Assessment of tissue levels of dickkopf‐1 in androgenetic alopecia and alopecia areata

Androgenetic alopecia (AGA) is the commonest form of hair loss in men. Alopecia areata (AA) is an organ-specific autoimmune disease. Studies revealed that Dickkopf 1 (DKK-1), a powerful suppressor of the Wnt/β-catenin signaling pathway, induced anagen-to-catagen transition in mice. Moreover, in vitro studies suggested that DKK-1 played a role in dihydrotestosterone (DHT)-induced balding.To evaluate the tissue levels of DKK-1 in patients with AGA and AA, to assess its possible role as a pathogenetic mechanism in both disorders.This study included 24 patients with AGA, 31 patients with AA, and 33 healthy controls. Scalp biopsies were taken from all participants for the detection of tissue DKK-1 levels.Tissue DKK-1 levels were significantly higher in patients with AGA than in controls (P = 0.000) as well as in patients with AA than in controls (P = 0.001). In addition, they were significantly higher in patients with AGA than in patients with AA (P = 0.000). DKK-1 was higher in male than in female patients with AGA. DKK-1 was negatively correlated with disease duration in AGA.In conclusion, this study suggests an important role for DKK-1 in the pathogenesis of AGA and AA through documenting higher tissue DKK-1 levels in patients with both hair disorders compared to controls and suggests that DKK-1 may be a promising therapeutic target for these hair diseases.