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

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.

How Does Vitamin D Affect Immune Cells Crosstalk in Autoimmune Diseases?

Vitamin D is a secosteroid hormone that is highly involved in bone health. Mounting evidence revealed that, in addition to the regulation of mineral metabolism, vitamin D is implicated in cell proliferation and differentiation, vascular and muscular functions, and metabolic health. Since the discovery of vitamin D receptors in T cells, local production of active vitamin D was demonstrated in most immune cells, addressing the interest in the clinical implications of vitamin D status in immune surveillance against infections and autoimmune/inflammatory diseases. T cells, together with B cells, are seen as the main immune cells involved in autoimmune diseases; however, growing interest is currently focused on immune cells of the innate compartment, such as monocytes, macrophages, dendritic cells, and natural killer cells in the initiation phases of autoimmunity. Here we reviewed recent advances in the onset and regulation of Graves' and Hashimoto's thyroiditis, vitiligo, and multiple sclerosis in relation to the role of innate immune cells and their crosstalk with vitamin D and acquired immune cells.

Circulating Vitamin D Levels and Risk of Vitiligo: Evidence From Meta-Analysis and Two-Sample Mendelian Randomization

Background: The association between circulating vitamin D levels and risk of vitiligo was inconsistent among observational studies, and whether these observed associations were causal remained unclear. Therefore, we aimed to evaluate the effect of vitamin D on the risk of vitiigo using meta-analysis and Mendelian randomization (MR).

Methods: At the meta-analysis stage, literature search was performed in PubMed and Web of Science to identify eligible observational studies examining the association of circulating 25-hydroxyvitamin D [25(OH)D] or 25-hydroxyvitamin D₃ [25(OH)D₃] levels with risk of vitiligo up to April 30, 2021. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) of 25(OH)D and 25(OH)D₃ in patients with vitiligo relative to controls were pooled. Then at the MR stage, genetic instruments for circulating 25(OH)D (N = 120,618) and 25(OH)D₃ (N = 40,562) levels were selected from a meta-analysis of genome-wide association studies (GWAS) of European descent, and summary statistics of vitiligo were obtained from a meta-analysis of three GWASs including 4,680 cases and 39,586 controls. We used inverse-variance weighted (IVW) as main method, followed by weighted-median and likelihood-based methods. Pleiotropic and outlier variants were assessed by MR-Egger regression and MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO) test.

Results: In the meta-analysis, patients with vitiligo had a lower level of circulating 25(OH)D compared with controls [SMD = −1.40; 95% confidence interval (CI): −1.91, −0.89; P < 0.001], while no statistically significant difference of 25(OH)D₃ between vitiligo cases and controls was found (SMD = −0.63; 95% CI: −1.29, 0.04; P = 0.064). However, in the MR analyses, genetically predicted 25(OH)D [odds ratio (OR) = 0.93, 95% CI = 0.66–1.31, P = 0.66] and 25(OH)D₃ levels (OR = 0.95, 95% CI = 0.80–1.14, P = 0.60) had null associations with risk of vitiligo using the IVW method. Sensitivity analyses using alternative MR methods and instrumental variables (IV) sets obtained consistent results, and no evidence of pleiotropy or outliers was observed.

Conclusion: Our study provided no convincing evidence for a causal effect of 25(OH)D or 25(OH)D₃ levels on the risk of vitiligo. Further longitudinal and experimental studies, as well as functional studies are warranted to elucidate the role of vitamin D in the development of vitiligo.

Decreased circulatory levels of Vitamin D in Vitiligo: a meta-analysis

BACKGROUND

The serum Vitamin D status in patients with vitiligo is ambiguous when compared to controls. A systematic review and updated meta-analysis were conducted to evaluate the association between Vitamin D and vitiligo.

