Pemphigus: Current and Future Therapeutic Strategies

The efficacy and safety of low-dose rituximab in the treatment of pemphigus vulgaris: a cohort study

BACKGROUND

Rituximab (RTX) is considered the first-line treatment for pemphigus vulgaris (PV), which is a B-cell-mediated acquired autoimmune disease. However, no consensus on the optimum dosage has been achieved.

OBJECTIVES

To investigate the efficacy and safety of low-dose RTX (a single infusion of 500 mg) for the treatment of PV, a cohort study was conducted for patients with PV, along with a 12-month follow-up following the administration of RTX.

METHODS

Patients with moderate or severe PV were divided into group A (low-dose RTX combined with corticosteroids) and group B (corticosteroids alone). Data on complete remission (CR) rates, doses of corticosteroids, cumulative doses of corticosteroids at the third, sixth, and twelfth months, pemphigus disease area index and adverse effects (AEs) were collected.

RESULTS

Forty-four patients with moderate or severe PV were enrolled in this study (19 in group A and 25 in group B). Patients treated with low-dose RTX had higher CR rates, lower doses of corticosteroids at the third, sixth, and twelfth months, lower cumulative doses of corticosteroids at the sixth and twelfth months, and fewer AEs than those who received corticosteroids alone.

CONCLUSIONS

This study indicated that low-dose RTX may be a beneficial and secure therapy option for patients with moderate to severe PV.

Distorted Frequency and Functionality of Natural Killer Cells in Pemphigus Vulgaris: A Potential Therapeutic Target

Pemphigus vulgaris (PV) is a rare autoimmune disorder where autoantibodies target the desmosomal proteins resulting in blistering of oral mucosa and skin. While the pathogenesis of PV is mainly mediated by the adaptive immune system, key players of innate immunity are also emerging. This study outlines the phenotypic as well as functional attributes of NK cells in PV. Through in-depth analysis using flow cytometry we identified an increase in the frequency of CD56+ CD3- NK cells and their subtypes in periphery. Along with this there is an increased frequency of IFNγ+ CD56bright CD16dim NK cells. mRNA expression of sorted NK cells for differentially expressed genes, particularly key transcription factors such as T-bet and EOMES, as well as surface receptors like NKG2D and KIR2D, and the cytokine IFNγ, displayed significant upregulation. A significant activation of NK cells was seen in the disease state. The levels of perforin and IFNγ were significantly elevated in the culture supernatants of patients. Additionally, a significantly higher cytotoxicity of NK cells in PV was observed. In lesioned tissues of PV, NK related markers were significantly increased. Lastly, we observed NK cells using confocal microscopy in the tissue biopsies of patients which showed significant infiltration of CD56+ CD3- NK cells at the lesional sites. This study aimed to shed light on the pivotal role of NK cells in the immunopathology of PV, offering a thorough understanding of their behavior and changes in expression which might help in contributing to the development of novel therapeutics.

Nail changes in pemphigus: a systematic review and meta-analysis

Pemphigus is a group of autoimmune mucocutaneous bullous disorders characterized by acantholysis resulting from autoantibodies targeting epithelial cell surface antigens. Studies reflect the presence of nail manifestations in some patients and suggest a potential correlation with clinical severity. This study examines the overall prevalence and characterizes the diverse manifestations of nail changes in pemphigus. We searched Cochrane, MEDLINE, EMBASE, and LILACS from 1990 to June 26, 2023 for studies reporting different nail changes in pemphigus patients. Data were collected and pooled to obtain proportions of the prevalence of nail changes in patients with pemphigus and subgroup analysis for pemphigus foliaceous and pemphigus vulgaris. The risk of bias was assessed with the Joanna Briggs Institute Checklist. Of 321 studies screened, 14 studies with 1,208 patients were included. Paronychia (n = 185) and Beau's lines (n = 104) were the most common nail changes identified. The pooled prevalence of nail disease in pemphigus patients was 0.389 (number of studies; [95% CI]: n = 9; [0.160-0.680], with high heterogeneity between studies (I2 = 95.0%, P < 0.001). Subgroup analysis revealed the highest prevalence in pemphigus foliaceous at 0.342 (n = 3; [0.109-0.688]) and pemphigus vulgaris at 0.396 (n = 5; [0.114-0.769]). Nail changes exhibited varied temporal relationships with disease onset and flares, preceding, concurrent, or following these events. Correlation with disease severity was noted, although discrepancies between studies were reported. Nail changes in pemphigus, particularly pemphigus vulgaris and pemphigus foliaceous, may be underrecognized. Observations regarding temporal associations and potential correlations with disease severity highlight the diagnostic and prognostic implications of nail changes in pemphigus. The limitations of this study include study heterogeneity and possible bias. Further research to establish the correlation of the presence and severity of nail changes on the overall disease course would be helpful.

Desmosomal Cadherin Tension Loss in Pemphigus Vulgaris Mediated by the Inhibition of Active RhoA at Cell-Cell Adhesions

Binding of autoantibodies to keratinocyte surface antigens, primarily desmoglein 3 (Dsg3) of the desmosomal complex, leads to the dissociation of cell-cell adhesion in the blistering disorder pemphigus vulgaris (PV). After the initial disassembly of desmosomes, cell-cell adhesions actively remodel in association with the cytoskeleton and focal adhesions. Growing evidence highlights the role of adhesion mechanics and mechanotransduction at cell-cell adhesions in this remodeling process, as their active participation may direct autoimmune pathogenicity. However, a large part of the biophysical transformations after antibody binding remains underexplored. Specifically, it is unclear how tension in desmosomes and cell-cell adhesions changes in response to antibodies, and how the altered tensional states translate to cellular responses. Here, we showed a tension loss at Dsg3 using fluorescence resonance energy transfer (FRET)-based tension sensors, a tension loss at the entire cell-cell adhesion, and a potentially compensatory increase in junctional traction force at cell-extracellular matrix adhesions after PV antibody binding. Further, our data indicate that this tension loss is mediated by the inhibition of RhoA at cell-cell contacts, and the extent of RhoA inhibition may be crucial in determining the severity of pathogenicity among different PV antibodies. More importantly, this tension loss can be partially restored by altering actomyosin based cell contractility. Collectively, these findings provide previously unattainable details in our understanding of the mechanisms that govern cell-cell interactions under physiological and autoimmune conditions, which may open the window to entirely new therapeutics aimed at restoring physiological balance to tension dynamics that regulates the maintenance of cell-cell adhesion.

What is novel in the clinical management of pemphigus vulgaris?

