Development of a disease registry for autoimmune bullous diseases: initial analysis of the pemphigus vulgaris subset

Human dental mesenchymal stem cells restorate immune response in sera of pemphigus vulgaris patients

Pemphigus is an IgG-mediated autoimmune condition characterized by autoantibodies targeting desmogleins, leading to acantholysis. Current treatments, including systemic corticosteroids and immunosuppressive drugs, are associated with significant adverse effects. Mesenchymal stem cells (MSCs) offer a promising alternative due to their immunomodulatory properties and low immunogenicity. This study evaluates the immunomodulatory effects of dental follicle mesenchymal stem cells (DF-MSCs) obtained from healthy donors on Pemphigus vulgaris (PV) patients and healthy controls by examining T-cell proliferation, apoptosis, cytokine levels, and anti-desmoglein 1/3 IgG profiles. Peripheral blood mononuclear cells (PBMCs) were isolated from twenty-one symptomatic PV patients and eleven healthy volunteers. DF-MSCs were characterized and differentiated into osteocytes, adipocytes, and chondrocytes. Peripheral blood mononuclear cells (PBMCs) were co-cultured with DF-MSCs, and various assays were conducted to evaluate T-cell proliferation, apoptosis, regulatory T cells, cytokine expression, and autoantibody levels. Results showed that DF-MSC co-cultures significantly reduced lymphocyte proliferation (43.58-16.27%), IL-4 (38.06 ng/L to 32.26 ng/L), TNF-α (32.45 ng/L to 29.41 ng/L), and DSG1 (3.29 ng/ml to 3.00 ng/ml) and DSG3 (262.40 ng/ml to 245.08 ng/ml) levels in PV patients. An increase in regulatory T cells (1.22-3.75%), IL-10 (47.46 pg/ml to 54.94 pg/ml), and IFN-γ (12.39 ng/ml to 19.70 ng/ml) was also observed. No significant changes were noted in healthy controls. These findings suggest that DF-MSCs could potentially offer a curative approach for treating pemphigus by restoring immune balance. However, further clinical trials are necessary to confirm their efficacy.

Burden of pemphigus vulgaris with a particular focus on women: A review

Pemphigus vulgaris is a chronic autoimmune mucocutaneous blistering disorder. Apart from the disease itself, other aspects of patients' life, including psychological, social, and financial, can be affected. Women are particularly more disposed to the impact of the disease due to their physiological characteristics, the specific periods of pregnancy and lactation as well as their social and familial role. In this review, we summarized the burden of pemphigus vulgaris on various aspects of women's lives. It is essential to understand these problems and provide appropriate support for patients with such a burdensome disease.

Case report: Documentation of cutaneous only pemphigus vulgaris without history of mucosal lesions in North America

Background

Pemphigus is a group of autoimmune blistering diseases including Pemphigus vulgaris (PV) and Pemphigus foliaceus (PF). These conditions exhibit lesions with mucosal or mucocutaneous (PV) or cutaneous (PF) morphology, as framed by the Desmoglein Compensation Hypothesis (DCH). However, some PV patients present with solely cutaneous disease (cPV), and growing evidence suggests the existence of a cPV subtype without any history of mucosal erosions/blisters (cPVwohm), neither of which are predicted by the DCH.

Methods

Participants were recruited from several outpatient clinical settings and patient support group meetings throughout the US. On intake, subjects provided blood samples and completed questionnaires regarding their disease status.

Results

We report three cases of clinically and histologically confirmed cPV without history of mucosal lesions (cPVwohm). Of these patients, two do not carry the most common PV associated HLA alleles, DRB1*0402 or DQB1*0503. The same two patients also tested negative for the primary PV associated autoantibodies, anti-desmoglein 3 and anti-desmoglein 1, while in active disease status.

Conclusion

We confirm the first documented individual cases of cPVwohm in North America, supporting the existence of PV patients that develop cutaneous disease without a history of mucosal lesions, challenging the fidelity of the DCH. Two of the 3 patients reported did not type for the common PV-associated HLA genes or display anti-desmoglein autoantibodies while in active disease, suggesting cPV patients may develop Pemphigus via genetic and immune mechanisms that differ from typical mucosal or mucocutaneous PV.

