Evidence for an autoimmune pathogenesis of vitiligo

Topical application of simvastatin acid sodium salt and atorvastatin calcium salt in vitiligo patients. Results of the randomized, double-blind EVRAAS pilot study

Contemporary treatment of vitiligo remains a great challenge to practitioners. The vast majority of currently conducted clinical trials of modern therapeutic methods are focused on systemic medications, while there is only a very limited number of reports on new topical treatment in vitiligo. With their pleiotropic activities statins turned out to be efficient in the treatment of various autoimmune/autoinflammatory disorders. The randomized, double-blind placebo-controlled study of topical administration of the active forms of simvastatin and atorvastatin has been designed to evaluate their efficacy in patients with vitiligo. The study was registered in clinicaltrials.gov (registration number NCT03247400, date of registration: 11th August 2017). A total of 24 patients with the active form of non-segmental vitiligo were enrolled in the study. The change of absolute area of skin lesions, body surface area and vitiligo area scoring index were evaluated throughout the 12 week application of ointments containing simvastatin and atorvastatin. Measurements were performed with planimetry and processed using digital software. Use of active forms of simvastatin and atorvastatin did not result in a significant repigmentation of the skin lesions throughout the study period. Within the limbs treated with topical simvastatin, inhibition of disease progression was significantly more frequent than in the case of placebo (p = 0.004), while the difference was not statistically significant for atorvastatin (p = 0.082). Further studies of topical simvastatin in vitiligo patients should be considered.

Vitiligo Treated with Combined Piperine-Based Topical Treatment and Narrowband Ultraviolet B Therapy: Follow-Up with Reflectance Confocal Microscopy

BACKGROUND

Reflectance confocal microscopy (RCM) has a defined in vivo morphology of vitiligo and re-pigmentation. Combination therapies seem more effective than monotherapies.

OBJECTIVE

We aim to describe the clinical and RCM features of re-pigmentation with combined narrowband ultraviolet B (NB-UVB) and piperine-based topical treatment in localized vitiligo.

METHODS

Eight patients enrolled at a single center received combined treatment: topical treatment was applied twice daily + NB-UVB twice weekly for 2 × 2-month periods. Clinical changes were analyzed by the Vitiligo Noticeability Scale (VNS) and percentage of re-pigmentation. The evaluator agreement was assessed. Predefined RCM features had the presence/absence of (i) blood vessels, (ii) dendritic cells, and the quantity of (i) an irregular honeycombed pattern and (ii) non-pigmented papillae. Clinical and RCM monitoring was performed at the baseline, 2, 3, 5, and 7 months.

RESULTS

Macules were "slightly less noticeable" with 25-50% re-pigmentation. Irregular honeycomb patterns and non-pigmented papillae were significantly less frequently observed, and in less extended areas (T1 vs. T2, p = 0.039; T0 vs. T1, p = 0.005 and T2 vs. T4, p = 0.033). Dendritic cells and blood vessels improved, with significant changes in blood vessels (T1 vs. T2, p = 0.005 and T3 vs. T4, p = 0.008).

CONCLUSIONS

RCM confirms the morphological changes induced by combined treatment for localized vitiligo.

The effect of antioxidant dietary supplements and diet-derived circulating antioxidants on vitiligo outcome: evidence from genetic association and comprehensive Mendelian randomization

Background

Previous studies have indicated that antioxidant diets may have a positive impact on vitiligo by interfering with oxidative stress mechanisms. However, there has been a lack of research utilizing the Mendelian randomization (MR) method to analyze the relationship between antioxidant diet intake and vitiligo.

Methods

In this study, we employed both univariate Mendelian randomization (UVMR) and multivariate Mendelian randomization (MVMR) approaches. The specific antioxidant dietary supplements (such as coffee intake, green tea intake, herbal tea intake, standard tea intake, and average weekly red wine intake) as well as diet-derived circulating antioxidants, including Vit. C (ascorbate), Vit. E (α-tocopherol), Vit. E (γ-tocopherol), Carotene, Vit. A (retinol), Zinc, and Selenium (N = 2,603-428,860) were significantly associated with independent single-nucleotide polymorphisms (SNPs). We obtained pooled statistics on vitiligo from a meta-analysis of three genome-wide association studies (GWASs) of European ancestry, including 4,680 cases and 39,586 controls. Inverse variance weighted (IVW) was employed as the primary analytical method, and sensitivity analysis was conducted to assess the robustness of the main findings.

Results

Genetically, coffee intake [odds ratio (OR) = 0.17, 95% confidence interval (CI) 0.07-0.37, p = 1.57 × 10-5], average weekly red wine intake (OR = 0.28, 95% CI 0.08-1.00, p = 0.049), and standard tea intake (OR = 0.99, 95% CI 0.98-0.99, p = 5.66 × 10-7) were identified as protective factors against vitiligo. However, no causal effect between the intake of other antioxidant diets and vitiligo was found. Moreover, no instances of pleiotropy or heterogeneity were observed in this study.

Conclusion

Our study indicates that coffee, standard tea, and red wine consumption can potentially reduce the risk of vitiligo. However, there is insufficient evidence to support that other antioxidant diets have a significant effect on vitiligo.

Compromised melanocyte survival due to decreased suppression of CD4+ & CD8+ resident memory T cells by impaired TRM-regulatory T cells in generalized vitiligo patients

Regulatory T cells (Tregs) are involved in the suppression of activated T cells in generalized vitiligo (GV). The study was aimed to investigate resident memory (TRM)-Tregs and antigen-specific Tregs' numbers and functional defects in 25 GV patients and 20 controls. CD4+ & CD8+ TRM cell proliferation was assessed by BrDU assay; production of IL-10, TGF-β, IFN-γ, perforin and granzyme B were assessed by ELISA and enumeration of TRM cells was done by flowcytometry. GV patients showed significantly increased frequency and absolute count of CD4+ & CD8+ TRM cells in lesional (L), perilesional (PL) and non-lesional (NL) skin compared to controls (p = 0.0003, p = 0.0029 & p = 0.0115, respectively & p = 0.0003, p = 0.003 & p = 0.086, respectively). Whereas, TRM-Treg (p < 0.0001 & p = 0.0015) and antigen-specific Tregs (p = 0.0014 & p = 0.003) exhibited significantly decreased frequency and absolute counts in L & PL skin. GV patients showed reduced suppression of CD8+ & CD4+ TRM cells (with increased IFN-γ, perforin & granzyme B) and decreased TRM-Tregs and antigen-specific Tregs (with decreased IL-10 & TGF-β production) and reduced proliferation of SK-Mel-28 cells in co-culture systems. Immunohistochemistry revealed increased expression of TRM stimulating cytokines: IL-15 & IL-17A and reduced expression of TGF-β & IL-10 in L, PL, NL skins compared to controls. These results for the first time suggest that decreased and impaired TRM-Tregs and antigen-specific Tregs are unable to suppress CD4+ & CD8+ TRMs' cytotoxic function and their proliferation due to decrease production of immunosuppressive cytokines (IL-10 & TGF-β) and increased production of TRM based IFN-γ, perforin and granzyme B production, thus compromising the melanocyte survival in GV.

Risk of Melanoma and Nonmelanoma Skin Cancer in People with Vitiligo: United Kingdom Population-Based Cohort Study

Although genetic studies have found an inverse relationship between vitiligo and skin cancer, epidemiological evidence is conflicting. We investigated the risk of skin cancer in adults with vitiligo using United Kingdom electronic primary care records from the Optimum Patient Care Research Database 2010-2020. Vitiligo cases were age, sex, and general practitioner practice matched to population controls without vitiligo. Incidence of melanoma, nonmelanoma skin cancers (squamous cell carcinoma and basal cell carcinoma), and actinic keratoses was compared between vitiligo cases and controls using Cox regression. A total of 15,156 vitiligo cases were matched to 60,615 controls. Vitiligo was associated with a 38% reduced risk of new-onset skin cancer (adjusted hazard ratio [aHR] = 0.62, 95% confidence interval [CI] = 0.52-0.75, P < 0.001) and skin cancer subtypes; melanoma (aHR = 0.39, 95% CI = 0.23-0.65, P < 0.001), squamous cell carcinoma (aHR = 0.67, 95% CI = 0.49-0.90, P < 0.01), basal cell carcinoma (aHR = 0.65, 95% CI = 0.51-0.83, P < 0.001). There was no significant association for actinic keratosis (aHR = 0.88, 95% CI = 0.77-1.01). People with vitiligo have a markedly reduced incidence of melanoma and nonmelanoma skin cancer. Given concerns that some treatments, such as phototherapy, may increase skin cancer risk, this finding provides reassurance to people with vitiligo and clinicians managing the condition.

