A review of the worldwide prevalence of vitiligo in children/adolescents and adults

Meta-Analysis of Alterations in Regulatory T Cells' Frequency and Suppressive Capacity in Patients with Vitiligo

Vitiligo is a noncontagious autoimmune skin depigmenting disease. Regulatory T cells (Tregs) play a key role in maintaining peripheral tolerance; however, Tregs' number, suppressive function, and associated suppressive molecules (FOXP3, IL-10, and TGF-β) are found to be reduced in vitiligo patients. Although, the role of Tregs in vitiligo pathogenesis is well established, there are several contrary findings which suggest a controversial role of Tregs in vitiligo. Therefore, to clarify the role of Tregs in vitiligo pathogenesis, we aimed to study Tregs' frequency, suppressive capacity, and associated suppressive molecules (FOXP3, IL-10, and TGF-β) in vitiligo patients through meta-analysis approach. A total of 30 studies involving 1223 vitiligo patients and 1109 controls were included in the study. Pooled results from our meta-analysis suggested significantly reduced Treg cells' frequency in vitiligo patients (p = 0.002). Interestingly, Tregs' suppressive capacity was also significantly reduced in vitiligo patients (p = 0.0002); specifically, Treg-mediated suppression of CD8+T cells was impaired in vitiligo patients (p < 0.00001). Moreover, FOXP3, a key Tregs' transcription factor, was significantly reduced in blood and skin of vitiligo patients (p < 0.00001). Intriguingly, the FOXP3 expression was significantly reduced in the lesional skin as compared to perilesional and nonlesional skin (p = 0.007 and p = 0.04). Furthermore, the expression of key Treg-associated suppressive cytokines IL-10 and TGF-β were significantly reduced in vitiligo patients (p = 0.0005 and p = 0.01). The disease activity-based analysis suggested for reduced Tregs' frequency and FOXP3 expression in active vitiligo patients (p = 0.05 and p = 0.01). We also studied the effect of microRNA-based treatment, narrow band-UVB phototherapy, and Treg-associated treatments on Tregs' frequency, FOXP3, and IL-10 expression. Interestingly, we found increased Tregs' frequency, FOXP3, and IL-10 expression after the treatment (p = 0.007, p < 0.0001, and p = 0.002). Overall, our meta-analysis suggests that the Tregs play a crucial role in pathogenesis and progression of vitiligo, and hence, Treg-based therapeutic interventions could be effective in vitiligo patients.

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.

Evaluation of the Behavioral and Psychological Symptoms in Patients with Vitiligo in China

Background

Vitiligo is a common, acquired depigmenting disorder. The pathogenesis is not clear, neuropsychological factors may be involved. Vitiligo will affect the individual’s physical and psychological health, leading to different levels of psychological behavior problems. However, there are few research on psychological symptoms in patients with vitiligo in China.

Methods

Adult patients with vitiligo were selected in convenient sampling method from March 2019 to November 2019 from the dermatology clinic. They were evaluated by the DLQI (Dermatology Life Quality Index), SCL-90 (Symptom Checklist-90), SADS (Social Avoidance and Distress Scale) and MCMQ (Medical Coping Modes Questionnaire).

Results

The DLQI score was 7.56 ± 6.11, which was in the third level. The SCL-90 score of patients with vitiligo was 136.44 ± 39.19, significantly higher than the Chinese norms (P < 0.05), and it mainly manifested as interpersonal sensitivity, depression, anxiety and phobia, which may be affected by the patient’s gender, marital status, severity of disease, stage and location of skin lesions. The total score of SADS in patients was 10.30 ± 6.38. The total score and scores in all dimensions of SADS were significantly higher than the Chinese norms (all P < 0.05), which were related with the patient’s gender, educational attainment, severity, type and stage of skin lesions. For MCMQ, the facing score was significantly lower than the Chinese norms (P < 0.05), and the avoiding and yielding scores were significantly higher than the Chinese norms (all P < 0.05).

Conclusion

In China, vitiligo affects the patient’s quality of life to varying degrees, resulting in a series of psychological and behavioral problems. We should actively concern and improve the psychological health status and behavior of patients, and multidisciplinary treatment strategies and education about vitiligo should be given to the patients.

Inflammatory bowel disease and immune-mediated inflammatory diseases: looking at the less frequent associations

Patients with inflammatory bowel disease (IBD) often have other immune-mediated inflammatory diseases (IMIDs), and the prevalence of any IMID is higher in IBD patients than in the general population. IBD and other IMIDs involve alterations in innate and adaptive immune responses. Their co-occurrence depends on shared immune and inflammatory processes, pathogenic mechanisms, and genetic and environmental risk factors, including drugs, especially tumor necrosis factor inhibitors. The more common IMIDs associated with IBD have been widely described, so this review focuses on the less frequent associations. The IMIDs discussed here are skin disorders (psoriasis, atopic dermatitis, vitiligo, epidermolysis bullosa acquisita, cutaneous polyarteritis nodosa, and hidradenitis suppurativa), hepato-pancreatic diseases (autoimmune hepatitis, granulomatous hepatitis, and autoimmune pancreatitis), endocrine diseases (autoimmune thyroid diseases, and type 1 diabetes mellitus), multiple sclerosis, and respiratory diseases (asthma, bronchiectasis, and interstitial pneumonia). The early detection of IMIDs in IBD patients is important to prevent their deleterious clinical course and limit their psychological impact. Care for IBD patients with IMIDs should be multispecialist, with a single therapeutic strategy instead of treating each disease separately.

Altered Levels of Negative Costimulatory Molecule V-Set Domain-Containing T-Cell Activation Inhibitor-1 (VTCN1) and Metalloprotease Nardilysin (NRD1) are Associated with Generalized Active Vitiligo

BACKGROUND

Vitiligo is characterized by depigmented macules on the skin caused due to autoimmune destruction of melanocytes. V-set domain-containing T-cell activation inhibitor-1 (VTCN1) is a negative costimulatory molecule that plays a vital role in suppressing autoimmunity and tuning immune response. Nardilysin (NRD1), a metalloproteinase, cleaves membrane-tethered VTCN1 resulting in the shedding of soluble-VTCN1 (sVTCN1). However, the role of VTCN1 and NRD1 in vitiligo pathogenesis is unexplored.

OBJECTIVES AND METHODS

This study was aimed to (i) Investigate the association of VTCN1 intronic polymorphisms (rs10923223 T/C and rs12046117 C/T) with vitiligo susceptibility in Gujarat population by using Polymerase Chain Reaction- Restriction Fragment Length Polymorphism (PCR-RFLP) (ii) Estimate VTCN1 & NRD1 transcript levels from peripheral blood mononuclear cells (PBMCs) and skin samples of vitiligo patients by real-time PCR, (iii) Estimate sVTCN1 and NRD1 protein levels from plasma by ELISA and (iv) Estimate VTCN1 protein levels in the skin samples of vitiligo patients by immunofluorescence.

RESULTS

The analysis revealed increased VTCN1 and NRD1 transcript levels in the skin (p = .039, p = .021 respectively), increased sVTCN1 and NRD1 levels (p  = .026, p = .015 respectively) in the plasma, and decreased VTCN1 protein levels (p = .0002) in the skin of vitiligo patients as compared to healthy controls. The genetic analysis revealed no significant association of VTCN1 intronic polymorphisms rs10923223 T/C and rs12046117 C/T with vitiligo susceptibility in Gujarat population (p = .359, p = .937, respectively).

CONCLUSIONS

The present study revealed altered VTCN1 and NRD1 expressions in the blood and skin of vitiligo patients, suggesting their potential role in the development and progression of Vitiligo.

Current Concepts of Vitiligo Immunopathogenesis

Vitiligo is an acquired immune-mediated disorder of pigmentation clinically characterized by well-defined depigmented or chalk-white macules and patches on the skin. The prevalence of vitiligo varies by geographical area, affecting 0.5% to 2% of the population. The disease imposes a significant psychological burden due to its major impact on patients’ social and emotional aspects of life. Given its autoimmune background, vitiligo is frequently associated with other autoimmune diseases or immune-mediated diseases. Vitiligo is a multifaceted disorder that involves both genetic predisposition and environmental triggers. In recent years, major predisposing genetic loci for the development of vitiligo have been discovered. The current findings emphasize the critical role of immune cells and their mediators in the immunopathogenesis of vitiligo. Oxidative-stress-mediated activation of innate immunity cells such as dendritic cells, natural killer, and ILC-1 cells is thought to be a key event in the early onset of vitiligo. Innate immunity cells serve as a bridge to adaptive immunity cells including T helper 1 cells, cytotoxic T cells and resident memory T cells. IFN-γ is the primary cytokine mediator that activates the JAK/STAT pathway, causing keratinocytes to produce the key chemokines CXCL9 and CXCL10. Complex interactions between immune and non-immune cells finally result in apoptosis of melanocytes. This paper summarizes current knowledge on the etiological and genetic factors that contribute to vitiligo, with a focus on immunopathogenesis and the key cellular and cytokine players in the disease’s inflammatory pathways.