INTRODUCTION

Pemphigus, an uncommon autoimmune blistering disorder affecting the skin and mucous membranes, currently with mortality primarily attributed to adverse reactions resulting from treatment protocols. Additionally, the existing treatments exhibit a notable recurrence rate. The high incidence of relapse and the considerable adverse effects associated with treatment underscore the imperative to explore safer and more effective therapeutic approaches. Numerous potential therapeutic targets have demonstrated promising outcomes in trials or preliminary research stages. These encompass anti-CD-20 agents, anti-CD-25 agents, TNF-α inhibition, FAS Ligand Inhibition, FcRn inhibition, BAFF inhibition, Bruton's tyrosine kinase (BTK) inhibition, CAAR T Cells, JAK inhibition, mTOR inhibition, abatacept, IL-4 inhibition, IL-17 inhibition, IL-6 inhibition, polyclonal Regulatory T Cells, and autologous hematopoietic stem cell transplantation.

AREAS COVERED

The most significant studies regarding the impact and efficacy of the mentioned treatments on pemphigus were meticulously curated through a comprehensive search conducted on the PubMed database. Moreover, the investigations of interest cited in these studies were also integrated.

EXPERT OPINION

The efficacy and safety profiles of the other treatments under discussion do not exhibit the same level of robustness as anti-CD20 therapy, which is anticipated to endure as a critical element in pemphigus treatment well into the foreseeable future.

Juvenile pemphigus vulgaris: Literature review and a rare case report

Pemphigus vulgaris (PV) is a chronic autoimmune blistering disorder characterized by the loss of intraepithelial adhesion affecting the skin and mucous membranes, predominantly affects females in their fifth and sixth decades of life. Due to its rare occurrence in children and adolescents, there is often a delay in diagnosis and treatment in this age group. PV should always be considered in the differential diagnosis of oral ulcerative and vesiculobullous lesions in both children and adolescents.

Rituximab in Childhood and Juvenile Pemphigus Vulgaris: A Systematic Review

Pemphigus vulgaris (PV) is a chronic autoimmune blistering disorder characterized by the loss of intraepithelial adhesion, affecting the skin and mucous membranes. Both males and females are affected, although it predominantly affects females in their fifth and sixth decades of life. Approximately 1.4 to 3.7% of PV cases occur in the pediatric population (≤18 years of age), and may be classified into childhood/pediatric PV, which affects individuals under 12 years old, and juvenile/adolescent PV, affecting those between 12 and 18 years old. Due to its rare occurrence in children and adolescents, there is often a delay in diagnosis and treatment in this age group. A systematic literature search was conducted on MEDLINE/PubMed, Web of Science, EMBASE, SCOPUS, and Cochrane Library databases to evaluate the efficacy of rituximab (RTX) in childhood and juvenile PV patients. The Joanna Briggs Institute (JBI) Critical Appraisal Checklist was employed to assess the risk of bias in case reports and series, while the Cochrane ROBINS-I tool was utilized for evaluating observational studies or non-randomized intervention studies. A total of 18 studies encompassing 46 juvenile or childhood PV patients in the pediatric and adolescent age groups were included for qualitative synthesis. The studies included nine case reports, two case series, five retrospective studies, one prospective study, and one open-label pilot study. Almost all cases of childhood and juvenile PV achieved either complete or partial remission after undergoing RTX treatment during the final follow-up periods. Furthermore, most cases reported no relapse, and only minor adverse events were noted in the RTX treatment group. Despite its potential benefits, the utilization of RTX in pediatric patients raises concerns due to the scarcity of evidence and the absence of controlled studies specific to this age group. Further exploration is necessary to establish a standardized treatment regimen for RTX in pediatric PV, which involves identifying the optimal dosage, frequency, treatment cycle duration, and maintenance therapy duration.

Repurposing of rituximab biosimilars to treat B cell mediated autoimmune diseases

Rituximab, the first monoclonal antibody approved for the treatment of lymphoma, eventually became one of the most popular and versatile drugs ever in terms of clinical application and revenue. Since its patent expiration, and consequently, the loss of exclusivity of the original biologic, its repurposing as an off-label drug has increased dramatically, propelled by the development and commercialization of its many biosimilars. Currently, rituximab is prescribed worldwide to treat a vast range of autoimmune diseases mediated by B cells. Here, we present a comprehensive overview of rituximab repurposing in 115 autoimmune diseases across 17 medical specialties, sourced from over 1530 publications. Our work highlights the extent of its off-label use and clinical benefits, underlining the success of rituximab repurposing for both common and orphan immune-related diseases. We discuss the scientific mechanism associated with its clinical efficacy and provide additional indications for which rituximab could be investigated. Our study presents rituximab as a flagship example of drug repurposing owing to its central role in targeting cluster of differentiate 20 positive (CD20) B cells in 115 autoimmune diseases.

Alterations of circulating free fatty acids in patients with pemphigus vulgaris

Free fatty acids (FFA) have gained research interest owing to their functions in both local and systemic immune regulation. Changes in the serum levels of anti-inflammatory short chain fatty acids (SCFA), primarily derived from the gut microbiota, and pro-inflammatory medium (MCFA) and long (LCFA) chain fatty acids, derived from either the gut microbiota or the diet, have been associated with autoimmunity. Circulating FFA were retrospectively analysed by a gas chromatography-mass spectrometry method in the serum of 18 patients with pemphigus vulgaris (PV) at the baseline and 6 months (n = 10) after immunosuppressive treatments, and 18 healthy controls (HC). Circulating FFA were correlated with the Pemphigus Disease Area Index (PDAI) and serum concentrations of interferon-gamma (IFN-γ), Interleukin (IL)-17A, IL-5, IL-10 and IL-21. Principal Component analysis computed on FFA abundances revealed significant differences in the profile of SCFA (p = 0,012), MCFA (p = 0.00015) and LCFA (p = 0,035) between PV patients and HC, which were not significantly changed by immunosuppressive treatments. PV patients showed a significantly lower serum concentration of propionic (p < 0.0005) and butyric (p < 0.0005) acids, SCFA with anti-inflammatory functions, while hexanoic (p < 0.0005) and hexadecanoic (p = 0.0006) acids, pro-inflammatory MCFA and LCFA respectively, were over-represented. Treatments induced a significant decrease of hexanoic (p = 0.035) and a further increase of hexadecanoic (p = 0.046) acids. Positive correlations emerged between IFN-γ and acetic acid (Rho = 0.60), IFN-γ and hexanoic acid (Rho = 0.46), IL-5 and both hexadecanoic acid (Rho = 0.50) and octadecanoic acid (Rho = 0.53), butyric acid and PDAI (Rho = 0.53). PV was associated with a remarked imbalance of circulating FFA compared to HC. The serum alterations of SCFA, MCFA, and LCFA may contribute to promoting inflammation in PV. Deeper insights into the immunomodulatory functions of these molecules may pave the way for personalized dietary interventions in PV patients.