Disease progression and response to therapy in pemphigus based on a registry

BACKGROUND AND OBJECTIVES

Pemphigus diseases are potentially life-threatening and rare autoimmune bullous disorders characterized by blisters and erosions of the skin and mucous membranes. These disorders can be largely divided into two major subtypes: pemphigus vulgaris (PV) and pemphigus foliaceus (PF). The objective of this study was to evaluate the autoantibody profile and response to therapy of PV and PF patients by analyzing the clinicopathological data from a registry for bullous autoimmune dermatoses.

PATIENTS AND METHODS

In a retrospective study, data from 69 patients with PV and PF were included in the analysis. The Autoimmune Bullous Skin Intensity Score (ABSIS) was used to assess the clinical course, remissions, relapses and severity of the disease at first manifestation and throughout the observation period. ELISA was performed to assess levels of anti-desmoglein (Dsg)-1 and anti-Dsg3 IgG serum autoantibodies.

RESULTS

The mean remission time in PV and PF patients was 63 weeks. PV patients with mucosal involvement showed a more favorable healing process. In PV patients with a moderate/high anti-Dsg1 IgG serum level at baseline, anti-Dsg3 IgG levels decreased during the observation period.

CONCLUSIONS

Our study provides additional insights into the clinical course of patients with PV and PF, revealing that a mucosal phenotype is associated with a higher tendency towards remission.

Register-Studie zu Krankheitsentwicklung und Therapieansprechen bei Pemphigus

HINTERGRUND UND ZIELE

Pemphigus gehört zu den seltenen, aber potentiell lebensbedrohlichen Autoimmunerkrankungen. Typisch sind Blasen und Erosionen der Haut und der Schleimhäute. Grundsätzlich unterscheiden wir zwei Subtypen: Pemphigus vulgaris (PV) und Pemphigus foliaceus (PF). In dieser Studie wurden die klinisch-pathologischen Daten aus einem Register für bullöse Autoimmundermatosen analysiert mit dem Ziel, das Autoantikörperprofil und das Therapieansprechen bei Patienten mit PV und PF genauer zu charakterisieren.

PATIENTEN UND METHODEN

In einer retrospektiven Studie wurden die Daten von 69 Patienten mit PV und PF analysiert. Zur Beurteilung des klinischen Verlaufs, der Remissionen und Rezidive sowie des Schweregrads der Krankheit bei Erstmanifestation und während des gesamten Beobachtungszeitraums diente der ABSIS (Autoimmune Bullous Skin Intensity Score) (ABSIS). Mittels ELISA wurden die Spiegel von Anti-Desmoglein (Dsg)-1- und Anti-Dsg- IgG-Autoantikörpern im Serum bestimmt.

ERGEBNISSE

Die mittlere Remissionszeit bei Patienten mit PV und PF betrug 63 Wochen. PV-Patienten mit Schleimhautbeteiligung zeigten eine schnellere Heilung. Bei PV-Patienten mit moderat oder stark erhöhten Anti-Dsg1-IgG-Autoantikörpern im Serum zu Beginn erfolgte im Lauf des Beobachtungszeitraums ein Absinken der Anti-Dsg3-IgG-Spiegel.

SCHLUSSFOLGERUNGEN

Unsere Studie liefert neue Erkenntnisse zum Krankheitsverlauf bei Patienten mit PV und PF und offenbart, dass ein Phänotyp mit Schleimhautbeteiligung eine stärkere Neigung zur Remission aufweist.

Komorbidität bei Pemphigus: eine Fall-Kontroll-Studie

HINTERGRUND UND ZIELE

Pemphigus ist mit physischen und psychischen Erkrankungen assoziiert. Diese Studie soll derartige Zusammenhänge bei Patienten mit Pemphigus näher untersuchen sowie die Komorbidität nach Geschlecht, Alter, dem Pemphigus Disease Area Index, der Diagnoseverzögerung und der Beteiligung von Haut/Schleimhaut analysieren.

PATIENTEN UND METHODEN

Jedem Pemphigus-Patienten wurden acht Kontrollen mit ähnlichem Alter, Geschlecht und Wohnsitz zugeordnet. Die Wahrscheinlichkeit für Begleiterkrankungen bei Patienten und Kontrollpersonen wurde anhand univariater konditionaler Regressionsmodelle bestimmt. Begleiterkrankungen, die in den univariaten Modellen mit P < 0,05 mit der Diagnose Pemphigus assoziiert waren, wurden dann in einem Vorwärtsverfahren in ein multivariates konditionales Regressionsmodell eingefügt.

