Pemphigus autoimmunity: hypotheses and realities

Serum interleukin-6 concentration in patients with pemphigus

Pemphigus is a rare blistering autoimmune disease that damages the integumentary system and lowers the quality of life of patients. Interleukin-6 (IL-6) has been linked to the immunopathogenesis of pemphigus, according to recent research. Thus, the investigation purpose was to assess the function of IL-6 in the development and intensity of pemphigus disease. Between January 2022 and August 2022, a case-series study involving 26 patients with pemphigus vulgaris (PV), four patients with pemphigus foliaceus (PF), and 20 healthy volunteers was carried out at the Ho Chi Minh City Hospital of Dermato-Venereology. Patients with PV and PF had significantly higher serum IL-6 concentrations than healthy volunteers (p<0.001). Patients with a positive Nikolsky sign had significantly higher serum IL-6 concentrations than those with a negative sign (p<0.001). The serum IL-6 concentration and the pemphigus disease area index were found to significantly correlate (r=0.8, p<0.001). According to our findings, IL-6 might be a significant factor in pemphigus development and severity. Thus, novel treatments that specifically target IL-6 could be a good option for managing pemphigus, particularly in its more severe forms.

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.

Autoimmunity to Neuronal Nicotinic Acetylcholine Receptors

Nicotinic acetylcholine receptors (nAChRs) are widely expressed in many and diverse cell types, participating in various functions of cells, tissues and systems. In this review, we focus on the autoimmunity against neuronal nAChRs, the specific autoantibodies and their mechanisms of pathological action in selected autoimmune diseases. We summarize the current relevant knowledge from human diseases as well as from experimental models of autoimmune neurological disorders related to antibodies against neuronal nAChR subunits. Despite the well-studied high immunogenicity of the muscle nAChRs where autoantibodies are the main pathogen of myasthenia gravis, autoimmunity to neuronal nAChRs seems infrequent, except for the autoantibodies to the ganglionic receptor, the α3 subunit containing nAChR (α3-nAChR), which are detected and are likely pathogenic in Autoimmune Autonomic Ganglionopathy (AAG). We describe the detection, presence and function of these antibodies and especially the recent development of a cell-based assay (CBA) which, contrary to until recently available assays, is highly specific for AAG. Rare reports of autoantibodies to the other neuronal nAChR subtypes include a few cases of antibodies to α7 and/or α4β2 nAChRs in Rasmussen encephalitis, schizophrenia, autoimmune meningoencephalomyelitis, and in some myasthenia gravis patients with concurrent CNS symptoms. Neuronal-type nAChRs are also present in several non-excitable tissues, however the presence and possible role of antibodies against them needs further verification. It is likely that the future development of more sensitive and disease-specific assays would reveal that neuronal nAChR autoantibodies are much more frequent and may explain the mechanisms of some seronegative autoimmune diseases.

The Role of Non-Neuronal Acetylcholine in the Autoimmune Blistering Disease Pemphigus Vulgaris

The importance of acetylcholine (ACh) in keratinocyte adhesion and acantholysis has been investigated over the last three decades, particularly in the pathophysiology of autoimmune blistering dermatoses. Pemphigus vulgaris (PV) is an autoimmune blistering skin disease where autoantibody-mediated suprabasilar intraepidermal splitting causes flaccid blisters and non-healing erosions of the oral mucosa and sometimes also of the skin. Historically, acantholysis in PV was thought to be driven by anti-desmoglein (Dsg) antibodies. Herein, we describe the role of autoantibodies against keratinocyte muscarinic and nicotinic acetylcholine receptors, as well as the annexin-like molecule pemphaxin that also binds ACh, in the immunopathogenesis of PV. The identification of targets in this disease is important, as they may lead to novel diagnostic and therapeutic options in the future for this potentially deadly disease.

Patient genetics shape the autoimmune response in the blistering skin disease pemphigus vulgaris

Background and aim

Pemphigus vulgaris (PV) is known to have one of the strongest HLA associations among autoimmune diseases. DRB1*0402 and DQB1*0503 in particular are significantly overrepresented in PV patients in certain worldwide populations. Yet, there remain significant gaps in our understanding regarding the precise link between PV-associated HLA molecules, the specificity of the autoimmune response, and clinical expression. In this study we assessed correlations between factors including HLA genotype, ethnicity, autoantibody levels, and lesion distribution in a cohort of 293 patients.

Methods and population

Participants were recruited from multiple outpatient dermatology clinic settings and patient support meetings in the USA. On intake, patients provided venous blood samples and answered questionnaires regarding their current disease activity.

Results

Eighty-one percent of patients typed as either DRB1*0402 or DQB1*0503 with a high prevalence of DRB1*0402 in patients of Ashkenazi Jewish or Caucasian (non-Jewish) descent (86% and 42%, respectively) and DQB1*0503 in patients of Southeast Asian descent (78%). Patients typing as HLA DRB1*0402 had higher levels of anti-desmoglein (Dsg)3 antibodies (204.6 +/- 340.5 IU/ml) than patients without DRB1*0402 (138.5 +/- 236.4 IU/ml) (p=0.03) and had mucosal only lesions more often than cutaneous only or mucocutaneous lesions. Patients typing as DQB1*0503 had higher levels of anti-Dsg1 antibodies (47.3 +/- 59.8 IU/ml) compared to other groups (27.8 +/- 43.7 IU/ml) (p=0.06) and higher rates of mucocutaneous disease than other lesion types. We also report an unexpected HLA association of DRB1*0804 in PV patients of African descent. Sixty-four percent of this population carried the DRB1*0804 allele, and presented with highly elevated levels of anti-Dsg3 (p=0.02). However, neither African heritage nor the presence of DRB1*0804 correlated with a predilection to any specific lesion morphology. Patients that carried neither DRB1*0402, nor DQB1*0503 or DRB1*0804 had the lowest levels of anti-Dsg3 antibodies (60.0 +/- 80.0 IU/ml) and the highest rate of solely cutaneous disease compared to carriers of these alleles.

Conclusion

Our data illuminate the broader impact of genetic factors on disease development by showing that differences in HLA expression among patients and ethnicities play a large role in driving distinct patterns of antibody selection and disease phenotype in PV. These findings provide insights regarding clinical heterogeneity, and are relevant to developing improved, patient tailored management strategies.