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

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

Type 2 T-Cell Responses against Distinct Epitopes of the Desmoglein 3 Ectodomain in Pemphigus Vulgaris

Pemphigus vulgaris (PV) is an autoimmune blistering disorder of the skin and/or mucous membranes caused by IgG autoantibodies that predominantly target two transmembrane desmosomal cadherins: desmoglein (DSG)1 and DSG3. DSG-specific T cells play a central role in PV pathogenesis because they provide help to autoreactive B cells for autoantibody production. In this study, we characterized DSG3-specific peripheral T cells in a cohort of 52 patients with PV and 41 healthy controls with regard to cytokine profile and epitope specificity. By ELISpot analysis, type 2 T cells reactive with the DSG3 ectodomain were significantly increased in patients with PV compared with those in healthy controls. By dextramer analysis, CD4+ T cells specific for an epitope within the extracellular domain of DSG3, DSG3(206-220), were found at significantly higher frequencies in patients with PV than in HLA-matched healthy controls. T-cell recognition of two distinct DSG3 epitopes, that is, DSG3(206-220) and DSG3(378-392), correlated significantly, suggesting a synergistic effect in B-cell help. Immunization of HLA-DRB1∗04:02-transgenic mice with PV with the same set of DSG3 peptides induced pathogenic DSG3-specific IgG antibodies, which induced loss of keratinocyte adhesion in vitro. Thus, DSG3 peptide-specific T cells are of particular interest as surrogate markers of disease activity and potential therapeutic targets in PV.

Gingival Manifestations in Oral Chronic Autoimmune Bullous Diseases: A Retrospective Study

Background and Objectives: Desquamative gingivitis (DG) is a clinical term indicating "peeling gums" and is associated with different oral manifestations. In this study, we aimed to assess the association between DG and autoimmune blistering mucocutaneous diseases (ABMD) with oral manifestations. Materials and Methods: A retrospective study including 88 patients diagnosed between 1998 and 2019 with ABMD (intraepithelial and subepithelial autoimmune blistering diseases) was performed at the Oral Medicine Department, Faculty of Dentistry, "Carol Davila" University of Medicine and Pharmacy in Bucharest. For each patient, the sociodemographic and anamnestic data, as well as clinical features of oral lesions (location), histological evaluation, and direct immunofluorescence data were collected. Results: Most of the patients involved in the study were female (78.4%). In total, 34 patients (38.63%) were diagnosed with subepithelial autoimmune diseases (SAD) and 54 (61.36%) had intraepithelial autoimmune diseases (IAD). Differences in the anatomic distribution of oral involvement were found between SAD and IAD. The presence of DG was significantly more common in patients with SAD compared to those with a diagnosis of IAD. Conclusions: Specific anatomical locations of the oral lesions are significantly associated with different subtypes of ABMD, with gingiva and hard palate mucosa being more involved in SAD and the soft palate and buccal mucosa in IAD. Desquamative gingivitis is a clinical sign that raises diagnostic challenges for several conditions in oral medicine.

Efficacy and safety of Bruton's tyrosine kinase inhibitors in the treatment of pemphigus: A comprehensive literature review and future perspective

Bruton's tyrosine kinase (BTK) is a protein involved in B-cell-receptor signaling and B-cell proliferation. The pathophysiology of several autoimmune diseases, such as pemphigus disorder, relies on the BTK signaling pathway. Therefore, BTK inhibitors were found to be beneficial alternatives to conventional treatmentsThe current study aimed to assess the efficacy and safety of BTK inhibitors in treating pemphigus. A complete search was performed on databases including PubMed/MedLine, Scopus, Web of Science, as well as Google Scholar search engine for studies published by September 20th, 2023. The current review indicates that BTK inhibitors alone or in combination with conventional treatments are promising options in the management of pemphigus. The overall safety profile of BTK inhibitors has been acceptable, and the reported adverse reactions were not severe or life-threatening.

Profile of Cutaneous Bacterial Flora in Pemphigus Patients

Objectives  Pemphigus, a group of autoimmune bullous diseases, can be fatal, resulting from overwhelming opportunistic infection of lesions secondary to cutaneous bacterial infections. This study aimed to look into the cutaneous bacterial infection profile of pemphigus patients as timely identification and appropriate treatment can play a major role in reducing mortality. Materials and Methods  Pus samples/swabs received from patients with pemphigus over a 2-year period from July 2018 to June 2020 were subjected to standard microbiological culture techniques and susceptibility testing. The frequency of isolation and susceptibility profile of the different bacterial pathogens toward various antimicrobial agents were interpreted and analyzed as per the Clinical and Laboratory Standards Institute's guidelines. Results  Samples from 315 patients were received during the study period comprising of 203 (64.4%) males and 112 (35.5%) females. Of 211 samples which were culture-positive, a total of 245 bacterial isolates were obtained, comprising of 158 Gram-positive cocci and 87 Gram-negative bacilli. Staphylococcus aureus (138, 56.3%) was the most common isolate followed by Pseudomonas aeruginosa (41, 16.7%) and Escherichia coli (16, 6.5%). Methicillin resistance was observed in 24.6% Staphylococcus aureus isolates and carbapenem resistance in 9.5 to 14.6% Gram-negative bacilli. Conclusions  Study findings emphasize the need for continuous monitoring of cutaneous pemphigus lesions for appropriate choice of antimicrobial therapy.

Dexamethasone solution and dexamethasone in Mucolox™ for the treatment of oral inflammatory ulcerative diseases: A phase II randomized clinical trial

BACKGROUND

Mucolox™ is a mucosal drug delivery system that prolongs the contact time between the oral mucosa and topical corticosteroids, potentially reducing the need for multiple applications daily. This study aimed to assess the clinical efficacy and tolerability of dexamethasone 0.5 mg/5 mL solution in Mucolox™ for the management of oral inflammatory ulcerative diseases.

METHODS

Participants were randomly assigned to receive dexamethasone 0.5 mg/5 mL in Mucolox™ (Mucolox™ arm) or dexamethasone 0.5 mg/5 mL solution (standard arm) and instructed to swish/gargle for 5 min three times daily. Changes from pre- to posttreatment patient's sensitivity score (0-10 on a visual analog scale), reticulation/erythema/ulceration score, and oral health-related quality of life were evaluated at baseline and at the end of the study period.

