Search Results (89)

The Group-1 carcinogen Helicobacter pylori (H. pylori) secretes the serine protease high-temperature requirement A (HtrA), which is directly involved in the disruption of the epithelial barrier in the stomach. HtrA cleaves the extracellular domains of junctional proteins, including E-cadherin (CDH1), claudin-8, occludin, or desmoglein-2, to open intercellular adhesions, allowing H. pylori to transmigrate to subepithelial regions of the gastric mucosa. In our previous work, we found that Zn²⁺ and Cu²⁺ ions efficiently blocked the HtrA activity. However, the impact of other divalent ions on HtrA activity is rather unknown. In this report, we unexpectedly found a stimulating effect through Mn²⁺, Ni²⁺ and Co²⁺ ions on HtrA oligomerization and activity. In contrast to other tested ions, increasing concentrations of Mn²⁺, Ni²⁺ and Co²⁺ strongly enhanced HtrA multimerization as determined in SDS-PAGE under non-reducing conditions and in casein zymography. Increased proteolytic activity of HtrA was further assessed in in vitro cleavage experiments using casein and CDH1 as substrates. Mechanistically, divalent ions bound to HtrA and induced an active conformation, which strongly increased CDH1 cleavage in vitro. The importance of enhanced HtrA activity was finally underlined by the analysis of CDH1 cleavage in H. pylori infection experiments, showing that Ni²⁺ potentiated HtrA-mediated CDH1 shedding. In summary, this study demonstrates that divalent ions exhibit different effects on HtrA activity and that Ni²⁺ and Co²⁺ enhance proteolytic activity by promoting oligomerization, suggesting that metal availability in the gastric environment affects H. pylori virulence. Full article

Background and Objectives: Pemphigus vulgaris (PV) is a rare autoimmune blistering disease caused by IgG au-toantibodies against desmoglein 1 and/or desmoglein 3, leading to flaccid blisters on the skin and mucous membranes. The course of PV during pregnancy represents a special clinical challenge due to immunological changes accompanying physiological immunosuppression and the need to protect the developing fetus. Materials and Methods: To analyze the current state of knowledge, a literature review was performed covering the years 2015–2025. Publications describing PV diagnosed during pregnancy or in neonates were screened, and nine case reports discussing ten patients meeting the inclusion criteria were selected for detailed analysis. In this study, we also present our own clinical case of PV in pregnancy to complement the literature review and provide practical insight into disease management. Results: In most cases, the disease was diagnosed in the first trimester of pregnancy, and the most common symptoms were flaccid blisters and erosions of the oral mucosa. The diagnosis was confirmed by direct immunofluorescence (DIF) and ELISA testing. The first-line treatment remained systemic glucocorticosteroids (GCS), mainly prednisolone, which is considered the safest. In resistant cases, intravenous immunoglobulins (IVIg) were used, which were considered effective and safe, though their use may limit the transplacental transfer of autoantibodies to the fetus. In newborns, the symptoms rarely occurred, were mild, and resolved spontaneously. Drugs with proven teratogenic effects, such as methotrexate, cyclophosphamide, and mycophenolate mofetil, are contraindicated during pregnancy. In the case of rituximab therapy, it is recommended to postpone pregnancy for at least 12 months after the completion of treatment to minimize the potential risk of immunosuppression in the newborn. Conclusions: The treatment of PV during pregnancy requires close interdisciplinary cooperation. Therapy should be carefully individualized, taking into account both therapeutic efficacy and fetal safety. Perhaps then, pregnancy-related pemphigus diseases, given their peculiarities, should be classified as a distinct variety within the desmosomal type of autoimmune blistering diseases. Full article

Corneodesmosomes are specialized intercellular junctions that mediate adhesion between corneocytes in the stratum corneum (SC). The degradation of these structures is regulated by kallikrein-related peptidases (KLKs) and their inhibitors. This study aimed to elucidate the effects of Shotokuseki extract (SE), a substance rich in various trace elements, on molecules related to SC adhesion using a three-dimensional cultured human epidermis model. SE was applied to a three-dimensional epidermis model, and analyses were conducted on gene expression, protease activity, protein levels, and tissue structure. SE treatment significantly upregulated the mRNA expression of corneodesmosomal components (desmoglein1, desmocollin1, and corneodesmosin) and the major protease inhibitor serine peptidase inhibitor Kazal type 5. Concurrently, SE increased the mRNA expression of the trypsin-like protease KLK5,while significantly decreasing the mRNA expression and activity of the chymotrypsin-like protease KLK7. Although no significant changes were observed in the protein levels of corneodesmosomal components, histological analysis revealed that SE significantly increased the ratio of SC thickness to total epidermal thickness. These findings suggest that SE contributes to the homeostasis of the SC by simultaneously promoting the expression of genes encoding corneodesmosomal components, and regulating the balance of the protease/inhibitor system involved in their degradation. The selective suppression of KLK7 activity may appropriately regulate the final stage of desquamation, thereby stabilizing barrier function. Full article

