Single-cell sequencing reveals distinct immune cell features in cutaneous lesions of pemphigus vulgaris and bullous pemphigoid.

Bullous pemphigoid (BP) and pemphigus vulgaris (PV) are two common subtypes of autoimmune bullous disease (AIBD). The key role of circulating autoreactive immune cells contributing to skin damage of AIBD has been widely recognized. Nevertheless, the immune characteristics in cutaneous lesions remain unclear. Here, we performed single-cell RNA sequencing (scRNA-seq) and single-cell VDJ sequencing (scRNA-seq) to generate transcriptional profiles for cells and T/B cell clonetype in skin lesions of BP and PV. We found that the proportions of NK&T, macrophages/ dendritic cells, B cells, and mast cells increased in BP and PV lesions. Then, BP and PV cells constituted over 75% of all myeloid cell subtypes, CD4+ T cell subtypes and CD8+ T cell subtypes. Strikingly, CD8+ Trm was identified to be expanded in PV, and located in the intermediate state of the pseudotime trajectory from CD8+ Tm to CD8+ Tem. Interestingly, CD8+ Tem and CD4+ Treg highly expressed exhaustion-related genes, especially in BP lesions. Moreover, the enhanced cell communication between stromal cells and immune cells like B cells and macrophages/ dendritic cells was also identified in BP and PV lesions. Finally, clone expansion was observed in T cells of BP and PV compared with HC, while CD8+ Trm represented the highest ratio of hyperexpanded TCR clones among all T cell subtypes. Our study generally depicts a large and comprehensive single-cell landscape of cutaneous lesions and highlights immune cell features in BP and PV. This offers potential research targets for further investigation.

Survey: Preferred practice patterns in the diagnosis of mucous membrane pemphigoid amongst cornea specialists.

PURPOSE: To evaluate preferred diagnostic tools and treatment decision-making factors in cases suspicious of mucous membrane pemphigoid (MMP) amongst ophthalmologists and cornea specialists. METHODS: Web-based survey, consisting of 14 multiple choice questions, posted to the Cornea Society Listserv Keranet, the Canadian Ophthalmological Society Cornea Listserv, and the Bowman Club Listserv. RESULTS: One hundred and thirty-eight ophthalmologists participated in the survey. Eighty-six percent (86%) of respondents were cornea trained and practiced in either North America or Europe (83%). Most respondents (72%) routinely perform conjunctival biopsies for all suspicious cases of MMP. For those who do not, fear that biopsy will exacerbate inflammation was the most common reason to defer investigation (47%). Seventy-one percent (71%) performed biopsies from perilesional sites. Ninety-seven percent (97%) ask for direct (DIF) studies and 60% for histopathology in formalin. Most do not recommend biopsy at other non-ocular sites (75%), nor do they perform indirect immunofluorescence for serum autoantibodies (68%). Immune-modulatory therapy is started following positive biopsy results for most (66%), albeit most (62%) would not let a negative DIF influence the choice of starting treatment should there be clinical suspicion of MMP. Differences in practice patterns as they relate to level of experience and geographical location are contrasted to the most up-to-date available guidelines. CONCLUSION: Responses to the survey suggest that there is heterogeneity in certain practice patterns for MMP. Biopsy remains an area of controversy in dictating treatment plans. Identified areas of need should be targeted in future research.

Tissue Remodeling in Ocular Mucous Membrane Pemphigoid.

Purpose: Ocular mucous membrane pemphigoid (OcMMP) is a rare eye disease characterized by relapsing-remitting or persisting long-lasting inflammatory events associated with progressive scarring. Despite long-term immunomodulating therapy, abnormal fibrosis keeps worsening in patients with OcMMP. This study investigates the fibrotic process in patients with OcMMP, as well as the critical role of the epithelium in modulating the local fibrosis. Methods: In this prospective, observational pilot study, patients affected by long-lasting OcMMP were compared with age- and gender-matched healthy controls. Clinical grading was assessed, and conjunctival biopsy and impression cytology were performed. Conjunctival samples were used for quantifying the expression of transcripts regulating the inflammatory and fibrogenic processes. Results: Ocular surface clinical and functional markers worsened in patients with OcMMP with fibrotic disease progression. In more advanced disease stages, both impression cytologies and conjunctival biopsies revealed increased tissue remodeling and profibrotic markers (α-SMA and TGF-ß), and decreased levels of inflammatory markers (I-CAM1, IL-10, and IL-17). Increased epithelial expression of profibrotic markers and histological changes were detected. Conclusions: Chronic OcMMP is characterized by a progressive, aberrant self-sustaining fibrotic process that worsens clinical signs and symptoms. Conjunctival epithelial cells may transdifferentiate into myofibroblast-like phenotypes when chronically exposed to high levels of inflammation, as in the case of OcMMP. Tissue remodeling markers in OcMMP could be used as early diagnostic, prognostic, and therapeutic biomarkers, harvested in a non-invasive and painless procedure such as impression cytologies.

