Pemphigus group (vulgaris, vegetans, foliaceus, herpetiformis, brasiliensis)

Mechanisms of Resistance to Rituximab Used for the Treatment of Autoimmune Blistering Diseases

Autoimmune blistering diseases represent a group of chronic severe, disabling, and potentially fatal disorders of the skin and/or mucous membranes, primarily mediated by pathogenic auto-antibodies. Despite their rarity, these diseases are associated with significant morbidity and mortality and profound negative impact on the patient's quality of life and impose a considerable economic burden. Rituximab, an anti-CD-20 monoclonal antibody, represents the first line of therapy for pemphigus, regardless of severity and a valuable off-label therapeutic alternative for subepidermal autoimmune blistering diseases as it ensures high rates of rapid, long-lasting complete remission. Nevertheless, disease recurrence is the rule, all patients requiring maintenance therapy with rituximab eventually. While innate resistance to rituximab in pemphigus patients is exceptional, acquired resistance is frequent and may develop even in patients with initial complete response to rituximab, representing a real challenge for physicians. We discuss the various resistance mechanisms and their complex interplay, as well as the numerous therapeutic alternatives that may be used to circumvent rituximab resistance. As no therapeutic measure is universally efficient, individualization of rituximab treatment regimen and tailored adjuvant therapies in refractory autoimmune blistering diseases are mandatory.

A Case of an Autoimmune Blistering Disease: Pemphigus Vulgaris

Pemphigus vulgaris is a rare autoimmune disorder characterized by the formation of intraepithelial blisters that clinically appear as erosions and flaccid bullae on the skin and mucus membranes. Herein, we report a case of pemphigus vulgaris in an elderly male. He was initially misdiagnosed by his primary care provider and given topical lidocaine and acetaminophen with hydrocodone, without improvement in symptoms. This delay in treatment caused a worsening of his condition. The patient presented to our dermatology office two months after his primary care visit and reported worsening blisters and pain. Clinically he presented with flaccid bullae, crusted erosions, and erythematous plaques on the chest, back, abdomen, arms, and legs, and a tender oral ulcer. Two punch biopsies were obtained and sent for direct immunofluorescence and routine histology. The biopsy results confirmed the diagnosis of pemphigus vulgaris. Our patient achieved clearance after four weeks of oral prednisone and maintained clearance after a slow prednisone taper and the addition of mycophenolate mofetil 1g twice daily. We aim to bring awareness of the clinical presentation and treatment regimen of pemphigus vulgaris to prevent misdiagnosis and delayed care.

Focus on pemphigus treatment publications: A bibliometric and visual analysis (1992-2022)

Pemphigus is a chronic recurrent disease in dermatology. Although it is not very common, its treatment has been an increasing concern in recent years because it is difficult and long-lasting. At present, there are many papers on pemphigus treatment, and to better understand the research trends and research frontiers of pemphigus treatment, it is necessary to conduct a comprehensive systematic review and analysis. We combined bibliometric and visualization methods to analyze 1365 papers published in the Web of Science database from 1992 to 2022, including basic information about countries, institutions and authors, to gain a general understanding of the treatment of pemphigus. Among them, the United States is the country with the most output, Iran's Tehran University of Medical Sciences is the institution with the most published works, and Ahmed, A. Razzaque of Tufts University is the most influential scholar. In addition, we also learned about the research hotspots and frontiers of pemphigus treatment through a series of analyses on the frequency, clustering, keywords bursts and cited literature, and we briefly reviewed the highly cited literature. We found that the current research focuses in the study of pemphigus treatment are the types, pathogenesis, and treatment of pemphigus, including glucocorticoids, immunosuppressants and many other major treatment methods. Hailey-Hailey disease, genetic susceptibility, and traditional Chinese medicine are potential research hotspots. Rituximab is a research frontier. In conclusion, we hope to provide new research ideas for promoting the development of pemphigus treatment.

Single-Cell Transcriptomes and Immune Repertoires Reveal the Cell State and Molecular Changes in Pemphigus Vulgaris

The etiology and pathogenesis of pemphigus vulgaris (PV) entail intricate interactions between immune cells and epithelial cells. However, the specific subtypes of immune cells involved in PV, along with their respective roles, remain elusive. Likewise, the precise functions and mechanisms by which glucocorticoids affect cell types within the disease context require further elucidation. To address these knowledge gaps, we performed 5' single-cell RNA sequencing, combined with V(D)J enrichment on buccal mucosal lesions and peripheral blood samples from treatment-naive patients with PV, in conjunction with post-treatment peripheral blood samples obtained after oral prednisone treatment. Our findings suggest that the IL-1α signaling pathway, myeloid APCs, inflammatory CD8+ resident memory T cells, and dysfunctional CD4+ regulatory T cells are involved in the pathogenesis of PV. Part of these findings were validated by immunohistochemical assays and multiplex immunofluorescence assays. Furthermore, our results highlight the significant impact of prednisone treatment on monocytes and mucosal-associated invariant T cells while revealing a limited effect on CD4+ regulatory T cells. Additionally, we present the CDR3 amino acid sequence of BCR related to PV disease and investigate the characteristics of TCR/BCR clonotypes. In conclusion, our study provides a comprehensive understanding of PV, particularly focusing on the mucosal-dominant type, and sheds light on the effects of glucocorticoids within the PV context. These insights hold promise for the development of new therapeutic strategies in this autoimmune disorder.

A Global View of Pemphigus: Geographical Variations

Pemphigus, an autoimmune intraepidermal bullous disease group with roughly eight distinct forms, includes pemphigus vulgaris (PV) and pemphigus foliaceus (PF) as its predominant global forms. Despite the increased utilization of global health records and reporting systems, epidemiological data remain limited and poorly categorized. Therefore, this study aimed to conduct a review to track, identify, and characterize cases of PV and PF published and categorized worldwide. A research question was formulated; studies were selected based on the inclusion criteria; and data from these publications were systematically collected, summarized, and presented using narrative descriptions. The search strategy yielded 3,212 articles, of which 95 underwent critical analysis and data extraction. Studies from 52 countries contributed to the dataset, covering various pemphigus variants. Notably, only two countries, Iran (18.87%) and South Korea (11.43%), accounted for approximately a third of the reported PV cases, while Brazil contributed 40.25% of the foliaceus variants cases documented in the literature. These findings offer valuable insights into the global distribution of pemphigus and inform future research and healthcare efforts.