Electron microscopy of desmosomal structures in the pemphigus human skin organ culture model

Pemphigus is a chronic autoimmune skin blistering disease, characterized by acantholysis and by the production of autoantibodies directed against the structural desmosomal proteins desmoglein 1 (DSG1) and/or DSG3. Model systems allow the identification and testing of new therapeutic targets. Here, we evaluated ultrastructural desmosomal morphology in the human skin organ culture (HSOC) model injected with either anti-desmoglein (DSG) 1/3 single-chain variable fragment (scFv, termed Px4-3), Staphylococcus aureus exfoliative toxin (ETA) as a reference and positive control, and normal human IgG as a negative control. Each experimental condition was evaluated in abdominal skin biopsies from five different donors. After 24 h of incubation, we processed the samples for histological and ultrastructural electron microscopy analyses. We found that Px4-3 or ETA induced a loss of desmosomes and increased interdesmosomal widening, similar to patient skin biopsies and other pemphigus models. Thus, we propose the HSOC pemphigus model as an attractive tool to unravel novel therapeutic targets.

A Comparison for Type 2 Cytokines and Lesional Inflammatory Infiltrations in Bullous Pemphigoid and Atopic Dermatitis

Background

Bullous pemphigoid (BP) and atopic dermatitis (AD) are both type 2 inflammatory skin diseases with similar clinical features. Thymic stromal lymphopoietin (TSLP) is an epithelial-derived cytokine which is upregulated in AD. However, the expression of TSLP in BP and the correlation between TSLP and inflammatory infiltrations have not been fully studied.

Objective

To characterize the serum Th2 cytokines level and Th2 inflammatory cell infiltrations in BP and AD. To study TSLP levels in serum, blister fluids and expression in lesional skin in patients with BP and AD.

Methods

TSLP level in serum and blister fluids was measured by enzyme-linked immunosorbent assay (ELISA). Inflammatory cells (CD4+ T cells, CD8+ T cells, CD1a+ cells, eosinophils and mast cells) were stained immunohistochemically and quantified by image analysis.

Results

TSLP level was significantly increased in blister fluids of BP and was highly expressed in lesional skin of BP and AD. Serum levels of IL-6, IL-4, IL-22, IFN-γ and thymic activation regulates chemokines (TARC) were significantly higher in patients with BP and AD than in healthy controls. CD4+ T cells, CD8+ T cells and CD1a+ cells were significantly more in upper dermis of BP and AD lesions. Eosinophils were found more in BP lesions while mast cells were found more in AD lesions than in healthy controls. A distinct correlation was found between TSLP levels and the intensities of CD4+ T cells, CD1a+ cells infiltrations.

Conclusion

TSLP was significantly higher in blister fluids and skin lesions of BP, suggesting that it might contribute to the pathogenesis of BP. BP exhibited a similar type 2 immune response and a slight difference in cells infiltrations with AD.

Investigation of comorbid autoimmune diseases in women with autoimmune bullous diseases: An interplay of autoimmunity and practical implications

Autoimmune bullous diseases are a group of skin disorders resulting from an autoimmune reaction against intercellular adhesion molecules or components of the basement membrane of skin and mucosa. Autoimmune disorders often occur in patients with a history of another autoimmune disease and most autoimmune diseases have a striking female predominance. In this review, we aim to analyze the different associations of autoimmune bullous diseases with other autoimmune diseases and highlight the distinctiveness of the female gender in these associations.

Desmoglein compensation hypothesis fidelity assessment in Pemphigus

The pemphigus group of autoimmune blistering diseases encompasses pemphigus vulgaris (PV) and pemphigus foliaceus (PF). Lesion location in pemphigus has been elegantly postulated by the Desmoglein Compensation Hypothesis (DCH), which references the distribution of desmoglein (Dsg) proteins in the epidermis along with a patient’s autoantibody profile to describe three different lesion phenotypes: PF is characterized by subcorneal lesions in the presence of anti-Dsg1 antibodies only, while lesions in PV are suprabasilar and accompanied by anti-Dsg3 antibodies only in mucosal PV, or both anti-Dsg3 and anti-Dsg1 in the case of mucocutaneous PV. While the validity of this hypothesis has been supported by several studies and is prominently featured in textbooks of dermatology, a number of logical inconsistencies have been noted and exceptions have been published in several small-scale studies. We sought to comprehensively assess the extent to which patient clinical and autoantibody profiles contradict the DCH, and characterize these contradictions in a large sample size of 266 pemphigus patients. Remarkably, we find that roughly half of active PV and PF patients surveyed present with a combination of lesion morphology and anti-Dsg3/1 levels that contradict the DCH, including: patients with a cutaneous only PV presentation, mucocutaneous disease in the absence of either Dsg3, Dsg1, or both, and mucosal disease in the absence of Dsg3 or presence of Dsg1. We also find stark differences in fidelity to the DCH based on ethnicity and HLA-association, with the lowest proportion of adherence in previously understudied populations. These findings underscore the need to expand our understanding of pemphigus morphology beyond the DCH, in particular for populations that have not been a focus in previous investigation.

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.

Mitochondrial Autoantibodies and the Role of Apoptosis in Pemphigus Vulgaris

Pemphigus vulgaris (PV) is an IgG autoantibody-mediated, potentially fatal mucocutaneous disease manifested by progressive non-healing erosions and blisters. Beyond acting to inhibit adhesion molecules, PVIgGs elicit a unique process of programmed cell death and detachment of epidermal keratinocytes termed apoptolysis. Mitochondrial damage by antimitochondrial antibodies (AMA) has proven to be a critical link in this process. AMA act synergistically with other autoantibodies in the pathogenesis of PV. Importantly, absorption of AMA inhibits the ability of PVIgGs to induce blisters. Pharmacologic agents that protect mitochondrial function offer a new targeted approach to treating this severe immunoblistering disease.

Apoptolysis: a less understood concept in the pathogenesis of Pemphigus Vulgaris

Pemphigus Vulgaris (PV) is a severe autoimmune disease characterized by supra-basal blisters in the skin and mucous membranes of a wide range of mammals, including humans. It not only affects the skin but also has severe oral manifestations. It has been stated that auto-antibodies are produced, for unknown reasons, which are directed against desmogleins present on the epithelium and thus leads to acantholysis and intraepithelial blistering. But the exact mechanism is still not completely understood. Here we would like to shed light on a new pathologic mechanism i.e., apoptolysis, which emphasizes that apoptotic enzymes contribute to acantholysis development both in terms of molecular events and chronologic sequence. A possible role of apoptolysis has been discussed in purview of PV.