RESULTS

Twenty nine patients (75% females) with a median age of 58 years (range 18-79) were enrolled and randomly allocated to the Mucolox™ or standard arm. One subject was excluded. Although statistically significant in both arms, the pre- to posttreatment sensitivity score reduction was higher in the Mucolox™ arm (6.3 vs. 4.4-point reduction). Both arms showed a decrease in the reticulation/erythema/ulceration score between the two visits (7.2 vs. 4.7 [Mucolox™ arm]; 8.0 vs. 4.8 [standard arm]; p > 0.05). Mucolox™ in dexamethasone 0.5 mg/5 mL solution was better tolerated when taste and level of comfort were considered.

CONCLUSIONS

Both treatments were effective in the management of oral inflammatory ulcerative diseases. Dexamethasone 0.5 mg/5 mL in Mucolox™ was better tolerated and was slightly better in controlling patients' oral sensitivity. Larger studies are needed to confirm these findings in oral inflammatory ulcerative diseases patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04540133.

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.

HLA class II antigens in Croatian patients with pemphigus vulgaris and their correlation with anti-desmoglein antibodies

Pemphigus vulgaris (PV) is an acquired autoimmune blistering disease characterized by the production of autoantibodies targeting desmosomal cadherins, primarily desmoglein 1 and desmoglein 3, leading to acantholysis. The etiology of PV is multifactorial, including genetic susceptibility. This retrospective study aimed to evaluate the association of HLA class II alleles and PV and to examine the impact of PV-associated HLA class II alleles on the concentration of anti-desmoglein antibodies. The study group included 30 patients in whom the diagnosis of PV was confirmed by histopathological analysis, immunofluorescence findings, and ELISA testing for detecting antibodies against desmoglein 1 and desmoglein 3. HLA class II alleles were typed by polymerase chain reaction with sequence-specific primers (PCR-SSP). The control group consisted of 190 healthy volunteer blood donors. Data analysis revealed a significantly higher frequency of HLA class II alleles in our population of patients with PV, including HLA-DRB1*04:02, HLA-DRB1*14:54, HLA-DQB1*03:02, HLA-DQB1*05:03, HLA- DQA1*03:01, and HLA-DQA1*01:04, as well as a significantly lower frequency of HLA-DQA1*05:01 compared to the control group. We have also investigated the influence of risk alleles for PV, recognized in almost all study populations, HLA-DRB1*04:02 and HLA-DQB1*05:03, on the concentration of antibodies against desmogleins 1 and 3 in relation to the presence of these alleles. The results showed significantly higher levels of antibodies directed against desmoglein 3 among patients with DRB1*04:02 compared to patients without this allele. No difference was found for anti-desmoglein 1 antibodies. Regarding DQB1*05:03 allele, statistical analysis showed no differences in the concentration of anti-desmoglein antibodies in patients carrying this allele versus those without it.

The PI3K-Akt-mTOR and Associated Signaling Pathways as Molecular Drivers of Immune-Mediated Inflammatory Skin Diseases: Update on Therapeutic Strategy Using Natural and Synthetic Compounds

The dysregulated phosphatidylinositol-3-kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) signaling pathway has been implicated in various immune-mediated inflammatory and hyperproliferative dermatoses such as acne, atopic dermatitis, alopecia, psoriasis, wounds, and vitiligo, and is associated with poor treatment outcomes. Improved comprehension of the consequences of the dysregulated PI3K/Akt/mTOR pathway in patients with inflammatory dermatoses has resulted in the development of novel therapeutic approaches. Nonetheless, more studies are necessary to validate the regulatory role of this pathway and to create more effective preventive and treatment methods for a wide range of inflammatory skin diseases. Several studies have revealed that certain natural products and synthetic compounds can obstruct the expression/activity of PI3K/Akt/mTOR, underscoring their potential in managing common and persistent skin inflammatory disorders. This review summarizes recent advances in understanding the role of the activated PI3K/Akt/mTOR pathway and associated components in immune-mediated inflammatory dermatoses and discusses the potential of bioactive natural products, synthetic scaffolds, and biologic agents in their prevention and treatment. However, further research is necessary to validate the regulatory role of this pathway and develop more effective therapies for inflammatory skin disorders.

Targeting therapy in pemphigus: Where are we now and where are we going?

Pemphigus is a heterogeneous group of autoimmune skin disorders characterized by blistering of the skin and mucosal membranes, potentially affecting the quality of life if left unchecked. The current mainstay of treatment is systemic corticosteroids and immunosuppressive agents. Nevertheless, long-term use of these drugs can easily cause infections and other life-threatening adverse reactions. Thus, currently, researchers are trying to develop new and safer therapeutic approaches. Specifically, targeted therapies to pathogenic immune pathways have been gradually introduced and used for the treatment of pemphigus or in clinical trials, such as monoclonal anti-CD20 antibody, BAFF inhibitor, BTK inhibitor, CAAR-T therapy, FcRn antagonist, and TNF-α inhibitor. In addition, IL-4Rα antibody, IL-17 blockade, mTOR pathway inhibitor, CTLA-4Ig, and p38 MAPK inhibitors are theoretically promising treatment for pemphigus. Here, we review the research progress on the mechanism of targeted therapies for pemphigus.

T Regulatory Cell-Associated Tolerance Induction by High-Dose Immunoglobulins in an HLA-Transgenic Mouse Model of Pemphigus

Pemphigus vulgaris (PV) is a potentially lethal autoimmune bullous skin disorder caused by IgG autoantibodies against desmoglein 3 (Dsg3) and Dsg1. During the last three decades, high-dose intravenous immunoglobulins (IVIgs) have been applied as an effective and relatively safe treatment regime in severe, therapy-refractory PV. This prompted us to study T- and B- cell polarization by IVIg in a human-Dsg3-dependent mouse model for PV. Using humanized mice transgenic for HLA-DRB1*04:02, which is a highly prevalent haplotype in PV, we employed IVIg in two different experimental approaches: in prevention and quasi-therapeutic settings. Our data show that intraperitoneally applied IVIg was systemically distributed for up to 42 days or longer. IVIg-treated Dsg3-immunized mice exhibited, in contrast to Dsg3-immunized mice without IVIg, significantly less Dsg3-specific IgG, and showed induction of T regulatory cells in lymphatic tissue. Ex vivo splenocyte analysis upon Dsg3-specific stimulation revealed an initial, temporarily reduced antigen-induced cell proliferation, as well as IFN-γ secretion that became less apparent over the course of time. Marginal-zone B cells were initially reduced in the preventive approach but re-expanded over time. In contrast, in the quasi-therapeutic approach, a robust down-regulation in both spleen and lymph nodes was observed. We found a significant down-regulation of the immature transitional 1 (T1) B cells in IVIg-treated mice in the quasi-therapeutic approach, while T2 and T3, representing a healthy stage of B-cell development, appeared to be up-regulated by IVIg. In summary, in two experimental settings employing an active PV mouse model, we demonstrate distinct alterations of T- and B-cell populations upon IVIg treatment, compatible with a tolerance-associated polarization in lymphatic tissue. Our data suggest that the clinical efficacy of IVIg is at least modulated by distinct alterations of T- and B-cell populations compatible with a tolerance-associated polarization in lymphatic tissue.

