Increased expression of Filaggrin and Claudin-1 in the ocular surface of patients with atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is an itchy, chronic and inflammatory skin condition, with dysfunctional immune response and skin barrier defects. Reduction of filaggrin (FLG) and tight junctions (TJ) proteins, such as claudin-1 (CLDN-1), expression in cutaneous epithelial barrier is remarkable in AD pathogenesis. Ocular involvement occurs in approximately 40% of AD patients leading to changes in the structure of the conjunctiva.

OBJECTIVES

We aimed to evaluate the expression of FLG and CLDN-1 in the ocular surface of adults with AD, analysing bulbar conjunctival cells collected by a novel non-invasive cellular imprint.

METHODS

Bulbar conjunctival epithelial cells were collected by cellular imprint technique, and FLG and CLDN-1 expression were assessed by immunofluorescence (IF) and real-time polymerase chain reaction (RT-PCR).

RESULTS

We detected increased expression of FLG and CLDN-1, as well as their transcript levels in AD patients compared with healthy controls (HC). There was a positive correlation between tear film break-up time (TBUT) and FLG expression. Fluorescein staining was inversely associated with FLG expression.

CONCLUSIONS

Our results may reflect a reactive response of the ocular surface to AD-related ocular inflammation and associated dry eye disease. Further investigations focusing on the role of FLG and TJ expression in the ocular surface of AD patients may increment the understanding of the pathophysiology of extracutaneous AD and developing future targeted therapies.

Increased expression of in situ IL-31RA and circulating CXCL8 and CCL2 in pemphigus herpetiformis suggests participation of the IL-31 family in the pathogenesis of the disease

BACKGROUND

Pemphigus herpetiformis (PH) is a rare clinical subtype of pemphigus with the presence of urticarial plaques, severe pruritus, rare acantholysis and eosinophilic spongiosis.

OBJECTIVES

The aim of this study was to investigate the influence of IL-31 and pro-inflammatory cytokines/chemokines in the pathogenesis of PH.

METHODS

Twenty-five patients with PH and three groups: pemphigus foliaceus (PF = 14), pemphigus vulgaris (PV = 15) and healthy controls (HC = 20) were selected for this study. The groups were analysed by immunohistochemistry utilizing IL-31, IL-31RA, IL-4, IL-17 and TNF-α antibodies. Serum levels of IL-4, IL-13, TNF, CXCL8, CCL5 and CCL2 were evaluated by cytometric bead array.

RESULTS

Analysis of IL-31 family of PH patients revealed the following findings: (i) Enhanced in situ expression of IL-31 in PH samples, compared to PF and to PV (epidermis); (ii) Cutaneous IL-31RA expression in PH samples was higher than in PF, PV and HC groups (epidermis and dermis); (iii) PF patients that evolved to PH showed significant increased IL-31RA epidermal expression during the PH phase. Profile of pro-inflammatory cytokines (IL-4, IL-17 and TNF-α) in PH patients' skin exhibited: (i) Enhanced IL-4 expression, when compared to patients with PF (epidermis and dermis) and with PV (epidermis); (ii) Augmented IL-17 expression than PF and PV patients (epidermis); (iii) Augmented expression of TNF-α when compared to PF at the epidermal level. Evaluation of circulating cytokines and chemokines showed higher levels of CXCL8 and CCL2 in PH sera compared to HC group.

CONCLUSIONS

IL-31 and IL-31RA, cytokines related to pruritus, and pro-inflammatory chemokines (CXCL8 and CCL2) seem to exert a role in the pathogenesis of PH. These findings support future studies to clarify the role of IL-31 pathway as a potential therapeutic target for patients with PH.

Clinical Features and Disease Management in Adult Patients With Atopic Dermatitis Receiving Care at Reference Hospitals in Brazil: the ADAPT Study

BACKGROUND

Atopic dermatitis is a chronic inflammatory skin disease with a prevalence of 0.02% to 8.1% in adults. Adult patients with moderate-to-severe atopic dermatitis are affected by frequent relapses and a significant disease burden. Objective: To determine the clinical, immunological, and therapeutic profile of Brazilian adults with atopic dermatitis.

METHODS

A multicenter, observational, retrospective, descriptive registry-based study was conducted at reference hospitals between December 2016 and October 2017. The data collected were demographics, personal and family history of atopic diseases, clinical manifestations, laboratory tests, disease severity and management.