ERGEBNISSE

Die Studie umfasste 163 Patienten mit Pemphigus. Die hauptsächlichen Erkrankungen zum Diagnosezeitpunkt waren kardiovaskuläre Erkrankungen, Hyperlipidämie, Autoimmunerkrankungen der Schilddrüse, autoimmune/entzündliche Dermatosen und Krebs. In der multivariaten konditionalen Regressionsanalyse waren Krebs und autoimmune/entzündliche Dermatosen unabhängig mit Pemphigus assoziiert. In Sensitivitätsanalysen, in denen vier Patienten mit paraneoplastischem Pemphigus ausgeschlossen wurden, waren diese Assoziationen ebenfalls signifikant.

SCHLUSSFOLGERUNGEN

Krebs und autoimmune/entzündliche Dermatosen sind möglicherweise auslösende Faktoren für Pemphigus dar und sollten als frühe Warnsignale für diese Erkrankung angesehen werden.

Comorbid diseases associated with pemphigus: a case-control study

BACKGROUND AND OBJECTIVES

Pemphigus has been associated with physical and psychiatric comorbid diseases. This study aims to further investigate these associations in patients with pemphigus, and to analyze the relationships of comorbid conditions with sex and age, pemphigus disease area index score, diagnostic delay and cutaneous/mucous involvement.

PATIENTS AND METHODS

Patients with pemphigus were matched by age, gender and area of residence with eight controls each. The odds of comorbid conditions in patients vs. matched controls was determined using univariate conditional logistic regression models. Comorbid diseases significantly associated with the diagnosis of pemphigus at P < 0.05 in univariate models were subsequently included in a multivariable conditional logistic regression model with a forward procedure.

RESULTS

The study sample included 163 patients with pemphigus. Cardiovascular diseases, hyperlipidemia, autoimmune thyroid disorders, dermatological autoimmune/inflammatory conditions and cancer were the most prominent conditions at the time of diagnosis. In the multiple conditional regression analysis, the two diagnoses independently associated with patients with pemphigus were cancer and dermatological autoimmune/inflammatory conditions. In sensitivity analyses excluding four patients with paraneoplastic pemphigus, these associations were still significant.

CONCLUSIONS

Cancer and dermatological autoimmune/inflammatory conditions may represent possible triggering conditions for pemphigus and should be considered as early warning signs for the disease.

Gene Expression Analysis in Four Dogs With Canine Pemphigus Clinical Subtypes Reveals B Cell Signatures and Immune Activation Pathways Similar to Human Disease

Pemphigus is a group of autoimmune-mediated mucocutaneous blistering diseases characterized by acantholysis. Pemphigus has also been recognized in dogs and shares similar clinical characteristics and variants with human pemphigus. While relationships between human and canine pemphigus have been reported, gene expression patterns across species have not been described in the literature. We sought to perform gene expression analysis of lesional skin tissue from four dogs with various forms of pemphigus to examine gene expression during spontaneous disease in dogs. We found increased T and B cell signatures in canine pemphigus lesions compared to controls, as well as significant upregulation of CCL3, CCL4, CXCL10, and CXCL8 (IL8), among other genes. Similar chemokine/cytokine expression patterns and immune infiltrates have been reported in humans, suggesting that these genes play a role in spontaneous disease. Direct comparison of our dataset to previously published human pemphigus datasets revealed five conserved differentially expressed genes: CD19, WIF1, CXCL10, CD86, and S100A12. Our data expands our understanding of pemphigus and facilitates identification of biomarkers for prediction of disease prognosis and treatment response, which may be useful for future veterinary and human clinical trials.

The epidemiology of autoimmune bullous diseases in Sudan between 2000 and 2016

Objectives

Autoimmune bullous diseases vary in their clinico-epidemiological features and burden across populations. Data about these diseases was lacking in Sudan. We aimed to describe the epidemiological profile and to estimate the burden of autoimmune bullous diseases in Sudan.

Methods

This was a retrospective cross-sectional study conducted at Khartoum Dermatological and Venereal Diseases Teaching Hospital. We used routinely collected health care data, and included all patients with an autoimmune bullous disease who presented to the hospital between 2001 and 2016.

