Evidence of a possible therapeutic role of vitamin D in a cohort of adult Caucasian vitiligo patients

The impact on the quality of life and sleep complaints in a vitiligo sample and the influence of inflammatory cytokines in the interaction between vitiligo and sleep

INTRODUCTION

Vitiligo is an autoimmune dermatosis that affects quality of life, which englobes sleep quality. Sleep regulates the immune system, including inflammatory cytokines, and other pathways, which may influence vitiligo pathogenesis.

OBJECTIVES

To analyze levels of immune serum components (cytokines) in a vitiligo group, and assess whether there was any association with sleep.

METHODS

This study comprised 30 vitiligo patients and 26 control individuals. Quality of life and sleep questionnaires were completed [Dermatology Life Quality Index (DLQI), Short-Form Health Survey (SF-36), Pittsburgh Sleep Quality Index (PSQI) and Insomnia Severity Index (ISI)]. Seven cytokines have been measured: IFN-γ, interleukin (IL)-4, IL-6, IL-10, IL-17A, IL-12 p40 and TNF-α.

RESULTS

The mean age of the vitiligo group was 47.7 years-old, with prevalence of females (66.7 %). Mucosal (70 %), acral (60 %) and focal subtype (53.3 %) predominated. Signs of vitiligo activity were identified in 63.3 % of the disease sample. Total PSQI scores and scores for domain 4 (sleep efficiency) were statistically worse in vitiligo group. The SF-36 and ISI total scores were worse in the vitiligo group, although not statistically significant compared with controls. Four SF-36 domains were statistically worse in vitiligo sample, and the DLQI mean score was mild to moderate (5.57). Cytokine levels were not different between groups, or when associated with PSQI. Higher ISI scores (more severe insomnia) were related to increased IL-17A. Higher IL-4, IL-6 and IL-10 levels were associated with previous phototherapy.

CONCLUSIONS

Poor sleep and impaired aspects of quality of life predominated in the vitiligo sample. Insomnia was related to IL-17A increase in vitiligo. Increased levels of IL-4, IL-6 and IL-10 were related to previous ultraviolet B narrow band (UVB-NB) phototherapy, suggesting an interaction of this treatment on immune system. Sleep disruption and the course of vitiligo may have common pathways in respect of circadian cytokines, which may represent an important subject in vitiligo management.

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.

Causal Associations between Vitamin D Levels and Psoriasis, Atopic Dermatitis, and Vitiligo: A Bidirectional Two-Sample Mendelian Randomization Analysis

BACKGROUND

Vitamin D level has been reported to be associated with psoriasis, atopic dermatitis, and vitiligo. However, its causal relationship with the risk of these three diseases remains unclear.

METHODS

We obtained genome-wide association statistics for three measures of circulating vitamin D levels (25(OH)D in 120,618 individuals, and 25(OH)D3 and epimeric form C3-epi-25(OH)D3 in 40,562 individuals) and for the diseases psoriasis (3871 cases and 333,288 controls), atopic dermatitis (21,399 cases and 95,464 controls), and vitiligo (4680 cases and 39,586 controls). We performed Mendelian randomization using inverse-variance weighted, weighted median, MR-Egger, and MR-pleiotropy residual sum and outlier methods. We carried out sensitivity analyses to evaluate the robustness of the results.

RESULTS

We showed that elevated vitamin D levels protected individuals from developing psoriasis (OR = 0.995, p = 8.84 × 10-4 for 25(OH)D; OR = 0.997, p = 1.81 × 10-3 for 25(OH)D3; and OR = 0.998, p = 0.044 for C3-epi-25(OH)D3). Genetically predicted risk of atopic dermatitis increased the levels of 25(OH)D (OR = 1.040, p = 7.14 × 10-4) and 25(OH)D3 (OR = 1.208, p = 0.048). A sensitivity analysis suggested the robustness of these causal associations.

CONCLUSIONS

This study reported causal relationships between circulating vitamin D levels and the risk of psoriasis, atopic dermatitis, and vitiligo. These findings provide potential disease intervention and monitoring targets.

