Vitiligo is a chronic acquired disease characterized by the loss of functional melanocytes in the skin and/or hair, resulting in depigmented patches. Accumulated evidence points to the role of autoimmune mechanisms and local immune activation [1].

Primary treatment approaches aim to halt progression and stimulate repigmentation: topical corticosteroids, calcineurin inhibitors, and narrowband UVB phototherapy (NB-UVB). If necessary, systemic immunomodulators or surgical melanocyte transplantation techniques are used. New targeted methods are emerging, including JAK (Janus kinase) inhibitors, but conventional regimens still play a key role in routine practice [2, 3].

The central problem is that response to therapy is often unpredictable: visible repigmentation develops slowly — sometimes over several months — and not in all patients. A lack of accessible, validated biomarkers to predict the likelihood of early response limits the potential for personalized treatment. It often forces practitioners to continue or modify regimens under conditions of uncertainty [4].

What the authors did

A prospective multilevel study (36 patients enrolled, 30 completed) was conducted to identify early markers of vitiligo treatment response.

Before therapy, researchers compared the proteomic profile of suction blister fluid from lesional and non-lesional skin. Over time (at 3 months), they evaluated immune cell populations in skin biopsies and blood and performed a broad proteomic analysis.

These biological changes were correlated with clinical outcomes, as measured by the Vitiligo Extent Score (VES) at 6 months. The work was published in the Journal of Investigative Dermatology, 2026 [1].

What the study showed

The analysis of a massive dataset enabled the authors not only to confirm known mechanisms of vitiligo but also to uncover hidden patterns that determine treatment success. The most significant findings include:

Baseline differences (before treatment):

• Researchers identified 53 proteins whose levels in vitiligo lesions differed significantly from those in healthy skin.
• In affected areas, concentrations of melanocyte-related proteins, such as PMEL (pre-melanosomal protein), were, as expected, lower.
• Conversely, markers of inflammation were elevated: STAT1 (Signal Transducer and Activator of Transcription 1), chemokines CXCL9 and CXCL10, and IL-12 (interleukin-12). This confirms that an inflammatory microenvironment hinders the survival and recovery of pigment cells.

Dynamics after 3 months of therapy:

• Within the skin, there was a reduction in CD8+ T cell populations (cytotoxic lymphocytes), CD3+ cells (the total T-lymphocyte population), and TRMs (tissue-resident memory T cells) with the CD69+CD103– phenotype.
• At the proteomic level, the expression of 47 proteins changed within the lesions.
• In the blood, the most significant shift was seen in the cTfh17 population (circulating follicular T helper type 17 cells). Decreases were also noted in CD336+ NKbright cells (a specific group of natural killer cells), Tr1 cells (type 1 regulatory T cells), and lymphocytes secreting IL-10 (interleukin-10).

Correlation with clinical outcomes (at 6 months):

• Local markers: The most closely linked to a better clinical response (repigmentation) was an early decrease in skin TRM cells (CD69+CD103–) and the proteomic marker FABP4 (fatty acid-binding protein 4).
• Systemic markers: In the blood, a decrease in Tr1 cells and their secreted IL-10 proved to be prognostically important.
• Clinical picture: The response to therapy was heterogeneous. Five patients achieved ≥50% repigmentation, 6 achieved 25–49%, 9 achieved <24%, and 10 showed no response or worsening.
• Combining topical therapy with phototherapy (NB-UVB) proved more effective than topical treatment alone: median repigmentation was 24.1% vs. –7.5%.

Safety, limitations, and practical value

This study did not focus on a detailed analysis of adverse events. The authors did not provide a comprehensive assessment of the tolerability of topical treatment or NB-UVB as an independent endpoint. Of the 36 patients enrolled, 6 did not complete the study: two withdrew due to COVID-19 pandemic restrictions, two due to concerns regarding sampling procedures, one for non-compliance, and one for personal reasons. Therefore, this study should not be used as a primary source for the safety profile of these treatments.

The study's limitations are evident but do not diminish its value as an important pilot step. This is a small prospective cohort; some results are exploratory, and several signals only appeared convincing before strict statistical correction. Additionally, the authors simultaneously analyzed different sample types — biopsies, blister fluid, and blood — and the work combined patients on two different treatment regimens. Finally, the identified markers have not yet undergone external validation, meaning they cannot yet be used as a standard clinical test.

The practical value of this research is significant:

• First, it reinforces a concept vital for daily practice: the baseline biological portrait of a lesion alone does not determine the prognosis.
• Second, the authors demonstrate that monitoring early dynamics may be more important for predicting treatment success than relying solely on baseline data.
• Third, the study highlights several promising targets — primarily FABP4 and local tissue-resident memory T cells — that could become reliable markers of response or new directions for therapeutic intervention.

Conclusion

Treating vitiligo remains complex, not only because repigmentation is slow but also because it is hard to predict. This new research shows that the greatest interest lies not just in the differences between lesional and non-lesional skin, but in the early changes within tissues and blood during therapy.

Decreased levels of the FABP4 protein and tissue-resident memory T cells (CD69+CD103– phenotype) in the skin, along with type 1 regulatory T cells (secreting IL-10) in the blood, were closely linked to better clinical outcomes. For the practitioner, this is a vital landmark: the future of personalized vitiligo management likely involves the use of dynamic biomarkers of early response. These findings now await confirmation in larger-scale clinical studies [1].

References

1. Ouwerkerk W., Narayan V.S., Chielie S. et al. Immune and biological changes during treatment in patients with nonsegmental vitiligo and their relation to repigmentation. J Invest Dermatol 2026; 146: 699–710.
2. Ezzedine K., Eleftheriadou V., Whitton M., van Geel N. Vitiligo. Lancet. 2015; 386(9988): 74–84.
3. Rodrigues M., Ezzedine K., Hamzavi I., et al. Current and emerging treatments for vitiligo. J Am Acad Dermatol 2017;  77(1):17–29.
4. Speeckaert R., Speeckaert M., De Schepper S., van Geel N. Biomarkers of disease activity in vitiligo: a systematic review. Autoimmun Rev 2017; 16(9): 937–945.