The genetics of generalized vitiligo and associated autoimmune diseases

Involvement of interferon-gamma genetic variants and intercellular adhesion molecule-1 in onset and progression of generalized vitiligo

Interferon-gamma (IFN-γ) is a paracrine inhibitor of melanocytes and genetic variability due to intron 1 polymorphisms in IFNG has been reported to be associated with increased risk for several autoimmune diseases. The aim of present study was to determine whether intron 1 +874A/T (rs2430561) and CA microsatellite (rs3138557) polymorphisms in IFNG are associated with generalized vitiligo (GV) susceptibility and expression of IFNG and intercellular adhesion molecule-1 (ICAM1) affects the disease onset and progression. Here we report that IFNG CA microsatellite but not +874A/T may be a genetic risk factor for GV; however, +874T allele plays a crucial role in increased expression of IFNG mRNA and protein levels which could affect the onset and progression of the disease. Active GV patients showed increased IFNG levels compared to stable GV patients. The genotype-phenotype analysis revealed that IFNG expression levels were higher in patients with +874 TT genotypes and 12 CA repeats. Patients with the early age of onset showed higher IFNG expression and female GV patients showed higher IFNG and ICAM1 expression implicating gender biasness and involvement of IFN-γ in early onset of the disease. Moreover, the increased IFN-γ levels in patients lead to increased ICAM1 expression, which could be a probable link between cytokines and T-cell involvement in pathogenesis of GV.

Correlation of increased MYG1 expression and its promoter polymorphism with disease progression and higher susceptibility in vitiligo patients

BACKGROUND

MYG1 (Melanocyte proliferating gene 1 or C12orf10) -119C/G promoter and Arg4Gln structural polymorphisms have a functional impact on its regulation. The promoter polymorphism was shown to be associated with vitiligo in Caucasian population.

OBJECTIVE

The present study explores MYG1 polymorphisms and correlates them with MYG1 mRNA expression, disease onset and progression in vitiligo patients.

METHODS

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was used for genotyping of MYG1 -119C/G promoter (rs1465073) and 11-12AA/GC structural polymorphisms (rs1534284-rs1534283; Arg4Gln) in 846 vitiligo patients and 726 age-matched unaffected controls. MYG1 mRNA levels were assessed in whole blood of 166 patients and 175 controls by Real-time PCR.

RESULTS

The MYG1 -119C/G promoter polymorphism was found to be in significant association with vitiligo being 'G' allele prevalent in patients. However, 11-12AA/GC structural polymorphism was prevalently monogenic in patients and controls with only MYG1 GC (4Arg) allele being present. Significant increase in MYG1 mRNA expression was observed in vitiligo patients compared to controls. The MYG1 mRNA expression was increased in patients with active and generalized vitiligo as compared to stable and localized vitiligo. MYG1 mRNA expression was increased in patients with susceptible -119 GG genotype compared to controls. Also, patients with susceptible -119 GG genotype had early age of onset of vitiligo. Moreover, patients with age groups 1-20 years and 21-40 years showed increased expression of MYG1 mRNA compared to those of controls. Female patients showed significant increase in MYG1 mRNA and early age of onset of vitiligo compared to male patients.

CONCLUSION

The present study suggests that MYG1 -119C/G promoter polymorphism may be a genetic risk factor for susceptibility and progression of vitiligo. The up-regulation of MYG1 transcript in patients with susceptible -119GG genotype advocates the crucial role of MYG1 in autoimmune pathogenesis of vitiligo.

Comparison of the 308-nm excimer laser with the 308-nm excimer lamp in the treatment of vitiligo--a randomized bilateral comparison study

BACKGROUND

Vitiligo is an acquired pigment disorder characterized by areas of depigmented skin resulting from the loss of epidermal melanocytes. Recently, several investigations have documented the benefits of excimer phototherapy (e.g., using the 308-nm excimer laser or the 308-nm excimer lamp) for the treatment of vitiligo.

AIM

To compare the effectiveness of the 308-nm excimer laser with the 308-nm excimer lamp in the treatment of vitiligo patients.

METHODS

This intervention study was designed as a randomized self-control trial. Fourteen subjects with 48 symmetrical vitiligo lesions were enrolled in this study. One lesion was treated with the 308-nm excimer laser, and its counterpart was treated with the 308-nm excimer lamp. Lesions were treated three times a week with the same dose on both sides for a total of 20 sessions.

RESULTS

All of the patients completed the study, and 48 lesions were treated. The two treatments exhibited similar results in terms of repigmentation.

CONCLUSIONS

The 308-nm excimer lamp and the 308-nm excimer laser exhibited similar efficacies in treating vitiligo.

WITHDRAWN: Comparision between 308-nm excimer laser and 308-nm excimer lamp in the treatment of vitiligo - a randomized self control study

Ahead of Print article withdrawn by publisher.

Vitiligo: interplay between oxidative stress and immune system

Vitiligo is a multifactorial polygenic disorder with a complex pathogenesis, linked with both genetic and non-genetic factors. The precise modus operandi for vitiligo pathogenesis has remained elusive. Theories regarding loss of melanocytes are based on autoimmune, cytotoxic, oxidant-antioxidant and neural mechanisms. Reactive oxygen species (ROS) in excess have been documented in active vitiligo skin. Numerous proteins in addition to tyrosinase are affected. It is possible that oxidative stress is one among the main principal causes of vitiligo. However, there also exists ample evidence for altered immunological processes in vitiligo, particularly in chronic and progressive conditions. Both innate and adaptive arms of the immune system appear to be involved as a primary event or as a secondary promotive consequence. There is speculation on the interplay, if any, between ROS and the immune system in the pathogenesis of vitiligo. The article focuses on the scientific evidences linking oxidative stress and immune system to vitiligo pathogenesis giving credence to a convergent terminal pathway of oxidative stress-autoimmunity-mediated melanocyte loss.

Tumor necrosis factor B (TNFB) genetic variants and its increased expression are associated with vitiligo susceptibility

Genetic polymorphisms in TNFB are involved in the regulation of its expression and are found to be associated with various autoimmune diseases. The aim of the present study was to determine whether TNFB +252A/G (rs909253) and exon 3 C/A (rs1041981) polymorphisms are associated with vitiligo susceptibility, and expression of TNFB and ICAM1 affects the disease onset and progression. We have earlier reported the role of TNFA in autoimmune pathogenesis of vitiligo, and we now show the involvement of TNFB in vitiligo pathogenesis. The two polymorphisms investigated in the TNFB were in strong linkage disequilibrium and significantly associated with vitiligo. TNFB and ICAM1 transcripts were significantly increased in patients compared to controls. Active vitiligo patients showed significant increase in TNFB transcripts compared to stable vitiligo. The genotype-phenotype analysis revealed that TNFB expression levels were higher in patients with GG and AA genotypes as compared to controls. Patients with the early age of onset and female patients showed higher TNFB and ICAM1 expression. Overall, our findings suggest that the increased TNFB transcript levels in vitiligo patients could result, at least in part, from variations at the genetic level which in turn leads to increased ICAM1 expression. For the first time, we show that TNFB +252A/G and exon 3 C/A polymorphisms are associated with vitiligo susceptibility and influence the TNFB and ICAM1 expression. Moreover, the study also emphasizes influence of TNFB and ICAM1 on the disease progression, onset and gender bias for developing vitiligo.