Results

Out of the 4736 patients who were admitted to the hospital during the study period, 923 (19.5%) had an autoimmune bullous disease. The average rate of patients at the hospital was 57.7 per year representing 1.3 per 100,000 population per year. After exclusion of patients where the final diagnosis was missing, 585 were included in the further analysis. Pemphigus vulgaris was the most common disease (50.9%), followed by bullous pemphigoid (28.2%), linear IgA disease/chronic bullous disease of childhood (8.4%), and pemphigus foliaceous (8.2%). Pemphigoid gestationis and IgA pemphigus constituted 1.4% and 1.2% of the cohort, respectively. Paraneoplastic pemphigus, mucous membrane pemphigoid, lichen planus pemphigoidis, bullous systemic lupus erythematosus, and dermatitis herpetiformis were rare. None of the patients had epidermolysis bullosa acquisita.

Conclusions

The clinico-epidemiological characteristics vary among the types of autoimmune bullous diseases. Females were more predominant in most of them. Sudanese patients tended in general to present at a younger age than other populations. The pool of Sudanese patients with autoimmune bullous diseases is large which requires investigation for the local risk factors and presents a field for future trials.

Immune serological diagnosis of pemphigus

Pemphigus is a rare autoimmune blistering disease which manifests with painful erosions and blisters of the skin and mucosa. This disorder is caused by autoantibodies attacking desmosomal proteins, necessary for cell-cell contact stability and epidermal integrity. Desmoglein (Dsg) 1 and Dsg3 are the two major target antigens in pemphigus. Yet, many other target proteins, which have been described over the years, seem to be involved in the loss of epidermal integrity. Clinical examination, combined to serological advances and detection of targeted antigens, permitted to differentiate among several pemphigus subtypes, in which pemphigus vulgaris and pemphigus foliaceus are the most common. Nowadays, serological analysis in pemphigus is a fundamental step of the diagnostic algorithm. This is based on analysis of clinical symptoms, histopathological examination of lesional skin, detection of tissue bound and circulating antibodies by direct and indirect immunofluorescence, and determination of target antigens either by enzyme-linked immunosorbent essay (ELISA) or by western blot analysis. A correct and exhaustive diagnostic algorithm is fundamental to characterize pemphigus subtypes, which lastly permits to adopt a correct treatment approach. Moreover, quality and quantity of circulating antibodies in patient's sera deliver important information regarding clinical course, disease severity and treatment response; thus, relevantly affecting physician's decision. To facilitate this process, "easy-to-perform" diagnostic kits with high sensitivity and specificity are being commercialized. In this review, we focus on available methods and established assays to correctly detect circulating autoantibodies in pemphigus. Moreover, we discuss subtype specific serological peculiarities in the five most relevant subtypes (pemphigus vulgaris, pemphigus foliaceus, pemphigus vegetans, paraneoplastic pemphigus and intercellular IgA dermatosis (also called as IgA pemphigus).

Disease burden of patients with pemphigus from a societal perspective

Introduction: Cost-of-illness studies are widely used for healthcare decision-making; however, no such study is available in pemphigus from the societal perspective. The purpose of this analysis was to estimate annual cost-of-illness per patient with pemphigus from a societal perspective. Areas covered: Between 2014 and 2017, a multicenter, cross-sectional study was carried out. Consecutive pemphigus patients aged ≥18 years were recruited at all four university dermatology departments in Hungary. Direct and indirect costs were calculated, including costs for treatments, outpatient visits, hospital admissions, informal care, travel costs and productivity loss. Generalized linear model was used to analyze predictors of costs. Atotal of 109 patients with pemphigus enrolled with amean age of 57.1 (SD 14.8) years. Total cost per pemphigus patient was €3,995 (SD €7,526) peryear, with productivity loss (58%) and informal care (19%) accounting for the majority. Annual means of 189 and 41 working hours were lost due to absence from work and reduced productivity, respectively. Younger age and pemphigus vulgaris were associated with higher costs (p < 0.05). Expert opinion: This is the first cost-of-illness study applying the societal perspective in pemphigus. Our results indicate a substantial economic burden on society, mainly driven by productivity loss and informal care.