Leucoderma in Buffaloes (Bubalus bubalis) in the Amazon Biome

Leucoderma is a condition that affects the skin and hair of animals, causing depigmentation and acromotrichia. In buffaloes, this condition results in significant economic losses for the production chain due to its impact on the leather trade. This study aimed to investigate the epidemiological and clinicopathological aspects of leucoderma in buffaloes in the Amazon biome and describe the prophylactic treatment to control the disease. The study included 40 buffaloes, 16 males and 24 females, aged between 1 and 10 years, and were of the Murrah, Jafarabadi, Mediterranean, and Murrah × Mediterranean crossbreed breeds. The animals were raised without mineral supplementation. The clinical signs observed in the animals included acromotrichia and depigmentation, with varying degrees and distribution of skin lesions. Histological examination of the epidermis showed interrupted melanin production, mild dermal fibrosis, mild perivascular mononuclear inflammatory infiltrate, and pigmentary incontinence. None of the animals had the genotype for albinism. After 120 days of mineral supplementation based on the use of copper sulfate, the clinical signs of leucoderma regressed. There was no predisposition by breed, sex, or age for the occurrence of the disease. The regression of skin lesions after proper mineral supplementation suggests that copper deficiency may be considered an important factor for the occurrence of leucoderma in buffaloes in the Amazon biome.

The efficacy of bimatoprost ophthalmic solution combined with NB-UVB phototherapy in non-segmental and segmental vitiligo: a single-blind randomized controlled study

Bimatoprost ophthalmic solution 0.03% (PGF2α analogues) combined with narrowband ultraviolet B (NB-UVB) was reported to be an effective treatment for vitiligo. To investigate the efficacy and safety of treatment for non-segmental/segmental vitiligo compared among bimatoprost ophthalmic solution 0.01% combined with NB-UVB phototherapy, bimatoprost monotherapy, and placebo. This single-blind randomized controlled study enrolled stable Thai vitiligo patients with at least three similarly sized lesions in the same anatomical area. The treatment duration was 6 months with 1- and 2-month post-treatment follow-ups. The 3 selected lesions on each patient were randomized to receive combination therapy, monotherapy, or placebo. The Vitiligo Area Scoring Index (VASI) was used to evaluate lesion response. Of the 25 initially enrolled subjects, 19 patients were analyzed. There were 13 and 6 non-segmental and segmental vitiligo cases, respectively. Eight and 11 cases had face/neck and non-face/neck lesions, respectively. Non-segmental vitiligo and non-face/neck vitiligo patients in the combination group had significant improvement in VASI score at 3 months, 6 months, and at the 2-month follow-up. No side effects were observed/reported. Bimatoprost combination therapy was shown to be safe and effective for treating Thai patients with non-segmental vitiligo in non-face/neck areas of the body.

Vitiligo and Crohn's disease form an autoimmune cluster: insights from a population-based study

BACKGROUND

While the coexistence of vitiligo and Crohn's disease (CD) has been reported in individual patients, the epidemiological association between these autoimmune conditions remains inconclusive.

OBJECTIVE

To assess the bidirectional association between vitiligo and CD.

METHODS

A population-based study was performed to compare vitiligo patients (n = 20,851) with age-, sex- and ethnicity-matched control subjects (n = 102,475) regarding the incidence of new-onset and the prevalence of preexisting CD. Adjusted hazard ratios (HRs) and adjusted odds ratios (ORs) were calculated by multivariable Cox regression and logistic regression, respectively.

RESULTS

The incidence rate of new-onset CD was evaluated at 3.6 (95% CI, 2.7-4.9) cases per 10,000 person-years (PY) in patients with vitiligo and 2.4 (95% CI, 2.0-2.9) cases per 10,000 PY in controls. Patients with vitiligo experienced an elevated risk of CD (fully adjusted HR, 1.60; 95% CI, 1.10-2.34; p = 0.015). Congruently, a history of preexisting CD predicted elevated odds of having subsequent vitiligo (fully adjusted OR, 1.49; 95% CI, 1.15-1.93; p = 0.002). Compared to other patients with vitiligo, those with vitiligo and comorbid CD were older and had a higher prevalence of diabetes mellitus, hyperlipidemia, and hypertension but a comparable all-cause mortality rate.

CONCLUSIONS

The current study depicts a robust bidirectional association between vitiligo and CD. This knowledge is of clinical implication for physicians managing patients with both conditions. The diagnostic threshold for CD should be lowered in vitiligo patients with compatible symptoms.

Vitiligo, from Pathogenesis to Therapeutic Advances: State of the Art

Vitiligo is an acquired hypopigmentation of the skin due to a progressive selective loss of melanocytes; it has a prevalence of 1-2% and appears as rounded, well-demarcated white macules. The etiopathology of the disease has not been well defined, but multiple factors contribute to melanocyte loss: metabolic abnormalities, oxidative stress, inflammation, and autoimmunity. Therefore, a convergence theory was proposed that combines all existing theories into a comprehensive one in which several mechanisms contribute to the reduction of melanocyte viability. In addition, increasingly in-depth knowledge about the disease's pathogenetic processes has enabled the development of increasingly targeted therapeutic strategies with high efficacy and fewer side effects. The aim of this paper is, by conducting a narrative review of the literature, to analyze the pathogenesis of vitiligo and the most recent treatments available for this condition.

Evidence for Epistatic Interaction between HLA-G and LILRB1 in the Pathogenesis of Nonsegmental Vitiligo

Vitiligo is the most frequent cause of depigmentation worldwide. Genetic association studies have discovered about 50 loci associated with disease, many with immunological functions. Among them is HLA-G, which modulates immunity by interacting with specific inhibitory receptors, mainly LILRB1 and LILRB2. Here we investigated the LILRB1 and LILRB2 association with vitiligo risk and evaluated the possible role of interactions between HLA-G and its receptors in this pathogenesis. We tested the association of the polymorphisms of HLA-G, LILRB1, and LILRB2 with vitiligo using logistic regression along with adjustment by ancestry. Further, methods based on the multifactor dimensionality reduction (MDR) approach (MDR v.3.0.2, GMDR v.0.9, and MB-MDR) were used to detect potential epistatic interactions between polymorphisms from the three genes. An interaction involving rs9380142 and rs2114511 polymorphisms was identified by all methods used. The polymorphism rs9380142 is an HLA-G 3'UTR variant (+3187) with a well-established role in mRNA stability. The polymorphism rs2114511 is located in the exonic region of LILRB1. Although no association involving this SNP has been reported, ChIP-Seq experiments have identified this position as an EBF1 binding site. These results highlight the role of an epistatic interaction between HLA-G and LILRB1 in vitiligo pathogenesis.

The efficacy of adding topical 5-fluorouracil to micro-needling in the treatment of vitiligo: A randomized controlled trial

BACKGROUND AND AIM

Vitiligo is an autoimmune skin disorder characterized by circumscribed depigmented macules and patches caused by the loss of functional melanocytes. Although there is no definitive treatment for vitiligo, several treatment options have been associated with relative satisfactory outcomes. The purpose of this study was to compare the efficacy of micro-needling in conjunction with topical 5-fluorouracil (5-FU) versus topical tacrolimus ointment in treating vitiligo patches.