Desmosomal junctions provide structural stability supporting concerted cardiomyocyte contractility. Previously, we demonstrated that a deficiency in the desmosomal transmembrane cadherin desmoglein 2 (Dsg2) reduces desmosome formation and disrupts cardiac morphogenesis, leading to excessive endothelial-to-hematopoietic cell transformation and embryonic lethality. It remained unclear whether this phenotype was specifically driven by Dsg2-deficiency or was a broader consequence of impaired desmosome adhesion. To address this question, we generated Pkp2^mt/mt mouse embryos lacking the desmosomal plaque protein Pkp2, which resulted in loss of desmosome formation. Despite the absence of cardiac wall rupture, Pkp2^mt/mt and some Pkp2^wt/mt presented accumulations of Ter-119⁺ blood cells and RUNX1⁺/CD44⁺ hematopoietic stem cells in the pericardial space. Remarkably, in Pkp2^mt/mt hearts, the epicardium was detached from the myocardium, contained rounded cells expressing the hematopoietic stem cell marker RUNX1, and showed altered intermediate filament expression. These findings suggest a potential trans-differentiation of the epicardial cells into hematopoietic cells. In conclusion, deficiencies in both Dsg2 and Pkp2 promote hematopoiesis in the developing murine heart but target different cell types, i.e., endothelial cells, which lack desmosomes, or desmosome-containing epicardial cells. Our results provide evidence for the involvement of Pkp2 in epicardial morphogenesis and remodeling. Full article

Background/Objectives: Pemphigus vulgaris (PV) and foliaceus (PF) are autoimmune blistering diseases mediated by IgG antibodies directed against desmogleins 1 and 3 and are still considered life-threatening disorders. In recent years, rituximab has been shown to be very effective, especially in PV and mainly in short follow-ups. The role of rituximab in achieving long-lasting complete clinical remission (cCR) in pemphigus still needs to be determined. Therefore, the aim of our study was to assess the efficacy, measured by achieving long-lasting cCR, and safety of rituximab in both PV and PF over an 8-year follow-up in light of several factors (body mass index—BMI, severity of disease—PDAI, age, gender, disease duration, COVID-19 period). Methods: In total, 28 patients with pemphigus were treated with rituximab and followed-up at one center. The entire analysis was performed using statistical methods. Results: Long-lasting cCR was achieved in 5 out of 6 patients (83%) with PF and 10 of 22 (45.5%) patients with PV. Univariate and multivariate analysis disclosed that studied factors did not statistically correlated with achieving long-lasting cCR. Among studied patients, few developed side effects, mainly urinary tract infection; one patient had sepsis, and one patient died. Conclusions: This study has demonstrated that rituximab is highly effective in PF and quite effective in PV over an 8-year follow-up in relation to independently studied factors. Moreover, the COVID-19 pandemic was not a negative factor influencing cCR achievement since 82% of patients treated with rituximab during that time still achieved cCR. Full article