[The main autoimmune bullous diseases]. / Les principales maladies bulleuses auto-immunes.

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.

Necrotizing fasciitis - a complication of autoimmune skin blistering diseases?

INTRODUCTION: Autoimmune bullous diseases (AIBD) are organ-specific skin blistering diseases clinically manifesting as bullae and vesicles of the skin and mucous membranes. The loss of skin barrier integrity renders patients susceptible to infection. Necrotizing fasciitis (NF), a rare yet severe infectious complication of AIBD has been insufficiently documented in the literature. CASE REPORT: We present a case of a 51-year-old male patient with NF initially misdiagnosed as herpes zoster. Given the local status, CT imaging, and laboratory parameters, NF diagnosis was made and the patient was taken for an urgent surgical debridement. In a further development, new bullae in remote areas erupted and a perilesional biopsy, direct immunofluorescence as well as local status, the patient's age, and atypical presentation, imposed an initial diagnosis of epidermolysis bullosa acquisita. Differential diagnoses were bullous pemphigoid (BP) and bullous systemic lupus. In the literature, 9 other described cases were found and are reviewed. CONCLUSIONS: Due to its unspecific clinical picture, necrotizing fasciitis itself presents a frequently misdiagnosed soft tissue infection. Altered laboratory parameters in immunosuppressed patients often lead to misdiagnosing of NF and loss of precious time, which plays a major role in survival. Given the manifestation of AIBD as loss of skin integrity and immunosuppressive therapy, these patients could be more predisposed to NF than the general population.

[Mucosal anomalies in autoimmune bullous diseases]. / Mucosale afwijkingen bij blaarvormende auto-immuunziekten.

Mucosal anomalies are frequently seen in autoimmune bullous diseases, particularly in pemphigus vulgaris and mucous membrane pemphigoid. The blistering, erosions, ulceration or erythema may present anywhere on the oral mucosa, but also on other mucosal sites. A differential diagnosis is needed of (erosive) oral lichen planus, systemic autoimmune disease, inflammatory bowel diseases, chronic graft-versus-host disease, infectious causes, Behçet's syndrome and recurrent aphthous stomatitis. A quick diagnosis and initiation of adequate treatment are important because of the potential severity of the disease and to prevent complications due to cicatrization. Besides a biopsy for histopathological analysis, a perilesional biopsy for direct immunofluorescence microscopy and immunoserological tests are needed for diagnosis of pemphigus or pemphigoid. In addition to a mucosal biopsy, a biopsy for direct immunofluorescence of the skin can contribute to a diagnosis of a bullous disease. Besides topical corticosteroids, immunosuppressive treatment is often required for treating autoimmune bullous diseases, such as treatment with rituximab in patients with pemphigus.

[Diagnostics of ocular mucous membrane pemphigoid]. / Diagnostik des okulären Schleimhautpemphigoids.

The diagnosis of ocular mucous membrane pemphigoid (MMP) remains a challenge as the timing and choice of diagnostic methods have a decisive influence on its quality. A systematic approach is required that includes a comprehensive medical history, critical evaluation of the clinical findings and targeted laboratory testing. The diagnosis is complicated by the fact that some patients present purely clinically the symptoms of MMP without fulfilling the required immunohistochemical and laboratory criteria. Basically, the diagnosis of ocular MMP is based on three pillars: 1) medical history and clinical findings, 2) positive immunohistological (direct immunofluorescence) tissue sample and 3) specific serological autoantibodies. As the diagnosis of ocular MMP often implies prolonged systemic immunomodulatory treatment in predominantly older patients, the accurate diagnosis and approach are of critical relevance. The aim of this article is to present the recently updated diagnostic procedure.

Gene expression profiling and multiplex immunofluorescence analysis of bullous pemphigoid immune-related adverse event reveal upregulation of toll-like receptor 4/complement-induced innate immune response and increased density of TH 1 T-cells.