Increased Tumor Necrosis Factor (TNF)-α and its promoter polymorphisms correlate with disease progression and higher susceptibility towards vitiligo

Tumor Necrosis Factor (TNF)-α, is a paracrine inhibitor of melanocytes, which plays a critical role in the pathogenesis of several autoimmune diseases including vitiligo, as abnormal immune responses have frequently been observed in vitiligo patients. Moreover, vitiligo patients show higher lesion levels of TNF-α. Genetic polymorphisms in the promoter region of TNF-α are involved in the regulation of its expression. The present study explores TNF-α promoter polymorphisms and correlates them with TNF-α transcript and protein levels in vitiligo patients and controls of Gujarat along with its effect on disease onset and progression. PCR-RFLP technique was used for genotyping of these polymorphisms in 977 vitiligo patients and 990 controls. TNF-α transcript and protein levels were measured by Real time PCR and ELISA respectively. The genotype and allele frequencies for the investigated polymorphisms were significantly associated with vitiligo patients. The study revealed significant increase in TNF-α transcript and protein levels in vitiligo patients compared to controls. In particular, haplotypes: AATCC, AACCT, AGTCT, GATCT, GATCC and AGCCT were found to increase the TNF-α levels in vitiligo patients. Analysis of TNF-α levels based on the gender and disease progression suggests that female patients and patients with active vitiligo had higher levels of TNF-α. Also, the TNF-α levels were high in patients with generalized vitiligo as compared to localized vitiligo. Age of onset analysis of the disease suggests that the haplotypes: AACAT, AACCT, AATCC and AATCT had a profound effect in the early onset of the disease. Moreover, the analysis suggests that female patients had an early onset of vitiligo. Overall, our results suggest that TNF-α promoter polymorphisms may be genetic risk factors for susceptibility and progression of the disease. The up-regulation of TNF-α transcript and protein levels in individuals with susceptible haplotypes advocates the crucial role of TNF-α in autoimmune pathogenesis of vitiligo.

Transcriptome analysis reveals markers of aberrantly activated innate immunity in vitiligo lesional and non-lesional skin

BACKGROUND

Vitiligo is characterized by the death of melanocytes in the skin. This is associated with the presence of T cell infiltrates in the lesional borders. However, at present, there is no detailed and systematic characterization on whether additional cellular or molecular changes are present inside vitiligo lesions. Further, it is unknown if the normal appearing non-lesional skin of vitiligo patients is in fact normal. The purpose of this study is to systematically characterize the molecular and cellular characteristics of the lesional and non-lesional skin of vitiligo patients.

METHODS AND MATERIALS

Paired lesional and non-lesional skin biopsies from twenty-three vitiligo patients and normal skin biopsies from sixteen healthy volunteers were obtained with informed consent. The following aspects were analyzed: (1) transcriptome changes present in vitiligo skin using DNA microarrays and qRT-PCR; (2) abnormal cellular infiltrates in vitiligo skin explant cultures using flow cytometry; and (3) distribution of the abnormal cellular infiltrates in vitiligo skin using immunofluorescence microscopy.

RESULTS

Compared with normal skin, vitiligo lesional skin contained 17 genes (mostly melanocyte-specific genes) whose expression was decreased or absent. In contrast, the relative expression of 13 genes was up-regulated. The up-regulated genes point to aberrant activity of the innate immune system, especially natural killer cells in vitiligo. Strikingly, the markers of heightened innate immune responses were also found to be up-regulated in the non-lesional skin of vitiligo patients.

CONCLUSIONS AND CLINICAL IMPLICATIONS

As the first systematic transcriptome characterization of the skin in vitiligo patients, this study revealed previously unknown molecular markers that strongly suggest aberrant innate immune activation in the microenvironment of vitiligo skin. Since these changes involve both lesional and non-lesional skin, our results suggest that therapies targeting the entire skin surface may improve treatment outcomes. Finally, this study revealed novel mediators that may facilitate future development of vitiligo therapies.

Clinical patterns of vitiligo and its associated co morbidities: A prospective controlled cross-sectional study in South India

Aim:

The purpose of this study is to assess the clinical patterns and associations of vitiligo, audiometric functions, and ocular involvement and to correlate the morphology, clinical behaviour and comorbidities associated with vitiligo.

Settings and Design:

For this prospective and cross-sectional study 80 self-reporting patients in the age group 7-75 years with vitiligo attending the outpatient department of Manipal hospital during the period August 2008 to February 2010 were selected and the data was analysed.

Materials and Methods:

The patients were subjected to detailed history, clinical examination and investigations [complete blood count (CBC), absolute eosinophil count (AEC), erythrocyte sedimentation rate (ESR), thyroid stimulating hormone (TSH), vitamin B12 estimation, fasting blood sugar (FBS), and post prandial blood sugar (PPBS),antibody titre estimations that is antithyroid peroxidase (ATPA), antithyroglobulin (ATA), antinuclear antibodies (ANA),urine analysis], audiometric evaluation and ophthalmic examination.

Statistical Analysis Used:

The Fisher exact test has been used to find the significance of study parameters on categorical scale between two or more groups.

Results:

In the present series of 80 cases, 41 (51.25%) were males and 39 (48.75%) were females. The male to female ratio was 1.05:1. In our study 20% cases gave definite family history of vitiligo and patients in the age group of 20 - 30 years were the most commonly affected. Generalized vitiligo (31.3%) was the most common type followed by segmental (30%), focal (18.8%), acrofacial (8.8%), and mucosal vitiligo (11.3%). In the present study there was a high incidence of autoantibodies (22.5%), vitamin B12 deficiency (30%), hypothyroidism (11.3%), elevated absolute eosinophil count (16.3%), hypoacusis (10%) and retinal changes (8.8%). This suggests multisystem autoimmunity in vitiligo.