Profile of pediatric vitiligo in India

We analyzed the records of 211 pediatric patients with vitiligo. 57.8% of patients were females and 42.2% were males. Leukotrichia and family history were present in 29.4% and 15.6% of patients, respectively, while 39.3% of patients had anemia. Elevated thyroid-stimulating hormone and fasting blood glucose levels were seen in 5.2% and 3.3% of patients, respectively. Antinuclear antibody was positive in 12 (5.6%) patients.

Molecular mechanism of vitiligo treatment by bailing tablet based on network pharmacology and molecular docking

BACKGROUND

Bailing tablet, a patent Chinese medicine, is widely used to treat vitiligo in China. However, the underlying mechanism of this combined drug in treating vitiligo still remains unclear.

OBJECTIVE

This study aimed to investigate the pharmacological mechanism of bailing tablet in the prevention and treatment of vitiligo using network pharmacology and molecular docking.

METHODS

Genetic data of vitiligo and normal people were obtained by gene expression omnibus (GEO) DataSets database and GEO difference analysis was conducted to obtain differential genes. The main active compounds and corresponding target genes of bailing tablet were collected from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform. Combined with the results of GEO difference analysis, the main compounds and corresponding target genes of bailing tablet in the treatment of vitiligo were screened. The network diagram of "traditional Chinese medicine compound target" was constructed by Cytoscape software. According to the differential genes, the core targets with potential therapeutic effect were searched, the protein-protein interaction network was constructed, and the key proteins were explored by topological analysis (CytoNCA). Meanwhile, the core targets were analyzed by biological process (gene ontology) and signal pathway (Kyoto encyclopedia of genes and genomes) function enrichment. Molecular docking technology was adopted to verify the combination of main components and core targets.

RESULTS

A total of 170 active compounds and 1777 prediction targets were screened from 11 traditional Chinese medicines of bailing tablet, of which 65 active components and 68 related prediction targets were closely related to vitiligo. A total of 320 key proteins were obtained by analyzing the topological characteristics of the protein-protein interaction network, mainly including neurotrophic receptor tyrosine kinase 1, tumor protein P53, cullin 3, estrogen receptor 1, etc. The main biological processes involve oxidative stress response, cell response to reactive oxygen species, and reactive oxygen species metabolism. Bailing tablet treats vitiligo mainly by regulating immune inflammation, apoptosis, and autophagy, which involves phosphatidylinositol-4,5-bisphosphate 3-kinase Akt signal pathway, mitogen-activated protein kinase signal pathway, Janus kinase signal transducer and activator of transcription signal pathway, melanin production, and helper T cell (Th)1, Th2, and Th17 differentiation pathway, etc. Molecular docking results showed that the main components could bind to the target protein well.

CONCLUSIONS

Based on network pharmacology and molecular docking, the mechanism of bailing tablet in the treatment of vitiligo through multicomponent, multitarget, and multichannel was deeply explored.

Therapeutic Potential of Skin Stem Cells and Cells of Skin Origin: Effects of Botanical Drugs Derived from Traditional Medicine

Skin, the largest organ of the body, plays a vital role in protecting inner organs. Skin stem cells (SSCs) comprise a group of cells responsible for multiplication and replacement of damaged and non-functional skin cells; thereby help maintain homeostasis of skin functions. SSCs and differentiated cells of the skin such as melanocytes and keratinocytes, have a plethora of applications in regenerative medicine. However, as SSCs reside in small populations in specific niches in the skin, use of external stimulants for cell proliferation in vitro and in vivo is vital. Synthetic and recombinant stimulants though available, pose many challenges due to their exorbitant prices, toxicity issues and side effects. Alternatively, time tested traditional medicine preparations such as polyherbal formulations are widely tested as effective natural stimulants, to mainly stimulate proliferation, and melanogenesis/prevention of melanogenesis of both SSCs and cells of skin origin. Complex, multiple targets, synergistic bioactivities of the phytochemical constituents of herbal preparations amply justify these as natural stimulants. The use of these formulations in clinical applications such as in skin regeneration for burn wounds, wound healing acceleration, enhancement or decrease of melanin pigmentations will be in great demand. Although much multidisciplinary research is being conducted on the use of herbal formulas as stem cell stimulants, very few related clinical trials are yet registered with the NIH clinical trial registry. Therefore, identification/ discovery, in depth investigations culminating in clinical trials, as well as standardization and commercialization of such natural stimulants must be promoted, ensuring the sustainable use of medicinal plants.

Vitiligo Prevalence and Quality of Life Among Adults in Europe, Japan, and the United States

Background

Vitiligo, an autoimmune disorder characterised by skin depigmentation, is associated with reduced quality of life (QoL). Vitiligo may be under‐reported, in part because of misconceptions that it is a cosmetic disease.

Objectives

This survey sought to characterise vitiligo prevalence and explore the relationship between sociodemographic and clinical characteristics with QoL in a population‐based, multinational study.

Methods

Participants aged ≥18 years were recruited via an online panel in Europe, Japan and the USA to answer questions regarding skin disorders they may have experienced. Those reporting vitiligo (diagnosed or undiagnosed) or vitiligo signs (experiencing loss of skin colour but unaware of vitiligo and not diagnosed) were included in the analyses of vitiligo prevalence. Participants who self‐reported physician‐diagnosed vitiligo were given a broader survey to characterise disease progression, management and QoL (as measured with the Vitiligo‐specific QoL [VitiQoL] instrument).

Results

The total estimated vitiligo prevalence among 35 694 survey participants (Europe, n = 18 785; USA, n = 8517; Japan, n = 8392) was 1.3% (diagnosed, 0.6%; undiagnosed, 0.4%; vitiligo signs, 0.3%). Among 219 patients formally diagnosed with vitiligo (Europe, n = 150; USA, n = 48; Japan, n = 21), total VitiQoL scores were associated with age (P = 0.00017), disease extent (P < 0.0001), disease progression (P < 0.0001), disease management (P < 0.0001) and time since diagnosis (P = 0.0015). Behaviour scores varied based on skin phototype (P = 0.024) and ethnicity (P = 0.048). Higher total VitiQoL scores were reported in patients with head lesions (P = 0.027) and those with head and hand and/or wrist lesions (P = 0.018). Substantial high concern (rated 8–10 on an 11‐point Likert scale) for lesions was found across all body areas and varied with geographical region.

Conclusions

The vitiligo prevalence rate may be higher than previously reported, with a substantial proportion attributed to people who have not received a formal diagnosis. Among formally diagnosed patients with vitiligo, QoL was most severely impacted by more progressive and higher extent of disease.

A pilot study of combined oral minocycline and narrowband UVB phototherapy in vitiligo: A randomized, double-blind, placebo-controlled trial

Narrowband ultraviolet B (NBUVB) phototherapy is an effective therapeutic option for generalized vitiligo. Previous reports showed the potential benefit of minocycline to stop disease progression in vitiligo. Meanwhile, minocycline has antioxidative, anti-inflammatory, and immunomodulating properties. There is no clinical study combining oral minocycline and NBUVB for treating generalized vitiligo. This study aims to compare the efficacy and safety of the combination treatment of NBUVB plus oral minocycline with NBUVB alone in generalized vitiligo. A randomized, double-blinded, placebo-controlled pilot study was conducted. Patients were randomly treated with either combined oral minocycline 100 mg per day plus NBUVB phototherapy or placebo plus NBUVB. All patients recieved NBUVB two times per week, for 12 weeks. The outcomes were assessed using Vitiligo Area Scoring Index score (VASI) percent change, quartile grading scale (QGS) of repigmentation, and Vitiligo Disease Activity Index (VIDA) score. Fourteen generalized vitiligo patients were included, and seven cases were assigned in each group. At week 12, the mean VASI score was decreased by 28.87% (24.15) in the minocycline group compared to 27.26% (7.98) in placebo group (p = 0.886). No significant difference was observed between both treatment modalities in QGS of repigmentation and mean VIDA score change. Two of the seven patients (29%) receiving minocycline developed hyperpigmentation, dark-brown and muddy brown discoloration, which was only confined to some vitiliginous patches. In conclusion, combination therapy with oral minocycline does not enhance the efficacy of NBUVB in generalized vitiligo. Due to the high incidence of drug-induced skin hyperpigmentation, minocycline plus NBUVB should be avoided.