Alopecia areata (AA) is a chronic autoimmune disorder characterized by non-scarring hair loss, with subtypes ranging from patchy alopecia (AAP) to alopecia totalis and universalis (AT/AU). The aim of this research is to investigate molecular features across AA severity by performing an integrated analysis of scalp transcriptomic datasets (GSE148346, GSE68801, GSE45512, GSE111061) and matched serum proteomic data from GSE148346. Differential expression analysis indicated that, relative to normal scalp, non-lesional AA tissue shows early immune activation—including Type 1 (C-X-C motif chemokine ligand 9 (CXCL9), CXCL10, CD8a molecule (CD8A), C-C motif chemokine ligand 5 (CCL5)) and Type 2 (CCL13, CCL18) signatures—together with reduced expression of hair-follicle structural genes (keratin 32(KRT32)–35, homeobox C13 (HOXC13)) (FDR < 0.05, |fold change| > 1.5). Lesional AAP and AT/AU scalp showed stronger pro-inflammatory upregulation and greater loss of keratins and keratin-associated proteins (KRT81, KRT83, desmoglein 4 (DSG4), KRTAP12/15) compared with non-lesional scalp (FDR < 0.05, |fold change| > 1.5). Ferroptosis-associated genes (cAMP responsive element binding protein 5 (CREB5), solute carrier family 40 member 1 (SLC40A1), (lipocalin 2) LCN2, SLC7A11) and IRS (inner root sheath) differentiation genes (KRT25, KRT27, KRT28, KRT71–KRT75, KRT81, KRT83, KRT85–86, trichohyalin (TCHH)) were consistently repressed across subtypes, with the strongest reductions in AT/AU lesions versus AAP lesions, suggesting that oxidative-stress pathways and follicular structural integrity may contribute to subtype-specific pathology. Pathway analysis of lesional versus non-lesional scalp highlighted enrichment of IFN-α/γ, cytotoxic, and IL-15 signaling. Serum proteomic profiling, contrasting AA vs. healthy controls, corroborated scalp findings, revealing parallel alterations in immune-related proteins (CXCL9–CXCL10, CD163, interleukin-16 (IL16)) and structural markers (angiopoietin 1 (ANGPT1), decorin (DCN), chitinase-3-like protein 1 (CHI3L1)) across AA subtypes. Together, these data offer an integrated view of immune, oxidative, and structural changes in AA and found ferroptosis-related and IRS genes, along with immune signatures, as potential molecular indicators to support future studies on disease subtypes and therapeutic strategies. Full article

Oral Lichen Planus (OLP) is a chronic autoimmune disease with potential overlap with Pemphigus Vulgaris (PV), particularly in erosive forms. Desmoglein 1 and 3 are transmembrane glycoproteins of desmosomes, typically involved in PV. This scoping review aims to evaluate the presence and potential pathogenetic role of anti-desmoglein 1 (Dsg1) and anti-desmoglein 3 (Dsg3) antibodies in OLP. A literature search was conducted on MEDLINE/PubMed, Ovid, and Scopus up to April 2025. Human studies reporting OLP patients with anti-Dsg1 and/or anti-Dsg3 antibodies were included. Data from 11 studies were analyzed by diagnosis, age/sex, oral site involvement, immunofluorescence, and ELISA testing. Erosive OLP was most frequently associated with anti-Dsg1/Dsg3 positivity, mainly in women aged 40–60. Immunofluorescence was positive in some cases, while the ELISA test almost consistently detected anti-Dsg1 and Dsg3 antibodies. However, in many instances, antibody titers did not reach the threshold value, despite the presence being detectable. This finding suggests that anti-Dsg1/Dsg3 antibodies may represent epiphenomena of chronic inflammation in erosive OLP, indicating an immune-serological overlap with PV but lacking direct pathogenicity. Furthermore, the role of Dsg3 in oral squamous cell carcinoma, by promoting enzymes that degrade the extracellular matrix and enhance tumor invasiveness, highlights the complex functions of desmogleins beyond autoimmunity. Full article

Pemphigus-associated interstitial lung disease (P-ILD) is a severe complication observed in pemphigus patients that is characterized by pulmonary interstitial inflammation and fibrosis. This study investigated the role of anti-desmoglein (Dsg) 1/3 antibodies in P-ILD pathogenesis and evaluated the therapeutic potential of molecular hydrogen (H₂). Using a BALB/cJGpt mouse model, we demonstrated that anti-Dsg 1 antibodies, but not anti-Dsg 3 antibodies, induced interstitial inflammation and fibrosis. Immunofluorescence staining confirmed IgG deposition in the alveolar epithelium, suggesting immune complex formation and epithelial damage. Gene expression analysis revealed elevated pro-inflammatory cytokines (IL-1β, IL-13) and upregulated pro-fibrotic markers (α-SMA, S100A4, TGF-β, and collagen genes) in P-ILD progression. Elevated oxidative stress and impaired ROS metabolism further implied the role of oxidative damage in disease pathogenesis. To assess H₂’s therapeutic potential, hydrogen-rich water was administered to P-ILD mice. H₂ treatment significantly reduced oxidative stress, attenuated interstitial inflammation, and prevented pulmonary fibrosis. These protective effects were attributed to H₂’s antioxidant properties, which restored the pro-oxidant–antioxidant balance. Our findings underscore the critical role of anti-Dsg 1 antibodies and oxidative stress in P-ILD and highlight H₂ as a promising therapeutic agent for mitigating anti-Dsg 1 antibody-induced lung injury. Full article