Marked to Die-Cell Death Mechanisms for Keratinocyte Acantholysis in Pemphigus Diseases

Pemphigus is a group of blistering autoimmune diseases causing painful skin lesions, characterized by acantholysis and by the production of autoantibodies against, mainly, adhesion proteins. We reviewed the literature for molecules and/ or features involved in the 12 cell death pathways described by Nomenclature Committee on Cell Death, taking place in pemphigus patients, cell lines, or human skin organ cultures treated with sera or IgG from pemphigus patients or in pemphigus mouse models, and found 61 studies mentioning 97 molecules involved in cell death pathways. Among the molecules, most investigated were pleiotropic molecules such as TNF and CASP3, followed by FASL and CASP8, and then by FAS, BAX, BCL2, and TP53, all involved in more than one pathway but interpreted to function only within apoptosis. Most of these previous investigations focused only on apoptosis, but four recent studies, using TUNEL assays and/or electron microscopy, disqualified this pathway as a previous event of acantholysis. For PV, apoptolysis was suggested as a cell death mechanism based on pathogenic autoantibodies diversity, mitochondrial dysfunction, and p38 MAPK signaling. To answer those many questions that remain on cell death and pemphigus, we propose well-controlled, statistically relevant investigations on pemphigus and cell death pathways besides apoptosis, to overcome the challenges of understanding the etiopathology of pemphigus diseases.

Pemphigus patients with initial negative levels of anti- desmoglein; a subtype with different profile?

BACKGROUND

Pemphigus is a blistering autoimmune disease that is characterized by autoantibodies against desmoglins (Dsg), including anti-Dsg1 and anti-Dsg3. Despite the diagnosis of diseases, the anti-Dsg test by Enzyme-linked immunosorbent assay (ELISA) is negative in a small group of pemphigus patients. The aim of this study was to evaluate the clinical course, clinical symptoms, and response to treatment in pemphigus patients with negative levels of anti-Dsg1 and anti-Dsg3.

METHODS

In this study, the data of pemphigus patients referred to Razi Hospital were retrospectively collected from the medical records from 2016 to 2020. Eight patients, whose initial anti-Dsg1/anti-Dsg3 was negative by the ELISA test, were enrolled and their clinical course, clinical signs, and response to treatment were evaluated.

RESULTS

The mean age of the subjects (8 females) was 38.75±12.09. The most common phenotype of the subjects was pemphigus vulgaris (PV) with mucosal involvement. Additionally, the common site of blister inception was mouth of the patients. The mean prednisolone dose received by the patients at the initiation was 32.5±13.62 mg/day. According to Pemphigus Disease Area Index (PDAI), 6 patients had mild severity, wile 2 cases had moderate severity. Among the patients, 6 subjects received rituximab (RTX). Also, 5 patients experienced remission after 6.2±5.21 months.

CONCLUSION

PV is the most common phenotype of the disease and mucosal involvement is more common in patients with negative anti-Dsg-1/3 results. The severity of the lesions in most of the patients is mild at baseline and most patients seems to respond to RTX therapy and reach remission.

Immunohistochemical Expression of Galectin-3 in Pemphigus Vulgaris

ABSTRACT

Pemphigus vulgaris (PV) is an autoimmune bullous disorder related to immunoglobulin-G autoantibodies against desmoglein-3. Galectin-3 is one of the main elements of the immunoglobulin-E group which is essential in the cell-cell or cell-matrix adhesion. Although the presence of immunoglobulin-E autoantibodies in PV has been observed, no studies have been performed to describe the role of galectin-3 in PV. We evaluated galectin-3 expression in PV as a first step in assessing its impact in the pathogenesis of this autoimmune blistering process. In a retrospective study, 56 specimens from 45 patients diagnosed with PV were stained with antibodies to galectin-3. The percentages of nuclear and cytoplasmic galectin-3 expression as well as staining intensity were evaluated around blisters and adjacent unaffected skin. We observed a significant decrease in galectin-3 cytoplasmic and nuclear expression as well as stain intensity around blisters compared with adjacent unaffected skin. Although autoantibodies against desmogleins trigger the blister formation in PV patients, loss of galectin-3 may play a role in the extension of blister formation by initiating cell-cell disassembly at the level of the intercellular keratinocyte desmosome. We demonstrated a lower expression of galectin-3 around the blisters in PV. The pathogenesis of the blister formation may be related to lower expression of galectin-3. Additional studies are necessary to clarify the result of this outcome and determine the accurate pathogenesis of blister formation in PV.

Pemphigus Vulgaris in Old Patient

Pemphigus vulgaris (PV) is a chronic, autoimmune, intraepidermal blistering disease of the skin and mucous membranes. The first clinical manifestation is often the development of intraoral lesions, and later, the lesions involve the other mucous membranes and skin. The etiological factors of this disease still remain unknown, although the presence of autoantibodies is consistent with an autoimmune disease. A 73-year-old man had bullous lesions on gingiva, oral mucosa first, then scalp, trunk, and face. An oral medicine specialist suspects the lesion in differential diagnosis in the first presentation of oral lesions and follows up the patient, and then these bullous lesions presented on the skin. In this article, a patient had received oral prednisolone (80 mg/kg/day) and azathioprine, then tapered oral prednisolone to 40 mg/day, with a reduction of 5 mg/day every three weeks. The patient shows remission of these lesions, and complication of this treatment includes osteoporosis, hyperglycemia, and hypertension.

Mechanism-based therapeutic targets of pemphigus vulgaris: A scoping review of pathogenic molecular pathways

Pemphigus vulgaris (PV) is a potentially fatal autoimmune blistering disease characterised by cell-cell detachment or acantholysis. The mechanisms which follow antibody (Ab) binding and culminate in acantholytic changes and skin/mucosal blistering have not been fully clarified. Current treatment strategies are not specific to PV pathophysiology and although life-saving, harbour considerable side effects. We aimed to systematically assess the molecules amenable to targeted treatments that follow Ab binding and are associated with PV acantholysis. The resulting scoping review was conducted under PRISMA-ScR guidelines with clear inclusion and exclusion criteria and focused specifically on kinases, caspases, proteases, hydrolytic enzymes and other molecules of interest postulated to take part in the pathophysiology of PV. The review process resulted in the identification of 882 articles, of which 56 were eligible for qualitative synthesis. From the included articles, the majority (n = 42) used PV-IgG as the pathogenic agent, mainly via in vitro (n = 16) and in vivo (n = 10) models. Twenty-five molecules were found to play a pathogenic role in PV, including uPA, ADAM10, EGFR, Src, PKC, cdk2, ERK, PLC, calmodulin, NOS, p38MAPK and caspase-3. Selective inhibition of these molecules resulted in varying degrees of reduction in acantholysis and blistering. The pathogenic molecules identified in this review represent potential candidates for clinical translation.