Altered expression of ferroptosis markers and iron metabolism reveals a potential role of ferroptosis in vitiligo

Oxidative stress is one of the triggering factors for vitiligo, which leads to melanocyte (MC) destruction in vitiligo lesions. Ferroptosis, which is characterized by iron-dependent increase in oxidative stress and lipid peroxidation, has been widely explored in numerous diseases, whereas whether ferroptosis plays a role in MC loss of vitiligo remains to be elucidated. Quantitative real-time PCR and western blot analysis were used to determine the expression of ferroptosis markers in vitiligo patients. Immunonephelometry and electrochemiluminescence were performed to analyze iron status. Reactive oxygen species (ROS), Fe²⁺ , and lipid ROS were assessed by flow cytometry. The expression of ferroptosis markers was significantly altered in the epidermis of vitiligo patients. Iron deficiency was revealed in the blood of patients. Erastin reduced cell viability and led to oxidative stress, iron overload as well as lipid peroxide accumulation in human epidermal MCs in vitro. Altered expression of ferroptosis markers and inhibition of melanin synthesis in MCs were induced by erastin, which was attenuated by N-acetyl-L-cysteine (NAC) pretreatment or post-treatment in vitro. In conclusion, ferroptosis might take place during the process of vitiligo. Erastin could induce ferroptosis in human epidermal MCs and NAC could protect MCs from ferroptosis in vitro.

Inverse association between autoimmunity and elevated IgE among childhood vitiligo

BACKGROUND

Multiple factors contribute to the pathogenesis of childhood vitiligo. The characteristics in a different population under modified environmental factors need further reevaluation. The present study aimed to reevaluate the clinical and laboratory features in consequent children vitiligo patients.

MATERIALS AND METHODS

We retrospectively reviewed consequent children vitiligo patients who visited Children's Hospital of Fudan University (National Children's Medical Center of China). The prevalence rate of thyroid dysfunction, circulating autoantibodies, serum IgE, and associated factors were analyzed.

RESULTS

A total of 244 consequent vitiligo patients were included, of which 20 children had personal autoimmune history. Two hundred and nineteen of the 244 patients took a thyroid function test, and the abnormal rate was only 3.7% (8/219). The elevated IgE rate was 31.7% (52/157), the antinuclear antibody (ANA) positive rate was 9.8% (12/123), and the extractable nuclear antigens (ENA) positive rate was 4.4% (4/91), respectively. The elevated IgE was significantly associated with atopic disease history and male gender. Of note, personal autoimmune history showed a significant inverse association with elevated IgE.

CONCLUSIONS

Thyroid dysfunction rate was low among the consequent children vitiligo patients. Personal autoimmune history was inversely associated with elevated IgE. Various clinical characteristics and pathogenesis might contribute to different long-term outcomes of vitiligo.

Disease-Specific Health Disparities: A Targeted Review Focusing on Race and Ethnicity

Background: Wide disparities in health status exist in the United States across race and ethnicity, broadly driven by social determinants of health—most notably race and ethnic group differences in income, education, and occupational status. However, disparities in disease frequency or severity remain underappreciated for many individual diseases whose distribution in the population varies. Such information is not readily accessible, nor emphasized in treatment guidelines or reviews used by practitioners. Specifically, a summary on disease-specific evidence of disparities from population-based studies is lacking. Our goal was to summarize the published evidence for specific disease disparities in the United States so that this knowledge becomes more widely available “at the bedside”. We hope this summary stimulates health equity research at the disease level so that these disparities can be addressed effectively. Methods: A targeted literature review of disorders in Pfizer’s current pipeline was conducted. The 38 diseases included metabolic disorders, cancers, inflammatory conditions, dermatologic disorders, rare diseases, and infectious targets of vaccines under development. Online searches in Ovid and Google were performed to identify sources focused on differences in disease rates and severity between non-Hispanic Whites and Black/African Americans, and between non-Hispanic Whites and Hispanics. As a model for how this might be accomplished for all disorders, disparities in disease rates and disease severity were scored to make the results of our review most readily accessible. After primary review of each condition by one author, another undertook an independent review. Differences between reviewers were resolved through discussion. Results: For Black/African Americans, 29 of the 38 disorders revealed a robust excess in incidence, prevalence, or severity. After sickle cell anemia, the largest excesses in frequency were identified for multiple myeloma and hidradenitis suppurativa. For Hispanics, there was evidence of disparity in 19 diseases. Most notable were metabolic disorders, including non-alcoholic steatohepatitis (NASH). Conclusions: This review summarized recent disease-specific evidence of disparities based on race and ethnicity across multiple diseases, to inform clinicians and health equity research. Our findings may be well known to researchers and specialists in their respective fields but may not be common knowledge to health care providers or public health and policy institutions. Our hope is that this effort spurs research into the causes of the many disease disparities that exist in the United States.

Potential Role of Chronic Physical Exercise as a Treatment in the Development of Vitiligo

Vitiligo is an autoimmune disease characterized by progressive skin depigmentation and the appearance of white patches throughout the body caused by significant apoptosis of epidermal melanocytes. Despite not causing any physical pain, vitiligo can originate several psychosocial disorders, drastically reducing patients' quality of life. Emerging evidence has shown that vitiligo is associated with several genetic polymorphisms related to auto-reactivity from the immune system to melanocytes. Melanocytes from vitiligo patients suffer from excess reactive oxygen species (ROS) produced by defective mitochondria besides a poor endogenous antioxidant system (EAS). This redox imbalance results in dramatic melanocyte oxidative stress (OS), causing significant damage in proteins, lipid membranes, and DNA. The damaged melanocytes secret damage-associated molecular pattern (DAMPs), inducing and increasing inflammatory gene expression response that ultimately leads to melanocytes apoptosis. Vitiligo severity has been also associated with increasing the prevalence and incidence of metabolic syndrome (MetS) or associated disorders such as insulin resistance and hypercholesterolemia. Thus, suggesting that in genetically predisposed individuals, the environmental context that triggers MetS (i.e., sedentary lifestyle) may also be an important trigger for the development and severity of vitiligo disease. This paper will discuss the relationship between the immune system and epidermal melanocytes and their interplay with the redox system. Based on state-of-the-art evidence from the vitiligo research, physical exercise (PE) immunology, and redox system literature, we will also propose chronic PE as a potential therapeutic strategy to treat and prevent vitiligo disease progression. We will present evidence that chronic PE can change the balance of inflammatory to an anti-inflammatory state, improve both EAS and the mitochondrial structure and function (resulting in the decrease of OS). Finally, we will highlight clinically relevant markers that can be analyzed in a new research avenue to test the potential applicability of chronic PE in vitiligo disease.

