Localized pemphigus vulgaris on scalp: an atypical presentation

We present two middle-aged patients with pruritic, crusted scalp erosions. Skin biopsy showed epidermal acantholysis with IgG and C3 intercellular deposits on direct immunofluorescence, leading to the diagnosis of localized pemphigus vulgaris. Resolution of the lesions without relapse occurred after low doses of oral prednisone and intralesional triamcinolone acetonide.

Direct immunofluorescence (DIF) versus immunohistochemical (IHC) staining of complements and immunoglobulins (Ig) in pemphigus group

INTRODUCTION

Pemphigus is a group of bullous disorders of the skin characterized by the formation of autoantibodies present in the intercellular junction of the epidermis. Diagnosis is made by clinical, histopathological examination, and DIF. As DIF needs frozen sections, fluorescent tagged antibodies, UV light microscope for examination, and trained personnel, its non-availability makes a definitive diagnosis challenging.

AIMS AND OBJECTIVES

To evaluate the utility of IHC staining of complements and Ig in cases of Pemphigus.

MATERIALS AND METHODS

Twenty-six diagnosed cases of Pemphigus were stained by Peroxidase immunohistochemical method using monoclonal antibody to IgG, IgA, IgM, IgG4, C3, C4 d with DAB as chromogen. Pemphigus cases include twenty of pemphigus vulgaris (PV), four cases of pemphigus foliaceous (PF), and two of pemphigus vegetans (Pveg). Positivity was defined as the deposition of Ig and complements as distinct, continuous brown staining of keratinocytes at intercellular junctions.

RESULT

On IHC total of 20 PV 17 showed positivity (85%) for IgG, 11 (55%) C4d, 19 (95%) C3d, and 16 (80%) IgG4 deposits at the intercellular junction of the epidermis. All cases of PF showed a deposit of IgG, with three (75%) cases for IgG4, C3d, and C4d. Both cases of Pveg showed positivity for IgG and C4d while one case was negative for IgG4 and C3d. The overall IgG, C3, IgG4, and C4d expression for pemphigus was seen in 88%, 88%, 76.9%, and 61.5% of cases. The relation between these markers, combination of IgG and C3, was best related to each other ( P value = 0.80). The sensitivities for IgG, IgG4, and C3 were 77.8%%, 73%, and 73% resp.

CONCLUSION

We conclude that IHC is a useful tool in the diagnosis of PV with the highest sensitivity of IgG and C3d. The combination of IgG and C3d could replace the DIF in almost all of our cases, so IHC on FFPE sections be used as an alternative method to DIF.

Concordance of clinical, histopathologic and direct Immunofluorescence findings in patients with intraepidermal immunobullous disorders

Objective

To determine the concordance among clinical, histopathological and immunofluorescence as diagnostic methods for intraepidermal immunobullous disorders.

METHODS

The prospective cross-sectional study was conducted at the Institute of Skin Diseases, Karachi, from December 2020 to December 2022, and comprised adult patients of either gender presenting with complaints of bullae, vesicles, pustules and crusts on the skin or mucous membrane. Diagnostic findings of each patient as obtained by clinical assessment, microscopy and direct immunofluorescence were compared. Data was analysed using SPSS 19.

RESULTS

Of the 81 patients, 41(50.6%) were males and 40(49.4%) were females. The overall median age was 35 years (interquartile range: 23 years), with 66(75%) patients aged 19-55 years. The predominant body site involved was the trunk 49(60.5%), followed by mucosa 26(32.1%). Clinical diagnosis detected 80(98.7%) cases, compared to 76(93.8%) by microscopy and 81(100%) by direct immunofluorescence.

Conclusion

Direct immunofluorescence was found to be the gold standard for a confirmatory diagnosis of intraepidermal immunobullous disorders, especially when clinical and histopathology findings were inconclusive.

Demonstration of direct immunofluorescence on three substrates in a case of pemphigus

Direct immunofluorescence (DIF) on skin is considered as the gold standard in the diagnosis of pemphigus. However, alternate substrates can be used. We demonstrate DIF on three substrates, skin biopsy specimen, anagen hair and scrapings of oral erosions. Collection of alternative substrates can be more acceptable to young patients as it is less invasive. It may also be used to detect relapses in cases of pemphigus.