Evolving Mechanisms in the Pathophysiology of Pemphigus Vulgaris: A Review Emphasizing the Role of Desmoglein 3 in Regulating p53 and the Yes-Associated Protein

The immunobullous condition Pemphigus Vulgaris (PV) is caused by autoantibodies targeting the adhesion proteins of desmosomes, leading to blistering in the skin and mucosal membrane. There is still no cure to the disease apart from the use of corticosteroids and immunosuppressive agents. Despite numerous investigations, the pathological mechanisms of PV are still incompletely understood, though the etiology is thought to be multifactorial. Thus, further understanding of the molecular basis underlying this disease process is vital to develop targeted therapies. Ample studies have highlighted the role of Desmoglein-3 (DSG3) in the initiation of disease as DSG3 serves as a primary target of PV autoantibodies. DSG3 is a pivotal player in mediating outside-in signaling involved in cell junction remodeling, cell proliferation, differentiation, migration or apoptosis, thus validating its biological function in tissue integrity and homeostasis beyond desmosome adhesion. Recent studies have uncovered new activities of DSG3 in regulating p53 and the yes-associated protein (YAP), with the evidence of dysregulation of these pathways demonstrated in PV. The purpose of this review is to summarize the earlier and recent advances highlighting our recent findings related to PV pathogenesis that may pave the way for future research to develop novel specific therapies in curing this disease.

Oxidative Stress-Mediated YAP Dysregulation Contributes to the Pathogenesis of Pemphigus Vulgaris

Pemphigus Vulgaris (PV) is a life-threatening autoimmune disease manifested with blisters in the skin and mucosa and caused by autoantibodies against adhesion protein desmoglein-3 (Dsg3) expressed in epithelial membrane linings of these tissues. Despite many studies, the pathogenesis of PV remains incompletely understood. Recently we have shown Dsg3 plays a role in regulating the yes-associated protein (YAP), a co-transcription factor and mechanical sensor, and constraining reactive oxygen species (ROS). This study investigated the effect of PV sera as well as the anti-Dsg3 antibody AK23 on these molecules. We detected elevated YAP steady-state protein levels in PV cells surrounding blisters and perilesional regions and in keratinocytes treated with PV sera and AK23 with concomitant transient ROS overproduction. Cells treated with hydrogen peroxide also exhibited augmented nuclear YAP accompanied by reduction of Dsg3 and α-catenin, a negative regulator of YAP. As expected, transfection of α-catenin-GFP plasmid rendered YAP export from the nucleus evoked by hydrogen peroxide. In addition, suppression of total YAP was observed in hydrogen peroxide treated cells exposed to antioxidants with enhanced cell-cell adhesion being confirmed by decreased fragmentation in the dispase assay compared to hydrogen peroxide treatment alone. On the other hand, the expression of exogenous YAP disrupted intercellular junction assembly. In contrast, YAP depletion resulted in an inverse effect with augmented expression of junction assembly proteins, including Dsg3 and α-catenin capable of abolishing the effect of AK23 on Dsg3 expression. Finally, inhibition of other kinase pathways, including p38MAPK, also demonstrated suppression of YAP induced by hydrogen peroxide. Furthermore, antioxidant treatment of keratinocytes suppressed PV sera-induced total YAP accumulation. In conclusion, this study suggests that oxidative stress coupled with YAP dysregulation attributes to PV blistering, implying antioxidants may be beneficial in the treatment of PV.

Correlation of anti-γ/ε nicotinic acetylcholine receptor antibody levels with anti-desmoglein 1,3 antibody levels and disease severity in pemphigus vulgaris

BACKGROUND

A role for nondesmoglein antigens in the pathogenesis of pemphigus vulgaris (PV) has been suggested in several studies. Acetylcholine receptors (AchR), are one of the most important groups of these antigens. However, the exact role of both antimuscarinic (m) and nicotinic (n) AchR antibodies (Abs) is still controversial.

AIM

To evaluate anti-desmoglein (Dsg)1, Dsg 3 and anti-γ/ε nAchR Abs values in patients with PV before and 3 months after rituximab (RTX) treatment, and to assess their correlation with disease severity.

METHODS

In total, 75 patients with PV (26 men, 49 women) who were planned to receive RTX were enrolled. Disease activity was assessed by using the Pemphigus Disease Area Index (PDAI). Using ELISA, anti-Dsg1,3 and anti-γ/ε nAchR Abs were determined at baseline and 3 months after RTX treatment.

RESULTS

At baseline, 53.33% patients had positive values for anti-Dsg1, 89.33% for anti-Dsg3 and 13.33% for anti-γ/ε nAchR Abs. All patients with positive anti-γ/ε nAchR Abs had the mucocutaneous phenotype. PDAI, anti-Dsg1,3 and anti-γ/ε nAchR values were dramatically decreased 3 months after RTX infusion (P < 0.001). There was a significant positive correlation between disease activity and anti-γ/ε nAchR values at baseline (P = 0.04), whereas no significant correlation was observed between anti-Dsg1,3 and anti-γ/ε nAchR values at baseline and 3 months after RTX infusion.

CONCLUSION

The reduction in anti-γ/ε nAchR Abs with clinical improvement in this study may suggest a synergic role for anti-γ/ε nAchR Abs with anti-Dsg1,3 Abs, or it could be an epiphenomenon.

Molecular analysis and the toxin, MSCRAMM, and biofilm genes of methicillin-resistant Staphylococcus aureus strains isolated from pemphigus wounds: A study based on SCCmec and dru typing

INTRODUCTION

Pemphigus is a chronic autoimmune blistering disease. Pemphigus blisters can damage the natural skin barrier and increase the risk of life-threatening conditions. Colonization of pemphigus wounds with methicillin-resistant Staphylococcus aureus (MRSA) prolongs wound healing and increases mortality rate. Assessing MRSA prevalence, types, and toxin and adhesion genes can facilitate the detection of MRSA strains which cause infections, selection of appropriate treatments, and healing of pemphigus wounds. This study aimed to determine the SCCmec, the direct repeat unit (dru) types (dts), and the toxin, MSCRAMM, and biofilm genes of MRSA strains isolated from pemphigus wounds.

METHODS

In this cross-sectional study, 118 S. aureus isolates were gathered from 118 patients with pemphigus. MRSA detection was performed using the mecA gene. Using the polymerase chain reaction method, all MRSA isolates were assessed for the presence of the sea, seb, sec, tst, eta, pvl, hla, hlb, MSCRAMM, and ica genes. Typing and subtyping were performed through respectively SCCmec typing and dru typing methods. The Bionumerics software was used for analyzing the data and drawing the minimum spanning tree.

FINDINGS

From 118 S. aureus isolates, 51 were MRSA. SCCmec typing revealed the prevalence of SCCmec II with a prevalence of 64.7% (33 out of 51 isolates) and SCCmec III with a prevalence of 35.3% (18 out of 51 isolates). Dru typing indicated seven dts, namely dts 10a, 10g, 10m, 13i, 8h, 8i, and 9ca in two main clusters. The dt9ca was a new dru type and was registered in the dru-typing database (www.dru-typing.org). The prevalence rates of the hla, sea, and sec genes in MRSA isolates were respectively 54.9%, 27.4%, and 1.9%, while the hlb, seb, eta, and pvl genes were not detected at all. Only one MRSA with SCCmec III and dt10a carried the tst encoding gene. MSCRAMM gene analysis revealed the high prevalence of the eno (31.3%) and the fib (21.5%) genes. The prevalence rates of the icaA and icaD biofilm formation genes were 3.9% and 5.8%, respectively. There were no significant differences between the two detected SCCmec types and between the two detected dts clusters respecting the prevalence of the encoding genes of virulence factors and MSCRAMMs.

