Valeria Aoki

The Role of Intramolecular Epitope Spreading in the Pathogenesis of Endemic Pemphigus Foliaceus (Fogo Selvagem)

We report here a relationship between intramolecular epitope spreading and the clinical onset of the endemic form of pemphigus foliaceus in a Brazilian community with a high prevalence and incidence of the disease. Also known as Fogo Selvagem (FS), this disease is characterized by severe skin blistering and pathogenic anti–desmoglein-1 (Dsg1) autoantibodies. These autoantibodies bind the Dsg1 ectodomain and trigger keratinocyte cell detachment, the hallmark of FS. We show that (a) sera from FS patients in the preclinical stage recognized epitopes on the COOH-terminal EC5 domain of Dsg1, (b) disease onset was associated with the emergence of antibodies specific for epitopes on the NH2-terminal EC1 and EC2 domains, (c) all sera from FS patients with active disease recognized the EC1 and/or EC2 domains, and (d) sera from FS patients in remission showed reactivity restricted to EC5. These results suggest that anti-Dsg1 autoantibodies in FS are initially raised against the COOH-terminal EC5 domain of Dsg1 in individuals without skin disease; in genetically predisposed subjects the autoimmune response may then undergo intramolecular epitope spreading toward epitopes on the NH2-terminal EC1 and EC2 domains of Dsg1 leading to disease onset. Moreover, intramolecular epitope spreading may also modulate remissions and relapses of FS.

The Prevalence of Antibodies against Desmoglein 1 in Endemic Pemphigus Foliaceus in Brazil

Background Pemphigus foliaceus is an autoimmune skin disease mediated by autoantibodies against desmoglein 1. The endemic form is thought to have an environmental cause. The Terena reservation of Limao Verde in Mato Grosso do Sul, Brazil, is a recently identified focus of the disease, with a prevalence of 3.4 percent in the population. We tested the hypothesis that normal subjects living in an endemic area have antibodies against desmoglein 1. Methods We used an enzyme-linked immunosorbent assay to detect antibodies against desmoglein 1 in serum samples from 60 patients with endemic pemphigus foliaceus (fogo selvagem) who lived in Limao Verde or elsewhere in Brazil, 372 normal subjects (without pemphigus foliaceus) from Limao Verde and surrounding locations, and 126 normal subjects from the United States and Japan. Results Antibodies against desmoglein 1 were detected in 59 of the 60 patients with fogo selvagem (98 percent) but in only 3 of the 126 normal subjects from the United States and Japan (2 perce...

Definitions and outcome measures for bullous pemphigoid: recommendations by an international panel of experts

Our scientific knowledge of bullous pemphigoid (BP) has dramatically progressed in recent years. However, despite the availability of various therapeutic options for the treatment of inflammatory diseases, only a few multicenter controlled trials have helped to define effective therapies in BP. A major obstacle in sharing multicenter-based evidences for therapeutic efforts is the lack of generally accepted definitions for the clinical evaluation of patients with BP. Common terms and end points of BP are needed so that experts in the field can accurately measure and assess disease extent, activity, severity, and therapeutic response, and thus facilitate and advance clinical trials. These recommendations from the International Pemphigoid Committee represent 2 years of collaborative efforts to attain mutually acceptable common definitions for BP and proposes a disease extent score, the BP Disease Area Index. These items should assist in the development of consistent reporting of outcomes in future BP reports and studies.

Towards global consensus on outcome measures for atopic eczema research: results of the HOME II meeting

The use of nonstandardized and inadequately validated outcome measures in atopic eczema trials is a major obstacle to practising evidence‐based dermatology. The Harmonising Outcome Measures for Eczema (HOME) initiative is an international multiprofessional group dedicated to atopic eczema outcomes research. In June 2011, the HOME initiative conducted a consensus study involving 43 individuals from 10 countries, representing different stakeholders (patients, clinicians, methodologists, pharmaceutical industry) to determine core outcome domains for atopic eczema trials, to define quality criteria for atopic eczema outcome measures and to prioritize topics for atopic eczema outcomes research. Delegates were given evidence‐based information, followed by structured group discussion and anonymous consensus voting. Consensus was achieved to include clinical signs, symptoms, long‐term control of flares and quality of life into the core set of outcome domains for atopic eczema trials. The HOME initiative strongly recommends including and reporting these core outcome domains as primary or secondary endpoints in all future atopic eczema trials. Measures of these core outcome domains need to be valid, sensitive to change and feasible. Prioritized topics of the HOME initiative are the identification/development of the most appropriate instruments for the four core outcome domains. HOME is open to anyone with an interest in atopic eczema outcomes research.