The dysregulation of circulating innate lymphoid cells is related to autoantibodies in pemphigus vulgaris

BACKGROUND

Pemphigus vulgaris (PV) is a typical autoimmune disease caused by autoantibodies. Innate lymphoid cells (ILCs) are non-antigen-dependent populations composed of different subsets, also known as "mirror cells" of T cells, which play a crucial role in immune inflammatory diseases. However, the characteristics of ILCs in PV are unclear.

METHODS

Patients diagnosed with PV along with healthy controls in Second Xiangya Hospital of Central South University were studied. Flow cytometry was used to detect the proportion of ILC subsets in the peripheral blood. Anti-desmoglein (DSG) 1 and anti-DSG3 antibody levels of PV patients were detected.

RESULTS

Thirty-eight PV patients and 37 healthy controls were enrolled. There were no differences in sex or age between the two groups. Compared with controls, ILCs/CD45⁺ lymphocytes were significantly decreased in patients with PV. The frequency of ILC1s increased in patients with PV and was positively correlated with anti-DSG3 antibodies. However, the frequency of ILC3s decreased in patients with PV and was negatively correlated with anti-DSG1 antibodies. After methylprednisolone treatment, ILC1/ILC levels significantly decreased.

CONCLUSIONS

Circulating ILC subsets are associated with PV pathogenesis. Upregulated ILC1s seem to correlate positively with PV severity and can be restored after treatment.

IgG against the Membrane-Proximal Portion of the Desmoglein 3 Ectodomain Induces Loss of Keratinocyte Adhesion, a Hallmark in Pemphigus Vulgaris

Pemphigus vulgaris is a severe autoimmune blistering disease characterized by IgG autoantibodies (auto-abs) against the desmosomal adhesion molecules desmoglein (DSG) 3 and DSG1. Underlying mechanisms leading to blister formation upon binding of DSG-specific IgG auto-abs are not fully understood. Numerous studies showed the pathogenicity of IgG auto-ab binding to the aminoterminal region 1 (EC1) of the DSG3 ectodomain. However, auto-abs in pemphigus vulgaris are polyclonal, including IgG against both aminoterminal- and membrane-proximal epitopes of the DSG3 ectodomain. In this study, the pathogenicity of a previously uncharacterized murine monoclonal IgG antibody, 2G4, directed against the membrane-proximal region (EC5) of the DSG3 ectodomain was characterized and tested in various specificity and functionality assays. The results clearly show that 2G4 is capable of inhibiting intercellular keratinocyte adhesion and of inducing cellular DSG3 redistribution by activation of the p38MAPK signal transduction pathway. In this study, we provide evidence that an IgG auto-abs directed against the membrane-proximal region EC5 of DSG3 induces acantholysis, the hallmark in pemphigus vulgaris. These findings challenge the current concept that IgG auto-abs targeting the NH₂-terminal portion of the DSG3 ectodomain are pathogenic only. Our study provides further aspects for a deeper understanding of desmosomal keratinocyte adhesion and improves our insight into the complex auto-ab‒induced blister formation in pemphigus vulgaris.

Apremilast prevents blistering in human epidermis and stabilizes keratinocyte adhesion in pemphigus

Pemphigus vulgaris is a life-threatening blistering skin disease caused by autoantibodies destabilizing desmosomal adhesion. Current therapies focus on suppression of autoantibody formation and thus treatments directly stabilizing keratinocyte adhesion would fulfill an unmet medical need. We here demonstrate that apremilast, a phosphodiesterase 4 inhibitor used in psoriasis, prevents skin blistering in pemphigus vulgaris. Apremilast abrogates pemphigus autoantibody-induced loss of keratinocyte cohesion in ex-vivo human epidermis, cultured keratinocytes in vitro and in vivo in mice. In parallel, apremilast inhibits keratin retraction as well as desmosome splitting, induces phosphorylation of plakoglobin at serine 665 and desmoplakin assembly into desmosomal plaques. We established a plakoglobin phospho-deficient mouse model that reveals fragile epidermis with altered organization of keratin filaments and desmosomal cadherins. In keratinocytes derived from these mice, intercellular adhesion is impaired and not rescued by apremilast. These data identify an unreported mechanism of desmosome regulation and propose that apremilast stabilizes keratinocyte adhesion and is protective in pemphigus.

[Pemphigus: current and future treatment strategies]

Pemphigus diseases are a group of organ-specific autoimmune diseases which are characterised by the production of autoantibodies against intra-epidermal adhesion molecules and structural proteins of skin and mucosae. Depending on the entity, patients develop blisters and erosions on the skin and/or mucosae. According to the AWMF S2k guidelines for diagnosis and therapy of pemphigus diseases, a systemic therapy is recommended. Initially, high-dose, oral corticosteroids in combination with immunosuppressive drugs as corticosteroid-sparing agent, usually azathioprine or mycophenolate mofetil, can be used. Furthermore, rituximab, a monoclonal antibody directed against CD20 on B cells, was recently approved for pemphigus vulgaris and moderate or severe pemphigus foliaceus.

Applicability of glucocorticoid toxicity index in pemphigus: Comparison between two groups of rituximab-treated and rituximab-naïve patients

Rituximab (RTX) combined with short-term glucocorticoids (GC) is an effective therapeutic option for pemphigus. The newly developed Glucocorticoid Toxicity Index (GTI) tool provides the possibility to measure GC toxicities over time. To compare 1-year GTI between two groups of RTX-treated and RTX-naïve patients with pemphigus. The responsiveness of the GTI was also investigated. A prospective cohort of 129 adults with newly diagnosed pemphigus was conducted. GC-related toxicities were assessed at 3-month intervals according to Composite and Specific lists of the GTI. Of the patients, 76.7% (n = 99) received RTX. Throughout the time intervals, RTX-treated patients had lower GTI compared to RTX-naïve ones (p = 0.036). The mean GTI at 1-year was 34.3 in the RTX-treated group and 50.8 in the RTX-naïve group (p = 0.04). The most commonly observed GC-related toxicity was neuropsychiatric manifestations for 34% (224 events). The relapse rate of RTX-treated patients (1%) was significantly lower than RTX-naïve patients (10%) (p = 0.037). The GTI showed no correlation with cumulative GC consumption in both groups (p > 0.05, both). Patients treated with GC alone had remarkably higher GTI than patients treated with GC plus RTX. The GTI is an applicable tool to quantitatively capture GC toxicities at the patient level in pemphigus.