Oral Pemphigus Vulgaris: A Case Report With Review of Literature

Pemphigus vulgaris (PV) is a chronic autoimmune bullous disease that is characterized by mucocutaneous blister formation resulting in painful erosions. The autoantibody immunoglobulin (Ig) G directed toward glycoproteins desmoglein (Dsg) 3 and desmoglein 1 is the main underlying mechanism behind PV leading to intraepithelial clefting and bulla formation. Patients usually present with oral ulcers causing severe pain and dysphagia that can be misdiagnosed as erythema multiforme (EM) or viral infections. The diagnostic process requires the correlation between clinical, histopathological, and immunopathological findings. Systemic and/or local corticosteroids are considered the cornerstone therapy of PV cases. This article describes a case of a 42-year-old male patient who presented in the Department of Oral Medicine and Radiology with chronic oral ulcers that were diagnosed with PV and treated using systemic corticosteroids.

Immune cells in pemphigus vulgaris and bullous Pemphigoid: From pathogenic roles to targeting therapies

Pemphigus vulgaris (PV) and bullous pemphigoid (BP) are two major subtypes of autoimmune bullous diseases (AIBD), characterized by blisters and erosions of skin and/or mucous membranes with dysregulated immune activity. Current literature established that T and B cells are the main executors of PV and BP. Emerging evidence revealed that macrophages and related cytokines also contribute to these diseases. While the role of lymphocytes on PV and BP is well established, the definitive functions of macrophages in disease progression are not fully understood. Furthermore, current status of clinical trials targeting immune cells is poorly recapitulated in PV and BP. In this review, we summarized current knowledge in this rapidly advancing field, with emphasis on the individual functions of immune cells and their interactions, as well as ongoing clinical trials targeting immune cells, to provide novel insights in mechanistic understanding and clinical management of PV and BP.

The landscape of the immunoglobulin repertoire in endemic pemphigus foliaceus

Introduction

Primarily driven by autoreactive B cells, pemphigus foliaceus (PF) is an uncommon autoimmune blistering skin disease of sporadic occurrence worldwide. However, PF reaches a prevalence of 3% in the endemic areas of Brazil, the highest ever registered for any autoimmune disease, which indicates environmental factors influencing the immune response in susceptible individuals. We aimed to provide insights into the immune repertoire of patients with PF living in the endemic region of the disease, compared to healthy individuals from the endemic region and a non-endemic area.

Methods

We characterized the B-cell repertoire in i) nontreated patients (n=5); ii) patients under immunosuppressive treatment (n=5); iii) patients in remission without treatment (n=6); and two control groups iv) from the endemic (n=6) and v) non-endemic areas in Brazil (n=4). We used total RNA extracted from peripheral blood mononuclear cells and performed a comprehensive characterization of the variable region of immunoglobulin heavy chain (IGH) in IgG and IgM using next-generation sequencing.

Results

Compared to individuals from a different area, we observed remarkably lower clonotype diversity in the B-cell immune repertoire of patients and controls from the endemic area (p < 0.02), suggesting that the immune repertoire in the endemic area is under geographically specific and intense environmental pressure. Moreover, we observed longer CDR3 sequences in patients, and we identified differential disease-specific usage of IGHV segments, including increased IGHV3-30 and decreased IGHV3-23 in patients with active disease (p < 0.04). Finally, our robust network analysis discovered clusters of CDR3 sequences uniquely observed in patients with PF.

Discussion

Our results indicate that environmental factors, in addition to disease state, impact the characteristics of the repertoire. Our findings can be applied to further investigation of the environmental factors that trigger pemphigus and expand the knowledge for identifying new targeted and more effective therapies.

Severe Pemphigus Vulgaris Resistant to Conventional Therapies and with Hypersensitivity to Rituximab in a 12-Year-Old Child

Pemphigus vulgaris (PV) is a rare, potentially lethal blistering disease typically occurring in adulthood and characterized by autoantibodies directed against mucocutaneous desmosomal proteins. Clinically, flaccid vesicles, bullae and erosions after breakage are the main clinical features. According to the literature, the incidence of PV is rare in the pediatric population, ranging from 1 to 4% of reported cases. We describe an interesting case of a 12-year-old boy with severe PV that was referred to our university hospital for a mucocutaneous disease resistant to anti-infective therapy. Following the appearance of bullous lesions on the skin, antibody screening for autoimmune diseases showed positivity for PV and corticosteroid therapy was started. In view of the numerous adverse effects, we decided to set up biological therapy with rituximab, which was interrupted due to the onset of an urticarial reaction. Further second-line therapies were therefore attempted, with only a partial response. For this reason, a desensitizing therapy with rituximab was decided, thus allowing a clear improvement in the clinical picture and quality of life of the patient. To the best of our knowledge, this is the first report of a child with severe PV resistant to conventional therapies and with an urticarial reaction to rituximab. This case highlights that despite PV being extremely rare in the pediatric population, this diagnosis should not be entirely discounted. In case of severe clinical manifestations, rituximab represents a valid option in children and desensitization tests should be recommended in the presence of hypersensitivity to this drug.

Dsg3 epitope-specific signalling in pemphigus

Introduction

Pemphigus is an autoantibody driven disease that impairs the barrier function of the skin and mucosa by disrupting desmosomes and thereby impeding cellular cohesion. It is known that the different clinical phenotypes of pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are dependent on the autoantibody profile and target antigens that, amongst others, are primarily desmoglein (Dsg)1 and/or Dsg3 for PV and Dsg1 for PF. However, it was reported that autoantibodiesagainst different epitopes of Dsg1 and Dsg3 can be pathogenic or not. The underlying mechanisms are very complex and involve both direct inhibition of Dsg interactions and downstream signalling. The aim of this study was to find out whether there is target-epitope-specific Dsg3 signalling by comparing the effects of the two pathogenic murine IgGs, 2G4 and AK23.

Methods

Dispase-based dissociation assay, Western Blot analysis, Stimulated emission depletion microscopy, Fura-based Ca2+ flux measurements, Rho/Rac G-Protein-linked immunosorbent assay, Enzyme-linked immunosorbent assay.