PATIENTS AND METHODS

This study included nineteen participants, each of whom received both treatments on two randomly selected vitiligo patches of approximately the same size and location. On one patch, a combination of weekly micro-needling and topical application of 5-FU solution was used every other day, while on the other, 0.1% tacrolimus topical ointment was applied twice daily. The G-score was used to compare treatment outcomes after 3 months.

RESULTS

The median duration of the disease in our population was 7 years. Six patients (32%) in the micro-needling plus topical 5-FU treated group showed a moderate to excellent response, indicating a significant improvement between both treatments (p-value = 0.019). In contrast, all other patches treated with topical tacrolimus showed poor improvement. Lower extremity and trunk responded more to treatment with micro-needling plus topical 5-FU than upper extremity and acral areas. Moreover, none of those who have had the disease for more than ten years have responded to treatment. Mild erythema, pinpoint bleeding, and irritation were detected only in the micro-needling treated group.

CONCLUSION

The current study showed that using micro-needling in conjunction with 5-FU could treat vitiligo patients more efficiently than tacrolimus monotherapy. Despite showing moderate to excellent improvement in patches treated with micro-needling and 5-FU, this well-tolerated office-based modality still requires additional research.

Hashimoto's thyroiditis and coexisting disorders in correlation with HLA status-an overview

Hashimoto's thyroiditis (HT), also known as chronic lymphocytic thyroiditis, is a frequent disorder of the thyroid gland caused by autoimmune-trigged lymphocytic infiltration and destruction of the thyroid gland. With the progressive destruction of the organ, the thyroid gland shrinks in size, thus commonly leading to hypothyroidism. Therapy of HT is mainly focused on managing the thyroid dysfunction by oral substitution of L‑thyroxine. However, patients with HT often complain about a broad spectrum of symptoms, with some of them hardly explained by HT itself. Several other disorders are known to be associated with HT. The etiology of HT seems to be multifactorial, including environmental influences such as iodine supply, infections, and stress as triggers of immune modulation. In addition, also a genetic background based on changes of the human leukocyte antigen (HLA) status seems to be evident. The paper will provide an overview of diseases related to HT, including their correlation to certain HLA patterns. This presentation should give a broader view on HT-related disorders and facilitate detailed examination and management of patients with HT.

Leptin deficiency in CD8+ T cells ameliorates non-segmental vitiligo by reducing interferon-γ and Granzyme B

Background

Vitiligo is an autoimmune skin disease mainly mediated by CD8⁺ T cells, which affects about 0.1%-2% population of the world. Leptin plays a critical role in regulating the activation of CD8⁺ T cells. However, the effect of Leptin on vitiligo remains unclear.

Objectives

To explore the effect of leptin on CD8⁺ T cells and its influence on vitiligo.

Methods

RNA sequencing and Quantitative Real-time PCR (RT-qPCR) were used to explore the differentially expressed genes. Immunofluorescence staining was performed on skin lesions. Leptin in serum was detected by enzyme linked immunosorbent assay (ELISA). The peripheral blood mononuclear cells were detected by flow cytometry after leptin stimulation for 72 hours. A vitiligo model was established by monobenzone on Leptin KO mice.

Results

557 differentially expressed genes were found, including 154 up-regulated and 403 down-regulated genes. Lipid metabolism pathways showed a close relationship to the pathogenesis of vitiligo, especially the PPAR signaling pathway. RT-qPCR (p = 0.013) and immunofluorescence staining (p = 0.0053) verified that LEPR expressed significantly higher in vitiligo. The serum leptin level of vitiligo patients was significantly lower than that of healthy controls (p = 0.0245). The interferon-γ subset of CD8⁺LEPR⁺ T cells from vitiligo patients was significantly higher (p = 0.0189). The protein level of interferon-γ was significantly increased after leptin stimulation in vitro (p = 0.0217). In mice, Leptin deficiency resulted in less severe hair depigmentation. Leptin deficiency also resulted in significantly lower expressed vitiligo-related genes, such as Cxcl9 (p = 0.0497), Gzmb (p < 0.001), Ifng (p = 0.0159), and Mx1 (p < 0.001) after modeling.

Conclusion

Leptin could promote the progression of vitiligo by enhancing the cytotoxic function of CD8⁺ T cells. Leptin may become a new target for vitiligo treatment.

Thyroid Autoimmunity in Vitiligo: A Case-Control Study

Introduction There is scanty evidence regarding the role of autoimmunity in vitiligo, especially in the Asian population. Moreover, the existing studies reported conflicting results. This prompted the investigators to identify the association of thyroid autoimmunity with vitiligo by employing a case-control design in this setting. Methodology The present study was a hospital-based case-control study conducted in one of the tertiary care hospitals of North India. We recruited 30 subjects aged 16-60 years with vitiligo attending the skin and venereal diseases outpatient department. The subjects attending the general medicine outpatient department without having a diagnosis of vitiligo were considered for the control group. Thyroid hormones (FT3 and FT4), thyroid-stimulating hormones, anti-thyroid peroxidase (anti-TPO) antibodies, and anti-thyroglobulin (anti-TG) antibodies were the primary investigations performed among the study subjects. Results The mean age of the study subjects was 31.3 (SD: 13.3) years. Both the case and control groups were comparable based on selected socio-demographic variables (p > 0.05). There was a statistically significant difference in terms of mean anti-TPO and anti-TG values between the case and control groups in which subjects with vitiligo reported significantly higher values (p < 0.05). Conclusion Our study reported a significant elevation in the mean values of the thyroid antibodies (anti-TG and anti-TPO antibodies) in vitiligo subjects compared to control subjects in this setting. Hence, screening for autoimmune thyroid diseases among patients with vitiligo is suggested for the early detection and the initiation of appropriate intervention.

NRF2 in the Epidermal Pigmentary System

Melanogenesis is a major part of the environmental responses and tissue development of the integumentary system. The balance between reduction and oxidation (redox) governs pigmentary responses, for which coordination among epidermal resident cells is indispensable. Here, we review the current understanding of melanocyte biology with a particular focus on the "master regulator" of oxidative stress responses (i.e., the Kelch-like erythroid cell-derived protein with cap'n'collar homology-associated protein 1-nuclear factor erythroid-2-related factor 2 system) and the autoimmune pigment disorder vitiligo. Our investigation revealed that the former is essential in pigmentogenesis, whereas the latter results from unbalanced redox homeostasis and/or defective intercellular communication in the interfollicular epidermis (IFE). Finally, we propose a model in which keratinocytes provide a "niche" for differentiated melanocytes and may "imprint" IFE pigmentation.

The role of cytokines and vitamin D in vitiligo pathogenesis

Vitiligo is a pigment-related disease with a global prevalence of 0.2% to 1.8% associated with considerable burden on quality of life. The treatment is still a challenge because of relapses and/or incomplete re-pigmentation. Although the exact cause is still unclear, its pathogenesis seems to be justifiable with the autoimmune theory, supported by the results of clinical research. In this narrative review, we aimed to summarize the evidence related to cytokines and vitiligo development. This review is consisted of English articles published in PubMed and Google Scholar concerning levels of inflammatory mediators, especially interleukins, in vitiligo patients over the last 20 years. References of relevant articles were also considered for review. Crucial role of dysregulated levels of interleukins and their synergistic function to each other, in the onset or progression of the disease is evident. The theory of autoimmune vitiligo is reinforced by the results of the studies in the literature, due to the association of pathogenesis with increased secretion of pro-inflammatory mediators and reduction of anti-inflammatory mediators. Decreased vitamin D levels may have a considerable role in vitiligo development by affecting Th1- and Th17-related immune responses. Cytokines play an important role in the pathogenesis or progression of the disease. Moreover, we believe that decreased vitamin D level has a considerable role in vitiligo development by affecting Th1- and Th17-related immune responses.