Association analyses identify three susceptibility Loci for vitiligo in the Chinese Han population

To identify susceptibility loci for vitiligo, we extended our previous vitiligo genome-wide association study with a two-staged replication study that included 6,857 cases and 12,025 controls from the Chinese Han population. We identified three susceptibility loci, 12q13.2 (rs10876864, P(combined)=8.07 × 10(-12), odds ratio (OR)=1.18), 11q23.3 (rs638893, P(combined)=2.47 × 10(-9), OR=1.22), and 10q22.1 (rs1417210, P(combined)=1.83 × 10(-8), OR=0.88), and confirmed three previously reported loci for vitiligo, 3q28 (rs9851967, P(combined)=8.57 × 10(-8), OR=0.88), 10p15.1 (rs3134883, P(combined)=1.01 × 10(-5), OR=1.11), and 22q12.3 (rs2051582, P(combined)=2.12 × 10(-5), OR=1.14), in the Chinese Han population. The most significant single-nucleotide polymorphism in the 12q13.2 locus is located immediately upstream of the promoter region of PMEL, which encodes a major melanocyte antigen and has expression loss in the vitiligo lesional skin. In addition, both 12q13.2 and 11q23.3 loci identified in this study are also associated with other autoimmune diseases such as type 1 diabetes and systemic lupus erythematosus. These findings provide indirect support that vitiligo pathogenesis involves a complex interplay between immune regulatory factors and melanocyte-specific factors. They also highlight similarities and differences in the genetic basis of vitiligo in Chinese and Caucasian populations.

Tumor necrosis factor-α -308G/A polymorphism is associated with active vitiligo vulgaris in a northeastern Mexican population

Vitiligo is a skin disease characterized by depigmentation. Its etiopathogenesis is unclear, but it has been associated with autoimmune processes. Gene polymorphisms in the tumor necrosis factor-α (TNF-α) have been associated with several imflammatory diseases. In particular, the -308G/A polymorphism in the gene promoter region has been reported to be associated with increased plasma levels of TNF-α and with an increased risk to develop autoimmune diseases. To date, this polymorphism has not been associated with vitiligo. To assess a possible association between the TNF-α -308G/A and vitiligo vulgaris (VV), 198 vitiligo patients and 395 control subjects were recruited for the study. A complete demographic and clinical profile of each case was registered to analyze the possible risk factors of vitiligo. Genomic DNA isolated from peri pheral blood was subjected to PCR-RFLP for genotyping of the TNF-α -308G/A polymorphism. Causal associations were determined by χ(2) test and their respective OR was assessed in a 2×2 contingency table. When population variables of type of vitiligo, gender, age of disease onset, and active disease status were considered, an association between active VV and the TNF-α GA genotype was found (P=0.0295, OR=2.0; 95% CI 1.01-3.93). All other variables were irrelevant to vitiligo. Our data suggest a possible association between the TNF-α -308 GA genotype and the active form of VV in a Mexican population.

Halo naevi and leukotrichia are strong predictors of the passage to mixed vitiligo in a subgroup of segmental vitiligo

BACKGROUND

Until now, segmental vitiligo has been considered as a stable entity and mixed vitiligo, the association of segmental and nonsegmental vitiligo, has been reported rarely.

OBJECTIVES

The aim of this study was to search for factors associated with the generalization of vitiligo in patients with segmental vitiligo.

PATIENTS AND METHODS

This was a prospective observational study conducted in the vitiligo clinic of the Department of Dermatology of Bordeaux, France. The Vitiligo European Task Force questionnaire was completed for each patient attending the clinic with a confirmed diagnosis of segmental vitiligo after exclusion of other forms of vitiligo (focal, mucosal, not classifiable.) Thyroid function and antithyroid antibodies were screened if not obtained in the previous year.

RESULTS

One hundred and twenty-seven patients were recruited: 101 had segmental vitiligo and 26 had segmental vitiligo that evolved into mixed vitiligo; 56 were male and 71 were female. Most patients had onset of segmental vitiligo before the age of 18. When conducting multivariate analysis, we found the following to be independent factors associated with the evolution of patients' disease from segmental vitiligo to mixed vitiligo: initial percentage of body surface involvement of the segment >1% [odds ratio (OR) 15·14, P=0·002], the presence of halo naevi (OR 24·82, P=0·0001) and leukotrichia (OR 25·73, P=0·0009).

CONCLUSIONS

Halo naevi association and leukotrichia at first consultation in segmental vitiligo are risk factors for the progression of segmental vitiligo to mixed vitiligo. In addition, this progression of segmental vitiligo to mixed vitiligo carries a stronger link if initial segmental involvement is situated on the trunk.

Deregulated inflammasome signaling in disease

Inflammasomes are multi-protein complexes that sense microbial molecules and endogenous danger signals in intracellular compartments. Inflammasome assembly results in caspase-1 activation, which in turn drives maturation and secretion of the pro-inflammatory cytokines interleukin 1β (IL-1β) and IL-18, and induces pyroptosis to eliminate the infectious agent. The importance of inflammasomes in regulating immune responses was recognized with the discovery of polymorphisms in genes encoding inflammasome components and their linkage to aberrant production of IL-1β and IL-18 in autoimmune and hereditary periodic fevers syndromes. We review the current knowledge on the role of inflammasomes in regulating innate and adaptive immune responses with an emphasis on the role of these immune complexes in autoinflammatory disorders and autoimmune diseases such as colitis, type I diabetes, multiple sclerosis and vitiligo.

Generalized vitiligo and associated autoimmune diseases in Japanese patients and their families

BACKGROUND

Generalized vitiligo is an acquired disorder in which depigmented macules result from the autoimmune loss of melanocytes from the involved regions of skin. Generalized vitiligo is frequently associated with other autoimmune diseases, particularly autoimmune thyroid diseases (Hashimoto's thyroiditis and Graves' disease), rheumatoid arthritis, adult-onset type 1 diabetes mellitus, psoriasis, pernicious anemia, systemic lupus erythematosus, and Addison's disease.

METHODS

One hundred and thirty-three Japanese patients with generalized vitiligo were enrolled in this study to investigate the occurrence of autoimmune diseases in Japanese patients with generalized vitiligo and their families.

RESULTS

Twenty-seven of the patients with generalized vitiligo (20.3%) had autoimmune diseases, particularly autoimmune thyroid disease (sixteen patients, 12%) and alopecia areata (seven patients, 5.3%). Thirty-five patients (26.3%) had a family history of generalized vitiligo and/or other autoimmune diseases. Familial generalized vitiligo was present in fifteen (11.3%), including four families with members affected by autoimmune disorders. Twenty (15.0%) had one or more family members with only autoimmune disorders.

CONCLUSIONS

Among Japanese vitiligo patients, there is a subgroup with strong evidence of genetically determined susceptibility to not only vitiligo, but also to autoimmune thyroid disease and other autoimmune disorders.

Segmental vitiligo associated with generalized vitiligo (mixed vitiligo): a retrospective case series of 19 patients

BACKGROUND

Mixed vitiligo (MV), the association of segmental vitiligo (SV) and nonsegmental vitiligo, has been rarely reported.

OBJECTIVE

The aim of this study was to delineate the clinical spectrum of MV through a case series of patients with typical SV associated with patchy bilateral vitiligo.

METHODS

This was a cross-sectional evaluation in the setting of a prospective observational study conducted in the vitiligo clinic of the department of dermatology in Bordeaux, France.