Pemphigus vulgaris - approach and management

The place of pemphigus vulgaris (PV) among autoimmune bullous dermatoses is well known. In pemphigus, IgG autoantibodies are directed against desmogleins 1 and 3, which are part of the cadherin family of cell-cell adhesion molecules. These structures are responsible for maintaining the intercellular adherence in stratified squamous epithelia, such as the skin and oral mucosa. The incidence of autoimmune bullous dermatoses is steadily increasing, being associated with a high degree of morbidity. The pathophysiology of these dermatoses is very well understood, complemented by recent genetic studies. The gold standard for the diagnosis of pemphigus vulgaris is the detection of autoantibodies or complement component 3 by direct immunofluorescence microscopy of a perilesional biopsy. Early diagnosis and initiation of treatment are necessary in order to achieve a favorable prognosis. Although the first line of treatment is corticotherapy, there are no clear guidelines on dosing regimens, and long-term adverse effects are important. Corticosteroid-sparing adjuvant therapies have been employed in the treatment of PV, aiming to reduce the necessary cumulative dose of corticosteroids. In addition, therapies with anti-CD20 antibodies are used, but antigen-specific immune suppression-based treatments represent the future.

The pathogenesis of bullous skin diseases

Bullous skin diseases are a group of dermatoses characterized by blisters and bullae in the skin and mucous membranes. The etiology and pathogenesis of bullous skin diseases are not completely clear. The most common are pemphigus and bullous pemphigoid (BP). Autoantibodies play critical roles in their pathogenesis. Abnormalities in the adhesion between keratinocytes in patients with pemphigus leads to acantholysis and formation of intra-epidermal blisters. Anti-desmoglein autoantibodies are present both in the circulation and skin lesions of patients with pemphigus. The deficient adhesion of keratinocytes to the basement membrane in BP patients gives rise to subepidermal blisters. Autoantibodies against the components of hemidesmosome can be detected in BP patients. Many novel therapeutics based on knowledge of the pathogenesis have emerged in recent years.

Mucocutaneous Diseases

Mucocutaneous diseases affecting the oral cavity are predominantly immune mediated or inflammatory. Three of the most common and clinically significant conditions are reviewed in this article: lichen planus, pemphigus vulgaris, and mucous membrane pemphigoid. Because oral manifestations may be the first or only manifestation of mucocutaneous diseases, oral health professionals play a critical role in the early diagnosis and multidisciplinary management of these conditions.

A Retrospective Study of Patient-Reported Data of Bullous Pemphigoid and Mucous Membrane Pemphigoid From a US-Based Registry

Bullous pemphigoid (BP) and mucous membrane pemphigoid (MMP) are rare chronic autoimmune disorders characterized by subepidermal blistering. For the United States, there is a limited amount of studies in BP and MMP that address disease demographics and clinical data. In order to more comprehensively examine disease demographics and clinical factors, we performed a retrospective analysis of patient-reported data of 138 BP and 165 MMP patients enrolled in the International Pemphigus & Pemphigoid Foundation (IPPF) disease registry from 2010–2016. Patient-reported data was compared to Physician/Investigator reported data generated in our own local patient population (Western New York; 19 BP and 43 MMP patients). We confirm a female predominance in BP (M:F ratio 1:2.1) and MMP (M:F ratio 1:4.3), and a late onset within the 6th decade of life (average age at diagnosis, 59.1 ± 17.5 years for BP and 54.8 ± 11.2 years for MMP). MMP patients were significantly more likely to have a delay in diagnosis >12 months than BP patients (38 vs. 21%, respectively). Similar to other autoimmune conditions, a large number of BP (34%) and MMP (35%) patients present with other co-existing autoimmune disorders, with the most common being thyroid disease for both groups. Increased illness activity was paralleled by an increase in severe limitations of daily activities. The vast majority of of both BP and MMP patients received high intensity immunosuppression (49%). However, the majority of BP patients reported therapy with prednisone combined with other immunosuppressants (40%), while the majority of MMP patients received immunosuppressants other than prednisone (55%). With the exception of age at diagnosis, the clinical and demographic findings from both the national and local datasets were largely consistent with each other, and support those reported in other countries.

Clinical and immunological features of pemphigus relapse

BACKGROUND

More than half of patients with pemphigus experience relapse during the disease course. The risk factors and clinical and immunological characteristics of relapse remain largely unclear.

OBJECTIVES

To elucidate the risk factors and clinical features of pemphigus relapse.

METHODS

We carried out a retrospective review of the clinical records of 42 cases of pemphigus at a single centre.

