to prevention of NK cell attack. J Invest Dermatol 2008;128:1196-1206.
Meyer KC, Klatte JE, Dinh HV, Harries MJ, Reithmayer K, Meyer W, Sinclair R, Paus R: Evidence that the bulge region is a site of relative immune privilege in human hair follicles. Br J Dermatol 2008;159:1077-1085.
Fujisaki J, Wu J, Carlson AL, Silberstein L, Putheti P, Larocca R, Gao W, Saito TI, Lo Celso C, Tsuyuzaki H, Sato T, Côté D, Sykes M, Strom TB, Scadden DT, Lin CP: In vivo imaging of Treg cells providing immune privilege to the haematopoietic stem-cell niche. Nature 2011;474:216-219.
Barahmani N, Lopez A, Babu D, Hernandez M, Donley SE, Duvic M: Serum T helper 1 cytokine levels are greater in patients with alopecia areata regardless of severity or atopy. Clin Exp Dermatol 2010;35:409-416.
Kasumagic-Halilovic E, Prohic A, Karamehic J: Serum concentrations of interferon-γ (IFN-γ) in patients with alopecia areata: correlation with clinical type and duration of the disease. Med Arh 2010;64:212-214.
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