RESULTS

Nineteen patients with MV were identified. Four were male and 15 were female. Most patients had an onset of SV before the age of 18 years (18 of 19). In all patients, SV preceded nonsegmental vitiligo with a delay ranging from 6 months to more than 24 months.

LIMITATIONS

This study was cross-sectional and based on a single-center experience.

CONCLUSION

MV is not yet part of a conventional classification. However, this entity may have been neglected until now and should be included in the classification of vitiligo in addition to SV and nonsegmental vitiligo. Moreover, MV may be essential to the understanding of the pathogenesis of vitiligo as a primary skin disorder.

Autoantibodies against tyrosine hydroxylase in patients with non-segmental (generalised) vitiligo

Vitiligo is an acquired idiopathic hypomelanotic skin disorder characterised by depigmented macules because of loss of cutaneous melanocytes. Although the exact cause of vitiligo remains obscure, evidence suggests that autoimmunity plays a role in the pathogenesis of the disease. Previously, tyrosine hydroxylase (TH) was identified as a putative autoantigen in vitiligo using phage-display technology. In this study, the prevalence of TH antibodies in patients with vitiligo was investigated. A radioimmunoassay (RIA) was used to detect TH antibodies in sera from patients with either non-segmental vitiligo (n=79), segmental vitiligo (n=8) or other autoimmune diseases without concomitant vitiligo (n=91). Sera from healthy individuals (n=28) were also tested. Patients with segmental vitiligo, healthy controls and patients with other autoimmune diseases without concomitant vitiligo were all negative for TH antibody reactivity. Of 79 patients with non-segmental vitiligo, 18 (23%) were positive for TH antibodies in the RIA, and a significant increase in the prevalence of TH antibodies in patients with non-segmental vitiligo was evident when compared with controls (P=0.003). TH antibody prevalence was also significantly elevated in patients with active vitiligo compared to those with stable disease (P=0.009). Overall, the results indicate that TH is an antibody target in non-segmental but not in segmental vitiligo and that TH antibodies appear to be more frequent in patients with active vitiligo.

Pernicious anemia - genetic insights

Pernicious anemia (PA) is a complex, autoimmune, multi-factorial disease. Rapid progress has been made in the understanding of susceptibility to a spectrum of other autoimmune diseases through genome wide association studies (GWAS). However, PA has been conspicuous by its absence from this work. Here, we examine the evidence that PA has a significant heritable component through epidemiological evidence and its co-occurrence with other autoimmune diseases. Further, we consider how knowledge of the genetic susceptibility to other autoimmune diseases may provide insight into the etiology of PA.

Inflammasomes and autoimmunity

The NOD-like receptor (NLR) family members are cytosolic sensors of microbial components and danger signals. A subset of NLRs control inflammasome assembly that results in caspase-1 activation and, in turn, IL-1β and IL-18 production. Excessive inflammasome activation can cause autoinflammatory disorders, including the hereditary periodic fevers. Autoinflammatory and autoimmune diseases form a disease spectrum of aberrant, immune-mediated inflammation against self, through innate and adaptive immunity. However, the role of inflammasomes in autoimmune disease is less clear than in autoinflammation, despite the numerous effects IL-1β and IL-18 can have on shaping adaptive immunity. We summarize the role of inflammasomes in autoimmune disorders, highlight the need for a better understanding of inflammasomes in these conditions and offer suggestions for future research directions.

Association of UVRAG polymorphisms with susceptibility to non-segmental vitiligo in a Korean sample

Autoimmune, self-destructive, oxidative stress and genetic theories have been proposed for the pathogenesis of vitiligo. Autophagy is essential for cellular homeostasis and is implicated in many pathophysiological conditions such as cancer, response to oxidative stress and autoimmunity. The ultraviolet (UV) radiation resistance-associated gene (UVRAG) activates the Beclin1-PI(3)KC3 complex, promoting autophagy. To evaluate whether UVRAG polymorphisms are associated with non-segmental vitiligo (NSV) patients in a Korean sample, we conducted a case-control association study of 225 NSV patients and 439 matched healthy controls. A total of five single nucleotide polymorphisms (SNPs) of UVRAG were selected for analysis. Among these, two SNPs (rs1458836, rs7933235) showed significant genotypic differences between the NSV patient group and the control group. These two SNPs were located within a strong linkage disequilibrium (LD) block. In addition, the haplotype of the UVRAG polymorphism was associated with NSV. This study suggests a possible association between UVRAG and NSV susceptibility.

Abnormal DNA methylation in peripheral blood mononuclear cells from patients with vitiligo

BACKGROUND

Vitiligo is a skin disorder characterized by the destruction of melanocytes by autoreactive lymphocytes. The genetic and environmental factors that trigger the autoimmune response are poorly understood. However, alterations to epigenetic DNA methylation patterns contribute to many other autoimmune diseases.

OBJECTIVES

To investigate genomic and gene-specific DNA methylation levels in peripheral blood mononuclear cells (PBMCs) of patients with vitiligo and to relate any changes to the expression of genes that regulate methylation, as well as the autoimmune-related gene IL10.

METHODS

We quantified global methylcytosine levels in PBMCs from 20 patients with vitiligo and 20 healthy controls. mRNA levels of DNA methyltransferases (DNMTs), methyl-DNA binding domain proteins (MBDs) and interleukin (IL)-10 were measured by real-time reverse transcriptase-polymerase chain reaction. Methylation of an IL10 regulatory element domain was determined by bisulphite genomic sequencing.

RESULTS

Genomic DNA methylation in PBMCs of patients with vitiligo was increased relative to healthy controls (P = 0·012). DNMT1, MBD1, MBD3, MBD4 and MeCP2 expression was significantly higher than in control PBMCs (P = 0·013, 0·001, 0·005, 0·001 and 0·001, respectively). MBD1 and MBD3 expression correlated positively with global DNA methylation in vitiligo PBMCs (MBD1: r = 0·519, P = 0·019; MBD3: r = 0·529, P = 0·016). IL10 expression was significantly decreased (P = 0·030), and an IL-10 enhancer region was hypermethylated in vitiligo PBMCs compared with controls (P = 0·014).

CONCLUSIONS

These data show that levels of DNA methylation are altered in PBMCs of patients with vitiligo, and this may contribute to disease activity by affecting the expression of autoimmunity-related genes.

Promoter polymorphism -119C/G in MYG1 (C12orf10) gene is related to vitiligo susceptibility and Arg4Gln affects mitochondrial entrance of Myg1

Background

MYG1 (Melanocyte proliferating gene 1, also C12orf10 in human) is a ubiquitous nucleo-mitochondrial protein, involved in early developmental processes and in adult stress/illness conditions. We recently showed that MYG1 mRNA expression is elevated in the skin of vitiligo patients. Our aim was to examine nine known polymorphisms in the MYG1 gene, to investigate their functionality, and to study their association with vitiligo susceptibility.