Melanocytes and keratinocytes morphological changes in vitiligo patients. A histological, immunohistochemical and ultrastructural analysis

Vitiligo is an idiopathic acquired chronic stigmatizing disease. It is a pigmentary disorder that affects the skin and the mucous membranes, and it is characterized by well-circumscribed, depigmented milky white macules and patches. It has an estimated prevalence of 0.5-2% of the population worldwide. In the previous studies, several mechanisms such as autoimmune, oxidative stress, genetic factors, melanocytorrhagy, and neural hypothesis have been suggested for vitiligo pathogenesis.We aimed to assess the morphological changes of epidermal melanocytes and keratinocytes in patients with vitiligo. This aim will be fulfilled by histological, ultrastructural, and immunohistochemical analysis of skin biopsies from lesioned and non-lesioned sites in vitiligo patients.The study was carried out on 15 selected patients with stable vitiligo vulgaris but not receiving treatment in the last year and they fulfilled our inclusion criteria.Biopsies were taken from lesioned and non-lesioned sites in the same vitiligo patients, and they are processed for examinations by LM (using Hx & E, and Masson Fontana stain), immunohistochemical analysis (using Melan-A, E-cadherin, and caspase-3), and TEM (to demonstrate the ultra-structures).By LM, staining with Hx & E, lesioned skin in vitiligo patients showed hyperkeratosis, basal vacuolization, acanthosis with an increase in the epidermal thickness, ballooning of keratinocytes, and spongiosis. Regarding melanocytes, we observed a few numbers of melanocytes, also we detected some basal epidermal cells contain brown melanin granules. Using Fontana-Masson stain, we found that the melanin pigment is present in both lesioned and non-lesioned skin of vitiligo patients. We confirmed the presence of melanocytes in the lesioned skin by the immunohistochemical staining with Melan-A. The epidermal cells in lesioned skin of vitiligo patients showed weak positive expression of E-cadherin between them and an increase in the number of apoptotic Caspase-3 positive cells. BY TEM, the lesioned skin in vitiligo patients showed that the keratinocytes and melanocytes had various degenerative changes, disturbance of desmosomes in between keratinocytes, and absence of melanosomes in the keratinocytes. The detected melanocytes were degenerated and contained some melanosomes, melanin granules, and autophagosomes.We concluded that vitiligo pathogenesis is a combination of several factors and cannot be explained by only one mechanism. The pathology in the lesioned vitiliginous skin is a combination of several degenerative changes in keratinocytes, and melanocytes.

The Role of Oxidative Stress in the Pathogenesis of Vitiligo: A Culprit for Melanocyte Death

Vitiligo is a common chronic acquired pigmentation disorder characterized by loss of pigmentation. Among various hypotheses proposed for the pathogenesis of vitiligo, oxidative stress-induced immune response that ultimately leads to melanocyte death remains most widely accepted. Oxidative stress which causes elevated levels of reactive oxygen species (ROS) can lead to dysfunction of molecules and organelles, triggering further immune response, and ultimately melanocyte death. In recent years, a variety of cell death modes have been studied, including apoptosis, autophagy and autophagic cell death, ferroptosis, and other novel modes of death, which will be discussed in this review in detail. Oxidative stress is also strongly linked to these modes of death. Under oxidative stress, ROS could induce autophagy by activating the Nrf2 antioxidant pathway of melanocytes. However, persistent stimulation of ROS might eventually lead to excessive activation of Nrf2 antioxidant pathway, which in turn will inactivate autophagy. Moreover, ferroptosis may be triggered by oxidative-related transcriptional production, including ARE, the positive feedback loop related to p62, and the reduced activity and expression of GPX4. Therefore, it is reasonable to infer that these modes of death are involved in the oxidative stress response, and that oxidative stress also acts as an initiator for various modes of death through some complex mechanisms. In this study, we aim to summarize the role of oxidative stress in vitiligo and discuss the corresponding mechanisms of interaction between various modes of cell death and oxidative stress. These findings may provide new ideas for exploring the pathogenesis and potential therapeutic targets of vitiligo.

Accuracy and Quality of YouTube Videos as a Source of Information on Vitiligo

Purpose

Vitiligo is a skin condition characterized by patchy depigmentation in the skin, affecting not just the physical well-being of patients, but also the mental, emotional, and social aspects of their lives. Social media provides a platform where patients can interact and share experiences, and for physicians and experts to disseminate knowledge on the disease. This study aimed to evaluate the accuracy and overall quality of vitiligo-related content on YouTube.

Methods

Thirty videos were screened by relevance according to the inclusion criteria. Videos were categorized as either healthcare or non-healthcare sources, and viewer engagement ratio was calculated for each. Three independent vitiligo experts rated the content using the following assessment tools: DISCERN, Accuracy in Digital-health Instrument (ANDI), and Global Quality Scale (GQS). Lastly, Cronbach’s alpha was used to estimate the inter-rater reliability and consistency.

Results

Most of the screened videos came from health-care sources (57%). Non-healthcare sources achieved a slightly higher viewer engagement ratio, although the difference is not statistically significant (p = 0.23). DISCERN score was low overall in most videos. However, DISCERN score was higher for health-care sources as compared to non-healthcare sources (30.5 ± 9.4 vs 22.7 ± 4,2, p = 0.009). Scores of ANDI and GQS were higher for health-care sources but not statistically significant. There was a good internal consistency in DISCERN rating among the evaluators (0.86).

Conclusion

Our study shows a low overall accuracy and quality of YouTube videos on vitiligo. It is recommended that health-care sources improve their information material in terms of quality and viewer engagement, as very little can be done to prevent non-healthcare sources in publishing their own videos. Efforts in educating the public on making distinction between evidence and non-evidence-based claims should also be taken.

Variations in TAP1 and PSMB9 Genes Involved in Antigen Processing and Presentation Increase the Risk of Vitiligo in the Saudi Community

Background

The antigen processing 1 (TAP1) and proteasome 20S subunit beta 9 (PSMB9) genes are associated with strong susceptibility to many autoimmune diseases. Here, we explored whether TAP1/PSMB9 genetic variants, individually or combined, affected susceptibility to the complex, autoimmune-based skin disorder vitiligo.

Methods

Samples of genomic DNA from buccal cells of 172 patients with vitiligo and 129 healthy controls were analyzed using TaqMan™ genotyping assays for the TAP1 rs1135216 (A>G) and PSMB9 rs17587 (A>G) single nucleotide polymorphisms (SNPs). SNPStats software (https://www.snpstats.net) was utilized to choose the best interactive inheritance mode for selected SNPs.

Results

The genotype frequencies for the TAP1 rs1135216 and PSMB9 rs17587 SNPs were in Hardy-Weinberg equilibrium for cases (P= 0.11 and P= 0.10, respectively) but not for controls (P< 0.05). The TAP1 rs1135216 (D637G) and PSMB9 rs17587 (R60H) SNPs increased the risk of vitiligo four-fold and two-fold, respectively (odds ratio [OR]= 4.6; 95% confidence interval [CI], 3.2-6.5; P< 0.0001 and OR= 2.2; 95% CI, 1.5-3.1; P< 0.0001). The recessive model (G/G-D/G versus D/D) and the codominant model (R/R versus R/H) were the best models of inheritance for the rs113526 and rs17587 SNPs, respectively (OR= 16.4; 95% CI, 2.0-138; P= 0.0006 and OR= 1.7; 95% CI, 0.3-1.8; P= 0.013). Vulgaris, focal vulgaris, and acryl/acrofacial were the most common vitiligo subtypes in our sample (51%, 21%, and 19%, respectively). Heterozygous rs113526 (637D/G) and rs17587 (60R/H) were the most common genotypes in most vitiligo subtypes. The heterozygous 637D/G genotype and the 637G variant allele were significantly more common in patients with active disease than in patients with stable disease (P= 0.000052 and P= 0.0063, respectively).

Conclusion

Our findings suggest a crucial role for TAP1 rs1135216 and PSMB9 rs17587 in the risk and progression of vitiligo in the Saudi community. Genomic analyses are needed to identify more candidate genes and more genetic variants associated with vitiligo.

Vitiligo: An Autoimmune Skin Disease and its Immunomodulatory Therapeutic Intervention

Vitiligo is a chronic autoimmune depigmenting skin disorder characterized by patches of the skin losing functional melanocytes. Multiple combinatorial factors are involved in disease development, among which immune T cells play a prominent role. The immune cells implicated in melanocyte destruction through adaptive immunity include CD8⁺ cytotoxic T cells and regulatory T cells, and aberrantly activated skin-resident memory T cells also play a role in melanocyte destruction. Over the past several years, major progress in understanding vitiligo pathogenesis has led to the development of targeted therapies. Janus kinase (JAK) inhibitors, which share the similar mechanism that autoactivates CD8⁺ T cells in chronic inflammatory diseases, have been reported to have therapeutic significance in vitiligo. Recently, immunomodulatory therapeutic interventions in vitiligo have been emerging. Mesenchymal stem cells (MSCs) regulate cytokine secretion and the balance of T-cell subsets, which makes them a promising cell-based treatment option for autoimmune diseases. The induction of MSC-mediated immunomodulation is complicated and occurs by contact-dependent mechanisms and soluble extracellular vesicle (EV) mediators. EVs released from MSCs contain various growth factors and cytokines with anti-inflammatory effects in the skin immune response. Here, we summarize and discuss the progress to date in targeted therapies that immunomodulate the niche environment of vitiligo, from the clinical trial of JAK inhibitors to the potential of MSCs and MSC-EVs. The available information was collected to highlight the need for further research into the treatment of vitiligo.