Immune-mediated oral mucosal pathology: a comprehensive review and update for clinicians - part II

The oral mucosa can be involved in a wide variety of mucocutaneous conditions that may present primarily in the mouth or affect other cutaneous or mucosal sites. Many of these conditions are immune mediated and typically present as inflammatory mucosal pathology. Patients experiencing such conditions usually seek medical evaluation and treatment due to the associated pain and discomfort, and occasionally taste disturbance or dysphagia and the overall deterioration in the oral health-related quality of life. These conditions share some common features and there could be some overlap in their clinical presentation, which can lead to delays in diagnosis and proper management of patients. Clinicians dealing with such disorders, including dermatologists, need to be aware of the oral manifestations of mucocutaneous conditions, their clinical features, underlying mechanisms, diagnostic approaches, and treatment options, as well as the recent advances in the research on these conditions. This review provides a comprehensive, evidence-based reference for clinicians, with updated insights into a group of immune mediated conditions known to cause oral mucosal pathology. Part one will cover oral lichen planus, erythema multiforme and systemic lupus erythematosus, while part two will cover recurrent aphthous stomatitis, pemphigus vulgaris and mucous membrane pemphigoid, in addition to the less common disorders linear IgA disease, dermatitis herpetiformis and epidermolysis bullosa.

Adalimumab induced exacerbation of psoriasis in patients with combined pemphigus: A case report

RATIONALE

Psoriasis is an immune-related disease caused by genetic factors, abnormalities in the immune system and environmental factors, while pemphigus is an autoimmune disease caused by the autoimmune system attacking the skin and mucosal tissues. Herein, we aimed to report a rare case of adalimumab induced exacerbation of psoriasis patients with pemphigus. The rare disease causes considerable challenges for clinical diagnosis and treatment.

PATIENT CONCERNS

The patient was a 43-year-old man with intermittent erythema and scaling all over the body for more than 20 years, and blisters and vesicles on the trunk and limbs for 1 month. Half a year ago, the patient had blisters on the limbs, and was diagnosed with deciduous pemphigus in a hospital, and the blisters subsided after being given traditional Chinese medicine orally. Half a month ago, the erythema area was enlarged, and adalimumab 80 mg intramuscular injection was given for 1 time after consultation in the hospital. On the following day, the area of erythema and scales was suddenly enlarged obviously compared with the previous 1, and obvious blisters and vesicles appeared on the limbs, neck, and trunk, which were aggravated progressively and accompanied by obvious itching and pain.

DIAGNOSES

The patient was diagnosed with psoriasis in patients with combined pemphigus.

INTERVENTION

After combined treatment with methylprednisolone and cyclosporine, the skin lesions have basically recovered.

OUTCOMES

The skin lesions have basically healed. Follow up for 6 months without recurrence.

LESSONS

Methylprednisolone combined with cyclosporine may be an option in treating patients with psoriasis patients with pemphigus.

Pregnancy in pemphigus vulgaris: A systematic review

PROBLEM

Pemphigus vulgaris may worsen during pregnancy, leading to both maternal and fetal complications. The relationship between pemphigus vulgaris and pregnancy remains unclear, and the outcomes and treatments of pemphigus vulgaris during pregnancy have not been extensively discussed.

METHOD OF STUDY

This article systematically reviews the literature, focusing on the relationship between pemphigus vulgaris and pregnancy. We conducted comprehensive searches in PubMed, Embase, Cochrane Library, and Web of Science databases, identifying 42 studies reporting the disease course, pregnancy outcomes, and management of both pregnancy and pemphigus vulgaris.

RESULTS

A total of 57 cases were included in the analysis, categorized into three distinct forms: pemphigus vulgaris onset before pregnancy (n = 33), onset during pregnancy (n = 20), and onset during the postpartum period (n = 4). Fifty four cases reported treatment strategies, among them, 44 cases (81.5%) initially received systemic corticosteroid therapy during pregnancy. Out of these cases, 7 (15.9%) did not achieve successful remission and required alternative treatment approaches. In terms of pregnancy outcomes, 23 out of 62 neonates (37.1%) exhibited skin lesions or tested positive for anti-dsg IgG in their serum, while 16 neonates (25.8%) experienced other complications.

CONCLUSIONS

These findings highlight the importance of effectively managing pemphigus vulgaris during pregnancy to ensure optimal outcomes.