Methods

Nine single nucleotide polymorphisms (SNPs) in the MYG1 locus were investigated by SNPlex assay and/or sequencing in vitiligo patients (n = 124) and controls (n = 325). MYG1 expression in skin biopsies was detected by quantitative-real time PCR (Q-RT-PCR) and polymorphisms were further analysed using luciferase and YFP reporters in the cell culture.

Results

Control subjects with -119G promoter allele (rs1465073) exhibited significantly higher MYG1 mRNA levels than controls with -119C allele (P = 0.01). Higher activity of -119G promoter was confirmed by luciferase assay. Single marker association analysis showed that the -119G allele was more frequent in vitiligo patients (47.1%) compared to controls (39.3%, P < 0.05, OR 1.37, 95%CI 1.02-1.85). Analysis based on the stage of progression of the vitiligo revealed that the increased frequency of -119G allele occurred prevalently in the group of patients with active vitiligo (n = 86) compared to the control group (48.2% versus 39.3%, P < 0.05; OR 1.44, 95%CI 1.02-2.03). Additionally, we showed that glutamine in the fourth position (in Arg4Gln polymorphism) completely eliminated mitochondrial entrance of YFP-tagged Myg1 protein in cell culture. The analysis of available EST, cDNA and genomic DNA sequences revealed that Myg1 4Gln allele is remarkably present in human populations but is never detected in homozygous state according to the HapMap database.

Conclusions

Our study demonstrated that both MYG1 promoter polymorphism -119C/G and Arg4Gln polymorphism in the mitochondrial signal of Myg1 have a functional impact on the regulation of the MYG1 gene and promoter polymorphism (-119C/G) is related with suspectibility for actively progressing vitiligo.

308-nm excimer lamp vs. 308-nm excimer laser for treating vitiligo: a randomized study

BACKGROUND

The 308-nm excimer laser and 308-nm excimer lamp have both been shown to be effective in treating vitiligo but a direct comparison has never been performed.

OBJECTIVES

To test the equivalence of these two devices for treating nonsegmental vitiligo.

PATIENTS AND METHODS

A randomized monocentric study was undertaken. One lesion was treated with the 308-nm excimer laser and its counterpart with the 308-nm excimer lamp. Lesions were treated twice weekly with the same dose on both sides for a total of 24 sessions. The evaluation was done by two independent physicians blinded to the treatment on direct light and ultraviolet light photos.

RESULTS

Twenty patients were included: 17 completed the study and 104 lesions were treated. The two treatments showed similar results in terms of efficacy for a repigmentation of at least 50% (P = 0.006). The lamp induced more erythema than the laser.

CONCLUSIONS

The 308-nm excimer lamp and laser showed a similar efficacy in treating vitiligo. For the same fluence, the lamp induced more erythema suggesting photobiological differences between the two devices.

Interventions for vitiligo

BACKGROUND

Around one per cent of the world's population has vitiligo, a disease which causes white patches on the skin. There are a variety of treatments available, most of which are unsatisfactory.

OBJECTIVES

To assess all interventions used to manage vitiligo.

SEARCH STRATEGY

In November 2009 we updated searches of the Cochrane Skin Group Specialised Register, the Cochrane Central Register of Controlled Trials in The Cochrane Library (Issue 4, 2009), MEDLINE, EMBASE, AMED, PsycINFO, LILACS and ongoing trials databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs).

DATA COLLECTION AND ANALYSIS

At least 2 review authors independently assessed study eligibility and methodological quality, and carried out data extraction. Two of the 57 included studies could be combined for meta-analysis.

MAIN RESULTS

In this update, 57 trials, including 19 from the original review, were assessed with 3139 participants. Most of the RCTs, which covered a wide range of interventions, had fewer than 50 participants. All of the studies assessed repigmentation, 6 measured cessation of spread, and 5 investigated the effect of treatment on quality of life.Most of the studies assessed combination therapies which generally reported better results. New interventions include monochromatic excimer light (MEL), Polypodium leucotomos, melanocyte transplantation, oral antioxidants, Chinese zengse pill, and pimecrolimus. We analysed the data from 28 studies that met our outcome criteria of improvement in quality of life and greater than 75% repigmentation.Fifteen analyses from studies comparing various interventions showed a statistically significant difference between the proportions of participants achieving more than 75% repigmentation. The majority of analyses showing statistically significant differences were from studies that assessed combination interventions which generally included some form of light treatment.Topical preparations, in particular corticosteroids, reported most adverse effects. However, in the combination studies it was difficult to ascertain which treatment caused these effects. None of the studies was able to demonstrate long-term benefits. Very few studies were conducted on children or included segmental vitiligo. We found one study of psychological interventions and none evaluating micropigmentation, depigmentation, or cosmetic camouflage.

AUTHORS' CONCLUSIONS

This review has found some evidence from individual studies to support existing therapies for vitiligo, but the usefulness of the findings is limited by the different designs and outcome measurements and lack of quality of life measures. There is a need for follow-up studies to assess permanence of repigmentation as well as high quality randomised trials using standardised measures and which also address quality of life.

Association of TXNDC5 gene polymorphisms and susceptibility to nonsegmental vitiligo in the Korean population

BACKGROUND

Vitiligo is a pigmentary skin disorder characterized by a chronic and progressive loss of melanocytes. Although the aetiology of vitiligo is currently unknown, several theories have been proposed to explain the pathogenesis of this disease, including autoimmune, neural, self-destruction, oxidative stress, and genetic theories. Thioredoxin domain containing 5 (TXNDC5) is a newly identified member of the thioredoxin family. TXNDC5 has a protein disulphide isomerase-like domain which plays an important role in protein folding and chaperone activity, against endoplasmic reticulum (ER) stress induced by oxidative stress within the ER.

OBJECTIVES

To determine whether variation in the TXNDC5 gene contributes to the risk of developing nonsegmental vitiligo (NSV) in the Korean population.

METHODS

We conducted a case-control association study of 230 patients with NSV and 417 matched, unaffected controls. Seven single nucleotide polymorphisms (SNPs) in the TXNDC5 gene were selected for study.

RESULTS

Of the selected SNPs, three exonic SNPs (rs1043784, rs7764128 and rs8643) were statistically associated with NSV. Among them, rs1043784 remained a statistically significant association following Bonferroni correction. These three SNPs were located within a block of linkage disequilibrium; the haplotypes AGG and GAA, consisting of rs1043784, rs7764128 and rs8643, demonstrated a significant association with NSV.

CONCLUSIONS

These results suggest that TXNDC5 gene polymorphisms are associated with the development of NSV in the Korean population.

