Genome-wide analysis identifies a quantitative trait locus in the MHC class II region associated with generalized vitiligo age of onset.

Generalized vitiligo is a common autoimmune disease in which acquired patchy depigmentation of skin, hair, and mucous membranes results from loss of melanocytes from involved areas. Previous genetic analyses have focused on vitiligo susceptibility, and have identified a number of genes involved in disease risk. Age of onset of generalized vitiligo also involves a substantial genetic component, but has not previously been studied systematically. In this study, we report a genome-wide association study of vitiligo age of onset in 1,339 generalized vitiligo patients, with replication in an independent cohort of 677 cases. We identified a quantitative trait locus for vitiligo age of onset in the major histocompatibility complex (MHC) class II region, located near c6orf10-BTNL2 (rs7758128; P=8.14 × 10(-11)), a region that is also associated with generalized vitiligo susceptibility. In contrast, there was no association of vitiligo age of onset with any other MHC or non-MHC loci that are associated with vitiligo susceptibility. These findings highlight the differing roles played by genes involved in vitiligo susceptibility versus vitiligo age of onset, and illustrate that genome-wide analyses can be used to identify genes involved in quantitative aspects of disease natural history, as well as disease susceptibility per se.

Common variants in FOXP1 are associated with generalized vitiligo.

In a recent genome-wide association study of generalized vitiligo, we identified ten confirmed susceptibility loci. By testing additional loci that showed suggestive association in the genome-wide study, using two replication cohorts of European descent, we observed replicated association of generalized vitiligo with variants at 3p13 encompassing FOXP1 (rs17008723, combined P=1.04x10(-8)) and with variants at 6q27 encompassing CCR6 (rs6902119, combined P=3.94x10(-7)).

Variant of TYR and autoimmunity susceptibility loci in generalized vitiligo.

BACKGROUND: Generalized vitiligo is an autoimmune disease characterized by melanocyte loss, which results in patchy depigmentation of skin and hair, and is associated with an elevated risk of other autoimmune diseases. METHODS: To identify generalized vitiligo susceptibility loci, we conducted a genomewide association study. We genotyped 579,146 single-nucleotide polymorphisms (SNPs) in 1514 patients with generalized vitiligo who were of European-derived white (CEU) ancestry and compared the genotypes with publicly available control genotypes from 2813 CEU persons. We then tested 50 SNPs in two replication sets, one comprising 677 independent CEU patients and 1106 CEU controls and the other comprising 183 CEU simplex trios with generalized vitiligo and 332 CEU multiplex families. RESULTS: We detected significant associations between generalized vitiligo and SNPs at several loci previously associated with other autoimmune diseases. These included genes encoding major-histocompatibility-complex class I molecules (P=9.05x10(-23)) and class II molecules (P=4.50x10(-34)), PTPN22 (P=1.31x10(-7)), LPP (P=1.01x10(-11)), IL2RA (P=2.78x10(-9)), UBASH3A (P=1.26x10(-9)), and C1QTNF6 (P=2.21x10(-16)). We also detected associations between generalized vitiligo and SNPs in two additional immune-related loci, RERE (P=7.07x10(-15)) and GZMB (P=3.44x10(-8)), and in a locus containing TYR (P=1.60x10(-18)), encoding tyrosinase. CONCLUSIONS: We observed associations between generalized vitiligo and markers implicating multiple genes, some associated with other autoimmune diseases and one (TYR) that may mediate target-cell specificity and indicate a mutually exclusive relationship between susceptibility to vitiligo and susceptibility to melanoma.

Simplified cellular grafting for treatment of vitiligo and piebaldism: the "6-well plate" technique.

BACKGROUND: Vitiligo is a disfiguring depigmenting dermatosis that affects approximately 0.5% to 1% of the general population regardless of race and sex. In patients with stable vitiligo who fail conventional therapies, surgical transplant offers a viable alternative. Noncultured cellular grafting offers the advantage of repigmenting vitiligo 5 to 10 times the size of the donor skin and can be completed on the same day on an outpatient basis. In recent years, ways to simplify this procedure have been explored, including the use of commercially available kits. OBJECTIVES: To simplify the extraction of epidermal cells from donor skin using a 6-well plate and to evaluate the clinical efficacy of this simplified technique in repigmenting stable vitiligo and piebaldism. METHODS: Four patients with focal or segmental vitiligo and one with piebaldism were treated using the simplified noncultured cellular grafting protocol. Percentage of repigmentation 6 months after grafting was objectively measured using digital contour mapping. RESULTS: Patients with stable segmental or focal vitiligo achieved 65% to 92% repigmentation 6 months after grafting; the treated sites involved face or limbs. The patient with piebaldism achieved 86% repigmentation. One year after grafting, the extent of repigmentation remained for all patients. CONCLUSION: This set-up is simple and inexpensive; it reduces cell preparation time, amount of reagents used, and costs, and obviates the need of a laboratory for extraction of epidermal cells.