CONCLUSION

The toxin genes hla and sea are prevalent among MRSA strains with SCCmec II and III isolated from pemphigus wounds. The most prevalent dts are dt10a and dt10g among MRSA with SCCmec III and dt8h and dt8i among MRSA with SCCmec II.

ST18 affects cell-cell adhesion in pemphigus vulgaris in a tumour necrosis factor-α-dependent fashion

BACKGROUND

Pemphigus vulgaris (PV) is a life-threatening mucocutaneous autoimmune blistering disease. We previously showed that genetic variants within the ST18 gene promoter area confer a sixfold increase in the propensity to develop PV. ST18, a transcription factor, was found to be overexpressed in the epidermis of patients with PV. In addition, it was found to promote autoantibody-mediated abnormal epidermal cell-cell adhesion and secretion of proinflammatory mediators by keratinocytes.

OBJECTIVES

To delineate the mechanism through which ST18 contributes to destabilization of cell-cell adhesion.

METHODS

We used quantitative reverse-transcriptase polymerase chain reaction, immunofluorescence microscopy, a luciferase reporter system, site-directed mutagenesis, chromatin immunoprecipitation (ChIP) and the dispase dissociation assay.

RESULTS

The ChIP and luciferase reporter assays showed that ST18 directly binds and activates the TNF promoter. Accordingly, increased ST18 expression contributes to PV pathogenesis by destabilizing cell-cell adhesion in a tumour necrosis factor (TNF)-α-dependent fashion. In addition, dual immunofluorescence staining showed increased expression of both ST18 and TNF-α in the skin of patients with PV carrying an ST18-associated PV risk variant, which was found to be associated with a more extensive PV phenotype.

CONCLUSIONS

Our findings suggest a role for TNF-α in mediating the deleterious effect of increased ST18 expression in PV skin.

Identification of novel therapeutic targets for blocking acantholysis in pemphigus

Background and Purpose

Pemphigus is caused by autoantibodies against desmoglein (Dsg) 1, Dsg3, and/or non‐Dsg antigens. Pemphigus vulgaris (PV) is the most common manifestation of pemphigus, with painful erosions on mucous membranes. In most cases, blistering also occurs on the skin, leading to areas of extensive denudation. Despite improvements in pemphigus treatment, time to achieve remission is long, severe adverse events are frequent and 20% of patients do not respond adequately. Current clinical developments focus exclusively on modulating B cell function or autoantibody half‐life. However, topical modulation of PV autoantibody‐induced blistering is an attractive target because it could promptly relieve symptoms.

Experimental Approach

To address this issue, we performed an unbiased screening in a complex biological system using 141 low MW inhibitors from a chemical library. Specifically, we evaluated PV IgG‐induced Dsg3 internalization in HaCaT keratinocytes. Validation of the 20 identified compounds was performed using keratinocyte fragmentation assays, as well as a human skin organ culture (HSOC) model.

key Results

Overall, this approach led to the identification of four molecules involved in PV IgG‐induced skin pathology: MEK1, TrkA, PI3Kα, and VEGFR2.

Conclusion and Implications

This unbiased screening revealed novel mechanisms by which PV autoantibodies induce blistering in keratinocytes and identified new treatment targets for this severe and potentially life‐threatening skin disease.

Double-filtration plasmapheresis combined with immunosuppressive treatment for severe pemphigus: 10 years' experience of a single center in China

BACKGROUND

Pemphigus is a group of rare and severe autoimmune blistering disease mediated by pathogenic autoantibodies against desmogleins. Plasmapheresis can directly remove autoantibodies from circulation, which has been applied to the treatment of pemphigus as an adjuvant therapy. But the results of the researches are controversial. This study aims to evaluate the efficacy and safety of double filtration plasmapheresis (DFPP) combined with immunosuppressive treatment for patients with severe pemphigus in our single center.

METHODS

We retrospectively analyzed 17 patients with severe pemphigus who were unresponsive to high-dose corticosteroid and received DFPP treatment between January 2010 and January 2020. The information on demographic characteristics, clinical and laboratory data, treatment regimens, and clinical outcomes were collected.

RESULTS

All the patients were diagnosed as severe pemphigus and had a period of at least 1 week of high-dose prednisone (1-1.5 mg/kg/day), but they were unresponsive to corticosteroid and immunosuppressants treatment. They received DFPP treatment as an adjuvant therapy. After DFPP treatment, the titers of desmogleins antibodies significantly decreased (P < .001), Nikolsky's sign became negative and no new blisters appeared. The dosage of corticosteroid could begin to taper down rapidly in 9 ± 4 days. On discharge, the dosage of prednisone decreased significantly (51 ± 3 mg/day, P < .001). No major adverse events happened that could lead to the termination of DFPP treatment.

CONCLUSION

Double filtration plasmapheresis combined with immunosuppressive treatment is an effective and safe therapeutic regimen for severe pemphigus. DFPP can also contribute to the dosage reduction of steroid to avoid more drug-related side effect.

Oral Mucosal Injury Caused by Targeted Cancer Therapies

Targeted cancer therapies have fundamentally transformed the treatment of many types of cancers over the past decade, including breast, colorectal, lung, and pancreatic cancers, as well as lymphoma, leukemia, and multiple myeloma. The unique mechanisms of action of these agents have resulted in many patients experiencing enhanced tumor response together with a reduced adverse event profile as well. Toxicities do continue to occur, however, and in selected cases can be clinically challenging to manage. Of particular importance in the context of this monograph is that the pathobiology for oral mucosal lesions caused by targeted cancer therapies has only been preliminarily investigated. There is distinct need for novel basic, translational, and clinical research strategies to enhance design of preventive and therapeutic approaches for patients at risk for development of these lesions. The research modeling can be conceptually enhanced by extrapolating "lessons learned" from selected oral mucosal conditions in patients without cancer as well. This approach may permit determination of the extent to which pathobiology and clinical management are either similar to or uniquely distinct from oral mucosal lesions caused by targeted cancer therapies. Modeling associated with oral mucosal disease in non-oncology patients is thus presented in this context as well. This article addresses this emerging paradigm, with emphasis on current mechanistic modeling and clinical treatment. This approach is in turn designed to foster delineation of new research strategies, with the goal of enhancing cancer patient treatment in the future.