BACKGROUND: Immune checkpoint inhibitor (ICI)-based cancer therapies cause a variety of cutaneous immune-related adverse events (irAEs) including immunobullous skin eruptions like bullous pemphigoid (BP). However, little is known about the underlying immunopathogenic drivers of these reactions, and understanding the unique gene expression profile and immune composition of BP-irAE remains a critical knowledge gap in the field of oncodermatology/oncodermatopathology. METHODS: BP-irAE (n = 8) and de novo BP control (n = 8) biopsy samples were subjected to gene expression profiling using the NanoString® Technologies nCounter PanCancer Immune Profiling Panel. Multiplex immunofluorescence (mIF) studies using markers for T-cells (CD3 and CD8), T helper 1 (TH 1) cells (Tbet), TH 2 cells (Gata3), TH 17 cells (RORγT), and regulatory T-cells (Tregs; FoxP3) were further evaluated using InForm® image analysis. RESULTS: Compared with de novo BP controls, BP-irAE samples exhibited upregulation of 30 mRNA transcripts (p < 0.025), including toll-like receptor 4 (TLR4) and genes associated with complement activation, and downregulation of 89 mRNA transcripts (p < 0.025), including genes associated with TH 2, TH 17, and B-cell immune response. BP-irAE demonstrated a greater density of Tbet+ (TH 1) cells in the dermis (p = 0.004) and fewer Tregs in the blister floor (p = 0.028) when compared with that of de novo control BP samples. CONCLUSIONS: BP-irAE exhibited activation of the TLR4/complement-driven classical innate immune response pathway, with dermal TH 1 immune cell polarization and decreased Tregs in the blister floor. TLR/complement signaling may underlie the immunopathogenesis of BP-irAE.

Vesiculobullous Lesions of the Oral Cavity.

Several dermatological conditions may manifest in the oral cavity, particularly those that are immune-mediated, and they must be distinguished from the various other types of oral ulcerations. This chapter discusses the clinical features, pathogenesis, differential diagnosis, and diagnostic features, including histology and immunofluorescence findings, as well as management of vesiculobullous diseases. These diseases include pemphigus Vulgaris, benign mucous membrane pemphigoid, bullous pemphigoid, and epidermolysis bullosa acquisita. These diseases have a significant impact on the quality of life, as they can lead to serious complications, depending on the extent of the disease. Therefore, early recognition is crucial, helping to reduce disease-related morbidity, mortality and prevent life-threatening complications.

Prevalence, Spectrum and Clinical Implications of Malignancies in Patients with Bullous Pemphigoid.

Current research on the malignancy rate and spectrum of malignancies in patients with bullous pemphigoid is contradictory. The aims of this study were to determine the prevalence and spectrum of malignancy in patients with bullous pemphigoid and to compare demographic, clinical, therapeutic and outcome data between bullous pemphigoid patients with and without malignancy. This retrospective cohort study enrolled 335 patients (194 women and 141 men; mean age at diagnosis of bullous pemphigoid 77.5 ± 12 years) followed up at an Israeli tertiary centre between January 2009 and December 2019: 107 (32%) had malignancy and 228 (68%) did not. Malignancy occurred before and after bullous pemphigoid diagnosis in 82 (77%) and 25 (23%) patients, respectively. Bullous pemphigoid patients with cancer were older (p = 0.02) and had a higher mortality rate (p < 0.0001) than those without malignancy. The 2 groups did not differ in terms of sex, comorbidities, or clinical characteristics. Those who developed malignancy before bullous pemphigoid were younger than those who developed malignancy after bullous pemphigoid (mean age 69.3 vs 82.4 years, p < 0.0001). Overall malignancy rates did not differ between patients with bullous pemphigoid and the general population; therefore, comprehensive malignancy workup may be unnecessary. However, patients with bullous pemphigoid had a greater risk of melanoma (10.7% vs 4.3%, p = 0.0005); therefore, routine skin screening may be recommended.

Bullous pemphigoid associated with anti-programmed cell death protein 1 and anti-programmed cell death ligand 1 therapy: A case series of 13 patients.