Association of Human Endogenous Retrovirus-W (HERV-W) Copies with Pemphigus Vulgaris

BACKGROUND

Pemphigus is classified as a group of chronic, recurrent, and potentially fatal bullous autoimmune diseases that leads to blisters and skin lesions resulting from IgG antibodies and the loss of cellular connections in the epidermis. Human endogenous retrovirus (HERV) sequences and their products (RNA, cytosolic DNA, and proteins) can modulate the immune system and contribute to autoimmunity. The extent to which, HERV-W env copies may be involved in the pathogenesis of pemphigus remains to be elucidated.

AIM

This study aimed to comparatively evaluate the relative levels of HERV-W env DNA copy numbers in the peripheral blood mononuclear cells (PBMCs) of pemphigus vulgaris patients and healthy controls.

METHODS

Thirty-one pemphigus patients and the corresponding age- and sex-matched healthy controls were included in the study. The relative levels of HERV-W env DNA copy numbers were then evaluated by qPCR using specific primers, in the PBMCs of the patients and controls.

RESULTS

Our results indicated that relative levels of HERV-W env DNA copy numbers in the patients were significantly higher than that in the controls (1.67±0.86 vs. 1.17±0.75; p = 0.02). There was also a significant difference between the HERV-W env copies of male and female patients (p = 0.001). Furthermore, there was no relationship between the HERV-W env copy number and disease onset (p = 0.19) . According to the obtained data, we could not find any relationship between the HERV-W env copy number and serum Dsg1(p=0.86) and Dsg3 (p=0.76) levels.

CONCLUSION

Our results indicated a positive link between the HERV-W env copies and pathogenesis of pemphigus. The association between clinical severity score and HERVW env copies in the PBMCs as a biomarker for pemphigus needs further studies.

A case of herpetiform pemphigus mimicking bullous pemphigoid after using secukinumab and successfully treated with sulfasalazine

Interleukin 17A (IL-17A) inhibitors, such as secukinumab, have been widely used as the mainstream treatment for chronic plaque psoriasis; however, cutaneous adverse events have been reported. Here, we report a 43-year-old Chinese man who developed herpetiform pemphigus (HP) during secukinumab treatment for his psoriasis. He presented with (1) clinical features of HP, which resembled bullous pemphigoid; histopathological features of intraepidermal blisters, eosinophilic/neutrophilic spongiosis, and liquefactive degeneration of the basal cell layer; (3) positive anti-desmoglein 1 antibody by enzyme-linked immunosorbent assay and cell surface IgG reactivity within the epidermis by indirect immunofluorescence assay; and (4) a satisfactory response to salicylazosulfapyridine (sulfasalazine). To the best of our knowledge, this is the first report of the development of HP after the use of secukinumab for psoriasis.

A case report of esophageal cancer in a patient with pemphigus vulgaris: A coincidence or something beyond that?

BACKGROUND

Pemphigus is a group of rare but serious autoimmune blistering disorders, affecting skin and mucus membrane. Different reports have been published in respect to the coexistence of pemphigus with neoplasms, especially lympho-proliferative ones.

CASE

Here, we have reported a patient previously diagnosed with pemphigus vulgaris (PV) who developed esophageal squamous cell carcinoma (SCC).

CONCLUSION

Dyspepsia and dysphagia in patients with PV might not be merely due to pemphigus erosions or simply an adverse effect of systemic corticosteroid such as irritant or candidal esophagitis and should raise the suspicion of more serious conditions in case of resistant symptoms without appropriate response to treatment.

Two cases of cutaneous-type pemphigus vulgaris and a case of pemphigus foliaceus without mucosal involvement despite high anti-desmoglein 3 autoantibody levels

