Dickkopf-1 Expression in Androgenetic Alopecia and Alopecia Areata in Male Patients

Background: Androgenetic alopecia (AGA) results from shortening of the anagen phase of the hair cycle and, subsequently, miniaturization of hair follicles. Alopecia areata (AA) is a disease of autoimmunity where T cells attack anagen hair follicles and shows multifactorial etiology. Dickkopf-1 (DKK-1) is a gene that is responsible for transformation of anagen to catagen, which suggests that it is involved in development of both diseases. Objectives: To evaluate the tissue levels of dickkopf-1 in male patients with AGA and AA in comparison with controls, in an attempt to know its role in the pathogenesis of both disorders. Methods: DKK-1 immunohistochemical expression was evaluated in lesional scalp biopsies taken from 20 male patients with AGA evaluated clinically by the modified Norwood-Hamilton score, 20 male patients with AA evaluated clinically by SALT score, and 20 healthy controls within the same age and sex of the studied patients. Results: A highly significant difference in DKK-1 expression between patients with AGA and healthy controls was found (P-2 < 0.001). There were also significant differences in DKK-1 expression between patients with AA and healthy controls (P-3 = 0.013), and between both patient groups (P-1 = 0.002). Conclusions: Both AGA and AA showed significant increase in DKK-1 immunohistochemical expression. This may enhance the idea of its possible role in the pathogenesis of AGA and AA, and being a new target for treatment of these hair disorders.