Desmoglein-1–specific T lymphocytes from patients with endemic pemphigus foliaceus (fogo selvagem)

Fogo selvagem (FS), the endemic form of pemphigus foliaceus, is a cutaneous autoimmune disease characterized by subcorneal blistering of the epidermis and the production of autoantibodies against the desmosomal antigen desmoglein-1 (Dsg1). Previously, we showed that mice injected with autoantibodies from FS patients develop a skin disease that reproduces the clinical, histological, and immunological features of FS, indicating that autoantibodies play an essential role in the development of this disease. The purpose of this study was to characterize the autoimmune T-cell response associated with FS. We provide here the first evidence, to our knowledge, that the great majority of FS patients have circulating T lymphocytes that specifically proliferate in response to the extracellular domain of Dsg1. Long-term T cells developed from these patients also responded to Dsg1, and this antigen-specific response was shown to be restricted to HLA-DR molecules. These Dsg1-reactive FS T cells exhibited a CD4-positive memory T-cell phenotype and produced a T helper 2-like cytokine profile. These findings represent the initial steps in defining the role of T cells in FS autoimmunity.

Deep fungal infections in tropical countries

Deep mycoses are diseases that require knowledge of numerous medical specialties. According to modern concepts, deep mycoses are considered under two aspects: subcutaneous and systemic mycosis. Subcutaneous mycoses are characterized by a heterogeneous group of infections that often result from direct penetration of the fungus into the skin through trauma; and they spread by local tissue invasion in the inoculation area. The disease usually remains localized, slowly spreads to adjacent tissue, and eventually to lymphatic; or, more rarely, hematogenous dissemination is observed. A variety of clinical presentation is frequent, leading to a broad range of differential diagnoses. Chromomycosis, pheohyphomycosis, sporotrichosis, entomophthoramycosis, lobomycosis, and rhinosporidiosis belong to the group of the subcutaneous mycoses. Systemic mycosis consists of infections caused by truly pathogenic fungi and also those produced by fungi with small intrinsic pathogenicity, that is, enhanced by immunocompromised hosts, leading to the disease. In tropical regions, it is the first condition that leads to specific interest, whereas subcutaneous mycosis is found worldwide. The true systemic mycoses are produced in normal individuals when a minimal inoculated particle penetrates into the body. In the majority of cases, the respiratory tract may be the first site of entry, leading to initial lung infection; fungi then spread by hematogenous or eventually lymphatic vessels to other organs, including the skin. These diseases have a restricted geographic distribution due to the limited geographic occurrence of the etiologic agents. The majority of patients are represented by adult men as a consequence of prolonged exposure to fungi due to professional reasons. Apparently, black individuals show a higher risk of developing disseminated forms. The racial influence seems to have existed among Japanese immigrants in Brazil, who developed severe disseminated forms of paracoccidioidomycosis. Obviously, the direct contact with the land favors the opportunity to acquire fungal disease, justifying its higher frequency among rural peasants. After penetrating the human body, fungi usually arouse an adequate defensive response; these are the so-called infections without disease that occur in paracoccidioidomycosis, coccidioidomycosis, histoplasmosis, and cryptococcosis. Under these circumstances, the infection may be totally silent, or with discrete clinical symptoms, such as fever, with or without erythema nodosum; infectious state is detected only by positive intradermal tests utilizing involved fungal antigens. Epidemiological inquiries dealing with these intradermal tests show variable positive results in different regions, where they are performed according to fungi distribution; the percentage of positive results of these tests in populations demonstrate a direct relationship to the occurrence of the disease in the studied area. The association of these fungal diseases to other morbid processes, either infectious or carcinogenic, is occasionally cited. For example, cryptococcosis is sometimes associated with lymphomas, paracoccidioidomycosis, and pulmonary tuberculosis. Another possibility concerning systemic mycosis is the reactivation of a quiescent fungal focus in individuals living in endemic areas who acquired the silent infection, as demonstrated by positive response to intradermal tests. It is interesting to observe the development of the disease in these individuals after many years, due to multiple reasons that lead to an impaired immune response (aging, immunosupressant drugs, concomitant diseases). This event may happen many years after exposure to fungi, when the patient is no longer living in the endemic area, or is living in a country where the disease does not occur, making the diagnosis extremely difficult. This condition is the socalled imported pathology.

Advances in Pemphigus and its Endemic Pemphigus Foliaceus (Fogo Selvagem) Phenotype: A Paradigm of Human Autoimmunity

Pemphigus encompasses a group of organ specific, antibody mediated autoimmune diseases of the skin characterized by keratinocyte detachment that leads to the development of blisters and erosions, which can become life-threatening. The pathogenic autoantibodies recognize desmogleins, which are members of the desmosomal cadherin family of cell adhesion molecules. Desmoglein 3 is targeted in pemphigus vulgaris while desmoglein 1 is targeted in pemphigus foliaceus and its endemic form, Fogo Selvagem. This review will briefly define the salient features of pemphigus and the proposed steps in pathogenesis. We will then summarize the most recent advances in three important areas of investigation: (i) epidemiologic, genetic, and immunologic features of Fogo Selvagem, (ii) molecular mechanisms of injury to the epidermis, and (iii) novel therapeutic strategies targeting specific steps in disease pathogenesis. The advances in each of these three seemingly separate areas contribute to the overall understanding of the pemphigus disease model. These recent advancements also underscore the dynamic interplay between the treatment of patients in a clinical setting and basic science research and have led to an integrative understanding of disease pathogenesis and treatment, allowing pemphigus to serve as a paradigm of human autoimmunity.