Pemphigus is an autoimmune blistering disease with two major subtypes, pemphigus vulgaris (PV) and pemphigus foliaceus (PF). Although most patients with PV show oral lesions, cutaneous type PV (C-PV) is a rare subtype clinically characterized by predominant cutaneous involvement with no or subtle mucosal lesions. Patients with PF present with only skin involvement; they do not have mucosal lesions. Serologically, autoantibodies against desmoglein (Dsg) 3 and Dsg1 are observed in C-PV whereas PF is associated with anti-Dsg1 antibodies only. Herein, we describe three cases of pemphigus presenting with predominant skin lesions and no mucosal involvement despite high anti-Dsg 3 autoantibody levels in chemiluminescent enzyme immune assays (CLEIAs). In addition, anti-Dsg 1 autoantibodies were positive in patients 2 and 3, but negative in patient 1 based on CLEIAs. Histological examination of the skin showed suprabasal acantholysis in patients 1 and 2, and blister formation in the upper epidermis in patient 3. Histopathology of the oral membrane in patients 1 and 2 showed subtle acantholysis in the suprabasal layer. Thus, we diagnosed patients 1 and 2 as having cutaneous type PV and patient 3 as having PF. Ethylenediaminetetraacetic acid-treated enzyme-linked immunosorbent assay demonstrated a low proportion of anti-Dsg3 autoantibodies recognizing Ca2+ -dependent epitopes, antibodies against which are thought to be the main contributor to acantholysis. Thus, along with Dsg1 antibodies, weak anti-Dsg3 antibodies could induce acantholysis in the skin, but they are insufficient to induce mucosal lesions.

Is transition between subtypes of pemphigus possible? A series of pemphigus vulgaris patients showing the transition to pemphigus foliaceus

BACKGROUND

Pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are subtypes of pemphigus with distinct clinical and laboratory features. The transition between these two subtypes has rarely been reported previously.

METHODS

The data of PV patients who exhibited clinical and immunoserological transition to PF during the follow-up period were retrospectively evaluated regarding their demographical, clinical, and laboratory characteristics.

RESULTS

Among 453 patients diagnosed with PV, 13 (2.9%) patients exhibited clinical and immunoserological transition from PV to PF. The mean age of PV patients at the time of diagnosis was 39.8 ± 14.7 (19‒62) years and 7 (53.8%) of them were female. These patients showed clinical and immunoserological transition from PV to PF after a period ranging from 4 months to 13 years (mean 36.2 ± 41 months). In addition to typical clinical features of PF, all patients had positive anti-desmoglein-1 and negative anti-desmoglein-3 antibody levels after the clinical transition had occurred without any mucosal involvement. During a mean 7.8 ± 5.8 (2‒21) years of follow-up period after the transition from PV to PF, only one female patient had experienced a re-transition to PV characterized by a relapse of disease involving mucosal surfaces with positive anti-desmoglein-3 antibody levels following a 5-year period of remission period without treatment.

STUDY LIMITATIONS

Single-center study with a retrospective study design.

CONCLUSION

Our series is the largest group of patients reported to show the transition from PV to PF to date with a long follow-up period. The reason behind the disappearance of anti-desmoglein-3 antibodies and the pathogenesis of this phenomenon is not yet elucidated.

[The main autoimmune bullous diseases]

Autoimmune bullous diseases are disorders in which the immune system mistakenly attacks certain molecules that act as "glue" in the various layers of the skin, leading to the formation of bullae or vesicles. A bulla is a liquid-containing lesion over five millimeters in size on the skin or mucous membranes. It forms due to a loss of cohesion between the epidermis and dermis, or between keratinocytes within the epidermis. Diagnosis is based on biopsies, which show the presence of autoantibodies and the depth of skin detachment. A blood test can be used to identify circulating autoantibodies.

Current biologics in treatment of pemphigus foliaceus: a systematic review

Background

Pemphigus foliaceus (PF) differs from pemphigus vulgaris (PV) in that it affects only the skin and mucous membranes are not involved. Pemphigus is commonly treated with systemic corticosteroids and immunosuppressive agents (ISAs). More recently, biologics have been used. The current literature on biologic therapy often combines treatment of PF with PV, hence it is often difficult for clinicians to isolate the treatment of PF from PV. The purpose of this review was to provide information regarding the use of current biological therapy, specifically in PF.

Materials and methods

A search of PubMed, Embase, and other databases was conducted using keywords pemphigus foliaceus (PF), rituximab (RTX), intravenous immunoglobulin (IVIg), and biologics. Forty-one studies were included in this review, which produced 105 patients with PF, treated with RTX, IVIg, or a combination of both. Eighty-five patients were treated with RTX, eight patients with IVIg, and 12 received both RTX and IVIg.