RESULTS

Of the 187 patients included in the analysis, 56.1% were female and 71.7% were White, with a mean age of 24.7 years. Mean follow-up was 9 years. Asthma or other allergic diseases were reported by 80.2% of patients. The main comorbidity was hypertension (10.2%), and common disease manifestations included pruritus and erythema. Lesions generally affected flexural and nonflexural areas, with typical morphology. Around 83% of patients had moderate-to-severe disease, and 8.6% reported at least 1 hospitalization. Most patients received topical and/or systemic pharmacological therapies, including omalizumab (5.9%); 4.3% received phototherapy. Moreover, 66.8% of patients received adjuvant therapy, and 79.1% changed or discontinued treatment for atopic dermatitis due to remission (46.5%), poor effectiveness (33.7%), or lack of adherence (12.9%). Most patients presented characteristics of type 2 inflammation, with immunoglobulin E levels above 100 IU/mL (94.4%) and peripheral blood eosinophils above 5% (55.9%).

CONCLUSION

Brazilian adult patients with severe atopic dermatitis need treatment to efficiently control the disease and improve quality of life.

Lichen planus: altered AIM2 and NLRP1 expression in skin lesions and defective activation in peripheral blood mononuclear cells

BACKGROUND

Lichen planus (LP) is an inflammatory skin disease with unknown aetiology. Activation by pathogen-associated molecular patterns or environmental stimuli may activate some components of inflammasomes that contribute to the inflammatory process in LP lesions.

AIM

To characterize the inflammasomes in skin lesions and peripheral blood mononuclear cells (PBMCs) of patients with LP under Toll-like receptor (TLR) activation.

METHODS

In total, 15 patients with LP and 14 healthy controls (HCs) were enrolled in the study. Inflammasome expression in skin was evaluated by real-time PCR and immunohistochemistry, while ELISA was used to assess the production of interleukin (IL)-1β by PBMCs under stimulation with TLR4 and TLR7/TLR8 agonists and adenosine triphosphate (ATP).

RESULTS

Compared with the levels in HC samples, increased expression of the inflammasome AIM2 was verified in both epidermal and dermal sections of LP skin lesions, whereas NLRP1 and IL-β expression levels were enhanced in the dermis. LP skin lesion samples exhibited higher AIM2 transcript levels, similar NLRP1 levels and lower pro-IL-1β mRNA levels compared with HC samples. We verified that, compared with PBMCs from HC subjects, PBMCs from patients with LP produced similar amounts of IL-1β after induction by TLR4 agonists but lower IL-1β levels after induction by TLR7/TLR8 agonists, regardless of the addition of ATP.

CONCLUSION

Alterations in innate immunity, such as inflammasome component expression in skin lesions and PBMCs, were observed in patients with LP. Further investigations of dysfunctional inflammasome activation and the chronic inflammatory status of LP are required.

Comparative study of direct and indirect immunofluorescence for diagnosis of canine pemphigus foliaceus

ABSTRACT Pemphigus foliaceus (PF) is the most common autoimmune skin disease in dogs. It is characterized by pustules, erosions, and crusts which occur due to the presence of autoantibodies that target intercellular adhesion. Histopathological examination is considered the gold standard pattern in the diagnosis, but may sometimes be inconclusive, especially when the characteristic findings are not identified. New diagnostic tests are continuously being developed and immunofluorescence assays, could be a valuable alternative diagnostic tool. This study aimed to evaluate the applicability of direct and indirect immunofluorescence (DIF and IIF) tests for the diagnosis of canine PF. Twenty eight dogs were divided into two groups: Group I with 14 dogs with PF and Group II (control) with 14 dogs with Superficial pyoderma (differential diagnoses of PF). All animals were submitted to skin biopsy to histopathological and DIF. Blood samples were collected to assess IIF. Comparing the DIF results against the histopathology test, there was an agreement of 75% (9/12) with a Kappa index of 0.77 (P<0.001). Considering IIF, the agreement was 100% (14/14), with a Kappa index of 1.0 (P<0.001). We conclude that DIF and IIF are highly effective and were useful and effective complementary examination tests for an improvement in the diagnosis of canine PF.

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

This is the report from the fifth meeting of the Harmonising Outcome Measures for Eczema initiative (HOME V). The meeting was held on 12-14 June 2017 in Nantes, France, with 81 participants. The main aims of the meeting were (i) to achieve consensus over the definition of the core domain of long-term control and how to measure it and (ii) to prioritize future areas of research for the measurement of the core domain of quality of life (QoL) in children. Moderated whole-group and small-group consensus discussions were informed by presentations of qualitative studies, systematic reviews and validation studies. Small-group allocations were performed a priori to ensure that each group included different stakeholders from a variety of geographical regions. Anonymous whole-group voting was carried out using handheld electronic voting pads according to predefined consensus rules. It was agreed by consensus that the long-term control domain should include signs, symptoms, quality of life and a patient global instrument. The group agreed that itch intensity should be measured when assessing long-term control of eczema in addition to the frequency of itch captured by the symptoms domain. There was no recommendation of an instrument for the core outcome domain of quality of life in children, but existing instruments were assessed for face validity and feasibility, and future work that will facilitate the recommendation of an instrument was agreed upon.