METHODS

Relevant studies were identified by searching PubMed and other databases. The random effects model was used to obtain standardized mean differences and pooled correlation coefficients. Meta-regression and sub-group analyses were conducted to explore heterogeneity. The presence of publication bias and the study robustness were tested using funnel plot and sensitivity analyses, respectively.

RESULTS

This meta-analysis finally included 31 studies. Compared with controls, vitiligo patients showed significantly decreased serum Vitamin D levels (standardized mean difference = -1.03; p < 0.0001). The sub-group analysis showed that vitiligo patients with indoor/urban work had a significantly lower Vitamin D level when compared to their outdoor/rural counterparts (standardized mean differences = -0.45; p = 0.03). The sensitivity analysis indicated that no single study had a significant influence on the overall outcome, suggesting the robustness of this meta-analysis.

STUDY LIMITATIONS

Varied sample sizes and heterogeneous study populations from different countries are the limitations of this study. However, the between-study heterogeneity has been addressed by the random-effects model with meta-regression and sensitivity analyses.

CONCLUSIONS

This meta-analysis showed significantly decreased Vitamin D level in vitiligo, and its association with indoor/outdoor type of work of vitiligo patients. This study highlights the need to assess Vitamin D status for improving its level in vitiligo.

Effects of ultraviolet irradiation with a LED device on bone metabolism associated with vitamin D deficiency in senescence-accelerated mouse P6

Aims

This study investigated effects of narrow-range ultraviolet irradiation (UVR) by a new UV–LED device on vitamin D supply and changes of bone in senescence-accelerated mouse P6 (SAMP6) with vitamin D deficiency.

Main methods

We used female SAMP6 mice as a senile osteoporotic model. We set a total of 3 groups (n = 4 per group); D-UVR+ group (vitamin D deficient–dietary and UVR), D- (vitamin D deficient–dietary), and D+ groups (vitamin D contained–dietary). Mice in the D-UVR + group were UV–irradiated (305nm) with 1 kJ/m² twice a week for 12 weeks from 20 to 32 weeks of age. Serum 25(OH)D, 1,25(OH)₂D, and micro–computed tomography (CT) were assessed over time. Mechanical test, and histological assay were performed for femurs removed at 32 weeks of age.

Key findings

UVR increased both serum 25(OH)D and 1,25(OH)₂D levels at 4 and 8 weeks–UVR in the D-UVR+ group compared with that in the D- group (P < 0.05, respectively). Relative levels of trabecular bone mineral density in micro–CT were higher in the D-UVR+ group than in the D- group at 8 weeks–UVR (P = 0.048). The ultimate load was significantly higher in the D-UVR+ group than in the D- group (P = 0.036). In histological assay, fewer osteoclasts and less immature bone (/mature bone) could be observed in the D-UVR+ group than in the D- group, significantly.

Significance

UVR may have possibility to improve bone metabolism associated with vitamin D deficiency in SAMP6 mice.

What Is New in Narrow-Band Ultraviolet-B Therapy for Vitiligo?

Vitiligo is an acquired disorder of skin pigmentation that produces significant psychological impact especially in those with skin of color. Narrow-band ultraviolet B (NB-UVB) therapy, which was first used in vitiligo in 1997 by Westerhof and Nieuweboer-Krobotova, has emerged as one of the safest and most effective therapy for this dermatosis. The light source used for NB-UVB phototherapy is the TL-01 lamp, and the most common model of the NB-UVB phototherapy device is the upright in-office booth or chamber which has 24-48 such lamps. In recent years, there have been several advances in the understanding of the mechanism of action of NB-UVB and the use of combination treatments, many of which increase the efficacy of NB-UVB. In 2017, the Vitiligo Working Group made vital recommendations on the dosage, frequency, and safety of NB-UVB in vitiligo. Furthermore, home phototherapy devices are gaining popularity as they lead to an improved patient compliance. There is still need for large multicenter randomized controlled trials to assess benefits of home phototherapy in vitiligo and studies investigating additional benefits of phototherapy following surgical therapy.