Rituximab in the Management of a Child with Pemphigus Vulgaris: Case Study

Background. Pemphigus vulgaris is an autoimmune bullous dermatosis. Its management generally involves lifelong administration of maintenance dose of systemic glucocorticosteroids, that leading to serious adverse effects especially in children. Clinical case description. Patient is the 16 years old boy with severe course of pemphigus vulgaris. The diagnosis was confirmed by the results of cell smear study from fresh erosions (> 50 acantholytic cells were revealed), histological examination of the skin biopsy from the lesion with the vesicle element (suprabasal vesicle was localized in the center, it included fibrin, neutrophil granulocytes, and acantholytic cells), skin biopsy from the area near the lesion (visually healthy skin), via direct immunofluorescence methods (IgG deposition was detected on keratinocytes’ surface throughout the epidermis), and enzyme-linked immunosorbent assay (desmoglein 1 IgG autoantibodies — 121 U/mL (reference value < 20 U/mL) and desmoglein 3 — > 200 U/mL (reference value < 20 U/mL)). Genetically engineered biologic drug, rituximab, and systemic glucocorticosteroid, methylprednisolone, were prescribed as first-line therapy with gradual dose reduction to permanent discontinuation in 8 months. Complete remission maintained after the completion of therapy course and discontinuation of systemic glucocorticosteroid. Conclusion. Combined therapy with systemic glucocorticosteroids and rituximab can be considered as first-line therapy in pediatric patients with pemphigus vulgaris due to relatively low risk of recurrence after rather rapid and complete drugs’ discontinuation.

Potential shared therapeutic and hepatotoxic mechanisms of Tripterygium wilfordii polyglycosides treating three kinds of autoimmune skin diseases by regulating IL-17 signaling pathway and Th17 cell differentiation

ETHNOPHARMACOLOGICAL RELEVANCE

Tripterygium wilfordii polyglycosides (TWP) are extracted from Tripterygium wilfordii Hook. f., which has the significant effects of anti-inflammation and immunosuppression and has been widely used to treat autoimmune diseases in traditional Chinese medicine.

AIM OF STUDY

In Chinese clinical dermatology, TWP was generally used for the treatment of autoimmune skin diseases including psoriasis (PSO), systemic lupus erythematosus (SLE) and pemphigus (PEM). However, the potential hepatotoxicity (HPT) induced by TWP was also existing with the long-term use of TWP. This study aims to explore the potential shared therapeutic mechanism of TWP treating PSO, SLE, PEM and the possible hepatotoxic mechanism induced by TWP.

MATERIALS AND METHODS

Network pharmacology was used to predict the potential targets and pathways in this study. The main bioactive compounds in TWP was screened according to TCMSP, PubChem, ChEMBL databases and Lipinski's Rule of Five. The potential targets of these chemical constituents were obtained from PharmMapper, SEA and SIB databases. The related targets of PSO, SLE, PEM and HPT were collected from GeneCards, DrugBank, DisGeNET and CTD databases. The target network construction was performed through STRING database and Cytoscape. GO enrichment, KEGG enrichment and molecular docking were then performed, respectively. In particular, imiquimod (IMQ)-induced PSO model was selected as the representative for the experimental verification of effects and shared therapeutic mechanisms of TWP.

RESULTS

41 targets were considered as the potential shared targets of TWP treating PSO, SLE and PEM. KEGG enrichment indicated that IL-17 signaling pathway and Th17 cell differentiation were significant in the potential shared therapeutic mechanism of TWP. The animal experimental verification demonstrated that TWP could notably ameliorate skin lesions (P˂0.001), decrease inflammatory response (P˂0.05, P˂0.01, P˂0.001) and inhibit the differentiation of Th1/Th17 cells (P˂0.05, P˂0.01) compared to PSO model group. The molecular docking and qPCR validation then showed that TWP could effectively act on MAPK14, IL-2, IL-6 and suppress Th17 cell differentiation and IL-17 signaling pathway. The possible hepatotoxic mechanism of TWP indicated that there were 145 hepatotoxic targets and it was also associated with IL-17 signaling pathway and Th17 cell differentiation, especially for the key role of ALB, CASP3 and HSP90AA1. Meanwhile, the potential correlations between efficacy and hepatotoxicity of TWP showed that 28 targets were shared by therapeutic and hepatotoxic mechanisms such as IL-6, IL-2, MAPK14, MMP9, ALB, CASP3 and HSP90AA1. These significant relevant targets were also involved in IL-17 signaling pathway and Th17 cell differentiation.

CONCLUSIONS

There were shared disease targets in PSO, SLE and PEM, and TWP could treat them by potential shared therapeutic mechanisms of suppressing IL-17 signaling pathway and Th17 cell differentiation. The possible hepatotoxicity induced by TWP was also significantly associated with the regulation of IL-17 signaling pathway and Th17 cell differentiation. Meanwhile, the potential correlations between efficacy and hepatotoxicity of TWP also mainly focused on IL-17 signaling pathway and Th17 cell differentiation, which provided a potential direction for the study of the mechanism of "You Gu Wu Yun" theory of TWP treating autoimmune skin diseases in the future.

Therapeutic strategies for oral lichen planus: State of the art and new insights

Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa. Several clinical subtypes of OLP have been reported, including the reticular and erosive one. On the one hand, reticular OLP is usually asymptomatic and is characterized by white streaks surrounded by well-defined erythematous borders. On the other hand, erosive OLP shows ulcerations and erosions surrounded by erythematous mucosa. While reticular OLP is relatively easy to control, erosive OLP is extremely painful and refractory to therapies, limiting the quality of life of the patients. In addition, treating erosive OLP is extremely tricky, and a gold standard treatment has not yet been established. However, several therapeutic approaches have been reported as effective, including systemic corticosteroids, systemic retinoids, and anti-interleukin (IL)-17/anti-IL-23 drugs. Indeed, our group and other several authors reported the effectiveness of anti-IL17, anti-IL12/23, and anti-IL23 agents in refractory OLP, highlighting the urgency of clinical studies on the use of anti-IL agents in OLP patients. In this paper, we reviewed the English- and German-language literature about therapeutic strategies for treating OLP, focusing on new systemic therapies for erosive OLP.