Exploring the in situ expression of vascular endothelial growth factor and endoglin in pemphigus foliaceus variants and pemphigus vulgaris

BACKGROUND

Erythroderma is a severe manifestation of pemphigus foliaceus (PF), a blistering disease mediated by IgG autoantibodies against desmoglein 1. Increasing evidence supports the contribution of angiogenic mediators in the pathogenesis of erythroderma.

OBJECTIVE

To evaluate the in situ expression of vascular endothelial growth factor (VEGF) and endoglin in patients with PF with erythroderma.

METHODS

Formalin-fixed paraffin-embedded skin samples obtained from patients with erythrodermic PF (n = 19; 12 patients with endemic PF), non-erythrodermic PF (n = 17), pemphigus vulgaris (PV; n = 10), psoriasis (n = 10) and healthy individuals (HI; n = 10) were processed in an automated immunohistochemistry platform utilizing anti-VEGF and anti-endoglin as primary antibodies. Reactivity was evaluated both manually (0 = negative; 1+ = mild; 2+ = intense) and through an automated microvessel analysis algorithm.

RESULTS

Vascular endothelial growth factor expression in erythrodermic PF was higher than in non-erythrodermic PF (P = 0.034) and in HI (P = 0.004), and similar to psoriasis (P = 0.667) and PV (P = 0.667). In non-erythrodermic PF, VEGF positivity was similar to HI (P = 0.247), and lower than psoriasis (P = 0.049) and PV (P = 0.049). Both erythrodermic and non-erythrodermic PF presented similar endoglin expression (P = 0.700). In addition, endoglin positivity during erythrodermic PF was similar to psoriasis (P = 0.133) and lower than PV (P = 0.0009). Increased expression of in situVEGF suggests that healing processes are triggered in response to tissue damage led by autoantibodies in PF, especially during erythroderma. Reduced endoglin positivity suggests that an unbalanced angiogenesis may occur during erythrodermic PF. Further studies may help to confirm if the regulation of VEGF and endoglin expression in patients with PF can contribute to control the healing process and enable disease remission.

CONCLUSION

Overexpression of VEGF in erythrodermic PF as well as in PV and psoriasis points out a dysregulated repair process in severe forms of these diseases and suggests VEGF and endoglin could act as prognostic markers and future therapeutic targets to enable proper healing in PF.

Topical corticosteroid phobia in atopic dermatitis: International feasibility study of the TOPICOP score

BACKGROUND

Adherence to topical corticosteroids (TCS) is essential for the effective treatment of atopic dermatitis but can be limited by concerns about their use. This study examined the feasibility of applying the validated TOPICOP score for assessing TCS phobia across different countries.

METHODS

This was a prospective multicentre feasibility study conducted in 21 hospitals in 17 countries. Patients >3 months of age with atopic dermatitis or their parents or legal representatives completed a validated translation of the TOPICOP questionnaire in the country's native language. Respondents also completed questionnaires collecting opinions about the feasibility and acceptability of the TOPICOP questionnaire.

RESULTS

A total of 1564 participants in 15 countries were included in the analysis. 81% of respondents considered the questions clear or very clear, and 79% reported that it took less than 5 minutes to complete. Each of the individual items in the TOPICOP questionnaire was considered to be not at all difficult to answer by 49% to 74% of participants. The mean global TOPICOP score was 44.7%±20.5. Mean TOPICOP subscores were 37.0±22.8% for knowledge and beliefs, 54.7±27.8% for fears and 50.1±29.1% for behaviours. Global scores and subscores differed between countries, although the subscores did not always vary in parallel, suggesting different levels of TCS phobia and different drivers for each country.

CONCLUSIONS

The TOPICOP score can be feasibly applied across countries and may therefore be useful for obtaining qualitative and quantitative data from international studies and for adapting patient education and treatment.

Increased serum levels of vascular endothelial growth factor in pemphigus foliaceus patients with erythroderma

BACKGROUND

Erythroderma is a clinical skin syndrome shared by patients with cutaneous disorders of distinct aetiologies as a result of the combined actions of chemokines, adhesion molecules, and cytokines, such as vascular endothelial growth factor (VEGF).

OBJECTIVE

To evaluate the profile of serum levels of VEGF and soluble vascular endothelial growth factor receptor 1 (sVEGFR-1) in pemphigus foliaceus (PF) patients with erythroderma.

METHODS

We conducted a retrospective study, which included (i) a chart review of all PF patients from the Autoimmune Blistering Clinic, University of Sao Paulo, Brazil, from January 1991 to December 2014, together with an evaluation of demographic variables, hospitalization duration and complications and (ii) analysis of the circulating VEGF and sVEGFR-1 levels in PF patients with erythroderma by ELISA. The controls included patients with pemphigus vulgaris or psoriasis.