The Immunogenetics of Vitiligo: An Approach Toward Revealing the Secret of Depigmentation

Vitiligo is a hypomelanotic skin disease and considered to be of autoimmune origin due to breaching of immunological self-tolerance, resulting in inappropriate immune responses against melanocytes. The development of vitiligo includes a strong heritable component. Different strategies ranging from linkage studies to genome-wide association studies are used to explore the genetic factors responsible for the disease. Several vitiligo loci containing the respective genes have been identified which contribute to vitiligo and genetic variants for some of the genes are still unknown. These genes include mainly the proteins that play a role in immune regulation and a few other genes important for apoptosis and regulation of melanocyte functions. Despite the available data on genetic variants and risk alleles which influence the biological processes, only few immunological pathways have been found responsible for all ranges of severity and clinical manifestations of vitiligo. However, studies have concluded that vitiligo is of autoimmune origin and manifests due to complex interactions in immune components and their inappropriate response toward melanocytes. The genes involved in the immune regulation and processing the melanocytes antigen and its presentation can serve as effective immune-therapeutics that can target specific immunological pathways involved in vitiligo. This chapter highlights those immune-regulatory genes involved in vitiligo susceptibility and loci identified to date and their implications in vitiligo pathogenesis.

Variations in TAP1 and PSMB9 Genes Involved in Antigen Processing and Presentation Increase the Risk of Vitiligo in the Saudi Community

BACKGROUND

The antigen processing 1 (TAP1) and proteasome 20S subunit beta 9 (PSMB9) genes are associated with strong susceptibility to many autoimmune diseases. Here, we explored whether TAP1/PSMB9 genetic variants, individually or combined, affected susceptibility to the complex, autoimmune-based skin disorder vitiligo.

METHODS

Samples of genomic DNA from buccal cells of 172 patients with vitiligo and 129 healthy controls were analyzed using TaqMan™ genotyping assays for the TAP1 rs1135216 (A>G) and PSMB9 rs17587 (A>G) single nucleotide polymorphisms (SNPs). SNPStats software (https://www.snpstats.net) was utilized to choose the best interactive inheritance mode for selected SNPs.

RESULTS

The genotype frequencies for the TAP1 rs1135216 and PSMB9 rs17587 SNPs were in Hardy-Weinberg equilibrium for cases (P= 0.11 and P= 0.10, respectively) but not for controls (P< 0.05). The TAP1 rs1135216 (D637G) and PSMB9 rs17587 (R60H) SNPs increased the risk of vitiligo four-fold and two-fold, respectively (odds ratio [OR]= 4.6; 95% confidence interval [CI], 3.2-6.5; P< 0.0001 and OR= 2.2; 95% CI, 1.5-3.1; P< 0.0001). The recessive model (G/G-D/G versus D/D) and the codominant model (R/R versus R/H) were the best models of inheritance for the rs113526 and rs17587 SNPs, respectively (OR= 16.4; 95% CI, 2.0-138; P= 0.0006 and OR= 1.7; 95% CI, 0.3-1.8; P= 0.013). Vulgaris, focal vulgaris, and acryl/acrofacial were the most common vitiligo subtypes in our sample (51%, 21%, and 19%, respectively). Heterozygous rs113526 (637D/G) and rs17587 (60R/H) were the most common genotypes in most vitiligo subtypes. The heterozygous 637D/G genotype and the 637G variant allele were significantly more common in patients with active disease than in patients with stable disease (P= 0.000052 and P= 0.0063, respectively).

CONCLUSION

Our findings suggest a crucial role for TAP1 rs1135216 and PSMB9 rs17587 in the risk and progression of vitiligo in the Saudi community. Genomic analyses are needed to identify more candidate genes and more genetic variants associated with vitiligo.

Immune Checkpoint Blockade and Skin Toxicity Pathogenesis

Immune checkpoint blockade has revolutionized the treatment of multiple tumor types, including melanoma and nonmelanoma skin cancers. The use of immune checkpoint blockade is curtailed by tissue toxicities termed immune-related adverse events (irAEs), which occur most quickly and most often in the skin. We review the rationale for immune checkpoint blockade use, current agents, use in skin cancers, autoimmune manifestations in the skin, and considerations for predictive biomarkers and treatment options on the basis of skin pathogenesis. We also highlight major gaps in the field and the lack of preclinical modeling in the skin. A deeper understanding of irAE pathophysiology may help to uncouple toxicity and efficacy but mandates an interdisciplinary approach, including foundational skin immunology and autoimmune pathogenesis.

Prevalence of Vitiligo Among Adults in the United States

Question

What is the current point prevalence of vitiligo among adults in the US?

Findings

This cross-sectional, population-based online survey study of more than 40 000 adults in the US was conducted between December 2019 and March 2020. Participant self-report, and adjudication of vitiligo by 3 dermatologists through participant submission of photographs of their skin lesions, resulted in an estimated point prevalence for diagnosed and undiagnosed vitiligo combined of 1.38% (self-reported) and 0.76% (clinician adjudicated).

Meaning

This study provides current US population-based point prevalence estimates of all vitiligo, beyond just the diagnosed population, including estimates for undiagnosed, segmental, and nonsegmental vitiligo.

Importance

Vitiligo can have profound effects on patients and is often associated with other autoimmune comorbid conditions. It is important to understand the current prevalence of vitiligo, including diagnosed, undiagnosed, and subtypes (nonsegmental and segmental).

Objective

To estimate the point prevalence of vitiligo in the US.

Design, Setting, and Participants

For this population-based study of adults in the US, a cross-sectional online survey was administered between December 2019 and March 2020 to obtain participant self-reported vitiligo status. A representative sample of the US adult general population, aged 18 to 85 years, was recruited using a stratified proportional, sampling design from general population research panels. Additionally, 3 expert dermatologists adjudicated participants’ self-reported vitiligo diagnosis by reviewing photographs uploaded by the participants using a teledermatology app designed and tested specifically for this study.

Main Outcomes and Measures

The main outcomes were the point prevalence estimates of overall vitiligo, as well as diagnosed, undiagnosed, nonsegmental, and segmental vitiligo.

Results

Among the 40 888 eligible adult participants, the mean (SD) age was 44.9 (17.4) years, 23 170 (56.7%) were female, 30 428 (74.4%) were White, and 4225 (10.3%) were of Hispanic, Latino, or Spanish origin. Self-reported vitiligo prevalence was 1.38% (95% CI, 1.26%-1.49%), with 0.77% (95% CI, 0.68%-0.85%) for diagnosed and 0.61% (95% CI, 0.54%-0.69%) for undiagnosed. Based on expert dermatologist review of 113 photographs of participants with self-reported vitiligo, clinician-adjudicated vitiligo prevalence (sensitivity bounds) was 0.76% (0.76%-1.11%), with 0.46% (0.46%-0.61%) for diagnosed and 0.29% (0.29%-0.50%) for undiagnosed. Self-reported nonsegmental vitiligo prevalence was 0.77% (95% CI, 0.68%-0.85%), with 0.48% (95% CI, 0.41%-0.55%) for diagnosed and 0.29% (95% CI, 0.23%-0.34%) for undiagnosed. Clinician-adjudicated nonsegmental vitiligo prevalence (sensitivity bounds) was 0.58% (0.57%-0.84%), with 0.37% (0.37%-0.49%) for diagnosed and 0.21% (0.20%-0.36%) for undiagnosed. Self-reported segmental vitiligo prevalence was 0.61% (95% CI, 0.53%-0.69%), with 0.28% (95% CI, 0.23%-0.33%) for diagnosed and 0.33% (95% CI, 0.27%-0.38%) for undiagnosed. Clinician-adjudicated segmental vitiligo prevalence (sensitivity bounds) was 0.18% (0.18%-0.27%), with 0.09% (0.09%-0.12%) for diagnosed and 0.08% (0.08%-0.15%) for undiagnosed.

Conclusions and Relevance

Results of this survey study demonstrated that the current US population-based prevalence estimate of overall (diagnosed and undiagnosed combined) vitiligo in adults is between 0.76% (1.9 million cases in 2020) and 1.11% (2.8 million cases in 2020). Additionally, this study suggests that approximately 40% of adult vitiligo in the US may be undiagnosed. Future studies should be performed to confirm these findings.