Current and emerging therapy for the management of vitiligo.

Vitiligo is an acquired cutaneous disorder of pigmentation, with an incidence of 0.5% to 2% worldwide. There are three major hypotheses for the pathogenesis of vitiligo that are not exclusive of each other: biochemical/cytotoxic, neural and autoimmune. Recent data provide strong evidence supporting an autoimmune pathogenesis of vitiligo. As vitiligo can have a major effect on quality of life, treatment can be considered and should preferably begin early when the disease is active. Current treatment modalities are directed towards stopping progression of the disease and achieving repigmentation. Therapies include corticosteroids, topical immunomodulators, photo(chemo)therapy, surgery, combination therapies and depigmentation of normally pigmented skin. Topical class 3 corticosteroids can be used for localized vitiligo. The use of topical immunomodulators (TIMs) in vitiligo seems to be equally effective as topical steroids, especially when used in the face and neck region. In photo(chemo)therapy, narrowband ultraviolet-B therapy (NB-UVB) seems to be superior to psoralen ultraviolet-A therapy (PUVA) and broadband UVB. In surgical techniques, split-thickness grafting and epidermal blister grafting were shown to be effective methods, although the non-cultured epidermal suspension technique has many advantages and seems to be a promising development. Depigmentation therapy can be considered if vitiligo affects more than 60% to 80% of the body. Complementary therapies such as Polypodium leucotomos show promising results in combination with UVB therapy. No causative treatment for vitiligo is currently available. More randomized controlled trials on the treatment of vitiligo are necessary.

Topical pimecrolimus in the treatment of vitiligo.

Although the treatment of vitiligo has improved during the last decade, therapy is still not satisfactory for many patients. Recently topical calcineurin inhibitors were introduced in the treatment of atopic dermatitis. Considering the autoimmune hypothesis of vitiligo pathogenesis, the use of these topical calcineurin inhibitors seems reasonable. Most clinical vitiligo trials have been performed with tacrolimus and show beneficial effects. Concerning the value of pimecrolimus in the treatment of vitiligo only few data are available. Therefore we performed an open pilot study in 26 patients to evaluate the efficacy and safety of 1% pimecrolimus in the treatment of vitiliginous lesions in the head and neck region. In 13 of 26 (50%) evaluated target lesions, repigmentation was noted after a 6 month treatment period with a median percentage of repigmentation of 72.9% (interquartile range: 30.5-98.3%). Duration of vitiligo and total affected body surface area tended to be inversely correlated with the success rate of treatment. Side effects were mainly limited to a burning sensation at the application site. Despite the promising results of topical immunomodulators in the treatment of vitiligo, prudence is in order, as long-term follow up studies are still lacking.

Subjective and objective evaluation of noncultured epidermal cellular grafting for repigmenting vitiligo.

BACKGROUND: Noncultured epidermal cell transplantation in vitiligo permits the coverage of relatively large areas without culturing cells. OBJECTIVE: To investigate the effectiveness of noncultured epidermal cell transplantation in treating stabilized vitiligo using objective and subjective evaluation methods. METHODS: Noncultured autologous melanocytes and keratinocytes were grafted in a hyaluronic-acid-enriched suspension on superficially laser-abraded vitiligo lesions in 40 patients with refractory stable vitiligo (30 with generalized and 10 with localized vitiligo). The repigmentation was evaluated 3-12 months after grafting using a digital image analysis system. Furthermore the treatment was evaluated from the patients' point of view with the DLQI (Dermatology Life Quality Index) and a 'global assessment'. RESULTS: The mean percentage of repigmentation, evaluated at the last follow-up visit, was 72% (median 84%), and a repigmentation of >or=70% was observed in 62% of patients. The best results were achieved in the neck and the presternal region. A subjective evaluation was performed in half of the subjects. The mean DLQI score at inclusion (6.95, SD = 6.68, n = 20) was significantly decreased after treatment (p = 0.013, mean 3.85, SD = 4.13, n = 20). The patients were satisfied with the achieved result, found it worthwhile to undergo the treatment and would choose it again. CONCLUSION: According to both subjective and objective evaluation methods, noncultured epidermal cell transplantation is promising in patients with stable vitiligo.

Double-blind placebo-controlled study of autologous transplanted epidermal cell suspensions for repigmenting vitiligo.