Current Debates on Etiopathogenesis and Treatment Strategies for Vitiligo

Vitiligo is an acquired, chronic, and progressive depigmentation or hypopigmentation characterized by the destruction of melanocytes and the occurrence of white patches or macules in the skin, mucosal surface of eyes, and ears. Melanocytes are the melanin pigment-producing cells of the skin which are destroyed in pathological conditions called vitiligo. Approximately 0.5 - 2.0% of the population is suffering from vitiligo, and a higher prevalence rate of up to 8.8% has been reported in India. It is caused by various pathogenic factors like genetic predisposition, hyperimmune activation, increased oxidative stress, and alteration in neuropeptides level. Genetic research has revealed a multi- genetic inheritance that exhibits an overlap with other autoimmune disorders. However, melanocytes specific genes are also affected (such as DDR1, XBP1, NLRP1, PTPN22, COMT, FOXP3, ACE, APE, GSTP1, TLR, SOD, and CTLA-4). A number of therapeutic options are employed for the treatment of vitiligo. The topical corticosteroids and immunomodulators are currently in practice for the management of vitiligo. Phototherapies alone and in combinations with other approaches are used in those patients who do not respond to the topical treatment. The main focus of this review is on the etiopathological factors, pharmacological management (phototherapy, topical, systemic, and surgical therapy), and herbal drugs used to treat vitiligo.

Decreased GZMB, NRP1, ITPR1, and SERPINB9 Transcripts Lead to Reduced Regulatory T Cells Suppressive Capacity in Generalized Vitiligo Patients

Generalized vitiligo (GV) is an autoimmune skin disease characterized by bilateral white patches over the entire body. Regulatory T cells (Tregs) maintain peripheral tolerance; however, they are found to be reduced in numbers and function in vitiligo patients. The exact mechanism for reduced Treg suppressive capacity is unknown. Therefore, we aimed to assess transcript levels of Tregs-associated immunosuppressive genes (GZMB, NRP1, PDCD1, FASLG, and TNFRS18), regulatory molecules of Tregs suppressive function (SERPINB9, ITPR1, and UBASH3A), and Treg-associated transcription factors (GATA2, GATA3, RUNX1, STAT3, and STAT5) in 52 GV patients and 48 controls by real-time PCR (qPCR). We found significantly reduced GZMB, NRP1, SERPINB9, and ITPR1 transcripts in GV Tregs compared to controls (p = 0.03, p = 0.023, p = 0.0045, and p < 0.0001, respectively). There were 0.44-, 0.45-, 0.32-, and 0.54-fold decrease in GZMB, NRP1, SERPINB9, and ITPR1 transcripts in GV Tregs. Additionally, disease activity and severity-based analyses revealed significantly decreased GZMB (p = 0.019 and 0.034), SERPINB9 (p = 0.031 and p = 0.035), and ITPR1 (p = 0.0003 and p = 0.034) transcripts in active vitiligo and severe GV patients' Tregs. Interestingly, we found a positive correlation for ITPR1 with GZMB (r = 0.45, p = 0.0009) and SERPINB9 (r = 0.52, p = 0.001) transcripts in GV Tregs. Moreover, we found positive correlation for percentage Treg mediated suppression of CD4⁺ and CD8⁺T cells with ITPR1 (r = 0.54; r = 0.49), GZMB (r = 0.61; r = 0.58), NRP1 (r = 0.55; r = 0.52), and SERPINB9 (r = 0.56; r = 0.48) in GV Tregs. Further, calcium treatment of Tregs resulted into significantly increased ITPR1, SERPINB9, and GZMB transcripts in GV Tregs (p = 0.023, p = 0.0345, p = 0.02). Overall, our results for the first time revealed the crucial role of GZMB, NRP1, SERPINB9, and ITPR1 transcripts in decreased Treg suppressive capacity leading to GV pathogenesis, progression, and severity. In addition, our study highlighted that ITPR1 might be linked with decreased GZMB and NRP1 expression in GV Tregs. Moreover, our study for the first time suggest that increased SERPINB9 transcripts may lead to endogenous granzyme B-mediated Tregs apoptosis, and calcium treatment of Tregs may improve the Treg suppressive capacity. These findings may further aid in development of Treg-based therapeutics for GV.

Inhibition of Fam114A1 protects melanocytes from apoptosis through higher RACK1 expression

Fam114A1 is a gene closely related to the development of nerve cells, melanocytes, and nerve cells that originate from the neural crest of the embryonic ectoderm. Recent studies showed that Fam114A1 has a role in the occurrence of ankylosing myelitis spondylitis and autoimmune enteritis; still, its cellular function remains poorly understood. In this study, we investigated the effect of Fam114A1 on the biological activity of melanocytes. We found that the expression of Fam114A1 in vitiligo melanocytes (MCV-L, MCV-N, PI3V) was higher than that in normal melanocytes, and the biological function of melanocytes was significantly affected when the Fam114A1 gene was silenced. Inhibition of Fam114A1 increased proliferation, migration, and melanin synthesis proteins, decreased apoptosis, while its overexpression reversed this process. Mechanistically, we discovered that RACK1 is a target protein of Fam114A1 and that RACK1 can be negatively regulated by Fam114A1. Further study showed that Fam114A1 inhibition could not protect melanocytes from apoptosis once the expression of RACK1 protein was silenced. In summary, Fam114A1 is an effective regulatory protein for regulating the function of melanocytes. Inhibition Fam114A1 protects melanocytes from apoptosis through increasing RACK1.

The Study of Serum Level of Interleukin-2, Interleukin-6, and Tumor Necrosis Factor-alpha in Stable and Progressive Vitiligo Patients from Sina Hospital in Tabriz, Iran

Background:

Vitiligo is an acquired depigmenting disorder characterized by the loss of functional melanocytes from the epidermis. Although the etiology of vitiligo is unknown, over the last few years, substantial data from clinical research have greatly supported the "Autoimmune theory." Vitiligo has two major forms: progressive and stable. As cytokines are important mediators of immunity, the most important of them are IL-2, IL-6, and tumor necrosis factor-α (TNF-α).

Objectives:

We aimed to study the serum level of IL-2, IL-6, and TNF-α in stable and progressive vitiligo and compared them to find a useful lab test to determine the form of vitiligo for diagnose and treatment.

Materials and Methods:

Serum IL-2, IL-6, and TNF-α were done by the indirect enzyme-linked immunosorbent assay (ELISA) in 40 cases of stable and progressive vitiligo.

Results:

Twenty patients had progressive vitiligo and 20 patients were stable vitiligo. In every group, there were seven male patients. Twenty-one patients had a positive family history of vitiligo and four patients had other autoimmune diseases. The average age and familial history between two groups and two genders were not meaningful. The mean serum TNF-α level was significantly higher in progressive than stable vitiligo. No significant difference was observed in the serum levels of IL-2, IL-6 between stable and progressive vitiligo. The mean serum IL-6 and TNF-α had higher levels in male patients.

Conclusion:

Analysis of TNF-α levels in every age or gender can show us the type of vitiligo, stable or progressive and we can choose the best form of treatment for patients.

Vitiligo: What's old, what's new

Vitiligo is an acquired pigmentary disorder afflicting 0.5-2% of the world population for both sexes and all races with a capricious and unpredictable course. It has a complex etiology and varies in its manifestation, progression and response to treatment. Even if the precise aetiology and pathobiology of the disease are complex and still debated, recent evidence supports that vitiligo is a T CD8+ cell-mediated autoimmune disease triggered by oxidative stress. To date no clinical, biological and histological criteria allow us to establish the prognosis with certainty. The choice of the best therapy for adult and childhood vitiligo is based on various factors, such as the patient's age, psychological condition and expectations, distribution and extension of skin lesions, type of vitiligo (stable or not) and availability and cost of therapeutic options. Since vitiligo has a deep psychological impact on patients and their quality of life, treating the disease is very important. As dermatologists, we have important goals in the treatment of vitiligo patients: stabilization of the disease progression, repigmentation of the lesions and especially the persistence of the aforementioned repigmentation. Although several medical and surgical therapeutic options have been proposed, no definite cure has yet been developed and the long-term persistence of repigmentation is unpredictable. We review the different therapeutic options with particular attention on the recurrence rate.