Results

The IgGs are directed against the EC5 and EC1 domain of Dsg3, respectively. The data show that 2G4 was less effective in causing loss of cell adhesion, compared to AK23. STED imaging revealed that both autoantibodies had similar effects on keratin retraction and reduction of desmosome number whereas only AK23 induced Dsg3 depletion. Moreover, both antibodies induced phosphorylation of p38MAPK and Akt whereas Src was phosphorylated upon treatment with AK23 only. Interestingly, Src and Akt activation were p38MAPK-dependent. All pathogenic effects were rescued by p38MAPK inhibition and AK23-mediated effects were also ameliorated by Src inhibition.

Discussion

The results give first insights into pemphigus autoantibody-induced Dsg3 epitope-specific signalling which is involved in pathogenic events such as Dsg3 depletion.

A clinical and demographic analysis of oral pemphigus vulgaris: A retrospective cross-sectional study from 2001 to 2021

Background and Aims

Pemphigus vulgaris is an autoimmune vesiculobullous mucocutaneous disorder with life-threatening consequences. Early detection and adequate care are crucial for a good prognosis. This study aimed to determine the demographic data, clinical features, and the prognosis of patients with oral pemphigus vulgaris.

Materials and Methods

From 2001 to 2021, all diagnosed oral pemphigus vulgaris cases were extracted. Each patient's demographic and clinical data were gathered. Patients were called via phone to assess the prognosis, treatment type, and specialty of the physician who provided the diagnosis and therapy.

Results

The majority of the patients had only oral lesions with higher prevalence in female who also expressed severe pain than male. Only 14 of 29 patients responded phone calls. Except for one, all patients were in active disease. More than half of those respondents said pemphigus negatively affects social behavior and food intake. Correct diagnosis and treatment were decided by dermatology, oral medicine, and maxillofacial surgery specialists.

Conclusion

Oral pemphigus vulgaris was prevalent in females. Severe pain was common in females and older people. Even with effective therapy, the prognosis was poor. Medical and dental professionals had little knowledge of pemphigus vulgaris. Patients frequently report poor quality of life.

Clinical Patterns, Survival, Comorbidities, and Treatment Regimens in 149 Patients With Pemphigus in Tuscany (Italy): A 12-Year Hospital-Based Study

Introduction

Pemphigus encompasses a group of muco-cutaneous autoimmune bullous diseases characterized by the loss of adhesion between keratinocytes. The disease is associated with increased morbidity and mortality.

Materials and Methods

We characterized clinical patterns, survival, comorbidities, and drug prescriptions in patients with pemphigus referred to the Section of Dermatology of the University of Florence from January 2010 to December 2021.

Results

A total of 149 patients were identified (female/male sex ratio = 2.0). Median age at diagnosis was 57.7 ± 17.2 years; 108 patients were diagnosed with pemphigus vulgaris (PV) (72.5%) and 35 (23.5%) with pemphigus foliaceus (PF). Paraneoplastic pemphigus (PNP) and IgA-pemphigus accounted for three patients each. The overall survival rate was 86.9%. Accordingly, 14 (9%) patients died during the study period. The average age at death was 77.8 ± 9.3. Age at diagnosis was a risk factor for death in patients with pemphigus. Average concentration of Dsg3-IgG and Dsg1-IgG was 85.6 ± 68.8 and 75.9 ± 68.4, respectively. The most serious comorbid diseases included cerebro- and cardiovascular accidents and malignancies. Regarding the treatment regimen, we found a substantially stable use of systemic steroids in the 2010–2018 period; the prevalence of use of mycophenolic acid increased, whereas that of azathioprine decreased. The use of rituximab showed the highest increase in the 2013–2018 period. Proton-pump inhibitors and antibiotics were the most frequently prescribed non-immunomodulating drugs.

Conclusions

In this large series of the patients, patients with pemphigus showed a high incidence of serious comorbid diseases, highlighting the importance of a multidisciplinary approach for a proper management of the patients. Rituximab was the immunomodulating drug showing the highest increase in use over time, reflecting the growing evidence of its efficacy as a first-line treatment in pemphigus.

Delayed Diagnosis of Pemphigus Vulgaris Initially Presenting as an Oral Ulcer: A Case Report

Pemphigus vulgaris is a rare autoimmune mucocutaneous blistering disease clinically presenting as vesicles, bullae, and erosion and histologically characterized by suprabasal split and acantholysis. It usually affects mucous membranes and skin. Recurrent oral ulcers can only be the clinical manifestation before progressing into skin lesions. This can lead to the delayed diagnosis of this disease. Here we report a case of pemphigus vulgaris which was diagnosed after years of suffering from an oral ulcer that eventually progressed to widespread skin blistering and ulceration. The patient was treated with oral prednisolone which showed improvement within a week. Physicians should consider the differential diagnosis of pemphigus vulgaris in patients presenting with a recurrent oral ulcer.

Keywords

delayed diagnosis; oral ulcer; pemphigus vulgaris.

Pediatric Autoimmune Bullous Disease: A Literature Review and Update on Management

Pediatric autoimmune bullous disease is a rare group of blistering skin disorders in children that result from autoimmunity against intercellular and basement membrane antigens in the skin and mucous membranes. Most pediatric cases are treated with oral corticosteroids or longer-term immunosuppressants such as azathioprine or mycophenolate mofetil. Immunomodulating drugs such as rituximab are increasingly being considered as options for refractory disease.

Autoimmune Pemphigus: Latest Advances and Emerging Therapies

Pemphigus represents a group of rare and severe autoimmune intra-epidermal blistering diseases affecting the skin and mucous membranes. These painful and debilitating diseases are driven by the production of autoantibodies that are mainly directed against the desmosomal adhesion proteins, desmoglein 3 (Dsg3) and desmoglein 1 (Dsg1). The search to define underlying triggers for anti-Dsg-antibody production has revealed genetic, environmental, and possible vaccine-driven factors, but our knowledge of the processes underlying disease initiation and pathology remains incomplete. Recent studies point to an important role of T cells in supporting auto-antibody production; yet the involvement of the myeloid compartment remains unexplored. Clinical management of pemphigus is beginning to move away from broad-spectrum immunosuppression and towards B-cell-targeted therapies, which reduce many patients’ symptoms but can have significant side effects. Here, we review the latest developments in our understanding of the predisposing factors/conditions of pemphigus, the underlying pathogenic mechanisms, and new and emerging therapies to treat these devastating diseases.