Genome-wide association study of generalized vitiligo in an isolated European founder population identifies SMOC2, in close proximity to IDDM8

Generalized vitiligo is a common disorder in which patchy loss of skin and hair pigmentation principally appears to result from autoimmune loss of melanocytes from affected regions. We previously characterized a unique founder population in an isolated Romanian community with elevated prevalence of generalized vitiligo and other autoimmune diseases, including autoimmune thyroid disease, rheumatoid arthritis, and type I diabetes mellitus. Here, we describe a genome-wide association study (GWAS) of generalized vitiligo in 32 distantly related affected patients from this remote village and 50 healthy controls from surrounding villages. Vitiligo was significantly associated with single-nucleotide polymorphisms (SNPs) in a 30-kb LD block on chromosome 6q27, in close vicinity to IDDM8, a linkage and association signal for type I diabetes mellitus and rheumatoid arthritis. The region of association contains only one gene, SMOC2, within which SNP rs13208776 attained genome-wide significance for association with generalized vitiligo (P=8.51x10(-8)) at odds ratio 7.445 (95% confidence interval=3.56-15.53) for the high-risk allele and population attributable risk 28.00. SMOC2 encodes a modular extracellular calcium-binding glycoprotein of unknown function. Our findings indicate that SMOC2 is a risk locus for generalized vitiligo and perhaps other autoimmune diseases.

Fine-mapping of vitiligo susceptibility loci on chromosomes 7 and 9 and interactions with NLRP1 (NALP1)

Generalized vitiligo is the most common pigmentation disorder, the result of autoimmune loss of melanocytes from the skin and hair, with a high frequency of other autoimmune diseases in vitiligo patients and their relatives. We previously reported the linkage signals on chromosomes 1, 7, and 17 in Caucasian families with generalized vitiligo and associated autoimmune diseases and identified the risk loci of chromosomes 17 and 1 as NLRP1 (NALP1) and FOXD3, respectively. Here, we describe fine-scale genetic association analyses in two independent series of Caucasian multiplex families, refining localization of the chromosome 7 locus and a locus on chromosome 9. Three susceptibility signals, represented by single-nucleotide polymorphisms (SNPs) rs6960920 in 7p13, rs734930 in 7q11, and rs4744411 in 9q22, were significantly associated with vitiligo and other autoimmune diseases. We also detected significant three-way interaction effects of chromosome 7 SNP rs6960920, chromosome 9 SNP rs4744411, and NLRP1 SNP rs6502867 on both the vitiligo phenotype and an expanded autoimmune disease phenotype, and significant three-way interaction effects of both chromosome 7 SNPs and NLRP1 SNP rs6502867 on the vitiligo phenotype. These support the validity of the chromosomes 7 and 9 linkage/association signals and underscore the utility of gene-gene interaction analysis in characterizing the genetic effects of candidate association signals.

Immunogenetics of drug-induced skin blistering disorders. Part I: Perspective

The overall immunopathogenesis relevant to a large series of disorders caused by a drug or its associated hyperimmune condition is discussed based upon the examination of the genetics of severe drug-induced bullous skin problems (sporadic idiosyncratic adverse events, including Stevens-Johnson syndrome and toxic epidermal necrolysis). An overarching pharmacogenetic schema is proposed. Immune cognition and early-effector processes are focused upon and a challenging synthesis around systems evolution is explained by a variety of projective analogies. Etiology, human leukocyte antigen-B, immune stability, dysregulation, pharmacomimicry, viruses and an aggressive ethnically differentiated 'karmic' response are discussed.

Genetic variation of promoter sequence modulates XBP1 expression and genetic risk for vitiligo

Our previous genome-wide linkage analysis identified a susceptibility locus for generalized vitiligo on 22q12. To search for susceptibility genes within the locus, we investigated a biological candidate gene, X-box binding protein 1(XBP1). First, we sequenced all the exons, exon-intron boundaries as well as some 5′ and 3′ flanking sequences of XBP1 in 319 cases and 294 controls of Chinese Hans. Of the 8 common variants identified, the significant association was observed at rs2269577 (p__trend = 0.007, OR = 1.36, 95% CI = 1.09–1.71), a putative regulatory polymorphism within the promoter region of XBP1. We then sequenced the variant in an additional 365 cases and 404 controls and found supporting evidence for the association (p__trend = 0.008, OR = 1.31, 95% CI = 1.07–1.59). To further validate the association, we genotyped the variant in another independent sample of 1,402 cases and 1,288 controls, including 94 parent-child trios, and confirmed the association by both case-control analysis (p__trend = 0.003, OR = 1.18, 95% CI = 1.06–1.32) and the family-based transmission disequilibrium test (TDT, p = 0.005, OR = 1.93, 95% CI = 1.21–3.07). The analysis of the combined 2,086 cases and 1,986 controls provided highly significant evidence for the association (p__trend = 2.94×10⁻⁶, OR = 1.23, 95% CI = 1.13–1.35). Furthermore, we also found suggestive epistatic effect between rs2269577 and HLA-DRB1*07 allele on the development of vitiligo (p = 0.033). Our subsequent functional study showed that the risk-associated C allele of rs2269577 had a stronger promoter activity than the non-risk G allele, and there was an elevated expression of XBP1 in the lesional skins of patients carrying the risk-associated C allele. Therefore, our study has demonstrated that the transcriptional modulation of XBP1 expression by a germ-line regulatory polymorphism has an impact on the development of vitiligo.

Vitiligo is a genetically complex skin disorder that afflicts 0.1%–2% of the population throughout the world. Linkage and association studies in different populations have implicated several genomic regions and candidate genes that are linked to the development of vitiligo. Our previous genome-wide linkage analysis identified a genetic susceptibility locus for vitiligo on 22q12 in a Chinese population. In this study, we conducted a genetic and molecular study of a biologically plausible candidate gene, XBP1, within the region. We first performed a progressive association analysis in three independent samples of vitiligo, which revealed significant association between a putative promoter polymorphism, rs2269577, and vitiligo. Then, our functional analysis also demonstrated that the risk-associated allele of this variant has a stronger promoter activity and was associated with a significantly elevated expression of XBP1 in lesional skins in patients carrying the risk-associated allele. Our findings have provided the first evidence for XBP1 to play an important role in the development of vitiligo.

Distinct autoimmune syndromes in morphea: a review of 245 adult and pediatric cases

OBJECTIVE

To determine the prevalence of extracutaneous manifestations and autoimmunity in adult and pediatric patients with morphea.

DESIGN

A retrospective review of 245 patients with morphea.

SETTING

University of Texas Southwestern Medical Center-affiliated institutions. Patients Patients with clinical findings consistent with morphea.

MAIN OUTCOME MEASURES

Prevalence of concomitant autoimmune diseases, prevalence of familial autoimmune disease, prevalence of extracutaneous manifestations, and laboratory evidence of autoimmunity (antinuclear antibody positivity). Secondary outcome measures included demographic features.

RESULTS

In this group, adults and children were affected nearly equally, and African Americans were affected less frequently than expected. The prevalence of concomitant autoimmunity in the generalized subtype of morphea was statistically significantly greater than that found in all other subtypes combined (P = .01). Frequency of a family history of autoimmune disease showed a trend in favor of generalized and mixed subgroups. The linear subtype showed a significant association with neurologic manifestations, while general systemic manifestations were most common in the generalized subtype. Antinuclear antibody positivity was most frequent in mixed and generalized subtypes.

