Effect of narrowband ultraviolet B phototherapy on serum vitamin D levels in patients with vitiligo:

Implementation of the vitiligo area scoring index in clinical studies of patients with vitiligo: a scoping review

The vitiligo area scoring index (VASI) is a validated, reliable clinician-reported outcome measure widely used to assess the extent of skin depigmentation seen in patients with vitiligo and to measure patient responses to therapies for vitiligo in clinical trials. However, its implementation in studies is inconsistent and makes comparing results across different studies difficult. The aim of this scoping review is to summarize interventional clinical studies that applied the VASI to measure vitiligo and identify variability in VASI implementation. A systematic search of Ovid Medline, Embase, Web of Science, Cochrane, and ClinicalTrials.gov was performed. Interventional studies published between January 1946 and October 2020 that used the VASI as an outcome measure for assessing vitiligo response were reviewed for methodological approach. Great heterogeneity was found within the 55 included interventional studies that used VASI as an outcome measure. A total of 9 VASI subtypes were described by the authors within 10 intervention categories. VASI determined study eligibility in one study. Body surface area was most frequently established using inconsistent methods. We found unclear or ambiguously scaled assessments of depigmentation. Most VASI outcomes were reported as mean absolute difference, percentage VASI improvement, and percentage of patients who achieved the VASI endpoint. The VASI score was over 100 in one study. Our scoping review revealed many VASI methodology variations in interventional clinical studies of vitiligo. While VASI is a standard method to measure vitiligo changes, substantial heterogeneity in methodology limits reliable comparison and interpretation of findings from different clinical trials. Our findings may be used as a foundation to standardize the VASI outcome measure methodology, allowing for improved clinician training and rigorous data analysis across vitiligo research groups worldwide.

Evaluation of vitamin D receptor gene polymorphisms (ApaI and TaqI) as risk factors of vitiligo and predictors of response to narrowband UVB phototherapy

Vitiligo is acquired depigmentation due to multiple factors. Vitamin D in skin, through its receptors (VDR), regulates cell growth, differentiation, immune response and exerts both stimulatory and protective effects on melanocytes. The gene sequence encoding VDR has polymorphic forms such as ApaI and TaqI that may affect vitamin D actions. Narrowband ultraviolet B (NB-UVB) phototherapy became the mainstay of vitiligo treatment because of its efficacy and little side effects. The current work aimed at evaluating the possible association between VDR gene polymorphisms (TaqI and ApaI) and susceptibility of vitiligo and if they could be predictors of response to NB-UVB phototherapy in Egyptian vitiligo patients. 100 vitiligo patients indicated for NB-UVB phototherapy and 100 healthy age and sex matched controls were included. All participants were subjected to history taking, general and dermatological examinations, and VDR ApaI and TaqI gene polymorphisms analysis by PCR-RFLP. The patients received NB-UVB 3times per week for 6 months then revaluated. There was significant increase in Aa genotype of ApaI polymorphism in patients associated with significant increase in vitiligo activity. 66% of patient showed variable degrees of response to NB-UVB. The responders significantly had AA genotype of ApaI polymorphism. TaqI polymorphism showed nonsignificant effects on vitiligo susceptibility and response to NB-UVB. A allele of ApaI was significant independent predictor of NB-UVB phototherapy responders. VDR gene polymorphism (ApaI) may share in vitiligo pathogenesis and response to NB-UVB. Knowing the genetic background of the patient helps individualization of treatment to get better results.

Effect of narrow-band ultraviolet B on the serum of 25-hydroxyvitamin D in vitiligo patients

BACKGROUND

Narrow-band ultraviolet B (NB-UVB) is the gold standard in the treatment of vitiligo. 25-hydroxyvitamin D (25-OH- vitamin D) might play a physiological role in photo-induced melanogenesis in human skin so the association between vitamin D levels and vitiligo still needs to be investigated more thoroughly.

OBJECTIVE

we aim to investigate the influence of cumulative doses of NB-UVB phototherapy on vitamin D in patients with vitiligo and their correlation with NB-UVB-induced pigmentation.

METHODS

Eighty patients of vitiligo and twenty number of age and sex matched controls were recruited in a case-control study. Patients with vitiligo were treated with NB-UVB twice weekly for 24 weeks. 25-hydroxy vitamin D levels were measured at 0, 12, and 24 weeks in the cases and at 0 only in control by enzyme-linked immunosorbent assay (ELISA) and Vitiligo Area Severity Index (VASI) were calculated at 0 (baseline) and 24 weeks.

RESULTS

The mean baseline level of 25-hydroxyvitamin D (at 0 week) was significantly lower in patients than the control group. Levels of 25(OH) vitamin D at 12 and 24 weeks showed significant improvement and Patients show significant reduction in VASI score after 24 weeks of therapy.

CONCLUSIONS

Cumulative doses of NB-UVB therapy improve low vitamin D levels in patients with vitiligo, which might have a significant role in NB-UVB-induced repigmentation and may contribute to its therapeutic efficacy but further studies with larger sample size are needed to prove the complete mechanisms of NB-UVB-induced pigmentations and vitamin D in vitiligo.