Cutaneous JAK Expression in Vitiligo

Background: The Janus kinase-signal transducer and activator of transcription signaling pathway has been suggested as a promising therapeutic target in vitiligo. However, limited data is available on the cutaneous expression of JAK in vitiligo.

Aim: This study is designed to analyze the cutaneous expression patterns of JAK1, 2, and 3 in vitiligo and investigate their relation to the disease clinical parameters.

Methods: This case-control study recruited 24 patients having active vitiligo and 20 age, sex, and skin type-matched healthy volunteers. Skin biopsies were obtained from patients (lesional, perilesional and nonlesional) and controls for assessment of JAK1, 2, and 3 expression using RT-PCR.

Results: JAK1 and JAK3 were overexpressed in patients' skin compared to control skin and showed a stepwise pattern of upregulation from control to nonlesional, perilesional and lesional skin. However, JAK3 showed much stronger expression. In contrast JAK2 expression showed no significant difference in any of lesional, perilesional or nonlesional skin compared to control skin. JAK1 and JAK3 expression levels showed no correlation with neither the disease activity nor severity.

Conclusion: JAK1 and more prominently JAK3 are upregulated in vitiliginous skin and possibly contribute to the pathogenesis of the disease. Accordingly, selective JAK3/1 inhibition may provide a favorable therapeutic opportunity for vitiligo patients.This study is registered on the Identifier: NCT03185312.