CONCLUSIONS

High prevalences of concomitant and familial autoimmune disease, systemic manifestations, and antinuclear antibody positivity in the generalized and possibly mixed subtypes suggest that these are systemic autoimmune syndromes and not skin-only phenomena. This has implications for the management and treatment of patients with morphea.

Familial Coexisting and Colocalized Psoriasis and Vitiligo Responding to Alefacept

Background:

Psoriasis is an immune-mediated, chronic, inflammatory disease that significantly impairs both physical and emotional aspects of an individual's quality of life. Vitiligo leads to depigmentation of skin, in which some or all melanocytes in the interfollicular epidermis and occasionally those in the hair follicles are selectively destroyed. The coexistence of the two disorders is rarely seen.

Objective:

To report two cases of the rare coexistence of psoriasis and vitiligo in a family.

Methods:

After providing informed written consent, both patients were given alefacept 15 mg/kg weekly injections for 12 weeks. The patients were monitored both clinically and with all relevant laboratory investigations. These patients were then followed up once a month for 2 years.

Results:

Treatment with alefacept led to complete clearance of vitiligo along with the expected improvement in psoriasis. In the 2-year follow-up, vitiligo did not recur, although psoriasis relapsed and was appropriately treated.

Conclusion:

Use of alefacept in vitiligo may turn out to be a possible novel off-label treatment option in vitiligo. But the results need to be reproduced in larger studies

Association study between keratinocyte-derived growth factor gene polymorphisms and susceptibility to vitiligo vulgaris in a Taiwanese population: potential involvement of stem cell factor

BACKGROUND

Vitiligo vulgaris is a depigmentary disorder resulting from the disappearance of functional melanocytes. Currently, the pathogenesis of this disorder remains obscure.

OBJECTIVES

Genetic analysis of patients with vitilgo may provide important clues for elucidating the complex pathomechanisms involved in the disease process. Because dysfunctional keratinocytes have recently been implicated in the pathogenesis of vitiligo vulgaris, we conducted a case-control association study to investigate this phenomenon.

PATIENTS AND METHODS

Fifty-one patients with vitiligo vulgaris and 118 healthy controls from Taiwan were recruited to investigate the association between relevant keratinocyte-related genes and the occurrence of vitiligo vulgaris. This study genotyped 11 single-nucleotide polymorphisms (SNPs) in five genes including stem cell factor (SCF, also known as KITLG), basic fibroblast growth factor (bFGF, also known as NuDT6), endothelin-1 (EDN1), hepatocyte growth factor (HGF) and stem cell growth factor (SCGF, also known as CLEC11A).

RESULTS

Our results revealed that the A allele for SNP rs11104947 in the SCF gene and the T allele for SNP rs13866 in the SCGF gene were, respectively, associated with a 1.95- and a 2.14-fold risk of developing vitiligo vulgaris. A higher risk was also detected among subjects who carried the SCF rs995029/rs11104947 C/A haplotype (odds ratio = 2.45). Furthermore, the at-risk alleles for SCF rs11104947 (A allele) and for SCGF SNP rs13866 (T allele) were found to display a 7.92-fold increased gene-gene combined risk. No significant relationship between polymorphic frequency for genes bFGF, EDN1 as well as HGF and occurrence of vitiligo vulgaris was observed.

CONCLUSIONS

These novel genetic findings provide new insights in relation to the mechanisms that might be involved in the development of vitiligo vulgaris.

Sphingolipid-mediated restoration of Mitf expression and repigmentation in vivo in a mouse model of hair graying

Recent advances in the identification and characterisation of stem cell populations has led to substantial interest in understanding the precise triggers that would operate to induce activation of quiescent stem cells. Melanocyte stem cells (MSCs) reside in the bulge region of the hair follicles and are characterised by reduced expression of the microphthalmia-associated transcription factor (Mitf) and its target genes implicated in differentiation. Vitiligo is characterised by progressive destruction of differentiated melanocytes. However, therapies using UV irradiation therapy can induce a degree of repigmentation, suggesting that MSCs may be activated. As Mitf is implicated in control of proliferation, we have explored the possibility that inducing Mitf expression via lipid-mediated activation of the p38 stress-signalling pathway may represent a re-pigmentation strategy. Here we have isolated from placental extract a C18:0 sphingolipid able to induce Mitf and tyrosinase expression via activation of the p38 stress-signalling pathway. Strikingly, in age-onset gray-haired C57BL/6J mice that exhibit decaying Mitf expression, topical application of placental sphingolipid leads to increased Mitf in follicular melanocytes and fresh dense black hair growth. The results raise the possibility that lipid-mediated activation of the p38 pathway may represent a novel approach to an effective vitiligo therapy.

CTLA4 and generalized vitiligo: two genetic association studies and a meta-analysis of published data

Several lines of evidence have implicated the gene encoding cytotoxic T lymphocyte antigen 4 (CTLA4) in susceptibility to various autoimmune diseases. However, published studies of genetic association between CTLA4 polymorphisms and vitiligo have yielded conflicting results. Here, we describe two new genetic association studies of CTLA4 single-nucleotide polymorphisms (SNPs) and generalized vitiligo in two independent Romanian Caucasian (CEU) case-control cohorts. The first study, of SNPs rs1863800, rs231806, rs231775, rs3087243, rs11571302, rs11571297, and rs10932037, showed no allelic, genotypic, or haplotypic association with generalized vitiligo. The second study, of SNP rs231775, likewise showed no significant association. To enhance statistical power over that of any individual study, we carried out a meta-analysis that incorporated these two new studies and all other published genetic association studies of CTLA4 SNPs and vitiligo in CEU populations. While there was no association with vitiligo overall, the meta-analysis showed significant association of SNP rs231775 in that subgroup of vitiligo patients who also had other concomitant autoimmune diseases. Similarly, there was near-significant association in this same patient subgroup with several other CTLA4 SNPs that are in linkage disequilibrium with rs231775. Our results indicate that the association of CTLA4 with vitiligo is weak, and indeed may be secondary, driven by primary genetic association of CTLA4 with other autoimmune diseases that are epidemiologically associated with vitiligo.

The autoimmune regulator gene (AIRE) is strongly associated with vitiligo

BACKGROUND

Vitiligo is an autoimmune disorder that occurs with greatly increased frequency in the rare recessive autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome (APECED) caused by mutations of the autoimmune regulator (AIRE) gene on chromosome 21q22.3. We have previously detected an association between alopecia areata and single nucleotide polymorphisms (SNPs) in the AIRE gene.

OBJECTIVES

To report the findings of an extended study including haplotype analysis on six AIRE polymorphisms (AIRE C-103T, C4144G, T5238C, G6528A, T7215C and T11787C) in vitiligo, another APECED-associated disease.