Eosinophilic esophagitis (EoE) is a chronic disease which clinically presents with symptoms related to esophageal dysfunction, while pathologically it is characterized by eosinophilic infiltration of esophageal epithelium. Most patients with EoE present with food and/or inhalant allergy symptoms. The results of animal model studies and genetic studies, as well as the efficacy of elimination diets in managing the symptoms, suggest an atopic background of the disease. The aim of this study was to evaluate the prevalence of EoE in a group of patients with upper gastrointestinal symptoms and food and/or inhalant allergies and to assess the influence of drugs used in type I allergies on the results of endoscopic, histopathological, and immunohistochemical tests. Methods: This was a prospective observational study. Patients with inhalant/food allergies and upper esophageal symptoms constituted the study group while patients without allergies who were diagnosed with dyspepsia or irritable bowel syndrome constituted the control group. All study group subjects underwent allergy testing, including prick testing and blood tests. All participants underwent a gastroscopy with specimen collection. Esophageal specimens were stained for eotaxin-1 and desmoglein-1. Results: Based on histopathology results, eosinophilic esophagitis was found in 9 of the 73 patients from the study group. All patients with EoE presented with multimorbidity and were diagnosed with at least one allergic disease in addition to EoE. Positive staining for CCL-11 was found in 56 (78%) patients in the study group, including all patients with EoE while only 3 (17%) individuals from the control group showed positive staining. The presence of DSG-1 in esophageal specimens was detected in 6 (7%) subjects from the study group in contrast to 14 (78%) subjects from the control group. DSG-1 was not found in any of the specimens of patients diagnosed with EoE. Conclusions: EoE is a rare disease, usually accompanied by allergic multimorbidity. Positive staining for eotaxin-1 and negative staining for desmoglein-1 in patients with esophageal symptoms and allergies but who did not meet EoE diagnostic criteria could be indicative of subclinical course of the disease or a masking effect of corticosteroids. It is now vitally important for both researchers and practicing clinicians to recognize that eosinophilic esophagitis (EoE) is not a homogeneous disease but rather consists of multiple subtypes (phenotypes). The so-called “classic” form of EoE—defined by current diagnostic criteria as the presence of more than 15 eosinophils per high power field on histopathological examination—appears to represent only the tip of the iceberg. There is an urgent need for further research in order to refine endoscopic techniques, expand the scope of histopathological assessments, and identify novel biomarkers to better define the distinct phenotypes of eosinophilic esophagitis. Full article

Background: Ocular predominant mucous membrane pemphigoid (oMMP) is a severe subtype of autoimmune blistering disease (AIBD), which can result in scarring and vision loss. The diagnosis of oMMP is challenging as patients often have undetectable levels of circulating autoantibodies by conventional assays. Likewise, the principal autoantigen in oMMP has been an area of debate. Methods: In this preliminary experiment, we performed Phage Immunoprecipitation Sequencing (PhIP-seq) on sera from patients with oMMP, as well as non-ocular MMP, bullous pemphigoid, and mucocutaneous-type pemphigus vulgaris. Results: We identified several autoantigens unique to oMMP relative to other AIBDs. We then cross-referenced these antigens against previously published single-nuclei datasets, as well as the International Mouse Phenotyping Consortium Database. Several protein hits identified in our study demonstrated enriched expression on the anterior surface epithelia, including TNKS1BP1, SEC16B, FNBP4, CASZ1, GOLGB1, DOT1L, PRDM 15, LARP4B, and RPL6. Likewise, a previous study of mouse knockout models of murine analogs CASZ1, HIP1, and ELOA2 reported that these mice showed abnormalities in terms of the ocular surface and development in the eyes. Notably, PhIP-seq failed to identify the canonical markers of AIBDs such as BP180, BP230, desmogleins 1 and 3, or integrin β4, indicating that the patient autoantibodies react with conformational epitopes rather than linear epitopes. Conclusions: oMMP patients demonstrate a unique autoantibody repertoire relative to the other AIBDs. Further validation of the identified autoantibodies will shed light on their potentially pathogenic role. Full article