The scope of health insurance coverage of vitiligo treatments in the United States: Implications for health care outcomes and disparities in children of color

BACKGROUND

Patients of color are disproportionately impacted by vitiligo. Access to treatment depends greatly on insurance coverage. We, therefore, assessed current vitiligo treatment coverage policies across major United States health insurers to determine current patterns and coverage gaps for vitiligo.

METHODS

The study surveyed 15 commercial health care insurers, 50 BlueCross BlueShield (BCBS) plans, Medicare, Medicaid, and Veterans Affairs. Information on treatment coverage for vitiligo, specifically pimecrolimus and tacrolimus, excimer laser therapy, PUVA, and narrow-band (nb)UVB, was collected via an online review of insurance policy documents, confirmed with phone calls to organization representatives, or via a survey of Medicaid providers, and state Medicaid directors.

RESULTS

Of 17 organizations with regional or national coverage policies, 12% did not cover topical calcineurin inhibitors, 56% did not cover nbUVB phototherapy, 53% did not cover PUVA phototherapy, and 41% did not cover laser therapy. For BCBS, pimecrolimus and tacrolimus were not covered in 39% and 35% of states, respectively. NbUVB and PUVA therapy were not covered in 20% and 10% of states, respectively. Excimer laser therapy was not covered in 82% of states. Out of 32 states with accessible Medicaid information, 11 did not cover topicals, 5 did not cover nbUVB, 4 did not cover PUVA, and 7 did not cover laser. Two commonly cited reasons for coverage denial were that the treatment indication was considered cosmetic, and certain therapies are not FDA-approved.

CONCLUSIONS

There is inequity in the distribution of health among vitiligo patients given current patterns of insurance coverage for treatment, which may have disproportionate impact on patients of color.

Review article: Emerging issues in pediatric skin of color, part 1

Dermatology for the pediatric skin of color population is the application of dermatology to the genetically diverse and distinctive segment of the pediatric population that includes children of non-White racial and ethnic groups with increased pigmentation including individuals of Asian, LatinX, African, Native American, Pacific Island descent, Indigenous Peoples, among others, with overlap in particular individuals, and mixtures thereof. Treating children of color is a unique skill set within the field of pediatric dermatology, requiring knowledge and sensitivity. The discipline of pediatric skin of color can be challenging. Difficulty in diagnosis of common conditions stems from underlying pigmentation, variations in common hairstyling practices, and differences in demographics of cutaneous disease, whereas some conditions are more common in children of color, other conditions have nuances in clinical appearance and/or therapeutics with regard to skin color. This article is the first in a series of two articles looking at recently published skin-related issues of high concern in children of color. Conditions reviewed in Part 1 include (1) hairstyling hair-related concerns (traction alopecia, central centrifugal cicatricial alopecia, endocrine disruption), (2) autoimmune concerns (cutaneous lupus, vitiligo), and (3) infections (tinea capitis, progressive macular hypomelanosis).

Psychosocial Effects of Vitiligo: A Systematic Literature Review

Background

Patients with vitiligo experience reduced quality of life.

Objective

To comprehensively describe the available evidence for psychosocial burden in vitiligo.

Methods

A systematic review of observational studies and clinical trials identified using PubMed, EMBASE, Scopus, and the Cochrane databases was performed through 1 March, 2021, to assess psychosocial comorbidities in vitiligo. Two independent reviewers performed an assessment of articles and extracted data for qualitative synthesis.

Results

Included studies (N = 168) were published between 1979 and 1 March, 2021; 72.6% were published since 2010. Disorders including or related to depression (41 studies, 0.1–62.3%) and anxiety (20 studies, 1.9–67.9%) were the most commonly reported. The most prevalent psychosocial comorbidities were feelings of stigmatization (eight studies, 17.3–100%), adjustment disorders (12 studies, 4–93.9%), sleep disturbance (seven studies, 4.6–89.0%), relationship difficulties including sexual dysfunction (ten studies, 2.0–81.8%), and avoidance or restriction behavior (12.5–76%). The prevalence of most psychosocial comorbidities was significantly higher vs healthy individuals. Factors associated with a significantly higher burden included female sex, visible or genital lesions, age < 30 years (particularly adolescents), and greater body surface area involvement, among others. The most commonly reported patient coping strategy was lesion concealment.

Limitations

Available studies were heterogeneous and often had limited details; additionally, publication bias is possible.

Conclusions

The results of this systematic review show that vitiligo greatly affects psychosocial well-being. The extent of psychosocial comorbidities supports the use of multidisciplinary treatment strategies and education to address the vitiligo-associated burden of disease.

Protocol Registration

PROSPERO (CRD42020162223).

Graphic Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s40257-021-00631-6.

Autoimmunity in vitiligo: Therapeutic implications and opportunities

Vitiligo is an acquired chronic pigmentary disorder affecting the melanocytes, mainly in the skin and mucosae. It occurs due to the dynamic interaction between genetic and environmental factors leading to autoimmune destruction of melanocytes. Defects in melanocyte adhesion and increased oxidative stress further augment the immune response in vitiligo. It is a cosmetically disfiguring condition with a substantial psychological burden. Its autoimmune nature with resultant chronicity, variable responses to therapeutic modalities, and frequent recurrences have further diminished the quality of life. Hence, treatment should aim to provide more extended remission periods, prevent recurrences, provide good cosmetic outcomes and ensure patient satisfaction. These treatment goals seem plausible with the recent progress in our understanding of the complex pathogenic mechanisms underlying vitiligo at a molecular and genetic level. We provide a literature review of the pathogenic mechanisms and the therapies targeting these mechanisms.

Height and Risk of Vitiligo: A Nationwide Cohort Study

Adult height is linked to the risk of several diseases, but its association with vitiligo has not been established. This study aimed to investigate the relationship between adult height and vitiligo incidence. Korean nationwide claims data from 15,980,754 individuals (20 years of age or older) who received a health checkup during the period 2005–2008, were examined. Subjects were categorized into age- and gender-specific height quintiles. Participants were followed until vitiligo diagnosis or until the end of 2015. The Cox proportional-hazards model for cumulative risk was computed for height categories. During the follow-up period, 29,196 cases (136,020,214 person-years) of newly diagnosed vitiligo were reported. A positive association was found between height and risk of vitiligo in which the hazard ratio between the highest and lowest quintiles of height was 1.36 (95% confidence interval: 1.31–1.42). While more diverse cohort studies are needed, our findings suggest that taller stature increases the risk of vitiligo.

Reliability, Validity and Feasibility of the Vitiligo Extent Score (VES) and Self-Assessment Vitiligo Extent Score (SA-VES) Among Vitiligo Patients: A Cross-Cultural Validation

Background

The Vitiligo Extent Score (VES) and Self-Assessment Vitiligo Extent Score (SA-VES) have not been formally validated in Thai population.

Objective

To evaluate reliability, validity and feasibility of the VES and SA-VES in Thai vitiligo patients.

Methods

Vitiligo lesions from 100 patients were evaluated by 2 independent dermatologists using VES and Vitiligo Area Scoring Index (VASI). Reliability was assessed by comparing VES scores between physicians. Validity was determined by comparison among the VES, VASI, and SA-VES instruments. Patients scored their vitiligo severity using the SA-VES.

Results

The reliability of the VES was excellent (inter-rater reliability: 0.997, 95% confidence interval: 0.995–0.998). There was very strong correlation between the VES and VASI (r=0.976, p<0.001), and strong correlation between the VES and SA-VES (r=0.890, p<0.001), and between the VASI and SA-VES (r=0.866, p<0.001). Moderate correlation among the VES, VASI, and SA-VES was observed in patients with segmental or <1% body surface area (BSA) vitiligo. Ninety-five percent of patients rated the SA-VES as easy to moderately easy.

Conclusion

The VES has reliability and validity comparable to that of the VASI. The SA-VES is an user-friendly instrument that correlated well with physicians’ scoring methods in patients with non-segmental or >1% BSA vitiligo.

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.

Photodynamic therapy of vitiligo: A pilot study

BACKGROUND

Vitiligo is an acquired autoimmune skin disorder with depigmented macules and patches. There are several possible treatments for vitiligo, none of which could be considered as a definitive cure. Photodynamic therapy (PDT) is a novel treatment with controversial outcomes in vitiligo patients.

