Contribution of Skin Color in Stabilization of Active Cases of Vitiligo by Narrow Band UVB

Ain Shams University

Status and phase: Unknown; Phase 1

Conditions: Vitiligo

Treatments: Drug: Placebo oral tablet; Drug: Oral dexamethasone minipulse

Study type: Interventional

Funder types: Other

Identifiers

NCT04030988

u4xjkivz

Details and patient eligibility

About

Vitiligo is a disease in which autoimmunity plays a major role. Multiple treatment options are available, of which narrow-band UVB is a cornerstone, acting through immunosuppression and repigmentation by stimulating reservoir melanocytes.

It's expected that this immunsupression is lower in darker skin types, where increased basal melanin might act as a barrier.

Full description

Vitiligo is acquired depigmentation disorder. Several theories were hypothesized for causing vitiligo, of which the autoimmune theory is the most accepted.

The main targets of therapy are stabilization of the disease activity through immunosuppression, and repigmentation through stimulation of reservoir melanocytes proliferation and migration.

Narrow band ultraviolet phototherapy (NB-UVB) remains the cornerstone treatment of vitiligo. NB-UVB can induce both immunosuppression and repigmentation. Several factors can modulate the efficacy of NB-UVB therapy in treatment of vitiligo cases, including patient's age, lesion site, duration of the disease, and duration of the therapy.

The immunosuppressive function of NB-UVB was first detected in 1963 by Hanisko and Suskind, who observed that the contact hypersensitivity response in skin sensitized to dinitrochlorobenzene (DNCB) was reduced if skin was previously exposed to suberythemal doses of UVB.

Present evidence suggests that UVB suppress immune system through generation of T-suppressor cells, which inhibit the effector cells of Th1 type. It appears that UV-induced immunosuppression depresses the function of Th1 cells and enhances the activity of Th2 cells via cytokines such as Interleukin 10.

It's expected that this immunsupression is lower in darker skin types, where increased basal melanin might act as a barrier. However, skin was previously divided to UVB-resistant and UVB-sensitive (UVB-R and UVB-S) based on the contact hypersensitivity testing, regardless of the skin type. Moreover, A study on NB-UVB phototherapy for psoriasis revealed that photoadaptation during NB-UVB therapy Is Independent of skin type.

Enrollment: 100 estimated patients

Sex: All

Ages: 6 to 60 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Active cases of non-segmental vitiligo, VIDA +2 or more.
• All skin types
• Age above 6 years, both sexes.

Exclusion criteria

• Contraindications to NB-UVB ( photosensitive skin disorders, skin malignancy, patients on photosensitizing medications)
• Contraindications to mini-pulse steroid therapy (uncontrolled diabetes or hypertension, peptic ulcer)
• Stable disease (VIDA 0 & -1) and activity more than 6 months ago (VIDA +1).
• The use of other treatment for vitiligo during the 3 months previous to enrollment.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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100 participants in 2 patient groups, including a placebo group

Active

Active Comparator group

Description:

50 patients will receive mini pulse dexamethasone therapy in a dose of 3 mg/ day for adults or 1.5 mg/day for children on two consecutive days per week plus NB-UVB phototherapy at starting dose of 0.3 J/cm2, at a rate of 3 times per week for 6 months (72 sessions) with gradually increasing increments.

Treatment:

Drug: Oral dexamethasone minipulse

Placebo

Placebo Comparator group

Description:

50 patients will receive placebo having the same color, form and packaging as the dexamethasone therapy for 6 months plus NB-UVB phototherapy at starting dose of 0.3 J/cm2, at a rate of 3 times per week for 6 months (72 sessions) with gradually increasing increments.

Treatment:

Drug: Placebo oral tablet