Emerging role of Tissue Resident Memory T cells in vitiligo: From pathogenesis to therapeutics

Vitiligo is an acquired depigmenting disorder which affects both skin and mucous membranes and autoimmunity has been strongly suggested to play a role in loss of melanocytes. The recurrence of skin macules at the same sites where they were observed prior to the treatment, suggests the existence of Tissue Resident Memory T cells (TRMs) that persist within the skin or peripheral tissues with a longer survivability. Emerging studies have shown that reactivation of these skin TRMs results into autoreactive TRM cells in various autoimmune diseases including vitiligo. This review focuses on different subsets (CD8⁺ TRMs and CD4⁺ TRMs) of TRM cells, their retention and survivability in the skin along with their pathomechanisms leading to melanocyte death and progression of vitiligo. In addition, the review describes the TRM cells as potential targets for developing effective therapeutics of vitiligo.

Role of Amine Neurotransmitters and Their Receptors in Skin Pigmentation: Therapeutic Implication

Skin pigmentation can occur due to increased melanin, including melanocyte proliferation, melanin biosynthesis, or melanocyte migration. There are many factors that influence the melanin production process, but the role of neurotransmitters in this process is still unclear. We found that histamine and serotonin influence the different stages of melanogenesis and melanogenesis, which increase melanogenesis. Since then, several related papers have been published, and from these papers, it has been recognised that the role of neurotransmitters in skin-pigment-related diseases needs to be summarised. By introducing the role of neurotransmitters in the regulation of various pigment disorders, including vitiligo and melasma, through this review, many researchers can be expected to try to apply neurotransmitter-related agonists and antagonists as treatments for skin pigment disorders.

Increased Circulatory Interleukin-17A Levels in Patients with Progressive and Leukotrichial Vitiligo

Background

Vitiligo is a chronic condition characterized by skin depigmentation. Although not life-threatening, it significantly impacts quality of life. The pathophysiology of vitiligo remains poorly understood, and treatment options are limited. Mounting evidence supports the importance of autoreactive T cells and, particularly interleukin-17A- (IL-17A-) secreting Th17 cells, in vitiligo. IL-17A targeting has been proven successful in various inflammatory dermatological conditions, including psoriasis and lupus erythematosus.

Objective

We evaluated the relationship between serum levels of IL-17A and the clinicopathological characteristics of Vietnamese vitiligo patients.

Methods

In this cross-sectional study, we analyzed data from 52 nonsegmental vitiligo patients and 50 age- and sex-matched healthy individuals. Serum levels of IL-17A were measured using an enzyme-linked immunosorbent assay. We evaluated the correlation between IL-17A levels and clinical characteristics including leukotrichia, disease duration, vitiligo activity, and body surface area involvement.

Results

Patients with progressive vitiligo had significantly higher IL-17A levels than patients with stable vitiligo (P = 0.014) or healthy individuals (P = 0.002). In addition, serum IL-17A levels were higher in vitiligo patients with leukotrichia than in patients without it (P = 0.04). Furthermore, serum IL-17A levels were negatively correlated with age (r = -0.39, P = 0.004) and age of onset (r = -0.33, P = 0.016) in vitiligo patients.

Conclusions

Higher serum levels of IL-17A in patients with progressive vitiligo and leukotrichia suggest a potential role of IL-17A in melanocyte destruction in the epidermis and the follicular matrix.

Pregnancy outcomes in women with vitiligo: A Taiwanese nationwide cohort study

Vitiligo is perceived as an autoimmune skin disease. Previous studies showed conflicting data about vitiligo and pregnancy outcomes. To delineate the associations between vitiligo and the pregnancy outcomes, we used the National Health Insurance Research Database of Taiwan to conduct a retrospective cohort study from January 1, 2000 to December 31, 2015. This study population was composed of 1,096 women with vitiligo and 4,384 women without vitiligo, who were all matched according to age, comorbidity, and index year. Compared with the non-vitiligo controls, women with vitiligo had a higher risk of abortion (aHR 1.158, 95% confidence interval (CI) 1.095–1.258, P < .001). Perinatal events, such as preterm delivery, pre-eclampsia/eclampsia, gestational diabetes mellitus, stillbirth, and intrauterine growth retardation, were not different between both groups (aHR 1.065, 95% CI 0.817–1.157, P = .413). To determine if systemic treatment before conception decreases the risk of abortion, we assessed the medical history of pregnant women with vitiligo 1 year before pregnancy. Patients who were treated with oral medications had a lower risk of abortion than those who were not (aHR: 0.675, 95% CI: 0.482–0.809, P < .001). Our study indicates that there is a higher risk of abortion in pregnant women with vitiligo and the control of disease activity with systemic treatment before conception could improve pregnancy outcomes.

Association between vitiligo and subsequent risk of dementia: A population-based cohort study

Increasing evidence suggests a positive association between autoimmune disorders and the subsequent risk of dementia, supporting the idea that neuroinflammation is a major contributor to dementia. However, whether or not adults with vitiligo have an increased risk of dementia remains unclear. We aimed to investigate the association between vitiligo and the subsequent risk of dementia. A total of 1320 patients with vitiligo and 5280 matched controls were identified from the Taiwan National Health Insurance Research Database between 1998 and 2011. Dementia was diagnosed by board-certificated psychiatrists or neurologists in the follow-up period. Cox proportional hazards models were used to estimate the adjusted hazard ratios (aHR) after controlling for age, sex, income-related monthly premium, residence and comorbidities associated with dementia. The incidence rate of dementia (per 100 000 person-years) was 502.8 among patients with vitiligo and 101.9 among the controls. Patients with vitiligo were more likely to develop any type of dementia (aHR, 5.30; 95% confidence interval [CI], 3.30-8.51), Alzheimer's disease (aHR, 12.22; 95% CI, 3.71-40.28) and vascular dementia (aHR, 3.99; 95% CI, 1.31-12.15) compared with the controls. In conclusion, middle-aged and old patients with vitiligo are more likely to develop dementia compared with those without vitiligo. This novel finding reminds physicians to be more careful about signs of dementia when managing patients with vitiligo and provides the basis for further investigations that clarify the underlying mechanisms.

Targeting the PD-1/PD-L1 Axis in Human Vitiligo

Autoreactive CD8⁺ T cells play a pivotal role in melanocyte destruction in autoimmune vitiligo. Immunotherapy for melanoma often leads to autoimmune side-effects, among which vitiligo-like depigmentation, indicating that targeting immune checkpoints can break peripheral tolerance against self-antigens in the skin. Therapeutically enhancing immune checkpoint signaling by immune cells or skin cells, making self-reactive T cells anergic, seems a promising therapeutic option for vitiligo. Here, we review the current knowledge on the PD-1/PD-L1 pathway in vitiligo as new therapeutic target for vitiligo therapy.

Comparative efficacy between localized 308-nm excimer light and targeted 311-nm narrowband ultraviolet B phototherapy in vitiligo: A randomized, single-blind comparison study

BACKGROUND

There are limited data to compare efficacy between recent 308-nm excimer and conventional 311-nm narrowband ultraviolet B (NB-UVB) light in the treatment of vitiligo.

OBJECTIVE

To compare efficacy between 308-nm excimer light and 311-nm NB-UVB in patients with symmetrical vitiligo lesions.

METHODS

Thirty-six symmetrically paired vitiligo lesions on the same anatomical area were enrolled. One side of the symmetrical lesions was treated with localized 308-nm excimer light, and the opposite side was treated with targeted 311-nm NB-UVB assigned randomly by computer. All lesions were treated with the same protocol, for 48 sessions. Repigmentation was evaluated using Vitiligo Area Scoring Index (VASI) and grading the repigmentation was carried out with three independent investigators.

