Functional cloning of a gp100-reactive T-cell receptor from vitiligo patient skin.

We isolated gp100-reactive T cells from perilesional skin of a patient with progressive vitiligo with superior reactivity toward melanoma cells compared with tumor-infiltrating lymphocytes 1520, a melanoma-derived T-cell line reactive with the same cognate peptide. After dimer enrichment and limited dilution cloning, amplified cells were subjected to reverse transcription and 5' RACE to identify the variable TCRα and TCRβ subunit sequences. The full-length sequence was cloned into a retroviral vector separating both subunits by a P2A slippage sequence and introduced into Jurkat cells and primary T cells.

Anti-oxidant defence mechanism in vitiliginous skin increases with skin type.

Background: Vitiligo skin shows different burning capacity in people with different phototype. In normal skin antioxidant status is correlated to skin phototype, but unexpectedly it appears that there is a gradual decrease in burning susceptibility of depigmented skin of individuals with increasing phototype (II→VI).

Objective: To assess if the antioxidant response in the lesional vitiligo skin is involved in those protection mechanisms.

Koebner's phenomenon in vitiligo: European position paper.

Koebner's phenomenon (KP) has been observed in a number of skin diseases, including vitiligo. Its clinical significance in vitiligo with respect to disease activity and course is still debatable, while its relevance for surgical techniques has been demonstrated in some reports. We present a literature review on the currently known facts about KP in vitiligo, including details of clinical, experimental, and histopathological changes.

The haptenation theory of vitiligo and melanoma rejection: a close-up.

The 'Haptenation theory' concerns the multicausal pathogenesis of vitiligo ending ultimately in the (partial) disappearance of melanocytes from the skin and/or hairs. The melanocyte specificity is attributed to the tyrosinase-catalysed production of haptogenic ortho-quinones that covalently bind to tyrosinase or other melanosomal proteins to generate neo-antigens. These latter, in turn, trigger an immunological cascade resulting in a melanocyte-specific delayed-type hypersensitivity reaction that eliminates melanocytes and produces the characteristic depigmentation.

A reactive ortho-quinone generated by tyrosinase-catalyzed oxidation of the skin depigmenting agent monobenzone: self-coupling and thiol-conjugation reactions and possible implications for melanocyte toxicity.

Monobenzone (hydroquinone monobenzylether, 1) is a potent skin depigmenting agent that causes irreversible loss of epidermal melanocytes by way of a tyrosinase-dependent mechanism so far little understood. Herein, we show that 1 can be oxidized by mushroom tyrosinase to an unstable o-quinone (1-quinone) that has been characterized by comparison of its properties with those of a synthetic sample obtained by o-iodoxybenzoic acid-mediated oxidation of 1. Preparative scale oxidation of 1 with tyrosinase and catalytic l-DOPA, followed by reductive workup and acetylation, led to the isolation of two main products that were identified as the acetylated catechol derivative 4 and an unusual biphenyl-type dimer of 4, acetylated 5, arising evidently by coupling of 4 with 1-quinone.

A global survey of the role of ultraviolet radiation and hormonal influences in the development of melasma.

Background: It has been generally believed that the four main causes of melasma are pregnancy, hormonal contraception, family history and sun exposure; however, there are few published comprehensive studies that confirm these assertions. The Pigmentary Disorders Academy - an international group of experts in pigmentary disorders - designed and conducted a global survey of women to investigate the effect of these factors on onset and chronicity of melasma and the course of the disease in order to gain a better understanding of the causative factors associated with this disorder, with a particular focus on hormonal factors and UV exposure in females.

Methods: A 40-item largely self-administered questionnaire was completed by 324 women being treated for melasma in nine clinics worldwide.

Ultrastructural findings in progressive macular hypomelanosis indicate decreased melanin production.

Background: The pathogenesis of progressive macular hypomelanosis (PMH) is unknown. Recently, Westerhof et al. (Arch Dermatol 2004; 140: 210-214) hypothesized that Propionibacterium acnes produces a depigmenting factor that interferes with melanogenesis in the skin, resulting in hypopigmented spots.

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.

Antioxidants and narrow band-UVB in the treatment of vitiligo: a double-blind placebo controlled trial.

Background: Vitiligo is an acquired depigmenting disease with uncertain aetiopathogenesis, possibly associated with oxidative stress. Narrowband ultraviolet B phototherapy (NB-UVB) is the most widely used and effective treatment.

Aim: To evaluate the clinical effectiveness of NB-UVB and the repairing of oxidative stress-induced damage, using oral supplementation with an antioxidant pool (AP).