Diagnosis and Treatment Challenges of an Atypical Case of Pemphigus vulgaris During the COVID-19 Pandemic

Pemphigus defines a group of rare autoimmune blistering diseases that affect the skin and mucous membranes, with pemphigus vulgaris being the most common form that has increased morbidity and mortality in the absence of an early diagnosis and treatment.

We report the case of a 24-year-old male with an atypical form of pemphigus vulgaris with cutaneous onset and subsequent involvement of the oral cavity. The management of the patient initially consisted of long-term systemic corticosteroid therapy. Following a mild form of SARS-CoV-2 infection and a flare-up of the disease in this context, which was not controlled with high doses of systemic corticosteroids, targeted therapy with rituximab was initiated but immediately stopped due to the manifestations of urticaria and angioedema. Considering the magnitude of these reactions, dapsone systemic therapy i.e., a steroid-sparing agent with minimal risk of infections, was started and managed to control the underlying disease.

The management of this case of pemphigus vulgaris was challenging for both the patient and his physician, as the patient developed COVID-19 which caused disease complications and implied additional costs. This case highlights the importance of an accurate diagnosis given the atypical onset of the disease and the financial limitations with the impossibility of performing all confirmatory diagnostic tests.

Real world evidence: Patients with refractory pemphigus treated with Rituximab

BACKGROUND

Pemphigus is a group of autoimmune blistering diseases, potentially life-threatening. Rituximab received FDA approval in June 2018 for the treatment of moderate to severe pemphigus vulgaris.

OBJECTIVES

To evaluate the efficacy and safety of rituximab in patients with pemphigus, resistant to previous therapies or unable to receive classic immunosuppressive treatment due to serious adverse events or comorbidities.

MATERIALS AND METHODS

Twenty-five patients (9 men, 16 women), mean age 49.4 ± 15.9 years (range 21-74 years), mean disease duration 4 ± 2.7 years (range 0.25-10 years) were included in the study: 19 patients with pemphigus vulgaris and 6 with pemphigus foliaceous. The efficacy of rituximab was evaluated according to the control of disease, retention of remission, disease severity, previous treatments and adverse reactions. During COVID-19 pandemic patients are monitored closely through tele-dermatology.

RESULTS

Twenty-three out of 25 patients had great improvement, 2 out of 25 ceased therapy due to adverse events (arthralgias and dyspnea). Sixteen out of 23 received additional course after 8 months (range 5-60 months). More aged patients presented more frequently adverse events and underwent additional courses (p = 0.002). Rituximab was found superior to classic immunosuppressive treatment in terms of efficacy and safety, with larger periods of remission and lower doses of corticosteroids and immunosuppressants. No major adverse events were noticed.

CONCLUSIONS

Rituximab is a very effective treatment of pemphigus and, remarkably, superior to classic immunosuppressive treatment.

Autoantibodies against Desmoglein 1 and 3 in South Tunisian pemphigus

BACKGROUND

Desmoglein (Dsg) 1 and 3 are the 2 major autoantigens in pemphigus foliaceus (PF) and pemphigus vulgaris (PV).

AIM

We aimed to determine anti-Dsg1 and 3 Abs'usefulness in the diagnosis of pemphigus and to assess the correlation of these antibodies (Abs) with clinical phenotype and disease activity in south Tunisian patients.

METHODS

We retrospectively analyzed 131 samples from 82 patients (52 with PF and 30 with PV) during follow-up. Anti-Dsg1 and 3 Abs were measured by ELISA. Consecutive anti-Dsg1 and 3 Abs were correlated with disease activity. Receiver operating characteristics (ROC) curve were calculated to determine anti-Dsg1 and 3 Abs'cut-offs with optimal sensitivity and specificity for disease activity.

RESULTS

Anti-Dsg1 and 3 levels were associated to in PF and PV patients respectively (p<0,001). Anti-Dsg1 and 3 Ab were associated with skin (95%) and mucosal (60%) lesions, respectively. A significant decrease of anti-Dsg1 Abs was observed in patients with PF in clinical remission (36 ± 62 U/mL; (p=0,04). No correlation was found between anti-Dsg3 Abs and the course of mucosal lesions in PV (p=0,3). During follow-up, anti-Dsg1 Abs correlated with relapses (177 ±60 U/mL ; p=0,04). The 161,5 U/mL cut-off for anti-Dsg1 Abs provided 100% specificity and 86,4% sensitivity in PF disease activity. The 30,7U/mL cut-off for anti-Dsg3 provided 89,5% sensitivity and 100% specificity in PV.

CONCLUSIONS

High anti-Dsg3 Abs values are not always associated with PV disease activity. Anti-Dsg1 Abs showed a closer relationship with skin activity in PS and should be therefore taken into account in management of pemphigus patients.

Autoantibody-Specific Signalling in Pemphigus

Pemphigus is a severe autoimmune disease impairing barrier functions of epidermis and mucosa. Autoantibodies primarily target the desmosomal adhesion molecules desmoglein (Dsg) 1 and Dsg 3 and induce loss of desmosomal adhesion. Strikingly, autoantibody profiles in pemphigus correlate with clinical phenotypes. Mucosal-dominant pemphigus vulgaris (PV) is characterised by autoantibodies (PV-IgG) against Dsg3 whereas epidermal blistering in PV and pemphigus foliaceus (PF) is associated with autoantibodies against Dsg1. Therapy in pemphigus is evolving towards specific suppression of autoantibody formation and autoantibody depletion. Nevertheless, during the acute phase and relapses of the disease additional treatment options to stabilise desmosomes and thereby rescue keratinocyte adhesion would be beneficial. Therefore, the mechanisms by which autoantibodies interfere with adhesion of desmosomes need to be characterised in detail. Besides direct inhibition of Dsg adhesion, autoantibodies engage signalling pathways interfering with different steps of desmosome turn-over. With this respect, recent data indicate that autoantibodies induce separate signalling responses in keratinocytes via specific signalling complexes organised by Dsg1 and Dsg3 which transfer the signal of autoantibody binding into the cell. This hypothesis may also explain the different clinical pemphigus phenotypes.