RESULTS

Thirty-six symmetrically vitiligo lesions were randomly treated, one side with 308-nm excimer light and the opposite side with 311-nm NB-UVB. After 48 sessions, a significantly lower VASI score and a higher grade of repigmentation were observed in 308-nm excimer light-treated side (P < .001). Nine lesions (25%) treated with 308-nm excimer light and only five lesions (13.89%) treated with 311-nm NB-UVB achieved excellent repigmentation. The 308-nm excimer light and 311-nm NB-UVB-treated sides rapidly obtained 25% repigmentation within a mean of 19.42 sessions and 26.25 sessions, respectively (P = .002). There was no significant difference in mean cumulative UV dosage (P = .065). Side effect as phototoxicity was similar in both sides (P = .08).

CONCLUSION

Localized 308-nm excimer light appears to be more effective and also more rapidly induces repigmentation than targeted 311-nm NB-UVB for treatment of vitiligo.

Immunohistochemical study of perforin and apoptosis stimulation fragment ligand (FasL)in active vitiligo

Several studies demonstrated a major pathological role of melanocyte-specific cytotoxic CD8⁺ T cells in the pathogenesis of vitiligo. It has been suggested that apoptosis, rather than necrosis, is the mechanism of melanocyte depletion in vitiligo. The aim of this study was to evaluate the expression and distribution of perforin and apoptosis stimulation fragment ligand (FasL) in the epidermis and dermis of the perilesional and non-lesional skin of vitiligo patients in comparison to controls, to assess their possible role in mediating apoptosis in vitiligo. Twenty patients with active non-segmental vitiligo and 20 healthy controls were enrolled in the study. Skin biopsies were taken from perilesional and non-lesional skin of patients with vitiligo, as well as covered skin of controls. Immunostaining for perforin and FasL was performed and the quantitative analysis for the expression of perforin and FasL was carried out in the epidermis and dermis of biopsied specimens. Epidermal perforin, dermal perforin, epidermal FasL, dermal FasL were significantly higher in perilesional as well as non-lesional skin than controls. There was a statistically significant positive correlation between epidermal and dermal perforin in perilesional skin. There was a statistically significant positive correlation between epidermal and dermal perforin, as well as epidermal and dermal FasL in non-lesional skin. In conclusion, the significant expression of perforin and FasL in the epidermis and dermis of both perilesional and non-lesional skin of active vitiligo patients suggests the role of cytotoxic granules and apoptotic cell death pathways in the pathogenesis of active vitiligo.

Decreased suppression of CD8+ and CD4+ T cells by peripheral regulatory T cells in generalized vitiligo due to reduced NFATC1 and FOXP3 proteins

Regulatory T cells (Tregs) are involved in the suppression of activated T cells in generalized vitiligo (GV). The study was aimed to investigate Tregs functional defects in Treg:CD8⁺ and Treg:CD4⁺ T cells' co-culture systems of 55 GV patients and 45 controls. CD8⁺ and CD4⁺ T-cell proliferation was assessed by BrdU assay; production of IL-10, TGF-β and IFN-γ cytokines was assessed by ELISA; and FOXP3, CD25, NFATC1 and CD44 proteins were measured by flow cytometry. Generalized vitiligo patients showed reduced suppression of CD8⁺ and CD4⁺ T cells (P = .0384, P = .0084), increased IFN-γ (P < .0001, P = .0019), decreased IL-10 and TGF-β (P < .0001) and decreased FOXP3, CD25 and NFATC1 proteins (P < .0001). Active vitiligo (AV) patients showed reduced suppression of CD8⁺ & CD4⁺ T cells (P = .006, P = .015), increased IFN-γ (P = .036, P = .045), decreased IL-10 (P = .009, P = .021), FOXP3 (P = .0244) and NFATC1 (P = .019). Severe GV (50%-75% VASI) patients showed reduced suppression of CD8⁺ and CD4⁺ T cells (P = .0003, P = .001), increased IFN-γ (P = .0029, P < .0001), decreased IL-10 (P = .0057, P = .0017), FOXP3 (P = .002) and NFATC1 (P = .0347). VASI score was positively correlated with the suppression of CD8⁺ and CD4⁺ T cells (P = .0006, P < .0001), IL-10 (P = .0096, P = .029), FOXP3 (P = .0008) and NFATC1 (P = .043), whereas it was negatively correlated with IFN-γ (P = .0029, P = .0017). Early age of onset patients' Tregs demonstrated decreased suppression of CD8⁺ and CD4⁺ T cells (P = .0156, P = .0074), decreased TGF-β (P = .0212, P = .0083) and NFATC1 (P = .0103). NFATC1 was positively correlated with FOXP3 in Tregs (P < .0001). Our results suggest impaired Tregs suppressive function in GV patients due to decreased NFATC1, FOXP3, CD25, IL-10 and TGF-β resulting into increased CD8⁺ and CD4⁺ T-cell proliferation and IFN-γ production. For the first time, decreased NFATC1 levels were correlated with decreased FOXP3, thereby altering Treg cell function in GV patients. Additionally, decreased Treg cell function also affected onset, activity and severity of GV.

Decreased levels of interleukin 27 in the serum of vitiligo patients

BACKGROUND

Vitiligo is a common skin disorder in which melanocytes are destroyed by auto-reactive immune responses. The loss of melanocytes results in the appearance of depigmented areas in different parts of the body. Cytokines have remarkable roles in the pathogenesis of vitiligo, such as IL-1, IL-6, and TNF-α; interleukin 27 (IL-27) is a new member of the IL-6/IL-12 family, mainly released by activated antigen-presenting cells. IL-27 has been suggested to function as a pro-inflammatory as well as an anti-inflammatory cytokine. Altered concentrations of IL-27 have been shown in various auto-immune diseases such as multiple sclerosis, rheumatoid arthritis, and psoriasis. No studies have been conducted to determine the expression of this cytokine in vitiligo patients.

OBJECTIVE

The objective of this study was to determine the serum concentration of IL-27 in vitiligo patients and compare it with normal individuals.

METHODS

The serum concentration of IL-27 in 79 vitiligo patients was evaluated in comparison to 45 healthy controls using ELISA assay.

RESULTS

Results showed decreased concentration of IL-27 in vitiligo patients as compared with healthy subjects (p=0.026). Furthermore, no correlation between IL-27 concentrations and disease parameters such as vitiligo severity and the extension of the depigmented area was observed.

STUDY LIMITATION

A larger sample size would be more recommended for this study.

CONCLUSION

The reduction in the serum levels of IL-27 in vitiligo patients compared to normal subjects suggested the possible anti-inflammatory role of this cytokine in vitiligo. Thus, IL-27 may be considered as a new target for the manipulation of the immune system in vitiligo patients.

Chemical induced pathognomonic features observed in human vitiligo are mediated through miR-2909 RNomics pathway

BACKGROUND

Chemicals like Monobenzyl Ether of Hydroquinone (MBEH) and 4-Tertiary Butyl Phenol (4-TBP) have been widely recognized to induce clinical lesions that resemble vitiligo, but exact molecular pathway through which these chemicals initiate vitiligo is still far from clear.

OBJECTIVES

Since vitiligo is widely considered as an autoimmune disease, this study was an attempt to understand miR-2909 RNomics in vitiligo pathogenesis using MBEH treated primary melanocytes as an archetype cellular model because MBEH causes pathological features indistinguishable from clinical vitiligo.

METHODS

Primary melanocytes were treated with MBEH and 4-TBP and the role of miR-2909 RNomics at transcriptional and translational level was explored through qRT-PCR, western blot analysis, flow cytometry, immunocytochemistry, immunohistochemistry and in silico binding affinities. 4 mm punch biopsies were also obtained from lesional sites of vitiligo patients to validate the results observed in cell culture experiments.