Pemphigus herpetiformis is a rare clinical expression of nonendemic pemphigus foliaceus, fogo selvagem, and pemphigus vulgaris

BACKGROUND Pemphigus herpetiformis is a rare and atypical variant of pemphigus that resembles dermatitis herpetiformis. Most patients show antiepidermal autoantibodies that stain the epidermal intercellular spaces by immunofluorescence, similar to pemphigus autoantibodies, and lack the immunopathologic features of dermatitis herpetiformis. OBJECTIVE The study was aimed at characterizing the specificity of the antiepidermal autoantibodies in seven patients with pemphigus herpetiformis. METHODS The antiepidermal autoantibodies were characterized by immunofluorescence, immunoblotting, and immunoprecipitation studies in seven patients who fulfilled the clinical, histologic, and immunofluorescence diagnostic criteria for pemphigus herpetiformis. RESULTS Five patients with features of pemphigus herpetiformis either had classic pemphigus foliaceus, or their disease evolved into classic pemphigus foliaceus. One of these patients had fogo selvagem. Two of the seven patients showed features of or had disease that evolved into pemphigus vulgaris. The antiepidermal autoantibodies present in all seven patients recognized desmoglein 1. CONCLUSION Pemphigus herpetiformis is a rare clinical and histologic expression of nonendemic pemphigus foliaceus, fogo selvagem, and pemphigus vulgaris.

Report from the fourth international consensus meeting to harmonize core outcome measures for atopic eczema/dermatitis clinical trials (HOME initiative)

This article is a report of the fourth meeting of the Harmonising Outcome Measures for Eczema (HOME) initiative held in Malmö, Sweden on 23–24 April 2015 (HOME IV). The aim of the meeting was to achieve consensus over the preferred outcome instruments for measuring patient‐reported symptoms and quality of life for the HOME core outcome set for atopic eczema (AE). Following presentations, which included data from systematic reviews, consensus discussions were held in a mixture of whole group and small group discussions. Small groups were allocated a priori to ensure representation of different stakeholders and countries. Decisions were voted on using electronic keypads. For the patient‐reported symptoms, the group agreed by vote that itch, sleep loss, dryness, redness/inflamed skin and irritated skin were all considered essential aspects of AE symptoms. Many instruments for capturing patient‐reported symptoms were discussed [including the Patient‐Oriented SCOring Atopic Dermatitis index, Patient‐Oriented Eczema Measure (POEM), Self‐Administered Eczema Area and Severity Index, Itch Severity Scale, Atopic Dermatitis Quickscore and the Nottingham Eczema Severity Score] and, by consensus, POEM was selected as the preferred instrument to measure patient‐reported symptoms. Further work is needed to determine the reliability and measurement error of POEM. Further work is also required to establish the importance of pain/soreness and the importance of collecting information regarding the intensity of symptoms in addition to their frequency. Much of the discussion on quality of life concerned the Dermatology Life Quality Index and Quality of Life Index for Atopic Dermatitis; however, consensus on a preferred instrument for measuring this domain could not be reached. In summary, POEM is recommended as the HOME core outcome instrument for measuring AE symptoms.

Report from the third international consensus meeting to harmonise core outcome measures for atopic eczema/dermatitis clinical trials (HOME)

This report provides a summary of the third meeting of the Harmonising Outcome Measures for Eczema (HOME) initiative held in San Diego, CA, U.S.A., 6–7 April 2013 (HOME III). The meeting addressed the four domains that had previously been agreed should be measured in every eczema clinical trial: clinical signs, patient‐reported symptoms, long‐term control and quality of life. Formal presentations and nominal group techniques were used at this working meeting, attended by 56 voting participants (31 of whom were dermatologists). Significant progress was made on the domain of clinical signs. Without reference to any named scales, it was agreed that the intensity and extent of erythema, excoriation, oedema/papulation and lichenification should be included in the core outcome measure for the scale to have content validity. The group then discussed a systematic review of all scales measuring the clinical signs of eczema and their measurement properties, followed by a consensus vote on which scale to recommend for inclusion in the core outcome set. Research into the remaining three domains was presented, followed by discussions. The symptoms group and quality of life groups need to systematically identify all available tools and rate the quality of the tools. A definition of long‐term control is needed before progress can be made towards recommending a core outcome measure.