Background: Autoantibodies against Desmoglein-2 desmosomal protein (anti-DSG2-ab) were identified in Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) by Enzyme-Linked ImmunoSorbent Assay (ELISA); anti-intercalated disk autoantibodies (AIDAs) were identified in myocarditis and (ARVC) by indirect immunofluorescence (IFL). We aim to assess: (1) anti-DSG2-ab specificity in ARVC and myocarditis, (2) accuracy of anti-DSG2-ab detection by ELISA versus AIDA by IFL, and (3) clinical correlates of anti-DSG2-ab in ARVC. Methods: We included 77 patients with ARVC, 91 with myocarditis/dilated cardiomyopathy (DCM), 27 with systemic immune-mediated diseases, and 50 controls. Anti-heart antibodies (AHAs) and AIDAs were assessed by IFL, and anti-DSG2-ab by ELISA (assessed both by optical density, OD, and U/L). Receiving operator curve (ROC) analysis was used to assess ELISA diagnostic accuracy. Results: A relevant proportion (56%) of ARVC patients was anti-DSG2-ab-positive, with higher anti-DSG2-ab levels than controls. Anti-DSG2-ab titer was not different between ARVC and myocarditis/DCM patients (48% anti-DSG-ab positive). Frequency of anti-DSG2 positivity by ELISA was higher in AIDA-positive cases by IFL than AIDA-negative cases (p = 0.039 for OD, p = 0.023 for U/L). In ARVC, AIDA-positive patients were more likely to be AHA-positive (p < 0.001), had pre-syncope (p = 0.025), and abnormalities in cardiac rhythm (p = 0.03) than ARVC AIDA-negative patients, while anti-DSG2-ab positivity did not have clinical correlates. Conclusions: Anti-DG2-ab detection in ARVC and myocarditis/DCM reflects immune-mediated pathogenesis to desmosomal proteins. Higher frequency of anti-DSG2-ab positivity by ELISA by U/L was higher in AIDA-positive cases by IFL than AIDA-negative cases, in keeping with the hypothesis that DSG2 is one of AIDA autoantigens. In ARVC, AIDA status but not anti-DSG2-ab showed distinct clinical correlates, possibly reflecting a wider AIDA autoantigenic spectrum. Full article

Background/Objectives: Large-scale epidemiological studies have established a bidirectional association between hypertension and cancer. However, the underlying mechanisms explaining this connection remain unclear. In our study, we investigated whether serum from patients with hypertension (HT) could enhance the aggressiveness of cancer cells in vitro through alterations in endothelial cell phenotype. Methods: Experiments were performed using EAhy926 endothelial cells and ovarian (SKOV-3), colorectal (SW480), pancreatic (PSN-1), breast (MCF-7), and lung (A549) cancer cell lines. Results: This study showed that conditioned medium (CM) produced by EAhy926 cells, when exposed to serum from patients with untreated hypertension (HT-CM), promotes the proliferation, migration, and invasion of every cancer cell line tested. In addition, endothelial cells subjected to HT serum promote the adhesion of all cancer cell types except PSN-1. An intensified transendothelial invasion of cancer cells was accompanied by decreased expression of junctional proteins (connexin 43, E-cadherin, occluding, desmoglein) in HT serum-treated endothelial cells. Quantitative analysis of the secretome of endothelial cells subjected to HT serum showed that they secrete increased amounts of CCL2, CXCL1, CXCL8, bFGF, HGF, IL-6, PAI-1, and TGF-β1. Moreover, cancer cells exposed to HT-CM display increased mRNA expression for several pro-cancerogenic agents, including CXCL8, tPA, and VEGF. Conclusions: Our report shows that hypertension may potentiate cancer cell aggressiveness by modulating endothelial cell phenotype. Further tests with antihypertensive drugs are required to assess whether effective treatment of hypertension can mitigate its cancer-promoting potential. Full article

