Related Experiment Video
Updated: Feb 24, 2026

Quantification of Hypopigmentation Activity In Vitro
Published on: March 6, 2019
Repigmentation in vitiligo using the Janus kinase inhibitor tofacitinib may require concomitant light exposure
Lucy Y Liu1, James P Strassner2, Maggi A Refat2
1Yale University School of Medicine, New Haven, Connecticut.
Background:
Vitiligo is an autoimmune disease in which cutaneous depigmentation occurs. Existing therapies are often inadequate. Prior reports have shown benefit of the Janus kinase (JAK) inhibitors.
Objective:
To evaluate the efficacy of the JAK 1/3 inhibitor tofacitinib in the treatment of vitiligo.
Method:
This is a retrospective case series of 10 consecutive patients with vitiligo treated with tofacitinib. Severity of disease was assessed by body surface area of depigmentation.
Results:
Ten consecutive patients were treated with tofacitinib. Five patients achieved some repigmentation at sites of either sunlight exposure or low-dose narrowband ultraviolet B phototherapy. Suction blister sampling revealed that the autoimmune response was inhibited during treatment in both responding and nonresponding lesions, suggesting that light rather than immunosuppression was primarily required for melanocyte regeneration.
Limitations:
Limitations include the small size of the study population, retrospective nature of the study, and lack of a control group.
Conclusion:
Treatment of vitiligo with JAK inhibitors appears to require light exposure. In contrast to treatment with phototherapy alone, repigmentation during treatment with JAK inhibitors may require only low-level light. Maintenance of repigmentation may be achieved with JAK inhibitor monotherapy. These results support a model wherein JAK inhibitors suppress T cell mediators of vitiligo and light exposure is necessary for stimulation of melanocyte regeneration.
Related Concept Videos
Pigmentation
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...
Changes in Skin Color: Clinical Perspectives
Albinism
Albinism is a genetic disorder that affects (completely or partially) the coloring of skin, hair, and eyes. The defect is primarily...
Renewal of Skin Epidermal Stem Cells
Drugs for Treatment of Crohn's Disease in IBD Using Immunomodulatory Agents
Skin Cancer
Basal Cell Carcinoma (BCC): BCC is the most common type of skin cancer, accounting for about 80% of cases. It typically develops in...
TGF - β Signaling Pathway