RESULTS

We observed higher serum VEGF levels in PF patients during erythroderma than during the non-erythrodermic phase. PF patients showed increased serum levels of sVEGFR-1 during the erythrodermic phase in comparison to controls. Interestingly, the sVEGFR-1 and antidesmoglein-1 levels were positively correlated during the non-erythrodermic period.

CONCLUSION

Erythroderma, which represents one clinical form of PF, implies more severe outcomes. The circulating levels of VEGF, a potent endothelial activator, are increased in PF patients with erythroderma; this result suggests the contribution of the blood vessel endothelium to the pathogenesis of this clinical syndrome. Interestingly, our findings showed a positive correlation between the sVEGFR-1 and antidesmoglein-1 antibody levels, indicating a suppressive response to VEGF augmentation during the erythrodermic phase of PF.

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.

Profile of skin barrier proteins (filaggrin, claudins 1 and 4) and Th1/Th2/Th17 cytokines in adults with atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) in adults and profile of skin barrier proteins and inflammatory cytokines.

OBJECTIVE

Evaluation of the expression of skin barrier proteins such as filaggrin, claudins 1 and 4 and of circulating inflammatory cytokines (Th1/Th2/Th17) in adults with AD.

METHODS

Thirty-three adult patients with AD diagnosed according to the Hanifin & Rajkacriteria, and 25 healthy controls were enrolled in the study. AD severity was measured by Eczema Area and Severity Index (EASI). Laboratory assays included immunohistochemistry analysis of skin barrier proteins, such as filaggrin, claudins 1 and 4 and interleukin-17 (IL-17) from skin samples and determination of circulating cytokine levels (IL-2, 4, 5, 6, 10, 17A, TNF and IFN-γ) by flow cytometry (Cytometric Bead Array).

RESULTS

We observed a reduced expression of filaggrin and claudin 1 in lesional skin of AD patients, when compared to controls. There was an inverse correlation of filaggrin expression and disease severity. In addition, IL-17 expression was enhanced in AD patients. Similarly, higher levels of inflammatory cytokines (IL-2, 5, 6, 10, 17A and IFN-γ) were found in AD patients.

CONCLUSION

Our data reinforce the role of an altered skin barrier in the pathogenesis of AD. Our results show not only reduced expression of filaggrin and claudin 1 in lesional atopic skin but also inverse correlation of filaggrin expression and disease severity. Moreover, elevation of in situ IL-17 and of circulating interleukin levels in AD emphasize the systemic, inflammatory profile of this defective skin barrier dermatosis.

Atopy patch test with Aleuroglyphus ovatus antigen in patients with atopic dermatitis

BACKGROUND

Epicutaneous test made with dust mite antigens.

OBJECTIVE

Evaluation of the response of the epicutaneous test with Aleuroglyphus ovatus antigen in atopic patients.

METHODS

We patch tested 119 individuals, 48 with atopic dermatitis, 50 with respiratory allergy and 21 healthy controls. We compare the positive response frequency to a closed patch test using Aleuroglyphus ovatus antigen in different concentrations and 48 and 96h reading times among those individuals.

RESULTS

Six patients with atopic dermatitis (12.5%) and 4 with respiratory atopy (8.0%) had positive reactions. None of the non-atopic controls had a positive response. As the antigen concentration raised, the number of positive reactions to epicutaneous test raised as well.

CONCLUSION

Our data suggest a positive relation between Atopy Patch Test positive responses and Aleuroglyphus ovatus antigen concentration, no matter the kind of the atopic clinical expression.

Clinical and immunological profile of umbilical involvement in pemphigus vulgaris and pemphigus foliaceus

BACKGROUND

Pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are autoimmune vesicobullous disorders with IgG autoantibodies directed against desmoglein (Dsg)1 and 3, which lead to intraepidermal acantholysis.

AIM

To characterize the clinical and immunological profile of patients with PF or PV with umbilical involvement.

METHODS

In total, 10 patients (7 women, 3 men; age range 24-70 years, disease duration 3-16 years) diagnosed with either PV (n = 5) or mucocutaneous PF (n = 5) were assessed according to their clinical features, histopathology and immunological findings [direct and indirect immunofluorescence (DIF and IIF) and ELISA with recombinant Dsg1 and Dsg3].

RESULTS

Erythema, erosions, crusts and vegetating skin lesions were the main clinical features of the umbilical region. DIF of the umbilical region gave positive results for intercellular epidermal IgG and C3 deposits in eight patients and for IgG alone in the other two. Indirect immunofluorescence with IgG conjugate showing the typical pemphigus pattern was positive in all 10 patients, with titres varying from 1 : 160 to 1 : 2560. ELISA with recombinant Dsg1 gave scores of 24-266 in PF and 0-270 in PV. Reactivity to recombinant Dsg3 was positive in all five patients with PV (ELISA 22-98) and was negative in all PF sera.