Results

Most patients in this review had PF that was nonresponsive to conventional immunosuppressive therapies (CIST), and had significant side effects from their use. RTX treatment resulted in complete remission (CR) in 63.2%, a relapse rate of 39.5%, an infection rate of 19.7%, and a mortality rate of 3.9%. Relapse was greater in the lymphoma (LP) protocol than the rheumatoid arthritis (RA) protocol (p<0.0001). IVIg led to CR in 62.5% of patients, with no relapses or infections. Patients receiving both biologics experienced better outcomes when RTX was first administered, then followed by IVIg. Follow-up durations for patients receiving RTX, IVIg, and both were 22.1, 24.8, and 35.7 months, respectively.

Discussion

In pemphigus foliaceus patients nonresponsive to conventional immunosuppressive therapy or in those with significant side effects from CIST, RTX and IVIg appear to be useful agents. Profile of clinical response, as well as relapse, infection, and mortality rates in PF patients treated with RTX were similar to those observed in PV patients. The data suggests that protocols specific for PF may produce better outcomes, less adverse effects, and improved quality of life.

ODSS vs. ABSIS and PDAI oral parts in pemphigus vulgaris: inter-rater reliability and testing times

OBJECTIVES

The existence of standard methods for diagnosis and measuring the severity of diseases leads to a more accurate severity assessment, the possibility of following up, and the possibility of comparing the results of studies. This study aimed to compare different pemphigus vulgaris (PV) assessment methods regarding inter-observer reliability and testing times-focusing on oral parts.

MATERIALS AND METHODS

Two dermatologists evaluated orally involved PV patients by oral parts of Autoimmune Bullous Skin Disorder Intensity Score (ABSIS), Pemphigus Disease Area Index (PDAI), and Oral Disease Severity Score (ODSS).

RESULTS

Seventy patients completed the study. The intraclass correlation coefficient showed the evaluators' agreements on ABSIS, PDAI, and ODSS with 0.98, 0.94, and 0.95, respectively. Reliability analyses showed near-perfect relationships between each scoring methods pairs. There was no association between lesion sites and disease severity. The PDAI scoring duration was significantly shorter, and the ABSIS scoring duration was significantly longer.

CONCLUSION

ODSS is valid for evaluating oral involvement in patients with PV and relates to ABSIS and PDAI almost perfectly. Besides, it was shown that the evaluation of patients' oral involvement based on PDAI and ODSS is done in about 1 min, which seems clinically reasonable.

Immune-mediated oral mucosal pathology: a comprehensive review and update for clinicians. Part I

The oral mucosa can be involved in a wide variety of mucocutaneous conditions that may present primarily in the mouth or affect other cutaneous or mucosal sites. Many of these conditions are immune mediated and typically present as inflammatory mucosal pathology. Patients experiencing such conditions usually seek medical evaluation and treatment due to the associated pain and discomfort and occasionally taste disturbance or dysphagia and the overall deterioration in the oral health-related quality of life. These conditions share some common features and there could be some overlapping in their clinical presentation, which can lead to delays in diagnosis and proper management of patients. Clinicians dealing with such disorders, including dermatologists, need to be aware of the oral manifestations of mucocutaneous conditions, their clinical features, underlying mechanisms, diagnostic approaches, and treatment options, as well as the recent advances in the research on these conditions. This review provides a comprehensive, evidence-based reference for clinicians, with updated insights into a group of immune mediated conditions known to cause oral mucosal pathology. Part one will cover oral lichen planus, erythema multiforme and systemic lupus erythematosus, while part two will cover pemphigus vulgaris and mucous membrane pemphigoid, recurrent aphthous stomatitis, in addition to the less common disorders linear IgA disease, dermatitis herpetiformis and epidermolysis bullosa.

Efficacy of anti-desmoglein 1 and anti-desmoglein 3 levels by enzyme-linked immunosorbent assay compared to biopsy of chronic oral ulcerative diseases with positive Nikolsky's sign to diagnose oral pemphigus vulgaris with or without skin involvement: a retrospective institutional observational pilot study

OBJECTIVE

We assessed the efficacy of anti-desmoglein 1 (anti-DSG1) and anti-DSG3 levels by enzyme-linked immunosorbent assay (ELISA) as a preliminary diagnostic test in the diagnosis of oral pemphigus vulgaris (OPV) with or without skin involvement compared to biopsy.

