Clinical outcomes and Th17-associated immunomodulation in vitiligo treated with tacrolimus ointment plus narrow-band ultraviolet light

Background: Vitiligo, an autoimmune disorder causing skin depigmentation, has Narrow-Band Ultraviolet B (NB-UVB) and tacrolimus with limitations, warranting further research on the long-term efficacy, safety and T helper cell (Th) 17-related mechanisms of their combination. Objectives: This study assessed the Th17-related immunomodulation, efficacy and tolerability of tacrolimus plus NB-UVB in vitiligo. Methods: Retrospectively collected 132 vitiligo patients from our hospital (Jan 2020-Dec 2023); 124 were enrolled after excluding. Patients were divided into tacrolimus combined with NB-UVB group (n=63) and tacrolimus group (n=61). Primary outcomes: Vitiligo Area Scoring Index (VASI) scores and clinical efficacy. Secondary outcomes: Th17 cell proportion, serum Interleukin (IL)-17/IL-22 levels, Rretinoic Acid Receptor-Related Orphan Receptor ?t (ROR?t)-positive cell proportion, Dermatology Life Quality Index (DLQI) scores, Hospital Anxiety and Depression Scale (HADS) scores and adverse event incidence. Results: The combination group showed a greater reduction in VASI scores (P=0.041) and a higher effective rate (P=0.010) compared with the tacrolimus-group alone. The combination group had a significantly lower Th17 cell proportion (P=0.003), IL-17 levels (P<0.001), IL-22 levels (P=0.047), ROR?t-positive cell proportion (P=0.029). Adverse event incidence was not different between groups (P=0.714), while the combination group had a lower DLQI (P<0.001), HADS-A (P=0.018) and HADS-D (P=0.006) scores. Conclusion: Tacrolimus plus NB-UVB is more effective than tacrolimus alone for vitiligo, reducing lesion size and disease activity, down regulating Th17-associated immunity and improving systemic immune profile.