Current status and prospects for the diagnosis of pemphigus vulgaris

Introduction: Pemphigus vulgaris (PV) is an intraepidermal autoimmune bullous disease (AIBD) characterized by autoantibodies against desmosomal adhesion proteins, most commonly desmoglein (Dsg)3, leading to the suprabasal cleft formation and acantholysis.Areas covered: Direct immunofluorescence (DIF) and indirect immunofluorescence (IIF) studies display the intercellular deposition of IgG/C3 throughout the epidermis and presence of circulating autoantibodies respectively, as a net-like pattern. However, the target antigen remains unknown using immunofluorescence techniques. Thanks to the development of Dsg ELISA, using recombinant technology, circulating antibodies against Dsg1 and 3 could be detected sensitively. It is possible to differentiate PV from pemphigus foliaceus (PF) using this assay. BIOCHIP mosaic and multivariant ELISA are two novel serologic methods with the added value of the ability to screen several AIBDs simultaneously.Non-Dsg1/3 antigens are also involved in the pathogenesis of PV and investigated more deeply thanks to the protein microarrays technique. Additionally, patients with high values of anti-Dsg1/3 may be lesion-free, suggesting the presence of nonpathogenic autoantibodies.Expert opinion: Newer diagnostic methods to replace traditional techniques should possess high sensitivity and specificity and be widely available, noninvasive, and relatively cheap. The newly developed methods need to be further evaluated before being recommended for routine use.

Histopathology of Pemphigus Vulgaris Revisited

ABSTRACT

Pemphigus vulgaris (PV) is a severe, potentially life-threatening autoimmune blistering disease, which is common in India. Although there is abundant literature on clinical and immunologic features, comprehensive studies on its histopathology are lacking. The aim of this study was to describe the histopathologic and immunofluorescence features as well as discuss various diagnostic pitfalls of PV. Histopathologic and immunofluorescence (DIF/IIF) findings were reviewed for 169 biopsies from 2007 to 2017 (11 years). The 169 samples included 152 skin, 16 oral mucosal, and 1 corneal biopsy. Maximum prevalence was noted in the fifth decade (57%) with a slight male preponderance. Vesicles were seen in 149 cases (88%), the level of which was suprabasal in 91(61%) and both suprabasal and intraepidermal in 50 cases (33.5%). Acantholytic cells were present in 142 cases (95%). Acantholytic keratinocytes showed rounded and polygonal acantholysis. 86 (51%) cases showed evidence of regeneration. Adnexal involvement was seen in 92 cases, commonest in the hair follicles. Unusual histologic findings included: intraepidermal bulla, absence of dermal inflammation, free floating hair shafts, multinucleated epithelial cells, eosinophil predominance; all of which are discussed. DIF was performed in 166 cases, of which 163 were positive (98%), and IgG was the commonest immunoreactant (96%). IIF was performed in 11 cases, of which 9 cases were positive for Dsg3. Although the diagnosis of PV rests on combined clinical, histologic, and IF features, histopathology as the sole means is also a powerful tool. It is important to be aware of the diagnostic pitfalls to optimize its utility.

Evaluation of non-endemic pemphigus foliaceus in a large series of patients: a single-center retrospective study from Turkey focuses on the relapses

BACKGROUND

Pemphigus foliaceus is exceedingly rare around the world, except within the few regions where it occurs as an endemic variant. Various factors can trigger immune mechanisms that induce pemphigus foliaceus or worsen its course.

OBJECTIVE

To determine the demographic and clinical characteristics of the patients with pemphigus foliaceus in a large series from a non-endemic country, investigate the triggering factors, and seasonal patterns.

METHODS

The data of the patients diagnosed with pemphigus foliaceus in the study's center between 1989-2018 were retrospectively analyzed.

RESULTS

Sixty-eight patients (mean age, 45.7 ± 14.5 years) were included in the study. The number of onsets reached its peak in spring-summer (p = 0.008). A total of 117 relapses occurred in 42 patients and were most common in spring-summer (not significant). Specific trigger factors were detected in 45 relapses. In the other 72 relapses, the peak was observed in spring-summer (p = 0.005). There were no significant differences in the demographic and clinical variables investigated between relapsed and non-relapsed patients.

STUDY LIMITATIONS

Retrospective design.

CONCLUSIONS

Triggering factors could not be identified in more than half of the relapses in the study's series. The subgroup of relapses (without identified causes), as well as the onsets of the disease, showed a significant seasonal variation with a peak in spring-summer; however, the seasonal variable did not justify the total group of relapses. Although the seasonal variation may be caused by a combination of factors, UV radiation should be considered a trigger factor for the peaks in spring-summer, particularly in Turkey.

Clinicians' pearls and myths in pemphigus

Pemphigus comprises a heterogeneous group of autoimmune blistering diseases, which can affect both skin and mucous membranes, especially oral mucosa. This group of diseases shows usually a chronic-relapsing course. Since pemphigus is a rare disease, the diagnosis is often delayed, because it is based upon the recognition of consistent clinical, histologic, and direct immunofluorescence findings, as well as indirect immunofluorescence, and/or enzyme-linked immunosorbent assay. Usually the patients are treated for multiple other conditions before starting the correct therapy, leading to a critical reduction of the patients' quality of life. This review is a succinct compilation of pearls gathered from clinical experience in pemphigus and the myths that may have influenced everyday practice but have been proven false. This review provided a selection of such dilemmas and controversies, focusing on myths and pearls that can help young dermatologist in the clinic, while also dispelling them.

Pemphigus Vulgaris-Associated Anterior Scleritis: A Case Study

Ocular involvement in pemphigus vulgaris (PV) is relatively rare. The conjunctiva and eyelids are considered the most common affected sites in ocular pemphigus. Scleritis is rarely reported as a manifestation of PV. We present a case report of anterior scleritis as a manifestation of PV and its response to rituximab therapy.

Intraepithelial autoimmune bullous dermatoses disease activity assessment and therapy

Intraepithelial autoimmune blistering dermatoses are a rare group of skin disorders characterized by disruptions of inter-keratinocyte connections within the epidermis through the action of autoantibodies. The second article in this continuing medical education series presents validated disease activity scoring systems, serologic parameters of disease, treatments, and clinical trials for pemphigus and its subtypes.