STUDY DESIGN

We retrospectively analyzed data collected from 23 patients (mean age 45.13 years) who had presented with chronic oral ulcerations, desquamative gingivitis, and a positive Nikolsky's sign. We performed ELISA, histopathologic examination, and direct immunofluorescence (DIF) and then calculated the sensitivity and specificity of the results of ELISA, histopathology, DIF, and the presence of a positive Nikolsky's sign in diagnosis.

RESULTS

The ELISA results showed that 18 patients had elevated anti-DSG3 levels, of whom 8 also had elevated anti-DSG1 levels. The histopathology results indicated that 18 patients had OPV, of whom 4 had oral lichen planus, and 1 had sub-epithelial blistering disease confirmed to be mucous membrane pemphigoid MMP by DIF. ELISA, histopathology, and DIF had a 100% sensitivity and specificity, and the presence of a positive Nikolsky's sign had a sensitivity and specificity of 100% and 78.26%, respectively.

CONCLUSIONS

Measurement of anti-DSG1 and anti-DSG3 levels by ELISA warrants consideration as a first-line diagnostic test for early detection of OPV with or without skin involvement over biopsy.

Cut-off values for IL-21 and IL-23 as biochemical markers for pemphigus vulgaris

Pemphigus vulgaris (PV) is a potentially fatal mucocutaneous autoimmune disease characterized by severe skin lesions. Interleukin-21 (IL-21) and IL-23 have been linked to several autoimmune inflammatory diseases that may have a critical role in PV immunopathogenesis, including T-helper 17 (Th17) development. This study aimed to compare the serum levels of IL-21 and IL-23 in patients with PV and healthy controls. This case-control study included 90 participants (45 patients and 45 controls). Serum IL-21 and IL-23 were measured using the Sandwich-ELISA method provided by Sunlong Biotech, China. The findings revealed statistically significant results for IL-21 O.D. and Conc. (p=0.012*) and highly significant results for IL-23 O.D. and Conc. (p=0.000**). Furthermore, cut-off values were established for IL-21 (O.D.=0.071 pg/mL, Conc.=6.468 pg/mL) and IL-23 (O.D.=0.141 pg/mL, Conc.=6.745 pg/mL). These results indicate a potential association between PV and IL-21, IL-23, and the identified cut-off values. The particular roles of cytokines and how they can be utilized to treat PV require more investigation. To our knowledge, this was the first study to detect a cut-off point for IL-21 and IL-23 that may be used as novel and cost-effective biochemical markers for disease diagnosis.

Interleukin-37 inhibits desmoglein-3 endocytosis and keratinocyte dissociation via upregulation of Caveolin-1 and inhibition of the STAT3 pathway

BACKGROUND

Pemphigus vulgaris (PV) is a potentially fatal autoimmune bullous disease primarily caused by acantholysis of keratinocytes attributed to pathogenic desmoglein-3 (Dsg3) autoantibodies. Interleukin-37 (IL-37) reportedly plays important roles in a variety of autoimmune diseases, but its role in PV is not clear.

OBJECTIVES

To investigate whether IL-37 plays a role in the occurrence and progression of PV.

METHODS

HaCaT keratinocytes were stimulated with anti-Dsg3 antibody to establish an in vitro PV model, which was defined as anti-Dsg3 group. Cells incubated with medium without anti-Dsg3 treatment were used as control. IL-37 was cultured with these cells infected with or without lentiviral vector shRNA-Caveolin-1 (sh-Cav-1-LV). Cell dissociation assay and immunocytofluorescence were performed to assess keratinocyte dissociation, keratin retraction and Dsg3 endocytosis. Real-time PCR was used to detect the mRNA level of Cav-1, and western blot was used to determine the protein expression of Cav-1, Dsg3, STAT3 and phosphorylated-STAT3 (p-STAT3).

RESULTS

The anti-Dsg3 group showed more cell debris, increased keratin retraction, increased Dsg3 endocytosis, reduced Cav-1 expression and co-localization than the control group, while IL-37 treatment neutralized all of these changes. Interestingly, Cav-1 knockdown supressed the inhibitory effect of IL-37 on keratinocyte dissociation and Dsg3 internalization. The protein expression of p-STAT3 was increased in keratinocytes of the PV model but decreased by IL-37. Re-activation of the STAT3 pathway by colivelin supressed the inhibitory effect of IL-37 on keratinocyte dissociation and Dsg3 internalization, along with upregulation of Cav-1 and Dsg3.