Detection of anti-desmoglein antibodies in oral lichen planus: What do we know so far

Oral lichen planus (OLP) is an inflammatory disease of the oral mucosa. Clinically, two main subsets are described, namely non-erosive and erosive OLP. While non-erosive OLP is usually responsive to local therapies, erosive OLP is often refractory also to systemic therapies and extremely reduces the quality of life of the patients. Furthermore, in some erosive OLP cases different autoantibodies have been detected, including anti-desmoglein 1 and 3 autoantibodies, and anti-bullous pemphigoid 180 and 230 autoantibodies. However, their potential role is still not clear. In this paper, we reviewed the literature about the detection of autoantibodies against desmoglein 1 and 3, the main target antigens of pemphigus vulgaris, in patient with OLP, summarizing the more recent insights on this topic.

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

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

Pain management of pemphigus vulgaris

Pemphigus is a rare autoimmune bullous disease which affects the mucous membranes and skin. Pemphigus vulgaris (PV) is the most prevalent type of pemphigus. PV presents with extremely painful, non-healing oral erosions. However, there are only a handful of reports addressing the pain management of PV. We would like to present a case of a painful PV, which was successfully managed.

[Bullous autoimmune dermatoses of the mucous membranes]

Autoimmune bullous diseases (AIBD) comprise a group of organ-specific autoimmune diseases which are characterised by the production of autoantibodies against adhesion molecules and structural proteins of skin and mucosae. Depending on the target protein, AIBD are classified into intraepidermal (pemphigus group) and subepidermal (pemphigoid group, epidermolysis bullosa acquisita, dermatitis herpetiformis) blistering disorders. Depending on the clinical entity, patients can develop blisters, pustules, erosions, and erythema on the skin and mucosae.

Innate immune activation as cofactor in pemphigus disease manifestation

Molecular mechanisms underlying auto-antibody-induced acantholysis in pemphigus vulgaris are subject of current research to date. To decipher the discrepancy between ubiquitous antibody binding to the epidermal desmosomes, but discontinuous disease manifestation, we were able to identify Ultraviolet A (UVA) as a cofactor for acantholysis. UVA induces interleukin (IL)-1 secretion in keratinocytes, mirroring innate immune system activation. In an in vitro keratinocyte dissociation assay increased fragmentation was observed when UVA was added to anti-Desmoglein 3 Immunoglobulins (anti-Dsg3 IgG). These results were confirmed in skin explants where UVA enhanced anti-Dsg3-mediated loss of epidermal adhesion. The UVA-mediated effect was blocked in vitro by the pan-caspase-inhibitor zVAD-fmk. Thus, we introduce UVA as a caspase-dependent exogenous cofactor for acantholysis which suggests that local innate immune responses largely contribute to overt clinical blister formation upon autoantibody binding to epidermal cells in pemphigus vulgaris.

Rituximab in Mucous Membrane Pemphigoid: A Monocentric Retrospective Study in 10 Patients with Severe/Refractory Disease

Rituximab (RTX) is a monoclonal antibody directed against CD20 antigen indicated in an increasing number of immune-mediated diseases. While its efficacy in pemphigus vulgaris has been widely investigated, only a few data about its possible role in pemphigoid diseases have been reported in the literature. Accordingly, herein we evaluated a case series of patients with mucous membrane pemphigoid (MMP) treated with RTX. We included patients with a history of severe/refractory MMP who received at least one cycle of intravenous RTX between May 2018 and December 2021 and had 6 months of follow-up time. Disease control (DC) was our early endpoint, while complete remission (CR) and partial remission (PR) were late endpoints. CR off-therapy, relapses, and adverse events were evaluated as well. Our population included 10 MMP patients. Eight out of ten patients (80%) achieved DC in a mean of 8 weeks, while two patients with ocular MMP were non-responders. Among the eight patients who achieved DC, two reached CR off therapy, two CR on minimal therapy, and two achieved PR on minimal therapy. In our case series, the addition of RTX to conventional therapies was demonstrated to be safe and effective in reaching rapid disease control in the majority of refractory MMP patients.

Pregnancy outcomes in women with pemphigus exposed to rituximab before or during pregnancy

Rituximab (RTX) is an effective treatment for pemphigus; however, the drug labeling recommends not to use RTX within 1 year before conception.

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

Introduction

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

Materials and Methods

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

Results

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

Conclusions

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

Pemphigus during the COVID-19 Epidemic: Infection Risk, Vaccine Responses and Management Strategies

Pemphigus is a rare autoimmune blistering disease, involving potentially life-threatening conditions often requiring immunosuppression. Currently, the COVID-19 pandemic caused by severe acute respiratory disease coronavirus 2 (SARS-CoV-2) infection has become a global public emergency. Vaccines are the most effective defense against COVID-19 infection. However, in clinic, there are cases of new onset or flare of pemphigus following COVID-19 vaccination, where vaccines have manifested significantly desirable risk-benefit profiles for patients. Although Rituximab, as first-line therapy, may impair humoral immunity, pemphigus may not predispose to develop COVID-19 infection compared to a healthy population. Conversely, delay or interruption of immunosuppressants probably results in unfavorable clinical outcomes for disease progression. Overall, clinicians should encourage their patients to undergo the vaccination after a comprehensive assessment. The definite association between COVID-19 vaccination and pemphigus remains to be further elucidated. Herein, we provide an overview of the published studies to date on COVID-19 and pemphigus as well as the exploration of their complicated interplay. In addition, we discuss the management strategies for pemphigus patients in this special period, in an effort to more effectively establish a standard treatment paradigm for this particular patient group.

In Vitro, Ex Vivo, and In Vivo Models for the Study of Pemphigus

Pemphigus is a life-threatening autoimmune disease. Several phenotypic variants are part of this family of bullous disorders. The disease is mainly mediated by pathogenic autoantibodies, but is also directed against two desmosomal adhesion proteins, desmoglein 1 (DSG1) and 3 (DSG3), which are expressed in the skin and mucosae. By binding to their antigens, autoantibodies induce the separation of keratinocytes, in a process known as acantholysis. The two main Pemphigus variants are Pemphigus vulgaris and foliaceus. Several models of Pemphigus have been described: in vitro, ex vivo and in vivo, passive or active mouse models. Although no model is ideal, different models display specific characteristics that are useful for testing different hypotheses regarding the initiation of Pemphigus, or to evaluate the efficacy of experimental therapies. Different disease models also allow us to evaluate the pathogenicity of specific Pemphigus autoantibodies, or to investigate the role of previously not described autoantigens. The aim of this review is to provide an overview of Pemphigus disease models, with the main focus being on active models and their potential to reproduce different disease subgroups, based on the involvement of different autoantigens.