Intraepithelial autoimmune blistering dermatoses: Clinical features and diagnosis

Intraepithelial autoimmune blistering dermatoses are a rare group of skin disorders characterized by the intraepithelial disruption of intercellular connections through the action of autoantibodies. The first article in this continuing medical education series explores the background, epidemiology, clinical features, and diagnostic criteria of each of the major intraepithelial autoimmune blistering dermatoses, including pemphigus foliaceus, pemphigus erythematosus, pemphigus herpetiformis, fogo selvagem, pemphigus vulgaris, pemphigus vegetans, drug-induced pemphigus, IgA pemphigus, IgG/IgA pemphigus, and paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome.

Milestones in Personalized Medicine in Pemphigus and Pemphigoid

Pemphigus and pemphigoid diseases are autoimmune bullous diseases characterized and caused by autoantibodies targeting adhesion molecules in the skin and/or mucous membranes. Personalized medicine is a new medical model that separates patients into different groups and aims to tailor medical decisions, practices, and interventions based on the individual patient`s predicted response or risk factors. An important milestone in personalized medicine in pemphigus and pemphigoid was achieved by verifying the autoimmune pathogenesis underlying these diseases, as well as by identifying and cloning several pemphigus/pemphigoid autoantigens. The latter has become the basis of the current, molecular-based diagnosis that allows the differentiation of about a dozen pemphigus and pemphigoid entities. The importance of autoantigen-identification in pemphigus/pemphigoid is further highlighted by the emergence of autoantigen-specific B cell depleting strategies. To achieve this goal, the chimeric antigen receptor (CAR) T cell technology, which is used for the treatment of certain hematological malignancies, was adopted, by generating chimeric autoantigen receptor (CAAR) T cells. In addition to these more basic science-driven milestones in personalized medicine in pemphigus and pemphigoid, careful clinical observation and epidemiology are again contributing to personalized medicine. The identification of clearly distinct clinical phenotypes in pemphigoid like the non-inflammatory and gliptin-associated bullous pemphigoid embodies a prominent instance of the latter. We here review these exciting developments in basic, translational, clinical, and epidemiological research in pemphigus and pemphigoid. Overall, we hereby aim to attract more researchers and clinicians to this highly interesting and dynamic field of research.

Variation in genes implicated in B-cell development and antibody production affects susceptibility to pemphigus

Pemphigus foliaceus (PF) is an autoimmune blistering skin disease characterized by the presence of pathogenic autoantibodies against desmoglein 1, a component of intercellular desmosome junctions. PF occurs sporadically across the globe and is endemic in some Brazilian regions. Because PF is a B-cell-mediated disease, we aimed to study the impact of variants within genes encoding molecules involved in the different steps of B-cell development and antibody production on the susceptibility of endemic PF. We analysed 3,336 single nucleotide polymorphisms (SNPs) from 167 candidate genes genotyped with Illumina microarray in a cohort of 227 PF patients and 193 controls. After quality control and exclusion of non-informative and redundant SNPs, 607 variants in 149 genes remained in the logistic regression analysis, in which sex and ancestry were included as covariates. Our results revealed 10 SNPs within or nearby 11 genes that were associated with susceptibility to endemic PF (OR >1.56; p < 0.005): rs6657275*G (TGFB2); rs1818545*A (RAG1/RAG2/IFTAP);rs10781530*A (PAXX), rs10870140*G and rs10781522*A (TRAF2); rs535068*A (TNFRSF1B); rs324011*A (STAT6);rs6432018*C (YWHAQ); rs17149161*C (YWHAG); and rs2070729*C (IRF1). Interestingly, these SNPs have been previously associated with differential gene expression, mostly in peripheral blood, in publicly available databases. For the first time, we show that polymorphisms in genes involved in B-cell development and antibody production confer differential susceptibility to endemic PF, and therefore are candidates for possible functional studies to understand immunoglobulin gene rearrangement and its impact on diseases.

Therapeutic modalities and course of the disease in patients with autoimune pemphigus (AP) treated at the Clinic of dermatovenerology in the period 2013-2018

Introduction: Autoimmune pemphigus (AP) is one of the most severe dermatologic diseases. AP belongs to the group of organ-specific autoimmune disorders, with autoantibodies directed against cellsurface antigens on keratinocytes, mostly desmogleins. Three main types of AP have been described, depending on the clinical and histopathological features and the different target antigens: Pemphigus vulgaris (PV), Pemphigus foliaceus (PF), each with its own subtypes and paraneoplastic pemphigus (PNP). The clinical course and prognosis of AP depend on its subtype, therapeutic modalities and their side effects. The main goal of the treatment is to achieve and maintain remission without any systemic therapy or with minimal therapeutic doses ("maintenance therapy"). Aim: A retrospective study of hospitalized patients with various forms of AP, analysis of clinical course and evaluation of therapeutic modalities employed. Material and methods: A total of 158 inpatients with diagnosed AP, admitted to the Clinic of Dermatovenereology, Clinical Centre of Serbia, from 2013 to 2018, with a subsequent followup of 6 to 12 months, were included in this study. Demographic and clinical data as well as treatment approaches were analyzed using descriptive and analytic statistics. Results: The most common subtype encountered was PV (72.15%); in the largest number of patients (46.84%) the disease occurred between ages 39-59. Conventional corticosteroid treatment was most frequently used (67.41%), along with azathioprine (66.86%) as the most common immunosuppressive drug. In 60.8% of patients no side effects or disease complications were recorded. During the follow-up, at the end of 2018, 48.1% of patients achieved remission. Conclusion: We have shown a high incidence of PV. Treatment approaches used in our patients were in accordance with the pemphigus subtype and course of the disease. A significant number of patients achieved clinical remission.

