Increased serum levels of interleukin-17 in patients with alopecia areata and non-segmental vitiligo

Introduction
Alopecia areata (AA) and vitiligo are both skin diseases of autoimmune origin. AA is characterized by patchy hair loss primarily on the scalp but may involve other areas as well, while vitiligo is caused by the destruction of melanocytes and results in the appearance of white patches on any part of the body. Many facts indicate similar pathogenesis of these diseases. Both dermatoses are associated with frequent coexistence of other autoimmune diseases and share common genetic risk factors. Recent data support the theory of the involvement of IL-17 in the pathogenesis of both AA and vitiligo.

Aim
To evaluate and compare the serum levels of interleukin (IL)-17 in patients with AA and non-segmental vitiligo (NSV). To assess whether the pattern of serum cytokine concentration can be associated with clinical details and activity of the disease. Material and methods: A cross-sectional study was conducted on 33 patients with AA, 30 patients with NSV, and 30 healthy controls. Serum levels of IL-17 were determined quantitatively by ELISA method.

Results
Our analysis identified a systemic inflammatory signature associated with AA and NSV, characterized by elevated levels of IL-17. The levels of IL-17 did not differ significantly between AA patients and NSV patients.

Conclusions
Our results show that AA and vitiligo may share common etiopathogenetic pathways, which suggests the potential of developing targeted therapies for both AA and vitiligo treatment. Imbalance of T cell subpopulations and complex systemic cytokine profiles may contribute to the pathogenesis of AA and vitiligo.