Pemphigus is an autoimmune disease that affects the skin and mucous membranes, induced by the deposition of pemphigus IgG, which mainly targets desmogleins 1 and 3 (Dsg1 and 3). This autoantibody causes steric interference between Dsg1 and 3 and the loss of cell adhesion, producing acantholysis. This molecule and its cellular effects are clinically reflected as intraepidermal blistering. Pemphigus vulgaris-IgG (PV-IgG) binding involves p38MAPK-signaling-dependent caspase-3 activation. The present work assessed the in vitro effect of PV-IgG on the adherence of HaCaT cells dependent on caspase-3. PV-IgG induced cell detachment and apoptotic changes, as demonstrated by annexin fluorescent assays. The effect of caspase-3 induced by PV-IgG was suppressed in cells pre-treated with caspase-3-shRNA, and normal IgG (N-IgG) as a control had no relevant effects on the aforementioned parameters. The results demonstrated that shRNA reduces caspase-3 expression, as measured via qRT-PCR and via Western blot and immunofluorescence, and increases cell adhesion. In conclusion, shRNA prevented in vitro cell detachment and the late effects of apoptosis induced by PV-IgG on HaCaT cells, furthering our understanding of the molecular role of caspase-3 cell adhesion dependence in pemphigus disease. Full article

Proteomics studies often explore phenotypic differences between whole organs and systems. Within the heart, more subtle variation exists. To date, differences in the underlying proteome are only described between whole cardiac chambers. This study, using the bovine heart as a model, investigates inter-regional differences and assesses the feasibility of measuring detailed, cross-tissue variance in the cardiac proteome. Using a bovine heart, we created a two-dimensional section through a plane going through two chambers. This plane was further sectioned into 4 × 4 mm cubes and analysed using label-free proteomics. We identified three distinct proteomes. When mapped to the extracted sections, the proteomes corresponded largely to the outer wall of the right ventricle and secondly to the outer wall of the left ventricle, right atrial appendage, tricuspid and mitral valves, modulator band, and parts of the left atrium. The third separate proteome corresponded to the inner walls of the left and right ventricles, septum, and left atrial appendage. Differential protein abundancies indicated differences in energy metabolism between regions. Data analyses of the mitochondrial proteins revealed a variable pattern of abundances of complexes I–V between the proteomes, indicating differences in the bioenergetics of the different cardiac sub-proteomes. Mapping of disease-associated proteins interestingly showed desmoglein-2, for which defects in this protein are known to cause Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy, which was present predominantly in the outer wall of the left ventricle. This study highlights that organs can have variable proteomes that do not necessarily correspond to anatomical features. Full article

Autoimmune bullous diseases (AIBDs) are characterized by the formation of vesicles, bullous lesions, and mucosal erosions. The autoantibodies target the cellular anchoring structures from the surface of epidermal keratinocyte named desmosomes, leading to a loss of cellular cohesion named acantholysis. AIBDs are classified into intraepidermal or subepidermal types based on clinical features, histological characteristics, and immunofluorescence patterns. Pemphigus foliaceus (PF) is an acquired, rare, autoimmune skin condition associated with autoantibodies that specifically target desmoglein-1, leading to a clinical presentation characterized by delicate cutaneous blisters, typically sparing the mucous membranes. Several factors, including genetic predisposition, environmental triggers, malignancies, medication use, and vaccination (for influenza, hepatitis B, rabies, tetanus, and more recently, severe acute respiratory syndrome Coronavirus 2 known as SARS-CoV-2), can potentially trigger the onset of pemphigus. With the advent of vaccines playing a pivotal role in combatting the 2019 coronavirus disease (COVID-19), extensive research has been conducted globally to ascertain their efficacy and potential cutaneous adverse effects. While reports of AIBDs post-COVID-19 vaccination exist in the medical literature, instances of PF following vaccination have been less commonly reported worldwide. The disease’s pathophysiology is likely attributed to the resemblance between the ribonucleic acid (RNA) antigen present in these vaccines and cellular nuclear matter. The protein produced by the BNT-162b2 messenger ribonucleic acid (mRNA) vaccine includes immunogenic epitopes that could potentially trigger autoimmune phenomena in predisposed individuals through several mechanisms, including molecular mimicry, the activation of pattern recognition receptors, the polyclonal stimulation of B cells, type I interferon production, and autoinflammation. In this review, we present a comprehensive examination of the existing literature regarding the relationship between COVID-19 and PF, delving into their intricate interactions. This exploration improves the understanding of both pemphigus and mRNA vaccine mechanisms, highlighting the importance of close monitoring for PF post-immunization. Full article