Does interleukin-33 level correlate with the activity of Pemphigus vulgaris?: A case-control study

Pemphigus is a group of immune-mediated blistering diseases of skin and mucus membrane caused by destruction of the intercellular junction (desmosomes) by autoantibodies. Pemphigus vulgaris (PV) is considered the most common type of all pemphigus family. Various cytokines play a major role in pemphigus pathogenesis. Interleukin-33 (IL-33) role has been studied in various autoimmune diseases as; psoriasis and rheumatoid arthritis, yet it has not been studied in Egyptian patients with PV. The study aimed to evaluate the possible role of IL-33 in PV by assessing its level in the serum using ELISA and to detect its correlation with activity score using Pemphigus Disease Area Index (PDAI). Forty-four patients with PV and 36 age and sex-matched healthy controls were enrolled in the study. After full history taking and complete dermatological examination, the severity score was calculated using PDAI, then serum samples were taken from each patient and control subjects and subjected to quantitative measurement of serum IL-33 using ELISA. Serum level of IL-33 is significantly raised in PV patients compared to control subjects (P-value = .007). The level of IL-33 was found to be strongly correlated with the activity of the disease measured by PDAI. IL-33 might have a role in PV pathogenesis as shown by its rising level in PV patients. In addition, serum level of IL-33 is strongly correlated with the activity of PV. Thus, we suspect that IL-33 can be used as marker for monitoring PV severity and measuring treatment efficacy.

Deep pemphigus (pemphigus vulgaris, pemphigus vegetans and paraneoplastic pemphigus) in dogs, cats and horses: a comprehensive review

Pemphigus is the term used to describe a group of rare mucocutaneous autoimmune bullous diseases characterized by flaccid blisters and erosions of the mucous membranes and/or skin. When the autoantibodies target desmosomes in the deep layers of the epidermis, deep pemphigus variants such as pemphigus vulgaris, pemphigus vegetans and paraneoplastic pemphigus develop. In this article, we will review the signalment, clinical signs, histopathology and treatment outcome of pemphigus vulgaris, pemphigus vegetans and paraneoplastic pemphigus in dogs, cats and horses; where pertinent, we compare the animal diseases to their human homologue. Canine, feline and equine pemphigus vulgaris, pemphigus vegetans and paraneoplastic pemphigus have many features similar to the human counterpart. These chronic and often relapsing autoimmune dermatoses require aggressive immunosuppressive therapy. In animals, the partial-to-complete remission of pemphigus vulgaris and pemphigus vegetans has been achieved with high dose glucocorticoid therapy, with or without adjunct immunosuppressants; the prognosis is grave for paraneoplastic pemphigus.

Toll-like-Receptor Gene Polymorphisms in Tunisian Endemic Pemphigus Foliaceus

Pemphigus foliaceus (PF) is considered to be caused by the combined effects of susceptibility genes and environmental triggers. The polymorphisms of Toll-like receptors (TLRs) genes have been associated with the risk of various autoimmune diseases. The aim of this study was to evaluate the potential association of TLR2-3-4 and 7 gene polymorphisms with Tunisian PF. Fourteen polymorphisms were analyzed in 93 Tunisian PF patients compared to 193 matched healthy controls: rs5743703-rs5743709 and (GT)_n repeat (TLR2); rs5743305, rs3775294, and rs3775291 (TLR3), rs4986790 and rs4986791 (TLR4); and rs3853839 (TLR7). Our results showed that the genetic factors varied depending on the epidemiological feature stratification. In fact, in the whole population, no association with the susceptibility to PF was found. The TLR2 GT repeat seems to be closely associated with PF risk in patients originated from the endemic localities (group 3); the GT₁₈ allele and the heterozygous genotype GT₁₈/GT₁₉ seem to confer risk to endemic PF (P = 0.02; OR = 2.3 [1.1-4.9] and P = 0.0002, OR = 20 [2.5-171], respectively). In contrast, the GT₂₃ repeat could be considered as protector allele (P = 0.02, OR = 0.2 [0.06-0.87]). Furthermore, medium GT alleles which induce high promoter activity were also significantly more frequent in patients versus short or long GT repeats (P = 0.0018 with OR = 3.26 [1.5-7]). On the other hand, the TLR3-rs574305 AA genotype and A allele were significantly more frequent in patients whose age of the onset was above 35 years (group 2) (P = 0.038, OR = 1.78 and P = 0.009, OR = 3.92, respectively). Besides, the TLR4>rs3775294 A allele was found to be protector only in patients with sporadic features (groups 2 and 4) (P = 0.03, OR = 0.57 [0.3-0.9] and P = 0.006, OR = 0.24 [0.08-0.74], respectively). No statistically significant difference was observed in the genotypic and allelic frequencies of TLR-4 and TLR-7 gene polymorphisms. The present data suggest that TLR2and TLR3 polymorphisms are significantly associated with increased susceptibility to PF in the Tunisian population.

Pemphigus Vulgaris: A Clinical Study of 31 Cases (2004-2014) in Morocco

Background

Pemphigus vulgaris is a rare bullous autoimmune dermatosis whose evolution and prognosis are unpredictable.

Aim

The objective was to analyze long-term outcomes in patients with pemphigus vulgaris by identifying the factors that are able to influence prognosis, in particular the phenotype of pemphigus vulgaris, age at onset, multiplicity of mucosal involvement, relapse and remission rates, and survival functions.

Methods

A retrospective analysis of a cohort of 31 patients followed for pemphigus vulgaris during the period from January 2004 to January 2014. Inclusion criteria were a diagnosis of pemphigus vulgaris confirmed by histopathology and direct immunofluorescence (DIF) and a period of follow-up of at least five years from the diagnosis. The following information was collected by a single investigator.

Results

In total, 67.7% of patients presented a mucocutaneous pemphigus vulgaris. Male-female sex ratio was 2.4. The median duration of patient's follow-up was estimated at 7 (6–9) years. Multiple mucosal involvement in the oral cavity and at other mucosal sites was significantly associated with severe mucocutaneous pemphigus vulgaris (p=0.01). Multiple relapses were significantly associated with the disease severity (p=0.04).

Conclusion

Poor prognosis factors were severe mucocutaneous type of pemphigus vulgaris and multiple mucosal involvement in the oral cavity and at other mucosal sites.