RESULTS

Sixty-two per cent of patients experienced relapse, usually when oral prednisolone was tapered to around 0·1 mg kg^-1 . In mucocutaneous pemphigus vulgaris (mcPV), the initial doses (mean ± SD) of prednisolone were significantly lower in patients with relapse (0·78 ± 0·24 mg kg^-1 ) than in those without relapse (1·01 ± 0·01 mg kg^-1 ). At relapse, mcPV shifted to mucosal dominant PV (mPV; 40%), pemphigus foliaceus (PF) (20%) or 'other' (20%). In contrast, relapsing mPV and PF had the same clinical phenotypes as the initial phenotypes. Patients with both anti-desmoglein (Dsg)1 and anti-Dsg3 antibodies at onset had recurrence with anti-Dsg3 antibodies alone (40%), with both anti-Dsg1 and anti-Dsg3 antibodies (30%), with anti-Dsg1 antibody alone (20%) or were subthreshold (10%).

CONCLUSIONS

mcPV shows transitions in clinical phenotype and autoantibody profile at relapse. At least 1 mg kg^-1 daily of prednisolone, especially for patients with mcPV, and prudent tapering around 0·1 mg kg^-1 may lead to better outcomes.

The coexistence of pemphigus and psoriasis: a systematic review and meta-analysis

There is little consensus regarding the association between pemphigus and psoriasis. The aim of the current study is to synthesize existing data on the prevalence of psoriasis in patients with pemphigus and on the association between the two conditions. We performed a systematic review and meta-analysis of observational studies in Medline, Embase, and Web of Science (1900-2018). Reference lists of included studies were also searched for eligible studies. Quality of evidence was assessed using Newcastle-Ottawa scale (NOS). A meta-analysis was performed using random-effects models to estimate pooled prevalence rates and odds ratios (ORs) with 95% confidence intervals (CI). Subgroup and sensitivity analyses were also conducted. Twelve eligible studies comprising 12,238 patients with pemphigus were included in the quantitative synthesis. The overall random-effects pooled prevalence of psoriasis among patients with pemphigus was 2.4% (95% CI, 1.0-4.4) across all studies. The overall pooled multivariate OR for psoriasis in patients with pemphigus was significantly increased and estimated at 3.5 (95% CI, 1.6-7.6). In conclusion, a significant association was found between pemphigus and psoriasis. Physicians managing patients with pemphigus may be aware of this comorbidity. Further studies are warranted to establish the precise mechanisms underlying this relationship.

Anti-Thyroid Peroxidase Reactivity Is Heightened in Pemphigus Vulgaris and Is Driven by Human Leukocyte Antigen Status and the Absence of Desmoglein Reactivity

Pemphigus vulgaris (PV) belongs to an autoimmune disease cluster that includes autoimmune thyroid disease (AITD), suggesting common mechanisms driving autoimmune susceptibility. Our group has shown that PV patients exhibit significant reactivity to AITD-related anti-thyroid peroxidase (anti-TPO), and anti-TPO antibodies affect signaling pathways in keratinocytes similar to anti-desmoglein (Dsg) 3 antibodies. To further assess the relevance of anti-TPO reactivity in PV, we analyzed anti-TPO levels in 280 PV and 167 healthy control serum samples across a comprehensive set of variable and static parameters of disease activity and etiopathogenesis. PV patients have significantly higher activity rates (A.R.s) for anti-TPO than healthy controls, but levels do not differ between phases of clinical activity and remission. Patients that carry both the PV-associated human leukocyte antigen (HLA) alleles DRB1*0402 and DQB1*0503, or DQB1*0503 alone show a low prevalence of anti-TPO (A.R. 9.5 and 4.8%, respectively), while patients that lack expression of these alleles or carry DRB1*0402 alone have a much higher prevalence of anti-TPO (A.R. 23.1 and 15.8%, respectively), suggesting that the absence of DQB1*0503 may predispose patients to the development of anti-TPO antibodies. Similarly, anti-Dsg1⁻/3⁻ patients have a higher anti-TPO A.R. (26.9%) than anti-Dsg1⁻/3⁺ (18.8%), anti-Dsg1⁺/3⁻ (14.3%), and anti-Dsg1⁺/3⁺ (3.9%) patients. Our data suggest that anti-TPO reactivity in PV is driven by genetic markers that may be in linkage disequilibrium with the established PV-susceptibility alleles and that this association drives the selection of a combination of anti-Dsg and anti-TPO antibodies, with anti-TPO filling the gap in active patients that do not carry the established PV-associated autoantibodies and/or are lacking the established PV-HLA-susceptibility alleles.