OBJECTIVES: To investigate the efficacy of epidermal noncultured cellular grafting in patients with vitiligo and the role of postinflammatory, spontaneous, or UV-induced pigmentation in obtaining repigmentation. DESIGN: A prospective, randomized, double-blind, placebo-controlled study. SETTING: Ambulatory patients in an institutional practice. Patients were followed up for 3 to 12 months. PATIENTS: A total of 33 paired, symmetrically distributed leukodermic lesions, all resistant to therapy, were observed in 28 patients. Nineteen patients appeared to have a stable vitiligo (group 1), whereas there was doubt about the stability of the disease in 9 patients (group 2). INTERVENTION: After laser ablation, a hyaluronic acid-enriched cellular graft was applied to 1 lesion while the paired lesion received placebo. Three weeks later all lesions were exposed to UV irradiation twice per week for approximately 2 months. MAIN OUTCOME MEASURES: Primarily, the percentage of repigmentation was assessed after 3, 6, and 12 months using a digital image analysis system. The repigmentation pattern was also evaluated after 1 and 3 months. RESULTS: A strongly significant difference between cellular grafts and placebo was observed after 3, 6, and 12 months (P<.001, P = .002, and P = .002, respectively). In group 1, repigmentation of at least 70% of the treated area was achieved in 55%, 57%, and 77% of the actively treated lesions 3, 6, and 12 months after treatment, whereas in group 2 repigmentation of at least 70% of the treated area was not observed at any time point. The repigmentation pattern was diffuse in 94% of the responding patients. CONCLUSIONS: After a strict preoperative selection for disease stability, transplantation resulted in repigmentation of at least 70% of the treated area in most actively treated vitiligo lesions. Repigmentation was primarily caused by the transplanted melanocytes.

A new digital image analysis system useful for surface assessment of vitiligo lesions in transplantation studies.

So far there is no uniformity in the evaluation methods used in the assessment of treatment outcome in vitiligo studies. The ability to objectively measure surfaces of vitiligo lesions is important for both clinical practice and research. Our objective was to assess the reproducibility, accuracy, user-friendliness and time effectiveness of a new digital image analysis system for surface measurement of vitiligo lesions. Three different observers performed both a visual estimation and a digital image analysis on 30 images of 10 vitiligo lesions. Inter- and intra-observer variation were evaluated and results were compared with the 2D gold standard measurements and a 3D measurement. A high inter- and intra-observer variability was observed for the visual estimation of surfaces. With the digital image analysis system a significant improvement of the reproducibility was achieved (p = 0.01). Moreover, results were accurate and the measurement procedure was user-friendly. Importantly, a systematic underestimation was demonstrated when comparing the 2D with the 3D measurements. We introduced an objective measurement method that might be useful in the future for consistently measuring surfaces of selected vitiligo lesions both before and after different therapeutic modalities.

Management of vitiligo patients and attitude of dermatologists towards vitiligo.

As vitiligo does not cause any physical impairment, it is often considered unimportant by physicians. Vitiligo patients repeatedly experience disinterest from the medical world regarding their skin problem. A questionnaire survey was used to assess the management of vitiligo patients and the attitude of dermatologists towards vitiligo in Belgium. Vitiligo patients (n = 244) visiting an academic affiliated dermatology department were included and 454 out of 558 Belgian dermatologists returned a mailed questionnaire. Vitiligo patients do not often visit a doctor concerning their disease and do not often treat their disease. Disease severity as reported by the patient is correlated with the number of doctor visits (p = 0.001) but not to treatment of the disease. Information about the treatment and physician's encouragement to treat seem important in motivating patients to treat their vitiligo, but 50% of the patients were not adequately informed about their disease and its treatment during their first doctor visit. Today, nearly all the dermatologists report widely informing their patients, but only 36% of them encourage their patients to treat their disease, being pessimistic concerning expected treatment results. Interestingly, two thirds of the patients who ever treated their disease find it worthwhile.

Evidence for an autoimmune pathogenesis of vitiligo.

Vitiligo is a depigmenting disorder characterized by the development of white patches in various distributions, which are due to the loss of melanocytes from the epidermis. A variety of arguments from clinical observations to research findings in human and animal models support the hypothesis of autoimmunity and are reviewed in this article. The association with autoimmune diseases and organ-specific autoantibodies is well known. Various effective treatment options have an immunosuppressive effect. Today the autoimmune pathogenesis of the disease has become a rapidly evolving field of research. Detection of circulating melanocyte antibodies in human and animal models implicates a possible role of humoral immunity. Histological and immunohistochemical studies in perilesional skin suggest the involvement of cellular immunity in vitiligo. Recently, T-cell analyses in peripheral blood further support this hypothesis. Interestingly, new insights in the association of vitiligo and melanoma may help to clarify the role of autoimmunity in the development of vitiligo.