We present a case series of 13 patients, the first Australian single-centre study of bullous pemphigoid (BP) associated with immune checkpoint inhibitors (ICI): cytotoxic T-lymphocyte antigen (CTLA4) and programmed cell death receptor (PD1) inhibitors. All our patients achieved adequate control of BP with a combination of treatments including oral prednisolone, intravenous immunoglobulin, rituximab and omalizumab. The majority of patients ceased or interrupted immunotherapy treatment upon diagnosis of BP and greater tumour progression was seen in the cohort who ceased immunotherapy.

Radiation-Induced Laryngeal Mucous Membrane Pemphigoid.

OBJECTIVES: Bullous pemphigoid has previously been linked to radiotherapy, but here we report the first case of MMP suspected to be a consequence of RT. METHODS: The patient described is an 85-year-old male who underwent RT to treat squamous cell carcinoma of the palatine tonsil. Shortly after therapy, the patient developed blisters with worsening dyspnea and dysphonia. RESULTS: This patient was successfully treated with a combination of oral immunosuppressants and surgical intervention. CONCLUSION: This incident underscores that not all episodes of mucosal ulceration following radiation are a result of mucositis and MMP should be considered in the differential. LEVEL OF EVIDENCE: Level 4.

Skin Eosinophil Counts in Bullous Pemphigoid as a Prognostic Factor for Disease Severity and Treatment Response.

Dermal infiltration of eosinophils and eosinophilic spongiosis are prominent features of bullous pemphigoid lesions. Although several observations support the pathogenic role of eosinophils in bullous pemphigoid, few studies have examined the impact of skin eosinophil counts on disease severity and treatment response. This retrospective study assessed the association between eosinophil counts in skin biopsy samples of 137 patients with bullous pemphigoid and their demographic characteristics, comorbidities, disease severity, and treatment response. There was no relationship between eosinophil count and age, sex, or disease severity at disease onset. There was a positive relationship between eosinophil counts and neurological comorbidity and a negative relationship between eosinophil counts and treatment response. At all follow-up points patients with no tissue eosinophils had a better response to treatment than patients with any tissue eosinophil count. In conclusion, skin eosinophil counts in patients with bullous pemphigoid are not correlated with disease severity at onset, but can serve as a negative prognostic marker for treatment response.

Ocular Mucus Membrane Pemphigoid: A Primary Versus Secondary Entity.

PURPOSE: The purpose of this review was to investigate the idea that inflammatory events of the conjunctiva and ocular surface may act as triggering events for the onset of ocular mucus membrane pemphigoid (oMMP). METHODS: A retrospective chart review of patients with biopsy-proven oMMP and no systemic pemphigoid disease. The presence, or absence, of the following inflammatory conditions at the time of OMMP diagnosis was noted: significant eyelid disease, significant atopic eye disease, Stevens-Johnson syndrome, graft-versus-host disease, viral keratitis, sarcoidosis with ocular involvement, chemical burns, medicamentosa, Sjogren syndrome, systemic lupus erythematosus with ocular involvement, and epidemic keratoconjunctivitis. Response to immunomodulatory therapy (IMT) was also recorded. RESULTS: A total of 779 patient records were identified. Conjunctival biopsy was present in 724 patients, with 646 (89.2%) being positive. One hundred thirty-nine patients (21.5%) with positive biopsies had extraocular pemphigoid disease and were excluded from further analysis. Of the 507 included patients, 154 (30.4%) had at least one of the specified inflammatory conditions present at the time of OMMP diagnosis. One hundred eighteen patients (23.3%) had only 1 such condition, 35 (6.9%) had 2, and 1 patient had 3. In patients with at least one of these conditions present, response to IMT was seen in 84.9% of patients with sufficient follow-up. CONCLUSIONS: Our study suggests that oMMP may arise as a secondary pathology to acute inflammatory events or chronic inflammatory states of the conjunctiva and ocular surface.

Mucous Membrane Pemphigoid: A Case Report with Oral and Ocular Presentation.