Vitiligo puzzle: the pieces fall in place.

Over the years, the role of biochemical, immunological, genetic, and other biological aspects in the pathogenesis of vitiligo has been studied. So far, no convincing model describing the interplay of these contributing factors has been formulated. Based on existing research, we propose that vitiligo has a multi-factorial etiology, characterized by multiple steps, but always involving an increase of external or internal phenol/catechol concentration, serving as a preferred surrogate substrate of tyrosinase, competing with its physiological substrate tyrosine.

Evolutionary, biologic, and social aspects of skin color.

To understand the diversity of skin color now observed in people of the five continents, one has to go back in history. In fact, geology, archeological findings, biology and medical science, as well as anthropology, linguistics, and contemporary genetic techniques enable us to patch up a clear picture of the past up to the present - the evolution of the Homo sapiens. Owing to its undeniable visibility, skin color has always had a sociologic connotation, which has up to the present time caused division between people.

Treatment of vitiligo vulgaris with narrow-band UVB and oral Polypodium leucotomos extract: a randomized double-blind placebo-controlled study.

Background: The first choice treatment for vitiligo vulgaris is narrow-band UVB (NB-UVB), but no satisfactory treatment exists.

Objectives: To investigate if Polypodium leucotomos, an antioxidative and immunomodulatory plant extract, improves NB-UVB-induced repigmentation.

Methods: Fifty patients with vitiligo vulgaris randomly received 250 mg oral P.

Progressive macular hypomelanosis: an overview.

Progressive macular hypomelanosis (PMH) is a common skin disorder that is often misdiagnosed. Various authors have written about similar skin disorders, referring to them by different names, but we believe that all these similar disorders are part of the same entity.PMH is characterized by ill-defined nummular, non-scaly hypopigmented spots on the trunk, often confluent in and around the midline, and rarely extending to the proximal extremities and neck/head region.

Treatment of periungual vitiligo with erbium-YAG-laser plus 5-flurouracil: a left to right comparative study.

Despite the multiple treatment modalities available for vitiligo, none of them gives satisfactory results in the periungual type. In this study we tried to explore and evaluate the effects of the combination treatment of erbium:YAG laser resurfacing and topical 5-flurouracil in periungual vitiligo. Nine adult patients presenting with periungual vitiligo lesions were included in this prospective left-right comparative study.

Hydroquinone and its analogues in dermatology - a potential health risk.

Hydroquinone has been used for decades as a skin lightening agent. Since January 1, 2001, its use in cosmetics has been banned. This ban is as a result of mid-term effects such as leukoderma-en-confetti/occupational vitiligo and exogenous ochronosis.

Benzoyl peroxide/clindamycin/UVA is more effective than fluticasone/UVA in progressive macular hypomelanosis: a randomized study.

Background: There is no effective treatment for progressive macular hypomelanosis. Recent findings indicate that Propionibacterium acnes may play a role in the pathogenesis.

Objectives: We sought to compare the effectiveness of antimicrobial therapy with anti-inflammatory therapy in patients with progressive macular hypomelanosis.

Evaluation of the effects of NB-UVB in both segmental and non-segmental vitiligo affecting different body sites.

Background: Narrow band (NB)-UVB has been used in the treatment of vitiligo for years but statistical evaluation of the clinical response in both segmental and non-segmental vitiligo patients has yet to be assessed.

Objectives: Statistical evaluation of the clinical response of vitiligo patients to NB-UVB in both segmental and non-segmental types affecting different body sites.

Methods: This study included 150 patients with vitiligo either segmental (10%) or non-segmental (90%).

The discovery of the human melanocyte.

Around 2200 bc the first written description of a human pigmentation disorder, most likely vitiligo, was recorded, and from that moment the history of research into human pigmentation can be traced. For the following 4000 yr, the origins of human skin colour remained an enigma that was to generate a multitude of misconceptions. Even after European physicians began to dissect and compare dark and light coloured skin to reveal its underlying anatomy, the origins of skin and hair pigmentation were a matter of frequently erroneous speculation.

Noninvasive techniques for the evaluation of skin color.

Visual assessment remains one of the "gold standard" methods of assessing skin color and a number of tools are currently available to reduce the interobserver variability. Ultraviolet light examination remains a mainstay of the assessment of pigmentary disorders, while polarized light photography is useful for the appraisal of dermal changes, in particular those related to vascularity. With the introduction of modern instruments, reflectance spectroscopy using tristimulus colorimeters or narrowband spectrophotometers provides a convenient, objective, and reproducible methodology for the evaluation of pigmentation and skin color.