CONCLUSIONS

All 10 patients with pemphigus with umbilical presentation had the clinical and immunopathological features of either PF or PV. This peculiar presentation, not yet completely elucidated, has rarely been reported in the literature. A possible explanation for this unique presentation may be the presence of either novel epitopes or an association with embryonic or scar tissue located in the umbilical-cord region.

Clinical and immunopathological evaluation of epidermolysis bullosa acquisita

BACKGROUND

Epidermolysis bullosa acquisita (EBA) is a subepidermal blistering disease with IgG antibodies against collagen VII. The disease is heterogeneous and can lead to significant morbidity.

AIM

To characterize the clinical and laboratory profile of patients with EBA from Sao Paulo, Brazil.

METHODS

In total, 12 patients (mean age 24 years) were analysed for cutaneous and mucosal involvement, laboratory data and response to treatment.

RESULTS

Mucosal involvement occurred in 11 of the 12 patients (eyes in 4/12, nose in 4/9, pharynx-larynx in 5/9 and oesophagus in 4/10; 3 patients did not undergo nasopharyngeal examination and 2 paediatric patients did not undergo endoscopy). Using direct immunofluorescence, different patterns of deposits were found at the basement membrane zone: IgG (12/12), IgA (6/12), IgM (4/12), C3 (11/12). Indirect immunofluorescence (IIF) was positive in 6 of 12 patients, and IIF on salt-split skin detected dermal deposition in 10 of 12 patients. Antinuclear antibodies were found in 3 of 12 patients, but none of them fulfilled the criteria for systemic lupus erythematosus. After treatment, total remission was achieved in three patients and partial remission in five (three were maintained on minimal treatment, one on the full treatment and one was able to come off treatment). Two patients were lost to follow-up and the remaining two had disease flares. Complications were mainly mucosal (oesophageal stenosis, laryngeal synechia, symblephara and trichiasis).

CONCLUSIONS

Mucosal involvement in EBA is a determining factor for disease morbidity. Complete evaluation of the patient, focusing on both cutaneous and extracutaneous sites is essential, as EBA may evolve to refractory disease, severely compromising its outcome.

Oesophagitis dissecans superficialis: an acute, benign phenomenon associated with pemphigus vulgaris

Pemphigus vulgaris (PV) is an autoimmune dermatosis that may evolve to severely compromise the skin and/or mucosa. Autoantibodies directed against epithelial cadherins, such as desmogleins 1 and 3, lead to acantholysis and culminate in blister formation. Involvement of the oral mucosa is common, but other squamous stratified epithelia may also be the target of the autoimmune aggression. We report a woman with PV that was in partial remission, who developed an unusual acute phenomenon, known as oesophagitis dissecans superficialis.

Clinical and serological follow-up studies of endemic pemphigus foliaceus (fogo selvagem) in Western Parana, Brazil (2001-2002)

BACKGROUND

Fogo selvagem (FS) has been described in several regions of Brazil, including the Western regions of the state of Parana. In 1990, Empinotti et al. reported case studies of 213 patients with FS that were collected from 1976 to 1988. The same author (J.C.E.) has observed that the frequency of cases in these regions of Parana has decreased.

OBJECTIVES

The purpose of this study was to clinically and serologically evaluate a small group of the patients originally reported in 1990 and compare data with a group of control individuals. These patients were treated at the onset of the disease with systemic steroids.

PATIENTS AND METHODS

Patients with FS, their unaffected relatives (n = 80) and genetically unrelated controls (n = 15) were identified during a field study from 1 May 2001 to 30 June 2002. Sera from nine patients with FS and six normal controls that were collected in the 1976-1988 evaluation were available for this study. The sera were tested by indirect immunofluorescence, enzyme-linked immunosorbent assay (ELISA) and immunoprecipitation using recombinant human desmoglein 1 (Dsg1).

RESULTS

Only 16 of the originally identified 213 patients with FS were found during the field studies. Thirteen of the 16 patients were in clinical and serological remission; 20% of normal controls (19 of 95) were positive in the Dsg1 ELISA. The majority of these subjects (17 of 19) were genetically related to FS patients. Six normal controls that were positive in the Dsg1 ELISA in the original survey were found to be negative or weakly positive in this evaluation.

CONCLUSION

The reduced frequency of positive serological markers of disease in patients and normal controls from Western Parana, as well as the absence of recurrent disease in previously identified patients, suggest that environmental antigenic stimulation of the population at risk may have decreased in recent years.