Current and Innovated Managements for Autoimmune Bullous Skin Disorders: An Overview

Autoimmune bullous skin disorders are a group of disorders characterized by the formation of numerous blisters and erosions on the skin and/or the mucosal membrane, arising from autoantibodies against the intercellular adhesion molecules and the structural proteins. They can be classified into intraepithelial or subepithelial autoimmune bullous dermatoses based on the location of the targeted antigens. These dermatoses are extremely debilitating and fatal in certain cases, depending on the degree of cutaneous and mucosal involvement. Effective treatments should be implemented promptly. Glucocorticoids serve as the first-line approach due to their rapid onset of therapeutic effects and remission of the acute phase. Nonetheless, long-term applications may lead to major adverse effects that outweigh the benefits. Hence, other adjuvant therapies are mandatory to minimize the potential harm and ameliorate the quality of life. Herein, we summarize the current therapeutic strategies and introduce promising therapies for intractable autoimmune bullous diseases.

Immunotherapy for Pemphigus: Present and Future

Pemphigus is a chronic and severe autoimmune bullous disease caused by autoantibodies targeting adhesion molecules between keratinocytes. It requires 2–3 years on average to manage the disease. To date, although Rituximab combined with short-term systemic glucocorticoids was accepted as first-line therapy, systemic glucocorticoids remain the primary therapeutic option for pemphigus patients, successfully decreasing morbidity and mortality from pemphigus. However, novel therapeutic strategies are desirable due to the low efficacy in some subset of patients and the long-term severe adverse effects of traditional therapies. Recently, immunotherapy has proved to be encouraging for disease control or cure. Based on the current understanding of the immune mechanisms of pemphigus, we review the immune targets and corresponding agents applied in practice or under clinical trials. The goals of the novel treatments are to improve the quality of life of pemphigus patients by improving efficacy and safety, minimizing side effects, achieving fast disease control, or curing the disease.

"Listen to Your Immune System When It's Calling for You": Monitoring Autoimmune Diseases Using the iShU App

The immune system plays a key role in protecting living beings against bacteria, viruses, and fungi, among other pathogens, which may be harmful and represent a threat to our own health. However, for reasons that are not fully understood, in some people this protective mechanism accidentally attacks the organs and tissues, thus causing inflammation and leads to the development of autoimmune diseases. Remote monitoring of human health involves the use of sensor network technology as a means of capturing patient data, and wearable devices, such as smartwatches, have lately been considered good collectors of biofeedback data, owing to their easy connectivity with a mHealth system. Moreover, the use of gamification may encourage the frequent usage of such devices and behavior changes to improve self-care for autoimmune diseases. This study reports on the use of wearable sensors for inflammation surveillance and autoimmune disease management based on a literature search and evaluation of an app prototype with fifteen stakeholders, in which eight participants were diagnosed with autoimmune or inflammatory diseases and four were healthcare professionals. Of these, six were experts in human–computer interaction to assess critical aspects of user experience. The developed prototype allows the monitoring of autoimmune diseases in pre-, during-, and post-inflammatory crises, meeting the personal needs of people with this health condition. The findings suggest that the proposed prototype—iShU—achieves its purpose and the overall experience may serve as a foundation for designing inflammation surveillance and autoimmune disease management monitoring solutions.

Sacral Dimple, Conjunctiva, and Nipple as Less Obvious Pemphigus Vulgaris Locations around Natural Body Orifices: A Report of Three Cases

In this paper, we present our own clinical-laboratory experience concerning three less obvious presentations of pemphigus vulgaris (PV) and discuss the pertinent literature. The involvement of the sacral dimple reported here for the first time, as well as the nipple and the eyes, could initially be misleading clinically. These less stereotypical localizations may occur due to the transition of different epithelia, each with varying levels of cadherin (desmoglein, desmocollin) and thus altered sensitivity to mechanical stress. The role of dermatologists who have experience in treating autoimmune blistering dermatoses is fundamental for identifying promptly the initial and exacerbating PV lesions in such unusual locations.

Relationship Between Pemphigus Vulgaris Severity and PCR-positive Herpes Simplex Virus

Pemphigus vulgaris is a rare autoimmune skin disease. Although herpes simplex virus has been associated with autoimmune diseases, evidence regarding its association with pemphigus vulgaris exacerbations is scarce. This retrospective cohort study aimed to characterize the epidemiological and clinical features of patients with pemphigus vulgaris who were herpes simplex-positive, compared with those who were herpes simplex-negative, during disease onset. Of 62 patients with pemphigus vulgaris who underwent PCR testing for herpes simplex virus, 25 (40.3%) were positive, with a mean age of 56.1 ± 15.5 years; 35.5% were male. The herpes-positive group had significantly elevated levels of C-reactive protein, Pemphigus Disease Activity Index score, and shorter time to relapse. The time to remission, number of exacerbations per year, and remission status were non-significantly elevated in the herpes-positive group. Thus, routine testing lesions from patients with pemphigus for herpes simplex virus should be performed. If positive, antiviral treatment should be initiated; and preventive antiviral treatment should be considered in severe cases.

Factors associated with the healing time of pemphigus vulgaris oral lesions: a prospective study

OBJECTIVES

This study determines the healing time of lesions on different locations and the contributing factors to the healing time in patients with pemphigus.

METHODS

In this prospective study, newly diagnosed patients with mucosal lesions were included. A dermatologist evaluated the lesions, disease status, side effects and assigned the PDAI. Follow-up visits were conducted monthly until the patient reached complete remission and every three months thereafter. A Tzanck smear was performed on lesions clinically suspected to be herpetic in origin.

RESULTS

Sixty patients enrolled in the study with a mean age of 45.9 ± 11.7 years. The buccal lesions took the longest to resolve(73[33.5-105.5] days). However, the posterior pharynx lesions showed the shortest healing time(20[13.0-25.5] days). The likelihood of improvement in buccal and soft palate lesions decreased by 5% and 3% with each additional year of age, respectively. Also, the resolution duration of soft palate lesions was significantly shorter in female patients than males(median of 24.0 days vs. 38.5 days). In contrast, lower gingival lesions resolve significantly faster in male patients by a median of 9 days. HSV infection increases the healing time of lesions by 26 days(median of 55 days vs. 29 days, hazard ratio 2.62, 95%CI:1.04-5.92).

CONCLUSIONS

Buccal and lower gingival lesions are more recalcitrant to treatment, while posterior pharynx lesions heal most rapidly. Furthermore, older age was also associated with a lower rate of lesion improvement.