[Immunomorphology of bullous lesions of the oral mucosa]

The article is devoted to the study of immunohistochemical parameters in patients with bullous lesions of the oral mucosa. The biopsy samples of the oral mucosa were studied in 57 patients, including patients with pemphigoid bullosa (38 people) and pemphigus vulgaris (19 people). The results of immunohistochemical studies indicate the cellular mechanisms of damage to the epithelium, in which IL-1, IL-6 and HPV16 are involved.

Correlation of IgG autoantibodies against acetylcholine receptors and desmogleins in patients with pemphigus treated with steroid sparing agents or rituximab

Introduction

Autoantibodies (autoAbs) against desmoglein-1 (DSG1) and desmoglein-3 (DSG3) have conventionally been studied and well accepted in the pathogenesis of pemphigus vulgaris (PV) and foliaceus (PF). Recent studies have suggested that non-DSG autoAbs may contribute to the pathogenesis of pemphigus, including autoAbs directed at acetylcholine receptors (AChR) and thyroid peroxidase (TPO). The purpose of this study is to retrospectively analyze PV and PF patient sera to better understand the relationship between anti-AChR and -TPO Abs to disease activity and DSG reactivity between patients treated with prednisone and steroid sparing agents (SSA; n = 22) or prednisone and rituximab (n = 21).

Methods

Patients were evaluated at 2 time points, T1 and T2, for disease activity using the Pemphigus Disease Area Index (PDAI), and sera were tested for the presence of TPO, DSG1, DSG3, muscarinic (M3) and nicotinic (n) AChR IgG autoAbs, as well as antibodies against Varicella Zoster Virus (VZV) by ELISA.

Results

Disease activity significantly decreased in patients from T1 to T2 (p < .0001). A significant difference was seen in IgG anti-DSG1 (p < .0001) and anti-DSG3 (p = .0049) levels when T1 was compared to T2 in both treatment groups. A significant increase was found between pemphigus patients and normal subjects with nAChR (p < .0001) at T1 but not with m3AChR, TPO or VZV Abs. No significant difference was seen between T1 and T2 values in patients with pemphigus for the non–desmoglein Abs TPO (p = .7559), M3AChR (p = .9003), nAChR (p = .5143) or VZV (p = .2454). These findings demonstrate that although an increase in IgG anti-nAChR autoAbs was found in PV and PF subjects, these Abs did not decrease with treatment. No other non-DSG Abs were increased or significantly changed over time in patients with pemphigus. This suggests that anti -AChR and -TPO Abs may not play a direct role in the pathogenesis of most patients with pemphigus, but does not rule out a role for non-DSG auto antibodies in distinct subsets of pemphigus patient.

A New Solid-Phase Immunosorbent for Selective Binding of Desmoglein 3 Autoantibodies in Patients with Pemphigus Vulgaris

Autoantibodies, immunoglobulins G (IgG) against the desmosomal proteins desmogleins 1 and 3, play a significant role in the pathogenesis of pemphigus vulgaris. The basic therapy for pemfigus includes systemic corticosteroids, but their use should be as brief as possible because of the severe side effects. In cases of corticosteroid- resistant pemfigus, adjuvant therapy, in particular extracorporeal methods, is used. The most effective and safest extracorporeal therapy is immunosorbtion. Immunosorbtion is based on the removal of pemphigus antibodies from the blood using an affinity sorbent during a therapeutic apheresis procedure. Existing immunosorbents are nonselective and increase the risk of infection. We designed an immunosorbent based on an agarose matrix, Affi-Gel 15, and human recombinant desmoglein 3, as a ligand, for a selective removal of autoantibodies from pemphigus patients' sera. It was shown on a pemphigus experimental model in vivo (neonatal Balb/c mouse model) and in vitro that the immunosorbent can effectively remove desmoglein 3-associated autoantibodies. The experimental results demonstrate that the solid-phase matrix immunosorbent Affi-Gel 15-Dsg3 is a promising product for the development of pemphigus therapy.

Rationale for including intravenous immunoglobulin in the multidrug protocol of curative treatment of pemphigus vulgaris and development of an assay predicting disease relapse

Analysis of reported outcomes of treatment of pemphigus vulgaris (PV) patients demonstrated that the multidrug approach offers a lower relapse rate compared to the FDA-approved prednisone/rituximab regimen. The multidrug protocol protects keratinocytes from autoantibody attack by systemic corticosteroids and mitochondrion-protecting drugs, selectively eliminates pathogenic autoantibodies by intravenous immunoglobulin (IVIg) and inhibits autoantibody production by cytotoxic immunosuppressors. Therefore, IVIg should be always added to the prednisone/rituximab regimen that does not eliminate circulating autoantibodies. To decrease risk for relapse to a minimum, PV should be maintained in full clinical remission until the critical mass of autoreactive plasma cells dies off. The two major factors that determine patient's risk for a relapse are the composition of the pool of pathogenic autoantibodies and the innate abilities of keratinocytes to sustain an autoantibody attack. As it is currently impossible to evaluate the risk for a relapse, development of a biomarker assay that could do so would be helpful in a long-term management of PV patients. We compared the magnitude of cytochrome c (CytC) release in keratinocytes by serum from PV patients in acute disease stage vs. remission and identified very strong positive correlation with disease severity. PV patients whose serum contained autoantibodies requiring higher amounts of normal IgG to neutralize their ability to release CytC were found to be at a higher risk for disease relapse. However, lack of very strong statistical correlation suggested that CytC is not an ideal biomarker to predict disease relapse, which should prompt a search for alternative candidates.

Nikolsky's sign: A pathognomic boon

Nikolsky's sign has been a very useful diagnostic tool in cases of skin disorders like pemphigus, toxic epidermal necrolysis, etc., The sign is demonstrated when lateral pressure is applied on the border of an intact blister, which results in the dislodgment of the normal epidermis and extension of the blister.

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.

Oral Lesions in Autoimmune Bullous Diseases: An Overview of Clinical Characteristics and Diagnostic Algorithm

Autoimmune bullous diseases are a group of chronic inflammatory disorders caused by autoantibodies targeted against structural proteins of the desmosomal and hemidesmosomal plaques in the skin and mucosa, leading to intra-epithelial or subepithelial blistering. The oral mucosa is frequently affected in these diseases, in particular, in mucous membrane pemphigoid, pemphigus vulgaris, and paraneoplastic pemphigus. The clinical symptoms are heterogeneous and may present with erythema, blisters, erosions, and ulcers localized anywhere on the oral mucosa, and lead to severe complaints for the patients including pain, dysphagia, and foetor. Therefore, a quick and proper diagnosis with adequate treatment is needed. Clinical presentations of autoimmune bullous diseases often overlap and diagnosis cannot be made based on clinical features alone. Immunodiagnostic tests are of great importance in differentiating between the different diseases. Direct immunofluorescence microscopy shows depositions of autoantibodies along the epithelial basement membrane zone in mucous membrane pemphigoid subtypes, or depositions on the epithelial cell surface in pemphigus variants. Additional immunoserological tests are useful to discriminate between the different subtypes of pemphigoid, and are essential to differentiate between pemphigus and paraneoplastic pemphigus. This review gives an overview of the clinical characteristics of oral lesions and the diagnostic procedures in autoimmune blistering diseases, and provides a diagnostic algorithm for daily practice.