Changes in the autoimmune blistering response: a clinical and immunopathological shift from pemphigus foliaceus to bullous pemphigoid

We describe a 64-year-old Brazilian man who developed bullous pemphigoid (BP) 12 years after pemphigus foliaceus (PF) was diagnosed. On his first presentation in 1992, histological examination revealed intraepidermal blistering and acantholysis at the granular layer, direct immunofluorescence (DIF) demonstrated intercellular deposits of C3 in the epidermis, and indirect immunofluorescence showed the presence of IgG antibodies against the intercellular spaces. In 2004, laboratory findings revealed a subepidermal blister with neutrophils and eosinophils (by histology), DIF demonstrated deposition of IgG and C3 along the basement membrane zone, salt-split skin showed IgG deposition in the epidermal side of the blister, and immunoblotting showed reactivity against BP180. The occurrence of two autoimmune blistering conditions in the same patient is a rare event, and may suggest an intermolecular epitope-spreading phenomenon.

The role of subclass switching in the pathogenesis of endemic pemphigus foliaceus

Endemic pemphigus foliaceus, like the sporadic form seen in the developed world, is mediated by IgG antibodies to desmoglein-1. We studied an endemic focus in Limao Verde, Brazil, where disease prevalence is 3.4%. We previously detected IgG antibodies to desmoglein-1 in 97% of patients, but also in 55% of normal subjects in the endemic focus, with progressively lower levels in normal subjects in surrounding areas. An environmental trigger is hypothesized to explain these and other findings. In this study we sought to determine if patients and enzyme-linked-immunosorbent-assay-positive normal subjects in Limao Verde differ in IgG subclass response to desmoglein-1. We developed a sensitive and specific subclass enzyme-linked immunosorbent assay using recombinant desmoglein-1 and standardized the assay to enable comparability between the four subclasses. We found that normal subjects have an IgG1 and IgG4 response, whereas patients have similar levels of IgG1 but a mean 19.3-fold higher IgG4 response. Patients in remission have a weak IgG4 response, and a 74.3-fold higher IgG4 response is associated with active disease. Finally, in five patients in whom we had blood samples from both before and after the onset of clinical disease, a mean 103.08-fold rise in IgG4 was associated with onset of clinical disease, but only a mean 3.45-fold rise in IgG1. These results suggest that the early antibody response in normal subjects living in the endemic area and in patients before the onset of clinical disease is mainly IgG1. Acquisition of an IgG4 response is a key step in the development of clinical disease.

The prevalence of antibodies against desmoglein 1 in endemic pemphigus foliaceus in Brazil. Cooperative Group on Fogo Selvagem Research

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 Limão 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 Limão Verde or elsewhere in Brazil, 372 normal subjects (without pemphigus foliaceus) from Limão 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 percent). Antibodies were also detected in 51 of the 93 normal subjects from Limão Verde (55 percent) and in 54 of the 279 normal subjects from surrounding areas (19 percent). Serum samples obtained one to four years before the onset of disease were available for five patients; all five had antibodies in the initial serum samples, and the onset of disease was associated with a marked increase in antibody values.

CONCLUSIONS

The prevalence of antibodies against desmoglein 1 is high among normal subjects living in an area among where fogo selvagem is endemic, and the onset of the disease is preceded by a sustained antibody response. These findings support the concept that the production of antibodies against desmoglein 1 is initiated by exposure to an unknown environmental agent.

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.

Comparison of black fly species (Diptera: Simuliidae) on an Amerindian reservation with a high prevalence of fogo selvagem to neighboring disease-free sites in the State of Mato Grosso do Sul, Brazil. The Cooperative Group on Fogo Selvagem Research

Fogo selvagem is an autoimmune blistering skin disease that principally occurs among rural Brazilians living in geographically clumped disease foci. Exposure to hematophagous black flies possibly is related to the cause of the disease. We compared the occurrence, proportions, and richness of simuliid species immatures and the biting activity of adult females within a recently discovered, high prevalence focus of fogo selvagem, the Limão Verde Terena Reservation, to that of neighboring regions with no reported cases of fogo selvagem. Nine black fly species were collected from 12 stream sites during 5 trips to the fogo selvagem focus. The species showed longitudinal (upstream-downstream) trends in occurrence, proportions, and richness, and the abundance of simuliid immatures was greater at downstream sites. The most prevalent species at the focus, Simulium nigrimanum (Macquart), dominated the stream sites with highly abundant simuliid assemblages, and was the most common black fly in human bait collections. This species was absent or in very low numbers in neighboring valleys and villages that did not have cases of fogo selvagem.