CONCLUSIONS

IL-37 inhibited keratinocyte dissociation and Dsg3 endocytosis in an in vitro PV model through the upregulating Cav-1 and inhibiting STAT3 pathway.

The human skin organ culture model as an optimal complementary tool for murine pemphigus models

Pemphigus is a severe autoimmune bullous disease of the skin and/or mucous membranes caused by autoantibodies that mainly target the adhesion proteins desmoglein (Dsg) 3 and/or Dsg1. Clinically, pemphigus is characterized by flaccid blistering, leading to severe water and electrolyte loss. Before the introduction of corticosteroid treatment, the disease turned out to be fatal in many cases. Despite recent therapeutic improvements, treatment of pemphigus patients is centred on prolonged systemic immunosuppression and remains challenging. Current drug development for pemphigus has a strong focus on disease-causing B cells and autoantibodies and, more recently, also on modulating autoantibody-induced tissue pathology and keratinocyte signalling. This drug development requires reliable pre-clinical model systems replicating the pathogenesis of the human disease. Among those are neonatal and adult mouse models based on the transfer of Dsg3, Dsg1/3 or Dsg1-specific autoantibodies. To reduce the number of animal experiments, we recently established a standardized human skin organ culture (HSOC) model for pemphigus. This model reproduces the clinical phenotype of autoantibody-induced tissue pathology in pemphigus vulgaris. For induction of blistering, a recombinant single-chain variable fragment (scFv) targeting both Dsg1 and 3 is injected into pieces of human skin (obtained from plastic surgeries). Further characterization of the HSOC model demonstrated that key morphologic, molecular and immunologic features of pemphigus are being replicated. Thus, the pemphigus HSOC model is an excellent alternative to pemphigus animal model systems that are based on the transfer of (auto)antibodies.

cAMP: A master regulator of cadherin-mediated binding in endothelium, epithelium and myocardium

Regulation of cadherin-mediated cell adhesion is crucial not only for maintaining tissue integrity and barrier function in the endothelium and epithelium but also for electromechanical coupling within the myocardium. Therefore, loss of cadherin-mediated adhesion causes various disorders, including vascular inflammation and desmosome-related diseases such as the autoimmune blistering skin dermatosis pemphigus and arrhythmogenic cardiomyopathy. Mechanisms regulating cadherin-mediated binding contribute to the pathogenesis of diseases and may also be used as therapeutic targets. Over the last 30 years, cyclic adenosine 3',5'-monophosphate (cAMP) has emerged as one of the master regulators of cell adhesion in endothelium and, more recently, also in epithelial cells as well as in cardiomyocytes. A broad spectrum of experimental models from vascular physiology and cell biology applied by different generations of researchers provided evidence that not only cadherins of endothelial adherens junctions (AJ) but also desmosomal contacts in keratinocytes and the cardiomyocyte intercalated discs are central targets in this scenario. The molecular mechanisms involve protein kinase A- and exchange protein directly activated by cAMP-mediated regulation of Rho family GTPases and S665 phosphorylation of the AJ and desmosome adaptor protein plakoglobin. In line with this, phosphodiesterase 4 inhibitors such as apremilast have been proposed as a therapeutic strategy to stabilize cadherin-mediated adhesion in pemphigus and may also be effective to treat other disorders where cadherin-mediated binding is compromised.

Pemphigus Vulgaris: More Than Just a Skin Disease

INTRODUCTION

Pemphigus is a group of autoimmune diseases of the skin and mucous membranes that is characterized by multiple bullae formation. It is caused by autoantibodies directed against the cell surface of keratinocytes, resulting in the loss of cell-cell adhesion of keratinocytes. This disease can be very debilitating and difficult to treat if large surface areas are involved.

METHODS

We performed a retrospective review of a complex case of pemphigus vulgaris in a 24-year-old man who develop partial-thickness skin lesions distributed throughout the entire body with a total body surface of 80% short after an episode of strep throat treated with amoxicillin.

RESULTS

The patient had a complicated hospital course in which the standard treatment of the disease led to adverse effects that were successfully managed at our busy burn center.

CONCLUSIONS

Pemphigus vulgaris is a complex skin disease in which treatment techniques carry their risk and must be tailored to the patient's specific needs. Treatment of this conditions at a burn center would be beneficial as demonstrated with conditions like Stevens-Johnson syndrome and toxic epidermal necrolysis.