RESULTS

MBEH induced miR-2909 RNomics led to downregulation of MITF, TYR, TYRP1, and TYRP2 leading to decreased melanin synthesis which in turn is a characteristic trait of vitiligo. On the other hand, 4-TBP increased TGF-β which also has the intrinsic capacity to downregulate MITF leading to decreased melanin synthesis and thereby initiation of vitiligo.

CONCLUSION

Based upon our results we propose a molecular pathway which has the inherent capacity to resolve the mechanism through which these chemicals may induce vitiligo. This mechanism was also found to be involved in the lesional biopsies of vitiligo patients. These results could be exploited in better understanding the pathogenesis as well as in treatment of vitiligo.

Skin - a vast organ with immunological function (Review)

The skin is an organ with multiple functions, where important inflammatory and immunological processes take place. The integrity of the skin barrier is necessary for it to fulfill its roles. An intact skin barrier requires a physiological keratinization process, but also a normal cutaneous microbial flora. Any change in the proliferation and differentiation of keratinocytes entails the disruption of the skin barrier and the triggering of inflammatory and immunological processes at this level, in response to the aggression of external pathogens. Also, there are several specialised immune cells in the skin (Langerhans cells, T regulator cells, T helper cells), that maintain a balance between pro-inflammatory and anti-inflammatory processes at this level. Disturbing the immune homeostasis causes inflammation and allergic skin reaction. Psoriasis and atopic dermatitis are two inflammatory diseases of the skin, characterized by perturbation of the mechanisms of skin barrier formation. The immune system of the skin is also involved in the pathophysiology of vitiligo and pemphigus. The aim of this review is to offer a brief presentation of the inflammatory and immunological processes that occur in the skin.

Vitiligo: A Review

Vitiligo, a common depigmenting skin disorder, has an estimated prevalence of 0.5–2% of the population worldwide. The disease is characterized by the selective loss of melanocytes which results in typical nonscaly, chalky-white macules. In recent years, considerable progress has been made in our understanding of the pathogenesis of vitiligo which is now clearly classified as an autoimmune disease. Vitiligo is often dismissed as a cosmetic problem, although its effects can be psychologically devastating, often with a considerable burden on daily life. In 2011, an international consensus classified segmental vitiligo separately from all other forms of vitiligo, and the term vitiligo was defined to designate all forms of nonsegmental vitiligo. This review summarizes the current knowledge on vitiligo and attempts to give an overview of the future in vitiligo treatment.

Comparison of tyrosinase antibody, tyrosinase-related protein-1 and -2 antibodies, melanin-concentrating hormone receptor antibody levels with autologous serum skin test and autologous plasma skin test results in patients with vitiligo

Introduction

Although the exact etiopathogenesis of vitiligo is unknown, the autoimmunity hypothesis is much in evidence. The autologous serum skin test (ASST) and autologous plasma skin test (APST) are in vivo methods used in the diagnosis of some autoimmune diseases, which are easy and inexpensive to perform.

Aim

In this study, we investigated whether or not ASST and APST could determine autoimmunity in patients with vitiligo.

Material and methods

In this study, 30 vitiligo patients presenting to the dermatology outpatient clinic and 30 healthy volunteers without any known autoimmune diseases were included. Antibodies such as tyrosinase, tyrosinase-related protein-1 (TYRP1), tyrosinase-related protein-2 (TYRP2) and melanin-concentrating hormone receptor 1 (MCHR1) antibodies determined to be associated with vitiligo were examined. In addition, the association of these antibodies with the positivity of ASST and APST, which were suggested to be associated with autoimmunity, were examined.

Results

In our study, tyrosinase antibody was found to be significantly higher in vitiligo patients. ASST was positive in 12 (40%) patients with vitiligo and 8 (26.6%) control subjects. APST was positive in 8 (26.6%) of the patients with vitiligo and in 2 (6.6%) of the controls, and there was a significant difference between the groups in terms of APST positivity (p = 0.032). In addition, in our study, a significant correlation was found between TYRP1 antibody positivity and APST positivity in the patient group (p = 0.005).

Conclusions

These findings suggest that we may use APST to investigate the autoimmune etiopathogenesis of vitiligo.

Association Analysis of Tumor Necrosis Factor Alpha Promoter Polymorphisms and Vitiligo Susceptibility in South Indian Tamils

Tumor necrosis factor alpha (TNF-α) has been associated with the pathogenesis of several autoimmune diseases. Also, various studies in different ethnics showed an association between TNF-α gene polymorphisms and susceptibility to vitiligo. The paucity of genetic data led us to undertake this study to evaluate the association of five TNF-α SNPs (rs1799964, rs1800630, rs1799724, rs1800629, and rs361525) with the development of vitiligo in South Indian Tamils. A total of 264 vitiligo patients and 264 healthy controls were recruited and TNF-α genotyping was performed using amplification-refractory mutation system polymerase chain reaction and TaqMan allele discrimination assay. Circulatory TNF-α levels were measured by enzyme-linked immunosorbent assay. We observed that a single polymorphic allele A in the promoter region -308 (rs1800629) conferred significant risk to develop vitiligo (p = 0.0002, OR = 1.70, 95% CI = 1.28-2.25), whereas the other polymorphisms failed to contribute to disease risk (p > 0.05). From the constructed haplotypes, TCCAG was found to be a significant risk factor for vitiligo (p < 0.05). Also, a strong linkage disequilibrium was observed between the following SNPs: (1) rs1799964 and rs1800629 (2) rs1800630 and rs1799724 (D' = 0.90). Analysis of the influence of genotype on phenotypes revealed that the A allele of rs361525 was a risk factor for vitiligo in females (p = 0.04, OR = 0.45, 95% CI = 0.21-0.95), whilst the rs1800629 allele conferred protection against early disease onset (p < 0.05). A statistically significant difference in plasma TNF-α levels was found between cases and controls (p < 0.05). The TNF-α -308A allele and TCCAG haplotype were identified as genetic risk factors for vitiligo susceptibility in South Indian Tamils.

The effects of 308-nm excimer laser on the infiltration of CD4+, CD8+ T-cells, and regulatory T cells in the lesional skin of patients at active and stable stages of nonsegmental vitiligo

BACKGROUND

To explore the associations between this treatment and CD4+, CD8+ T-cells, and regulatory T cells (Treg).

METHODS

We collected the skin biopsies from 295 patients with nonsegmental vitiligo treated with or without 308-nm excimer laser. We revealed that patients at stable stage showed a better response to 308-nm excimer laser than those at active stage.

RESULTS

In comparison with untreated patients, CD4+ and CD8+ T cells were both reduced while Foxp3+ Treg cells, TGF-β, and IL-10 were elevated in the lesional sites of patients who showed effective reaction to the treatment. In the treated patients at active stage, the infiltration of CD4+ and CD8+ T cells was significantly declined but Foxp3+ Treg cells, TGF-β, and IL-10 were increased compared to those in untreated patients at active stage. These changes of cell infiltration were more obvious in the treated patients at stable stage, explaining why there were more patients at stable stage response better than patients at active stage.

CONCLUSIONS

308-nm excimer laser is effective to reduce the infiltration of CD4+ and CD8+ T cells but promote the infiltration Treg cells and secretion of TGF-β and IL-10 in the lesion skin of vitiligo patients, especially at stable stage.

A Parametric Targetability Evaluation Approach for Vitiligo Proteome Extracted through Integration of Gene Ontologies and Protein Interaction Topologies

Vitiligo is a well-known skin disorder with complex etiology. Vitiligo pathogenesis is multifaceted with many ramifications. A computational systemic path was designed to first propose candidate disease proteins by merging properties from protein interaction networks and gene ontology terms. All in all, 109 proteins were identified and suggested to be involved in the onset of disease or its progression. Later, a composite approach was employed to prioritize vitiligo disease proteins by comparing and benchmarking the properties against standard target identification criteria. This includes sequence-based, structural, functional, essentiality, protein-protein interaction, vulnerability, secretability, assayability, and druggability information. The existing information was seamlessly integrated into efficient pipelines to propose a novel protocol for assessment of targetability of disease proteins. Using the online data resources and the scripting, an illustrative list of 68 potential drug targets was generated for vitiligo. While this list is broadly consistent with the research community's current interest in certain specific proteins, and suggests novel target candidates that may merit further study, it can still be modified to correspond to a user-specific environment, either by adjusting the weights for chosen criteria (i.e., a quantitative approach) or by changing the considered criteria (i.e., a qualitative approach).