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.

The desmosomal cadherin desmoglein-3 acts as a keratinocyte anti-stress protein via suppression of p53

Desmoglein-3 (Dsg3), the Pemphigus Vulgaris (PV) antigen (PVA), plays an essential role in keratinocyte cell-cell adhesion and regulates various signaling pathways involved in the progression and metastasis of cancer where it is upregulated. We show here that expression of Dsg3 impacts on the expression and function of p53, a key transcription factor governing the responses to cellular stress. Dsg3 depletion increased p53 expression and activity, an effect enhanced by treating cells with UVB, mechanical stress and genotoxic drugs, whilst increased Dsg3 expression resulted in the opposite effects. Such a pathway in the negative regulation of p53 by Dsg3 was Dsg3 specific since neither E-cadherin nor desmoplakin knockdown caused similar effects. Analysis of Dsg3^-/- mouse skin also indicated an increase of p53/p21^WAF1/CIP1 and cleaved caspase-3 relative to Dsg3^+/- controls. Finally, we evaluated whether this pathway was operational in the autoimmune disease PV in which Dsg3 serves as a major antigen involved in blistering pathogenesis. We uncovered increased p53 with diffuse cytoplasmic and/or nuclear staining in the oral mucosa of patients, including cells surrounding blisters and the pre-lesional regions. This finding was verified by in vitro studies where treatment of keratinocytes with PV sera, as well as a characterized pathogenic antibody specifically targeting Dsg3, evoked pronounced p53 expression and activity accompanied by disruption of cell-cell adhesion. Collectively, our findings suggest a novel role for Dsg3 as an anti-stress protein, via suppression of p53 function, and this pathway is disrupted in PV.

Pemphigus foliaceus patients (Fogo Selvagem) treated with kinesiotherapy presented lower levels of proinflammatory cytokines

Fogo Selvagem (FS) is a rare autoimmune disease characterized by acantholysis and inflammation of the epidermis. It was evidenced in this disease the increase of proinflammatory cytokines levels which can be influenced by physical activities. Kinesiotherapy, as physiotherapeutic interventions, was associated improvement levels of the quality of live, mainly the pain. Understanding the impact of such methodology in immunology of the FS, may constitute an alternative and effective approach. We compare the levels of serum cytokines and chemokines between nine patients with FS submitted to kinesiotherapy for 12 weeks and ten patients not submitted to kinesiotherapy. The kinesiotherapy was composed by self-stretching followed by a resistance training for upper and lower limbs. The protocol was carried out in three sections of eight to ten repetitions with 70% of the maximum load measured by test maximum of ten repetitions. After strengthening period patients performed a passive stretching. The training sessions lasted 50 min and were performed 3 times a week at least 12 weeks. Cytokines and chemokines were assessed in plasma using enzyme-linked immunosorbent assay and/or cytometric bead array. Patients with FS were being kinesiotherapy presented minors levels of interferon-γ, interleukin (IL)-17, IL-22, and IL-15 when compared to those not submitted to kinesiotherapy. No differences were observed for the detection of the chemokines chemokine ligand (CCL)-2, CCL-3, CCL-5, CCL-11, C-X-C motif chemokine 8 (CXCL-8), and CXCL-10. These results suggest that kinesiotherapy had a positive impact on inflammatory markers that are associated with disease worsening in FS.

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.

Acantholysis may precede elevation of circulating anti-desmoglein 3 antibody levels in pemphigus vulgaris presenting with desquamative gingivitis

Pemphigus vulgaris (PV) is an autoimmune, blistering disease that affects the mucosa and skin. The current theory favors the concept that anti-desmoglein (Dsg) 3 autoimmunity is the only pathogenic event needed to induce acantholysis. However, a few cases of active PV in the oral cavity had no detectable anti-Dsg 3 antibody. The aim of this study was to evaluate the differences in clinical and laboratory findings, whether or not the anti-Dsg 3 antibodies were present. This study was based on a retrospective review of 10 PV cases. The evaluation of the circulating autoantibody titers to Dsg 3 was conducted by using enzyme-linked immunosorbent assay (ELISA). An index value of 20 or more was used as the cutoff for a positive reaction. Only five of the 10 PV cases had a positive Dsg 3 ELISA. There were no differences in clinical, cytological, histopathological, and direct immunofluorescence findings, whether or not the anti-Dsg 3 antibodies were present. Of the five patients with a negative reaction at the time of diagnosis, the Dsg 3 ELISA became positive in the follow-up period in three cases. In the remaining two cases, the Dsg 3 ELISA was consistently negative for 18 months. Dsg 3 ELISA was negative early in some PV cases. Therefore, PV acantholysis may precede the elevation of circulating anti-Dsg 3 antibody levels. The diagnosis of PV should be considered based on comprehensive clinical, histopathological, and immunofluorescent criteria.

Pharmacotherapy: Its impact on morphofunctional characteristics of the epidermal barrier

Various pharmaceuticals used for topical and systemic therapy are capable of exerting significant impact on morphological and physiological characteristics of human epidermis, as well as its barrier properties. This may affect the course of dermatologic diseases and the efficacy of their treatment. In this literature review, the author analyzes the impact of various pharmaceutical classes on the morphofunctional characteristics of the epidermal barrier and formulates recommendations for skin disease treatment.

[Epidemiology, etiology and pathogenesis of oral mucosa bullous lesions]

OBJECTIVE Based on the data available in modern literature, to conduct a study on the epidemiology, etiology and pathogenesis of bullous lesions of the oral mucosa (pemphigus vulgaris, pemphigoid bullosa, lichen ruber planus).

MATERIAL AND METHODS

The article is based on the study of materials of foreign and domestic research databases Pubmed and Elibrary. Used literature data over the past 15 years.