MATERIALS & METHODS

A total of 10 patches (5 patches on the trunk, 3 on the extremities, and 2 on the neck) were selected and received microderm abrasion. Then the lesion was covered with 5- aminolevulinic acid (ALA) for one hour. Afterwards, it received red light with a dose of 120 J/cm².This cycle was repeated monthly for 5 sessions. Another vitiligo patch was considered as a control and received topical mometasone twice a day during the study. The therapeutic results were compared by a blind dermatologist.

RESULTS

The median of repigmentation score, which was determined by a blind dermatologist, was 0.5 in the PDT group and 1 in the steroid group, which did not show any statistically significant difference.

CONCLUSION

The results of this study demonstrated that PDT does not have any additional therapeutic effect in comparison with topical corticosteroids as the traditional treatment of vitiligo.

Feasibility of oral tranexamic acid for vitiligo patients with melasma

Melasma and vitiligo are both common pigmentary disorders, and the treatment is challenging. Oral tranexamic acid (TA) is effective for refractory melasma; however, the feasibility of TA in vitiligo patients with melasma was not studied. To evaluate the treatment outcomes and adverse effects of oral TA in vitiligo patients with melasma. We conducted a retrospective analysis of vitiligo patients who received oral TA for melasma in a tertiary dermatologic center from January 2017 to August 2020. We enrolled 32 patients with concomitant vitiligo and melasma on the face. The mean duration of the improvement of melasma that patients reported is around 1.64 months of treatment. The first sign of repigmentation of the vitiligo lesions occurred at 1 month of treatment. 84.38% of the patients achieved a mild to good degree of improvement of melasma (0%-75% improvement), whereas 81.25% of the patients achieved a moderate to excellent degree of improvement of vitiligo (25%-100% improvement) via physician global assessments. No significant adverse event was noted. No patients experience vitiligo disease deterioration during TA treatment. Oral TA may be a feasible option for melasma in vitiligo patients.

Evaluation of HLA class I and HLA class II allele profile and its relationship with clinical features in patients with alopecia areata: a case-control study

BACKGROUND

Alopecia areata (AA) is an autoimmune disease where autoimmune dysregulations along with genetic susceptibility are hypothesized to play a role in pathogenesis.

OBJECTIVE

The aim of this study in to evaluate HLA-A, HLA-B, HLA-C, HLA-DQB1, and HLA-DRB1 profile and its relationship with clinical features in AA patients.

MATERIALS AND METHODS

Ninety-eight patients with AA and 100 healthy controls were included in the study. HLA-A, HLA-B, HLA-C, HLA-DQB1, and HLA-DRB1 frequencies were analyzed using polymerase chain reaction-sequence specific primers (PCR-SSP).

RESULTS

HLA-B*39 and HLA-HLA-DRB1*15 allele frequencies were increased (p = .022 and p = .023, respectively), HLA-A*11 and HLA-B*35 frequencies were decreased (p = .006 and p = .014, respectively) in AA patients. HLA-B*13 and HLA-DRB1*11 were associated with poor prognostic factors. A class I allele, HLA-B*13 was associated with recurrence (p = .023) and presence of nevus flammeus (p = .022), while the class II allele HLA-DRB1*11 was associated with widespread hair loss (diffuse or universal alopecia) (p = .026), presence of ophiasis (p = .049) and juvenile onset (p = .018).

CONCLUSION

Belonging to two different classes of HLA family, HLA-B*13 and HLA-DRB1*11 alleles identified separate set of risk factors. In addition to increasing the risk of AA, HLA alleles may affect the prognosis of the disease.

Alterations of the pigmentation system in the aging process

Human skin aging is a natural phenomenon that results from continuous exposure to intrinsic (time, genetic factors, hormones) as well as extrinsic factors (UV exposure, pollution, tobacco). In areas that are frequently exposed to the sun, photoaging blends with the process of intrinsic aging, resulting in an increased senescent cells number and consequently accelerating the aging process. The severity of photodamage depends on constitutional factors, including skin phototype (skin color, tanning capacity), intensity, and duration of sunlight/UV exposure. Aging affects nearly every aspect of cutaneous biology, including pigmentation. Clinically, the phenotype of age pigmented skin has a mottled, uneven color, primarily due to age spots, with or without hypopigmentation. Uneven pigmentation might be attributed to the hyperactivation of melanocytes, altered distribution of pigment, and turnover. In addition to direct damage to pigment-producing cells, photodamage alters the physiological crosstalk between keratinocytes, fibroblasts, endothelial cells, and melanocytes responsible for natural pigmentation homeostasis. Interestingly, age-independent diffuse expression of senescence-associated markers in the dermal and epidermal compartment is also associated with vitiligo, suggesting that premature senescence plays an important role in the pathology.

A novel mouse model to evaluate neuropeptide Y-mediated melanocyte pathology

Vitiligo is an autoimmune disease characterized by depigmented patches of skin due to loss of the pigment-producing melanocytes. No cure exists for vitiligo. The available treatments are inefficient for many patients, suggesting that universal treatment approaches may be inappropriate. Deeper understanding of the mechanistic basis for variability in vitiligo aetiologies is necessary. Genetic mutations in neuropeptide Y (NPY), a widely distributed protein, are associated with increased NPY expression and increased susceptibility for vitiligo. NPY is also upregulated in the circulation and lesional skin of some vitiligo patients. However, the contributions of NPY to melanocyte pathology are not understood, and presently there are no models with which to investigate this possibility. In this study, we employed NPY-overexpressing mice to explore the role of NPY in melanocyte dysfunction. Our results show that NPY overexpression induces progressive hair greying (depigmentation) due to premature depletion of follicular melanocyte stem cells. Additionally, NPY transcripts and protein are elevated in the skin and melanocytes of these mice, respectively, suggesting that these effects may be mediated locally. Together, these results suggest that supraphysiological levels of NPY in the skin can induce melanocyte dysfunction, thus identifying this mouse line as a novel model to study NPY-mediated melanocyte pathology.

Identification of TYR, TYRP1, DCT and LARP7 as related biomarkers and immune infiltration characteristics of vitiligo via comprehensive strategies

This study aims to explore biomarkers associated with vitiligo and analyze the pathological role of immune cell infiltration in the disease. We used the robust rank aggregation (RRA) method to integrate three vitiligo data sets downloaded from gene expression omnibus database, identify the differentially expressed genes (DEGs) and analyze the functional correlation. Then, the comprehensive strategy of combined weighted gene coexpression network analysis (WGCNA) and logical regression of the selection operator (LASSO), support vector machine recursive feature elimination (SVM-RFE), and random forest (RF) machine learning algorithm are employed to screen and biomarkers associated with vitiligo. Finally, the immune cell infiltration of vitiligo was evaluated by CIBERSORT, and the correlation between biomarkers and infiltrating immune cells was analyzed. Herein, we identified 131 robust DEGs, and enrichment analysis results showed that robust DEGs and melanogenesis were closely associated with vitiligo development and progression. TYR, TYRP1, DCT and LARP7 were identified as vitiligo-related biomarkers. Immune infiltration analysis demonstrated that CD4 T Cell, CD8 T Cell, Tregs, NK cells, dendritic cells, and macrophages were involved in vitiligo’s pathogenesis. In summary, we adopted a comprehensive strategy to screen biomarkers related to vitiligo and explore the critical role of immune cell infiltration in vitiligo.

Abbreviations: TYR, Tyrosinase; TYRP1, Tyrosinase-related protein-1; DCT, dopachrome tautomerase; LARP7, La ribonucleoprotein domain family, member-7; RRA, robust rank aggregation; DEGs, differentially expressed genes; WGCNA, weighted gene coexpression network analysis; LASSO, logical regression of the selection operator; SVM-RFE, support vector machine recursive feature elimination; RF, random forest; GWAS, Genome-wide association study; FasL, Fas-Fas ligand; Tregs, T-regulatory cells; NK, natural killer; GEPCs, gene expression profiling chips; GO, gene ontology; GSEA, gene set enrichment analysis; FDR, false discovery rate; AUC, area under the curve; ROC, receiver-operating characteristic; BP, biological process; CC, cellular component; MF, molecular function.

CCL17-CCR4 axis contributes to the onset of vitiligo in mice

BACKGROUND

Destruction of melanocytes mediated by autoimmunity is currently believed as the main cause of vitiligo. This article aims to identify the role of CC chemokine ligand 17 (CCL17)-CC chemokine receptor 4 (CCR4) axis in vitiligo and provide new possibilities for the clinical treatment of vitiligo.