HLA-G Polymorphisms Are Associated with Non-segmental Vitiligo among Brazilians

(1) Background: Vitiligo is characterized by white patches on the skin caused by loss of melanocyte activity or the absence of these cells. The available treatments minimize the symptoms by retarding the process of skin depigmentation or re-pigmenting the affected regions. New studies are required for a better comprehension of the mechanisms that trigger the disease and for the development of more efficient treatments. Studies have suggested an autoimmune feature for vitiligo, based on the occurrence of other autoimmune diseases in vitiligo patients and their relatives, and on the involvement of genes related to the immune response. (2) Methods: We evaluated, by massive parallel sequencing, polymorphisms of the HLA-G gene in vitiligo patients and control samples, to verify if variants of this gene could influence the susceptibility to vitiligo. (3) Results: We detected an association with non-segmental vitiligo regarding the haplotype Distal-010101a/G*01:01:01:01/UTR-1, adjusting for population stratification by using ancestry-informative markers (AIMs). (4) Conclusions: It remains unclear whether the HLA-G variants associated with vitiligo were detected because of the high linkage disequilibrium (LD) with HLA-A*02, or if the HLA-A variants previously reported as associated with vitiligo were detected because of the high LD with HLA-G*01:01:01:01/UTR-1, or if both genes jointly contribute to vitiligo susceptibility.

Skin-resident memory T cells as a potential new therapeutic target in vitiligo and melanoma

Tissue-resident memory T (T_RM ) cells are abundant in the memory T cell pool and remain resident in peripheral tissues, such as the skin, where they act as alarm sensors or cytotoxic killers. T_RM cells persist long after the pathogen is eliminated and can respond rapidly upon reinfection with the same antigen. When aberrantly activated, skin-located T_RM cells have a profound role in various skin disorders, including vitiligo and melanoma. Autoreactive T_RM cells are present in human lesional vitiligo skin and mouse models of vitiligo, which suggests that targeting these cells could be effective as a durable treatment strategy for vitiligo. Furthermore, emerging evidence indicates that induction of melanoma-reactive T_RM cells is needed to achieve effective protection against tumor growth. This review highlights seminal reports about skin-resident T cells, focusing mainly on their role in the context of vitiligo and melanoma, as well as their potential as therapeutic targets in both diseases.

The different roles of 5-HT1A/2A receptors in fluoxetine ameliorated pigmentation of C57BL/6 mouse skin in response to stress

BACKGROUND

5-HT1A receptor was participated in fluoxetine induced melanogenesis in melanocytes and in normal C57BL/6 mice, but we know little about whether other 5-HT receptors are involved in regulation of fluoxetine promotes pigmentation.

OBJECTIVE

To investigate the role of 5-HT receptors in regulation of fluoxetine ameliorates chronic unpredictable mild stress (CUMS) and chronic restraint stress (CRS) induce hypopigmentation in C57BL/6 mice.

METHODS

CUMS and CRS were used to induce depigmentation in mice and evaluate the effect of fluoxetine. Western blot, immunohistochemistry and Q-PCR assay were used to determine the levels of protein and mRNA. Masson Fontana staining was used for melanin staining and FITC-Phalloidin staining was used to detect the expression of F-actin. Zebrafish and B16F10 cells were used for the mechanism research.

RESULTS

Fluoxetine (2.6 mg/kg, ig) ameliorated hypopigmentation induced by CUMS and CRS in mice, significantly increased the mRNA and protein levels of 5-HT1 A and 5-HT2 A receptors in mice and B16F10 cells. The effect of fluoxetine on melanogenesis in B16F10 cells and zebrafish were inhibited by WAY100635 (a selective 5-HT1 A receptor antagonist) and ketanserin (a 5-HT2 A receptor antagonist), respectively. Activation of p38 MAPK signaling pathways was contributed to fluoxetine induced melanogenesis and inhibited by WAY100635, but not ketanserin. However, ketanserin selectively weakened the action of fluoxetine promoted migration and up-regulated Rab27a protein expression in B16F10 cells.

CONCLUSIONS

5-HT1 A and 2 A receptors contribute to melanogenesis and migration property of fluoxetine. The newly revealed mechanism indicates that fluoxetine and its analogues may be a potential drug for treatment of depigmentation disorders.

Systematic investigation of the Erigeron breviscapus mechanism for treating cerebrovascular disease

ETHNOPHARMACOLOGICAL RELEVANCE

Cerebrovascular diseases (CBVDs), characterized by striking morbidity and mortality, have become the most common life-threatening diseases. The existing drugs of CBVDs target one or a few of pathogenic factors, the efficacy of which is limited because of the complexity of CBVDs. Traditional Chinese medicine (TCM), featured by multi-component and multi-target endows the great effectiveness in CBVDs treatment. For instance, Erigeron breviscapus (vant.) Hand. Mazz. （Erigeron breviscapus) has been used to treat CBVDs for a long time and the efficacy has been verified through years' of practice. Nevertheless, the mechanisms of Erigeron breviscapus for treating CBVDs are still unclear.

THE AIM OF THE STUDY

Systematically decipher the mechanisms of Erigeron breviscapus for treating CBVDs.

MATERIALS AND METHODS

The systems pharmacology approach is utilized by integrating ADME pharmacokinetic screening, target fishing, protein-protein interaction (PPI), network analysis and in vitro experiments verification.

RESULTS

First, 14 potentially active molecules were screened out through in silico ADME pharmacokinetic evaluation, most of which have been reported with excellent biological activities. Then 169 targets of active molecules were read out using our in-house softwares, systems drug targeting (sysDT) and Weighted Ensemble Similarity(WES). We found that the targets of the active compounds were significantly enriched to the CBVDs therapeutic targets by analyzing their biological processes and protein-protein interactions (PPIs). A multi-layer network analysis including compound-target network, target-pathway network and "CBVDs pathway" indicated that the Erigeron breviscapus exerts a protective effect on CBVDs via regulating multiple pathways and hitting on multiple targets. Meanwhile in vitro experiments confirmed that the stigmasterol, scutellarein, and daucosterol from Erigeron breviscapus increased the MEK and PLCγ proteins levels, and decreased the expression of Bax, PI3K, and eNOS, which led to the cell survival, proliferation and contraction.

CONCLUSION

The approach used in this work offers a new exemplification for systematically understanding the mechanisms of herbal medicines, which will give an impulse to the CBVDs drug development.

The role of interleukins in vitiligo: a systematic review

Vitiligo is a disorder of the skin that causes depigmentation and asymptomatic macules whose exact cause is still unclear. Although its aetiology is not fully elucidated, the main theory of its pathomechanism is that it is associated with the autoimmune process. There is few summarized information about the role of inflammatory mediators, as interleukins, in vitiligo, so our aim was to present a systematic review of the role of interleukins in vitiligo, focusing on interleukins. In this review, we included all studies assessing interleukin levels in vitiligo patients conducted up to June 2017. Quality assessment of these studies was performed using the Newcastle-Ottawa Scale (NOS). The interleukins mainly involved were IL-2, IL-4, IL-6, IL-10 and IL-17. The studies highlight the crucial role of IL-17 in the onset and progression of the disease, and its synergistic action with IL-2, IL-6 and IL-33. Dysregulated levels of the interleukins were also correlated with the stage of disease, the affected skin surface area, and indicated as the main factor for lymphocyte infiltration found in depigmented regions. These findings illustrate the growing need for new therapies targeting vitiligo and further research into the role of interleukins as an area of particular interest.