Mucosal and mucocutaneous (generalized) pemphigus vulgaris show distinct autoantibody profiles

Pemphigus vulgaris is an autoimmune bullous disorder characterized by autoantibodies directed against desmoglein 3. A group of 19 pemphigus vulgaris sera were characterized by immunoblotting, immunofluorescence, immunoprecipitation, and the passive transfer mouse model. The aim of these studies was to determine the specificity of the autoantibody response in these patients. All patients had clinical and histologic evidence of pemphigus vulgaris. Fogo selvagem sera (n = 8), bullous pemphigoid sera (n = 8), antinuclear antibodies positive sera from patients with lupus erythematosus (n = 2), and normal human sera (n = 8) were used as controls. All pemphigus vulgaris patients showed titers of IgG autoantibodies by indirect immunofluorescence > or = 1:60, predominantly of the IgG4 subclass and immunoprecipitated recombinant desmoglein 3 expressed in the baculovirus system. Patients with disease localized to the mucous membranes showed no reactivity with desmoglein 1 and only one had weak reactivity with mouse skin by indirect immunofluorescence (titer = 1:20). Sera of four of these mucosal patients were tested in the mouse model and three of four did not elicit skin or mucosal disease in the animals. In contrast, sera from all seven patients with disease involving the skin and mucous membranes (generalized disease) produced disease in neonatal mice. In one patient the disease evolved from pure mucosal involvement associated with anti-desmoglein 3 antibodies to a disorder involving mucosas and skin. This transition was associated with the appearance of anti-desmoglein 1 antibodies in the patient's serum. These studies indicate that the autoantibody response in pemphigus vulgaris is heterogeneous. Epitopes recognized by some pemphigus vulgaris sera are species specific and others may be mucosal specific.

An epitope in the third hypervariable region of the DRB1 gene is involved in the susceptibility to endemic pemphigus foliaceus (fogo selvagem) in three different Brazilian populations

Endemic pemphigus foliaceus or fogo selvagem (FS) in an organ-specific autoimmune skin disease characterized by epidermal vesicles and mediated by autoantibodies. Family cases are frequent and not everyone living in endemic region develops FS suggesting that host factors play a role in determining whether exposed individuals will be affected. Because our previous works with Brazilian Mestizos and with Xavante Indians have shown that particular HLA alleles confer increased risk for the disease, we decided to extend these studies to another homogeneous population, the Terena Indians. 19 out of 20 Terena patients were either positive for DRB1*0404, 1402 or 1406 (p < 0.005, RR = 14). These findings were in agreement with the data obtained from the Xavante study. In Mestizos the association was with DRB1*01. All these alleles involved in predisposition to the disease in different populations shared the same amino acid sequence at position 67-74 on the third hypervariable region of the DRB1 gene: LLEQRRAA, suggesting that inheritance of this sequence is involved in the susceptibility to FS. When patients and controls data from different studies were pooled and analyzed disregarding the ethnic background and the HLA alleles involved, the results obtained clearly supported the hypothesis that matching for this epitope is highly significant and predictive of FS predisposition (p < 0.00001, RR = 6.4).

An active focus of high prevalence of fogo selvagem on an Amerindian reservation in Brazil. Cooperative Group on Fogo Selvagem Research

Fogo Selvagem (FS) is an autoimmune disease characterized by subcorneal vesicles and antidesmoglein-1 autoantibodies. Previous epidemiologic data have linked the onset of FS to exposure to an environmental antigen(s). This investigation describes a unique human settlement with an extraordinarily high prevalence of FS. This community is made up of Amerindians belonging to the Terena tribe, which has settled on the Limao Verde reservation in the state of Mato Grosso do Sul in Brazil. Twenty-six well-characterized FS cases have been identified within a total population of 998, yielding a prevalence of 2.6%. Seventeen of the patients (65 %) were males, and over 50% were older than 30 y of age. The incidence of the disease shows temporal periodicity, i.e., years with several cases of FS alternating with years with no cases. Over one-half of the cases occurred in genetically related family members. Another Terena reservation, the Ipegue/Taunay, located 90 km west of the Limao Verde reservation, was also evaluated as a control group. This reservation, with a population of 2203, had no recorded cases of FS. Thus, the Limao Verde reservation represents a new focus of FS in which the disease exhibits temporal, geographic, and familial clustering. These results suggest that the environmental antigen or antigens precipitating FS are endemic to the Limao Verde reservation. This reservation appears to be an ideal population for carrying out sero-epidemiologic, genetic, and environmental studies aimed at disclosing the etiology of FS.

Pemphigus herpetiformis is a rare clinical expression of nonendemic pemphigus foliaceus, fogo selvagem, and pemphigus vulgaris. Cooperative Group on Fogo Selvagem Research

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.