The First Reported Case of Metoprolol-Induced Pemphigus Foliaceus in the United States: A Critical Report and Review of Literature

Pemphigus is a rare family of autoimmune disorders characterized by epithelial and mucosal blisters. Pemphigus foliaceus (PF) commonly affects the scalp, face, and trunk. Lesions often arise as superficial blisters and develop into scaly, crusted erosions. Management includes corticosteroids with immunosuppressants. Novel therapies include immunoadsorption and active clinical trials. We present the only reported case of metoprolol-induced PF in the United States (US), with an extremely complicated hospital course. 

A 66-year-old male patient with a history of hypertension, diabetes, and hyperlipidemia presented to his doctor with a blistering, pruritic rash that started after switching to metoprolol for hypertension treatment. 

PF is very rare in North America. Given its solely superficial penetration, it creates no direct fatal complication. However, the developing blisters and subsequent wounds are susceptible to a wide array of secondary infections, which can be life-threatening.

Dapsone in the Management of Pemphigus and Pemphigoid: Rediscovery of its Long-Lost Efficacy

Introduction

Autoimmune mucocutaneous blistering dermatoses (AMCBD) are a group of disorders characterized by the production of autoantibodies that target specific adhesion molecules of the skin and/or mucous membranes. As a result, there is blister formation on the skin with or without mucous membrane involvement. Systemic corticosteroids have been used as the mainstay of treatment in AMCBD. However, due to the debilitating side effects associated with their use, there is significant morbidity and mortality, especially on the fragile elderly patients. Although the efficacy of dapsone in the treatment of AMCBD was identified decades ago, few recent studies shed light on that. Hence, further studies are needed to evaluate the efficacy of dapsone as a single agent in maintaining disease remission in patients with AMCBD.

Materials and methods

An observational retrospective study was performed. Patients with a known diagnosis of bullous pemphigoid (BP) or pemphigus vulgaris (PV) who are treated with dapsone with or without low-dose systemic corticosteroids were included in the study, and their medical files were reviewed. 

Results

A total of seven patients were included (three males and four females). All patients showed a satisfactory response to dapsone, achieving disease remission in a short period of time with no serious side effects necessitating treatment cessation.

Conclusions

Our findings support that dapsone may have a corticosteroid-sparing effect in the management of AMCBD. Further studies are warranted to confirm our findings.

Pemphigus vulgaris

Pemphigus vulgaris is a chronic autoimmune bullous dermatosis that results from the production of autoantibodies against desmogleins 1 and 3. It is the most frequent and most severe form of pemphigus, occurring universally, usually between 40 and 60 years of age. It usually begins with blisters and erosions on the oral mucosa, followed by lesions on other mucous membranes and flaccid blisters on the skin, which can be disseminated. There is a clinical variant, pemphigus vegetans, which is characterized by the presence of vegetating lesions in the large folds of the skin. Clinical suspicion can be confirmed by cytological examination, histopathological examination, and direct and indirect immunofluorescence tests. The treatment is performed with systemic corticosteroids, and immunosuppressive drugs may be associated, among them azathioprine and mycophenolate mofetil. More severe cases may benefit from corticosteroids in the form of intravenous pulse therapy, and recent studies have shown a beneficial effect of rituximab, an anti-CD20 immunobiological drug. It is a chronic disease with mortality around 10%, and septicemia is the main cause of death. Patients need long-term and multidisciplinary follow-up.

Association of NFKB1 -94ATTG ins/del polymorphism (rs28362491) with pemphigus vulgaris

Pemphigus vulgaris is a rare chronic blistering skin disease resulting from IgG autoantibodies directed against transmembrane desmosomal glycoprotein desmoglein 3 and is the most common form of pemphigus. Since interleukin-1 receptor-associated kinase (IRAK-1)/nuclear factor-kappa B (NF-kappa B) pathway plays an essential role in the pathogenesis of autoimmune diseases, the aim of the present study was to explore the role of polymorphisms in three genes, named IRAK1 (rs3027898), NFKBIA (rs696) and NFKB1 (-94ATTG insertion/deletion variant, - rs28362491), in PV susceptibility. Forty-four unrelated patients with PV (23 males) were enrolled in the study. Additionally, 77 ethnic matching healthy volunteers (45 males) with no personal or family history of chronic autoimmune or infectious diseases were studied. Strong statistical significant difference was observed between PV patients and controls for polymorphism -94 insertion/deletion ATTG in the promoter region of NFKB1 gene (P = 0.00005). Additional dedicated studies in larger groups of patients of various ethnicities are needed to replicate and confirm the preliminary findings.

Consensus on the treatment of autoimmune bullous dermatoses: pemphigus vulgaris and pemphigus foliaceus - Brazilian Society of Dermatology

Pemphigus are intraepidermal autoimmune bullous dermatoses that occur with lesions on the skin and / or mucous membranes. The most frequent types are pemphigus vulgaris and pemphigus foliaceus (classic and endemic). This consensus aims to present a complete and updated review of the treatment of these two more frequent forms of pemphigus, based on the literature and the personal experience of the authors. In moderate and severe cases of pemphigus vulgaris and foliaceus, systemic corticosteroid therapy (prednisone or prednisolone) is the treatment of choice. Adjuvant drugs, usually immunosuppressive drugs (azathioprine, mycophenolate mofetil, methotrexate, cyclophosphamide) may be prescribed as corticosteroid sparers in refractory cases or with contraindications to corticosteroids to minimize side effects. In severe and nonresponsive cases, corticosteroids in the form of intravenous pulse therapy, immunoglobulin and plasmapheresis / immunoadsorption can be administered. Immunobiological drugs, particularly rituximab, appear as a promising alternative. For milder cases, smaller doses of oral corticosteroid, dapsone and topical corticosteroids are options. At the end flowcharts are presented as suggestions for a therapeutic approach for patients with pemphigus vulgaris and pemphigus foliaceus.

Refractory pemphigus foliaceous treated with rituximab

Autoimmune blistering diseases are rare but potentially life-threatening conditions. Pemphigus foliaceus is one of these conditions, characterised by superficial erosions of the skin without mucosal involvement. We report the case of a 57-year-old woman who presented with a 4-week history of rash affecting her scalp with associated hair loss. Clinical and histopathological findings were in keeping with pemphigus foliaceus. She was successfully treated with rituximab, a chimeric monoclonal antibody against CD20, leading to a transient depletion of B cells. After 5 months of follow-up, her rash had cleared, and her hair had completely regrown.