METHODS

A total of 30 patients with vitiligo from Affiliated Huaian No. 1 People's Hospital of Nanjing Medical University were recruited based on the inclusion and exclusion criteria. Trephine was used to obtain skin samples from the lesion area and its surrounding normal areas, and the expression levels of CCL17, CCR4, Tbx21, Eomes, and Blimp1 were determined by quantitative reverse transcription polymerase chain reaction. Vitiligo mouse model was established by adoptively transferring CFP-PMEL CD8+ T cells into sublethally irradiated Krt14-Kitl* mice. Recipient mice received intraperitoneal injection of 1 × 10⁶ plaque-forming units of rVV-hPMEL on the same day of transfer. The degree of depigmentation was scored blindly by one observer 5 weeks after vitiligo induction. CFP-PMEL CD8+ T cells migration to skin, draining lymph nodes, spleen, and blood were detected by flow cytometry. CCR4 blockade was performed by intraperitoneal injection of neutralizing antibody.

RESULTS

The expression levels of CCL17, CCR4, Tbx21, Eomes, and Blimp1 in skin lesions were significantly increased compared with that in surrounding normal areas. CCL17^-/- and CCR4^-/- mice exhibited significantly lower disease scores than WT mice. The CFP-PMEL CD8+ T cells accumulation was significantly decreased in the skin of CCL17^-/- and CCR4^-/- mice, but was not changed in draining lymph nodes, spleen, and blood. Administration of CCR4 neutralizing antibody decreased the degree of depigmentation and the recruitment of CFP-PMEL CD8+ T cells to the skin, while keeping the number of T cells in draining lymph nodes unchanged.

CONCLUSION

Targeting CCL17-CCR4 axis might inhibit T cell migrating to skin and alleviate vitiligo progression.

Epidemiology of Vitiligo - A Dual Population-Based Approach

Background

Most epidemiological data on vitiligo refer to selected environments or focus on the prevalence of comorbidity unrelated to the population.

Objective

Aim of the study was to gain robust representative prevalence data on vitiligo and on associated dermatologic comorbidity in the German adult population.

Methods

A dual population-based approach was applied with 1) primary data obtained between 2004 and 2014 from dermatological exams in the general working population; 2) claims data from a large German statutory health insurance, reference year 2010.

Results

In the working cohort (N = 121,783; 57% male; mean age 43 years), the prevalence of vitiligo was 0.77% (0.84% in men; 0.67% in women). In the claims data (N = 1,619,678; 38% male; mean age 46 years), prevalence was 0.17% (0.14% in men; 0.18% in women). In the working cohort, vitiligo was significantly more common in people with fair skin type, ephelides and port-wine stains and less common in people with acne and solar lentigines. In the claims data, vitiligo was associated with a variety of skin conditions, eg, atopic dermatitis, psoriasis and alopecia areata.

Conclusion

The resulting discrepancy of claims vs primary data between 0.17% and 0.77% indicates the most probable spectrum of vitiligo prevalence in Germany. It is more frequently observed in clinical exams than recorded in claims data, indicating a marked proportion of people seeking no medical help. Such nonattendance may result from the fact that many treatment options do not provide satisfying benefits to the patients.

Updates and new medical treatments for vitiligo (Review)

Vitiligo is a multifactorial disease characterized by the loss of skin pigment, which results in achromic macules and patches. There are currently several medical treatments available, which aim to arrest progression and induce skin repigmentation. These treatments alone or combined have exhibited varying degrees of pigmentation, and the majority are safe and effective. All therapies for vitiligo are limited, and no known treatment can consistently produce repigmentation in all patients. Individualized treatment is appropriate according to the location, clinical presentation and the presence of disease activity. The present review summarizes the medical treatments available for vitiligo: Systemic and topic pharmacological therapies, physical and depigmentation treatments. Several treatments are still underway and have not yet been approved. However, due to the promising preliminary results, these are also mentioned in the present review.

Baicalein inhibits RLS3-induced ferroptosis in melanocytes

We explored the effect of baicalein on the ferroptosis of melanocytes in vitiligo. Melanocytes were treated with single RSL3 or combined RSL3 with FAC for 24 h and the effect of baicalein on RSL3 toxicity was further evaluated. Cell viability was examined by CCK8 assay. The mitochondrial membrane potential and the level of iron ion were measured by assay kit. Intracellular and lipid ROS production was detected by flow cytometry. The results indicated that RSL3 induced cell death, mitochondrial dysfunction, ROS production, and iron ion accumulation in melanocytes, which was aggravated by the addition of FAC. The damage induced by RSL3 was significantly relieved by baicalein treatment. Besides, baicalein up-regulated GPX4 and reduced TFR1 level in melanocytes treated with RSL3+FAC. Baicalein protected melanocytes against ferroptosis through up-regulating GPX4. Ferroptosis might be pervasive in the occurrence and development of vitiligo, and could be proposed as the potential therapeutic target.

Meta-Analytic Review of High Anxiety Comorbidity among Patients with Vitiligo

Background

Vitiligo is a disfiguring skin disease with profound psychosocial impacts, such as anxiety, but the reported effect sizes of associations vary. We aimed to conduct a meta-analysis to quantify the strength of association between anxiety and vitiligo and to estimate the prevalence of anxiety among individuals with vitiligo.

Methods

A systematic literature search was performed in five online databases (MEDLINE, Embase, Web of Science, Cochrane Library, and PsycINFO) from inception until March 20, 2020. All of the eligible studies were comprehensively reviewed, and all of the available data were analyzed according to our predefined criteria.

Results

Twenty-one studies involving 3259 patients in 11 countries were included in this meta-analysis. Compared with the healthy control group, patients with vitiligo often had concomitant anxiety (OR = 6.14 [95% CI: 3.35–11.24], I² = 30.1%). The pooled prevalence of anxiety in female patients was significantly higher than that in males (OR = 2.24 [95% CI: 1.31–3.84], I² = 0.0%). Subgroup analysis showed that the pooled prevalence of clinical anxiety disorder and anxiety symptoms was 12% (95% CI: 7%–16%, I² = 76.3%) and 34% (95% CI: 21%–46%, I² = 94.7%), respectively. No publication bias has been detected by Begg's funnel plot and Egger's test.

Conclusion

Patients with vitiligo have high anxiety comorbidity, with female predominance. Dermatologists and psychiatrists should be vigilant to the presence of anxiety, apply appropriate interventions to reduce the psychological impacts in a timely manner, and thus promote recovery in vitiligo patients. However, due to some objective limitations (poor information about the OR and diversity in assessment tools among included studies), findings should be interpreted with caution.

Prevalence of Hypopigmentary Disorders in Primary School Children in Zagazig City, Sharkia Governorate, Egypt

BACKGROUND

Epidemiologic data derived from population-based studies are very important to understand human diseases and their implications. Highlighting skin problems by identifying their incidence and prevalence is vital to direct suitable medical attention toward them.

AIM

The aim of the study was to detect the prevalence and most common causes of hypopigmentation in primary school children in Zagazig City.

METHODS

Cross-sectional study on 185 students selected from two schools. Data were collected by filling a questionnaire, clinical examination, and Wood's light examination to detect hypopigmented skin disorders.

RESULTS

The prevalence of hypopigmentation among studied population was 45.4%; the commonest cause was pityriasis alba 58.3%, followed by pityriasis versicolor 17.9%, postinflammatory hypopigmentation 10.7%, hypopigmented nevus 9.5%, and finally 3.6% vitiligo.

CONCLUSION

Hypopigmented skin disorders are important and easy to diagnosis skin diseases that need medical attention.

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.

Novel immunological and genetic factors associated with vitiligo: A review

Vitiligo is a skin disorder characterized by depigmentation of the skin due to a lack of melanin. This condition affects men and woman of all ages and its incidence is not restricted by ethnicity or region. Vitiligo is a multifactorial disease, in which melanocytes, which serve important functions in skin pigmentation and immune processes, are impaired. There is sufficient evidence that immunological and genetic factors are primarily responsible for the destruction and dysfunction of melanocytes. Therefore, genetic DNA sequence variants that participate in skin homeostasis, pigmentation and immune response regulation, as well as altered expression patterns, may contribute to the risk of developing vitiligo. The current review presented an overview of the mechanism of pigmentation and of currently known factors involved in depigmentation, as well as the classification, epidemiology, associated comorbidities, risk factors, immunopathogenesis and several genetic and molecular changes associated with vitiligo.