AIM: To describe the diagnosis and management of mucous membrane pemphigoid (MMP) with oral and ocular presentation. BACKGROUND: Mucous membrane pemphigoid constitutes a heterogeneous group of chronic, autoimmune vesiculobullous diseases characterized by blister formation that has a propensity to affect different mucous membranes of the body. The most commonly affected areas include the oral cavity, mucous membranes of the eyes, throat, genitalia, and nose. This disease usually affects elderly women with a peak incidence at around 50-70 years of age; however, rare cases have been diagnosed in children. The symptoms of MMP include recurrent blistering lesions which eventually rupture and occasionally heal with scarring that may lead to certain complications involving the eyes and throat regions. CASE DESCRIPTION: In this report, we describe a 66-year-old female patient who complained of oral and ocular lesions for a period of 2 years. Pain, burning mouth, and gingival inflammation were present. Ocular examination showed mild conjunctivitis with scar formation at the lateral canthus of the left eye. The patient also noticed periods of water-filled balloon-like formation in the gingiva that rupture spontaneously leaving sore spots. A biopsy was obtained from perilesional tissue and sent for histopathological examination, correlation of clinical and histological features directed us toward the diagnosis of MMP. The patient was treated for both oral and ocular lesions using topical corticosteroid therapy in conjunction with antifungal and antibacterial drugs. The response to local treatment was augmented via effective periodontal therapy to control the concurrent plaque-induced gingival inflammation and via using a customized application tray to sustain the drug efficacy. CONCLUSION: A multidisciplinary approach is often necessary in order to treat MMP lesions efficaciously. CLINICAL SIGNIFICANCE: Early diagnosis and effective treatment protocol using systemic or topical corticosteroid therapy along with other therapeutic means including periodontal therapy, good oral hygiene practice, and timely follow-up are very useful in preventing long-term complications due to this disease.

Dipeptidyl Peptidase-4 Inhibitor-Related Bullous Pemphigoid: Clinical, Laboratory, and Histological Features, and Possible Pathogenesis.

Dipeptidyl peptidase-4 inhibitor (DPP4i) is a widely used antidiabetic agent. Emerging cases of DPP4i-associated bullous pemphigoid (DBP), whose pathogenesis remains unclear, have been reported. Thus, a retrospective study was conducted from January 2016 to June 2021 to determine the clinical, laboratory, and histopathological features of DBP and idiopathic bullous pemphigoid (IBP). We set up in vitro experiments using vildagliptin-treated HaCaT keratinocytes to validate what we found by analyzing published RNA sequencing data about the genes related to the dermal-epidermal junction. We also observed IL-6 expression by HaCaT cells treated with vildagliptin. We enrolled 20 patients with DBP and 40 patients with IBP. The total Bullous Pemphigoid Disease Area Index (BPDAI) score was similar in both groups. However, the BPDAI score of erosions and blisters in DBP was significantly higher than that in IBP (24.6 vs. 16.68, p = 0.0189), and the score for urticaria and erythema was lower in DBP (12 vs. 19.05, p = 0.0183). The pathological features showed that the mean infiltrating eosinophil number per high-power field was significantly lower in DBP than in IBP (16.7 vs. 27.08, p = 0.023). The expression of LAMA3, LAMB3, LAMC2, DST, and COL17A1 decreased significantly in vildagliptin-treated human keratinocytes. On the other hand, IL-6, the hallmark cytokine of bullous pemphigoid (BP) severity, was found to be upregulated in HaCaT cells by vildagliptin. These experimental findings imply less of a requirement for eosinophil infiltration to drive the inflammatory cascades in DBP blistering. Both immunologic and non-immunologic pathways could be employed for the development of DBP. Our findings may help explain the higher incidence of non-inflammatory BP that was observed in DBP.

S2k Guideline for the diagnosis and treatment of mucous membrane pemphigoid.

Mucous membrane pemphigoid (MMP) is a pemphigoid disease with predominant mucous membrane involvement. It mainly affects the mucous membranes of the mouth, eyes, nose and pharynx, but also the larynx, trachea, esophagus, genital and perianal regions. The manifestation of the disease covers a wide spectrum from gingival erythema and single oral lesions to severe tracheal strictures that obstruct breathing and conjunctival scarring with marked visual impairment and, not infrequently, blindness. In addition to a clinical picture of predominant mucosal involvement, diagnosis is based on direct immunofluorescence of a peri-lesional biopsy and serology. The main target antigen is BP180 (collagen XVII), and reactivity with laminin 332 is associated with malignancy in approximately 25 % of MMP patients. The treatment of MMP is challenging. On the one hand, due to the involvement of different mucous membranes, good interdisciplinary cooperation is required; on the other hand, due to the rarity of the disease, no randomized controlled clinical trials are available. The aim of this guideline is to present the clinical picture, including severity and scoring systems, and to give guidance for diagnosing and treating this complex disease. In MMP, interdisciplinary cooperation plays an essential role as well as the prompt diagnosis and initiation of adequate therapy in order to avoid irreversible damage to the mucous membranes with serious complications.