Pemphigus

Pemphigus is a group of IgG-mediated autoimmune diseases of stratified squamous epithelia, such as the skin and oral mucosa, in which acantholysis (the loss of cell adhesion) causes blisters and erosions. Pemphigus has three major subtypes: pemphigus vulgaris, pemphigus foliaceus and paraneoplastic pemphigus. IgG autoantibodies are characteristically raised against desmoglein 1 and desmoglein 3, which are cell-cell adhesion molecules found in desmosomes. The sites of blister formation can be physiologically explained by the anti-desmoglein autoantibody profile and tissue-specific expression pattern of desmoglein isoforms. The pathophysiological roles of T cells and B cells have been characterized in mouse models of pemphigus and patients, revealing insights into the mechanisms of autoimmunity. Diagnosis is based on clinical manifestations and confirmed with histological and immunochemical testing. The current first-line treatment is systemic corticosteroids and adjuvant therapies, including immunosuppressive agents, intravenous immunoglobulin and plasmapheresis. Rituximab, a monoclonal antibody against CD20⁺ B cells, is a promising therapeutic option that may soon become first-line therapy. Pemphigus is one of the best-characterized human autoimmune diseases and provides an ideal paradigm for both basic and clinical research, especially towards the development of antigen-specific immune suppression treatments for autoimmune diseases.

Recruiting for health, medical or psychosocial research using Facebook: Systematic review

Recruiting participants is a challenge for many health, medical and psychosocial research projects. One tool more frequently being used to improve recruitment is the social networking website Facebook. A systematic review was conducted to identify studies that have used Facebook to recruit participants of all ages, to any psychosocial, health or medical research. 110 unique studies that used Facebook as a recruitment source were included in the review. The majority of studies used a cross-sectional design (80%) and addressed a physical health or disease issue (57%). Half (49%) of the included studies reported specific details of the Facebook recruitment process. Researchers paid between $1.36 and $110 per completing participants (Mean = $17.48, SD = $23.06). Among studies that examined the representativeness of their sample, the majority concluded (86%) their Facebook-recruited samples were similarly representative of samples recruited via traditional methods. These results indicate that Facebook is an effective and cost-efficient recruitment method. Researchers should consider their target group, advertisement wording, offering incentives and no-cost methods of recruitment when considering Facebook as a recruitment source. It is hoped this review will assist researchers to make decisions regarding the use of Facebook as a recruitment tool in future research.

Identification of a new disease cluster of pemphigus vulgaris with autoimmune thyroid disease, rheumatoid arthritis and type I diabetes

BACKGROUND

Pemphigus vulgaris (PV) is a potentially fatal autoimmune blistering skin disease. It is known that individuals with autoimmune diseases such as PV, as well as their family members, are at increased risk of developing other autoimmune diseases. However, it is unknown whether there are specific autoimmune diseases that cluster with PV.

OBJECTIVES

To investigate the frequency of coexisting autoimmune diseases in patients with PV and their relatives, to determine the prevalence of specific autoimmune diseases in patients with PV vs. the general population and to identify statistically significant clinical clusters linking PV with other autoimmune disorders.

METHODS

We performed a cross-sectional study and meta-analysis of patient data from our own patient database (n = 230), an anonymous online survey conducted by our laboratory (n = 171) and the International Pemphigus & Pemphigoid Foundation registry (n = 393).

RESULTS

We found that the prevalences of autoimmune thyroid disease (AITD), rheumatoid arthritis and type 1 diabetes were significantly increased in patients with PV compared with the general population. These diseases were also among the most frequent in family members of patients with PV, in addition to systemic lupus erythematosus (SLE). Descriptive cluster analysis using basic principle components methods revealed that PV forms a distinct cluster with AITD, rheumatoid arthritis and type 1 diabetes, and another cluster with SLE, AITD and rheumatoid arthritis.

CONCLUSIONS

PV belongs to an established autoimmune disease cluster that includes AITD, rheumatoid arthritis and type 1 diabetes. Our data suggest the possibility of common genetic elements across clinically distinct diseases that might underlie autoimmune susceptibility.