Erythroderma: analysis of 247 cases

The profile of 247 patients with erythroderma during a 23 year period from January, 1962 through March, 1985, with a follow-up period ranging from 1 to 26 years were analysed. The patients presented with diffuse erythema, scaling and pruritus of more than 2 months' duration, and the age ranged from 16 to 60 years. Psoriasis was the most frequent underlying disease with an estimated frequency of 44.9%, the reaction to the use of drugs appeared in 7.3% of total cases and association with reticulosis showed a frequency of 4.1%. The cause of the erythroderma could not be determined in 29.2% of the cases. Six differences in terms of underlying diseases were not observed. One or more skin biopsies along with clinical findings were diagnostic or suggestive of the underlying disease in 63.6% of the cases. Repeated skin biopsies are recommended as the best method for etiologic diagnosis of erythroderma. At P = 0.05 significance level, masculine/feminine ratio of 2:1 was found. The question arises whether causal agent of erythroderma may not be somehow related to different exposure by sex to environmental antigens.

Correlation of peptide specificity and IgG subclass with pathogenic and nonpathogenic autoantibodies in pemphigus vulgaris: a model for autoimmunity

Pemphigus vulgaris (PV) is a rare, potentially fatal, autoimmune disease that affects the skin and mucous membranes. The PV antigen (PVA) has been characterized as desmoglein 3. PV patients carry HLA-DR4- or HLA-DR6-bearing extended haplotypes. We recently demonstrated that patients with active disease have high titers of PV autoantibodies of the IgG1 and IgG4 subclasses. Patients in remission, healthy unaffected relatives, and some MHC-matched normal individuals have low levels of PV autoantibodies, which are IgG1 only. Furthermore, intraperitoneal injection of IgG from patients with active disease caused clinical disease in mice, but IgG from patients in remission, healthy relatives, or MHC-matched normal individuals did not. We prepared 12 peptides of 30 amino acids each (peptides Bos 1-12) spanning the extracellular domain of PVA. Patients with active disease recognize peptides Bos 1 and Bos 6 with high titers of IgG1 and IgG4 autoantibodies. Patients in remission have IgG1 autoantibodies to peptide Bos 1 only, in statistically significantly lower titers (P < 0.01). They no longer have IgG4 subclass autoantibodies to peptide Bos 6. Healthy relatives and normal unrelated individuals have low levels of only IgG1 autoantibodies that recognize only Bos 1. In vitro studies indicate that Bos 6-specific IgG and, to a lesser extent, Bos 1-specific IgG can cause acantholysis. Our data suggest that Bos 6-specific IgG4 is probably the main acantholytic autoantibody, while Bos 1-specific IgG4 may act as a facilitator or enhancer of the process. In this study we illustrate some of the paradigms that demonstrate the interactions between the MHC, subclass of autoantibodies, and peptide specificities of the autoantibodies in the autoimmune process. Thus, PV provides an important model to study the pathogenesis of autoimmunity.

Pemphigus foliaceus autoantibodies bind both epidermis and squamous mucosal epithelium, but tissue injury is detected only in the epidermis. The Cooperative Group on Fogo Selvagem Research

BACKGROUND

Fogo selvagem (FS) is an autoimmune intraepidermal blistering disease mediated by antidesmosomal autoantibodies. Patients with FS do not have mucosal lesions despite extensive skin involvement.

OBJECTIVE

Our purpose was to evaluate the epidermis and the oral epithelium of patients with FS as targets of antidesmosomal autoantibodies.

METHODS

Fifteen patients were studied clinically, histologically, and immunologically. Biopsy specimens from the skin and the oral mucosa were studied by light microscopy and direct immunofluorescence. The serum of each of these patients was also titrated by indirect immunofluorescence.

RESULTS

All patients showed skin lesions and subcorneal acantholyis, but none exhibited oral blisters or erosions. Direct immunofluorescence analysis demonstrated the presence of tissue-bound autoantibodies in both the epidermis and the oral epithelium of all patients with FS. Antiepidermal autoantibodies were also found in the sera of the patients.

CONCLUSION

Relevant epitopes on desmoglein 1 molecules of oral epithelium may not be available to react with pathogenic FS autoantibodies.

Brazilian pemphigus foliaceus, endemic pemphigus foliaceus, or fogo selvagem (wild fire)

Brazilian pemphigus foliaceus, also known as fogo selvagem, is the endemic form of pemphigus foliaceus occurring in certain regions of Brazil. Epidemiologic data strongly support the notion that this disease is caused by exposure to an environmental agent or agents. This form of pemphigus foliaceus is a true human autoimmune disease mediated by autoantibodies of the IgG class, IgG4 subclass. These autoantibodies are pathogenic and highly specific for the disease. The environment agent may sensitize the patient to produce autoantibodies. These autoantibodies may cross-react with the epidermis and induce disease in the patient.

[Tinea favosa. Report of a familial occurrence in Itapecerica da Serra (municipality of Greater São Paulo)]

Four cases of Tinea favosa occurred in the same family are reported in a small city of Brazil (Itapecerica da Serra--State of São Paulo). Trichophyton schoenleinii was isolated from all four cases. Treatment consisted of oral griseofulvin (10 mg/kg/day) for at least three months.