METHODS

A case-control analysis was performed.

RESULTS

Results showed a strong association between AIRE 7215C and vitiligo [P = 1.36 x 10(-5), odds ratio (OR) 3.12, 95% confidence interval (CI) 1.87-5.46]. We found no significant association with the other polymorphisms individually. However, haplotype analysis revealed that the AIRE haplotype CCTGCC showed a highly significant association with vitiligo (P = 4.14 x 10(-4), OR 3.00, 95% CI 1.70-5.28). To select the most informative minimal haplotypes, we tagged the polymorphisms using SNP tag software. Using AIRE C-103T, G6528A, T7215C and T11787C as tag SNPs, the haplotype AIRE CGCC was associated with vitiligo (P = 0.003, OR 2.49, 95% CI 1.45-4.26).

CONCLUSIONS

The link between vitiligo and AIRE raises the possibility that defective skin peripheral antigen selection in the thymus is involved in the changes that result in melanocyte destruction in this disorder.

HSP70i accelerates depigmentation in a mouse model of autoimmune vitiligo

Vitiligo is a T-cell-mediated autoimmune disease of the skin. Progressive depigmentation accelerates in response to stress. Personal trauma, contact with bleaching phenols, overexposure to UV, and mechanical injury can lead to progressive loss of melanocytes. This study was focused on the role of stress protein heat shock protein (HSP)70 for translating stress into an autoimmune disease to melanocytes. Intracellular HSP70 can act as a cytoprotectant, preventing apoptosis in cells under stress. Isoform HSP70i can be secreted by live cells, and in prior in vitro studies, HSP70 has been shown to activate dendritic cells and elicit an immune response to chaperoned proteins and peptides. Here, the role of HSP70 in precipitating and perpetuating vitiligo was assessed in vivo in a mouse model of autoimmune vitiligo. In this model, depigmentation was introduced by gene gun vaccination with eukaryotic expression plasmids encoding melanocyte differentiation antigens. Inclusion of human and mouse-derived inducible HSP70 in the vaccination protocol significantly increased and accelerated depigmentation in this model, accompanied by the induction of prolonged humoral responses to HSP70. Cytotoxicity toward targets loaded with a K(b)-restricted tyrosinase-related protein 2-derived peptide correlated with depigmentation. The data presented strongly support a role for HSP70i in progressive depigmentation in vivo.

Epigenetics in human autoimmunity. Epigenetics in autoimmunity - DNA methylation in systemic lupus erythematosus and beyond

Epigenetic mechanisms are essential for normal development and function of the immune system. Similarly, a failure to maintain epigenetic homeostasis in the immune response due to factors including environmental influences, leads to aberrant gene expression, contributing to immune dysfunction and in some cases the development of autoimmunity in genetically predisposed individuals. This is exemplified by systemic lupus erythematosus, where environmentally induced epigenetic changes contribute to disease pathogenesis in those genetically predisposed. Similar interactions between genetically determined susceptibility and environmental factors are implicated in other systemic autoimmune diseases such as rheumatoid arthritis and scleroderma, as well as in organ specific autoimmunity. The skin is exposed to a wide variety of environmental agents, including UV radiation, and is prone to the development of autoimmune conditions such as atopic dermatitis, psoriasis and some forms of vitiligo, depending on environmental and genetic influences. Herein we review how disruption of epigenetic mechanisms can alter immune function using lupus as an example, and summarize how similar mechanisms may contribute to other human autoimmune rheumatic and skin diseases.

Interface dermatitis

Interface dermatitis can be classified based upon the cell type that dominates the infiltrate (ie, neutrophilic, lymphocytic, or lymphohistiocytic) or by the intensity of the interface inflammation. Regarding lymphocytic interface dermatitis, there are 2 broad categories: cell-poor interface dermatitis, when only a sparse infiltrate of inflammatory cells is present along the dermoepidermal junction, or cell rich, which typically occurs as a heavy bandlike infiltrate that obscures the basal layers of the epidermis. In the case of lymphocytic interface dermatitis, the latter is often termed a lichenoid interface dermatitis. This review focuses upon the mononuclear cell-predominant forms of interface dermatitis.

Vitiligo pathogenesis: autoimmune disease, genetic defect, excessive reactive oxygen species, calcium imbalance, or what else?

The pathobiology of vitiligo has been hotly disputed for as long as one remembers, and has been a magnet for endless speculation. Evidently, the different schools of thought--ranging, e.g. from the concept that vitiligo essentially is a free-radical disorder to that of vitiligo being a primary autoimmune disease--imply very different consequences for the best therapeutic strategies that one should adopt. As a more effective therapy for this common, often disfiguring pigmentary disorder is direly needed, we must strive harder to settle the pathogenesis debate definitively--on the basis of sound experimental evidence, rather than by a war of dogmatic theories. Recognizing, however, that it is theories which tend to guide our experimental designs and choice of study parameters, the various pathogenesis theories on the market deserve to be critically, yet unemotionally re-evaluated. This Controversies feature invites you to do so, and to ask yourself: is there something important or worthwhile exploring in other pathogenesis scenarios than those already favoured by you that may help you improve your own study design, next time you have a fresh look at vitiligo? Vitiligo provides a superb model for the study of many fundamental problems in skin biology and pathology. Therefore, even if it later turns out that, as far as your own vitiligo pathogenesis concept is concerned, you have barked-up the wrong tree most of the time, chances are that you shall anyway have generated priceless new insights into skin function along the way.

PTPN22 is genetically associated with risk of generalized vitiligo, but CTLA4 is not

Generalized vitiligo is an acquired, multifactorial, polygenic disease in which depigmented spots of skin, overlying hair, and mucus membranes result from autoimmune-mediated loss of melanocytes from affected areas. We examined single-nucleotide polymorphisms (SNPs) in the PTPN22 and CTLA4 genes in 126 Caucasian families with multiple cases of generalized vitiligo and associated autoimmune diseases, using a family-based association study design. The PTPN22 1858T allele of SNP rs2476601 is significantly associated both with generalized vitiligo and with an expanded autoimmunity phenotype. Individuals carrying the PTPN22 1858T allele had an allelic odds ratio (OR) of 2.16 for generalized vitiligo and a genotypic OR of 2.35 as C/T heterozygotes. Similarly, individuals carrying the PTPN22 1858T allele had an allelic OR of 2.05 for the expanded autoimmunity phenotype, and a genotypic OR of 2.19 for C/T heterozygotes. Examination of five SNPs in the CTLA4 gene (rs1863800, rs231775, rs3087243, rs11571302, rs11571297, rs10932037) in the same 126 families yielded no evidence of allelic or genotypic association with either generalized vitiligo or the expanded autoimmune phenotype. These results implicate PTPN22 in mediating susceptibility to generalized vitiligo and associated autoimmune diseases, but do not support a role for CTLA4.