RESULTS

According to domestic and foreign studies, among dermatological diseases, the most frequently detected diseases are: lichen ruber planus, pemphigoid bullosa and pemphigus vulgaris. The initial signs of these diseases are often neglected, both in patients and doctors, which leads to irreversible changes and severe course of the pathological process. In this connection, the number of patients with these lesions of the oral mucosa increases every year in all countries of the world. Bullous lesions of the oral mucosa are inflammatory and destructive diseases characterized mainly by recurrent course, variety of clinical manifestations, resistance to various therapeutic drugs. The specific features of the course of these diseases are explained both by the anatomical and physiological features of the oral mucosa, and by the etiologic and pathogenetic mechanisms of development. Currently, autoimmune processes play a leading role in the genesis of diseases, developing in response to changes in the antigenic structure of epidermal and epithelial cells under the influence of various damaging agents.

CONCLUSION

Thanks to the study, it was found that currently there are no data confirming the presence of microbial contamination of the tissues of the oral mucosa in the pathology under study. Not enough information on the factors of the immune response, in particular, on proinflammatory cytokines in the tissues of the oral mucosa.

Skin Barrier and Autoimmunity-Mechanisms and Novel Therapeutic Approaches for Autoimmune Blistering Diseases of the Skin

One of the most important functions of the skin besides regulating internal body temperature includes formation of the barrier between the organism and the external environment, hence protecting against pathogen invasion, chemical and physical assaults and unregulated loss of water and solutes. Disruption of the protective barrier is observed clinically in blisters and erosions of the skin that form in autoimmune blistering diseases where the body produces autoantibodies against structural proteins of the epidermis or the epidermal-dermal junction. Although there is no cure for autoimmune skin blistering diseases, immune suppressive therapies currently available offer opportunities for disease management. In cases where no treatment is sought, these disorders can lead to life threatening complications and current research efforts have focused on developing therapies that target autoantibodies which contribute to disease symptoms. This review will outline the involvement of the skin barrier in main skin-specific autoimmune blistering diseases by describing the mechanisms underpinning skin autoimmunity and review current progress in development of novel therapeutic approaches targeting the underlying causes of autoimmune skin blistering diseases.

Pulse therapy: Opening new vistas in treatment of pemphigus

Pemphigus is comprised of a group of life-threatening autoimmune diseases that is characterized by circulating IgG antibodies targeting several types of keratinocyte antigens. After introduction of systemic steroids, survival has improved dramatically. However, mortality and morbidity were still very high due to side effects of steroids. Pulse therapy is defined as discontinuous/intermittent intravenous infusion of very high doses of corticosteroids along with certain immunosuppressive agents over a short period. This therapy was introduced to minimize the side effects of conventional corticosteroid therapy. The target is to achieve a faster response and stronger efficacy and to decrease the need for long-term use of systemic corticosteroids. As a result, this therapy has gained its popularity since three decades. The purpose of this article is to review the various available pulse therapy regimens with dosage, indications and contraindications and side effects.

Synergy among non-desmoglein antibodies contributes to the immunopathology of desmoglein antibody-negative pemphigus vulgaris

Pemphigus vulgaris (PV) is a potentially lethal mucocutaneous blistering disease characterized by IgG autoantibodies (AuAbs) binding to epidermal keratinocytes and inducing this devastating disease. Here, we observed that non-desmoglein (Dsg) AuAbs in the sera of patients with Dsg1/3 AuAb-negative acute PV are pathogenic, because IgGs from these individuals induced skin blistering in neonatal mice caused by suprabasal acantholysis. Serum levels of AuAbs to desmocollin 3 (Dsc3), M3 muscarinic acetylcholine receptor (M3AR), and secretory pathway Ca2+/Mn2+-ATPase isoform 1 (SPCA1) correlated with the disease stage of PV. Moreover, AuAb absorption on recombinant Dsc3, M3AR, or SPCA1 both prevented skin blistering in the passive transfer of AuAbs model of PV in BALB/c mice and significantly decreased the extent of acantholysis in a neonatal mouse skin explant model. Although acantholytic activities of each of these immunoaffinity-purified AuAbs could not induce a PV-like phenotype, their mixture produced a synergistic effect manifested by a positive Nikolskiy sign in the skin of neonatal mice. The downstream signaling of all pathogenic non-Dsg AuAbs involved p38 mitogen-activated protein kinase (MAPK)-mediated phosphorylation and elevation of cytochrome c release and caspase 9 activity. Anti-Dsc3 and anti-SPCA1 AuAbs also activated SRC proto-oncogene, nonreceptor tyrosine kinase (SRC). Of note, although a constellation of non-Dsg AuAbs apparently disrupted epidermal integrity, elimination of a single pathogenic AuAb could prevent keratinocyte detachment and blistering. Therefore, anti-Dsg1/3 AuAb-free PV can be a model for elucidating the roles of non-Dsg antigen-specific AuAbs in the physiological regulation of keratinocyte cell-cell adhesion and blister development.

Pemphigus and mucous membrane pemphigoid: An update from diagnosis to therapy

Pemphigus diseases (PDs) and mucous membrane pemphigoid (MMP) are a group of immune-mediated mucocutaneous disorders clinically characterized by the formation of blisters, erosions and ulcers. The skin and mucous membranes are predominantly affected, with the oropharyngeal mucosa as the initially involved site. Ocular involvement is also a frequent feature of these diseases. Because of the considerable overlap in their clinical presentations, the diagnosis of PDs vs. MMP can be challenging. A recognition of their specific immunological and histopathologic features is crucial in the differential diagnosis. Treatment modalities include systemically administered corticosteroids, steroid-sparing immunosuppressive agents, and biologic therapies (rituximab, intravenous immunoglobulins, and anti-tumor necrosis factor agents). Topical, oral, conjunctival, or intralesional corticosteroids as well as anti-inflammatory drugs and antibiotics are prescribed as needed.

The association between ST18 gene polymorphism and severe pemphigus disease among Iranian population

Recently, ST18 polymorphism has played a role in increasing the risk of pemphigus among some populations such as Egyptian and Jewish. In addition, a variant within the ST18 promoter gene was shown to induce ST18 upregulation and cytokine secretion leading to keratinocyte susceptibility to anti-desmoglein antibodies. Thus, the present study aimed to assess the ST18 single nucleotide polymorphisms (SNP) relationship with pemphigus, disease severity and family history among Iranian population. A total of 111 pemphigus patients and 201 healthy controls were genotyped for three ST18 SNPs rs2304365, rs10504140 and rs4074067 by using TETRA-ARMS PCR method. The results indicated that risk allele A in rs2304365 was significantly higher in pemphigus patients, compared with the amount in the control group (OR = 2.43 CI = 1.49-3.975, P < 0.001). Thus, A allele represents a risk factor for pemphigus. Further, the patients carrying the risk allele had a more severe disease and a higher age of disease onset while no relationship was observed between the number of relapses and positive family history of pemphigus with the risk allele. Finally, dominant model was regarded as the strongest inheritance model for the associated risk. The present study confirmed the relationship between ST18 gene with pemphigus disease, a more severe disease, and a higher age of disease onset.