Association Between Vitamin D, Zinc, and Thyroid Biomarker Levels With Vitiligo Disease: A Retrospective Cohort Study in a Tertiary Care Center

Objectives Vitiligo is a dermatological autoimmune disease that has been linked with numerous risk factors. There is an elevated level of evidence suggesting a linkage between vitiligo disease and zinc, vitamin D (Vit-D), thyroid hormones, and thyroid antibody levels. Methods This retrospective cohort study included patients of all age groups of both sexes. Patients were investigated for demographics, vitiligo characteristics, and laboratory tests, including zinc, Vit-D, T3 (triiodothyronine), T4 (thyroxine), thyroid-stimulating hormone (TSH), thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TGAb). Results Two hundred and ninety-seven patients were retrospectively assessed; they averaged 29 years for segmental vitiligo (SV) and 31 years for nonsegmental vitiligo (NSV). Gender-wise, our study included more females (57.5%) than males (42.5%). Females comprised approximately 51.8% of NSV patients, while males constituted 36.7%. Patients' T3, T4, and TPOAb levels correlated significantly with age (p=0.001, p <0.01, p=0.14), and elevated BMI recorded high TPOAb levels (p<0.001). An increase in TGAb was associated with extensive involvement in the depigmentation of body surface area (BSA). The segmental type had the lowest TGAb and TPOAb titers. The universal subtype of vitiligo recorded the highest TSH, T3, and TGAb levels. However, differences in laboratory test levels were insignificant for the sex, the type of vitiligo, or the subtype of vitiligo. Conclusion In conclusion, neither Vit-D nor zinc had a significant linkage with any of vitiligo's characteristics or treatments. Nonetheless, TGAb had a significant correlation to the BSA involved with vitiligo while T4 and TPOAb had a significant association with age, BMI, and BSA overall. Statistically, T3 was linked with age and BSA overall only. More studies with a higher level of evidence are required to establish the association of Vit-D, zinc, thyroid biomarkers, and thyroid antibodies.

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.

Nuclear factor erythroid 2-related factor 2 (Nrf2) as a potential therapeutic target for vitiligo

Vitiligo is an autoimmune disease of the skin which causes loss of melanocytes from the epidermis. Recently, it is demonstrated that oxidative stress (OS) plays a significant role in the immuno-pathogenesis of vitiligo. A major mechanism in the cellular defense against OS is activation of the nuclear factor erythroid2-related factor (Nrf2)-Kelch-like ECH-associated protein 1(Keap1)-antioxidant responsive element (ARE) signaling pathway. Recently it has been shown that vitiligo melanocytes have impaired Nrf2-ARE signaling. A number of drugs including those known as Nrf2 activators and those known to possess effects to activate Nrf2, have been used in treating vitiligo with certain therapeutic effects. Also, studies have shown that a number of compounds can protect melanocytes against OS via activating Nrf2. These compounds may be considered as candidates for developing new drugs for vitiligo in the future. Nrf2 can be considered as a potential therapeutic target for vitiligo.

Serum 25-hydroxyvitamin D concentration in Japanese Akita dogs: A survey

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Low serum 25-hydroxyvitamin D levels are detected in Japanese Akita dogs.

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Healthy Akitas show a higher level of vitamin D than pathological ones.

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Depigmented skin areas appearance is associated with low levels of vitamin D.

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Sebaceous adenitis is the prevalent disease recorded among investigated Akitas.

Low serum level of vitamin D has been linked to numerous diseases. The Akita breed of dog shows a high incidence of immune-mediated diseases such as uveodermatologic (UVD) syndrome and sebaceous adenitis (SA). Furthermore, in Japanese Akita dogs, skin depigmentation often appears after birth at different ages, in healthy dogs, and without any other symptoms. In humans poliosis is associated to low vitamin D level. The aim of this survey was to evaluate serum 25-hydroxyvitamin D (25(OH)D) levels in Japanese Akita dogs. One hundred and three Akita blood samples were collected for the 25(OH)D evaluation. Age, sex, current disease, presence and location of skin depigmentation, and diet were reported on a medical record. Based on history and clinical examination, dogs were classified according their health status as healthy (HE) or pathological (PA). The overall mean of 25(OH)D concentration was 82.42 ± 26.14 ng/mL, whereas the concentrations in the healthy dogs were significantly higher (84.90 ± 3.36 ng/mL) in comparison with the dogs with diseases (72.13 ± 4.09 ng/mL) (P < 0.01). In this study, the depigmented healthy dogs showed low level of 25(OH)D and very similar to the sick group. The appearance of depigmented areas associated with low levels of vitamin D could be considered as an alert sign in Akitas as well as in humans. However, clinical trials should also be carried out to establish whether vitamin D supplementation could be an effective preventive treatment to limit the onset of immune-mediated diseases in Japanese Akita dogs.