Comparison of serum cytokines and chemokines levels and clinical significance in patients with pemphigus vulgaris-A retrospective study.

In this study, we aimed to examine the relationship between the serum cytokine levels of patients with pemphigus vulgaris (PV) and the Pemphigus Disease Area Index (PDAI), along with the presence of anti-desmoglein (Dsg) 1 antibody, anti-Dsg3 antibody and co-infection among patients with pemphigus vulgaris. This retrospective study included 62 PV patients and 59 healthy individuals who attended the Second Affiliated Hospital of Kunming Medical University from November 2014 to November 2022. The serum concentrations of cytokines and chemokines were assessed using the Luminex 200 System (a high-throughput cytokine detection method). Additionally, anti-Dsg1 and anti-Dsg3 antibodies were determined through enzyme-linked immunosorbent assay, while disease severity was evaluated using the PDAI scoring system. The PV group exhibited elevated levels of Th1 cytokines (such as interleukin (IL)-1RA, IL-1ß, IL-2, IL-12p70, GM-CSF, TNF-α, IL-18, IFN-γ), Th2 cytokines (IL-5, IL-10, IL-13) and Th17/Th22-related cytokines (IL-17A, IL-22) compared to the healthy control group (p < 0.05). Conversely, the levels of chemokines (macrophage inflammatory protein-1 alpha (MIP-1α), stromal cell-derived factor-1 alpha (SDF-1α), interferon-inducible protein-10 (IP-10), Regulated on Activation in Normal T-Cell Expressed And Secreted (RANTES), growth-regulated on-gene-alpha (GRO-α), MIP-1ß) and Th2 (IL-31) were lower in the PV group compared to the healthy control group (p < 0.05). No significant differences were observed in other cytokines and chemokines (p > 0.05). Additionally, IL-7, IFN-γ, IL-18 and GRO-α showed positive correlations with PDAI, IL-6 correlated positively with anti-Dsg3 antibody levels, and IL-12p70, IL-18, and IFN-γ correlated positively with anti-Dsg1 antibody levels. Furthermore, IL-15 exhibited a positive association with skin infections. PV patients have elevated levels of various cytokines and chemokines, and there are different degrees of elevation in cytokines and chemokines associated with the activation of various T cell subsets. PDAI and the Dsg1 antibody levels are mainly related to the Th1-related cytokines.

Maintenance treatment of pemphigus with rituximab in real life: A single-center study of 50 patients.

BACKGROUND: Following the RITUX 3 therapeutic trial, the French national diagnosis and care protocol (NDCP) for the treatment of pemphigus was updated in 2018. The updated protocol recommends initial treatment with rituximab (RTX) followed by maintenance therapy at 12 and 18 months, and potentially at 6 months where there are risk factors for early relapse. We evaluated these recommendations regarding the management of our own patients. PATIENTS AND METHODS: Our single-center retrospective study included all patients with pemphigus diagnosed between 01/2015 and 10/2020 and receiving at least one initial infusion of RTX. We collected the following data: type of pemphigus, severity, levels of anti-desmoglein 1 and 3 antibodies at diagnosis and between 2 and 6 months after initial RTX, presence or absence of maintenance therapy and modalities, time to first relapse and duration of associated systemic corticosteroid therapy ≥5 mg/day. Maintenance treatment modalities were as follows: no maintenance treatment, maintenance "on demand" (MT1) i.e. not performed at the rate imposed by the NDCP, and maintenance "according to NDCP" (MT2). RESULTS: Fifty patients were included (women 54%, median age 58 years, pemphigus vulgaris 68%, moderate to severe 68%). Initial RTX was combined with systemic corticosteroid therapy at 0.5 to 1 mg/kg in 74% of cases. Twenty-seven patients (54%) received no maintenance therapy, 13 were on an MT1 regimen (26%), and 10 were on an MT2 regimen (20%). Median follow-up was 42 months. At the last follow-up, 39 patients (78%) were in complete remission. A total of 25 patients (50%) relapsed: 18/27 (67%) patients without maintenance, 5/13 (38%) with MT1, and 2/10 (20%) with MT2 (p = 0.026). The probability of relapse over time was significantly lower in patients receiving maintenance therapy compared to those who receiving none (p = 0.022). The median time to relapse was 15 months in patients without maintenance, and 30 and 28 in those with maintenance (p = 0.27). The median duration of systemic corticosteroid therapy ≥ 5 mg/day in the no-maintenance group was 10 months, compared to 7 and 9 months respectively in MT1 and MT2 (p = 0.91). CONCLUSION: Our study confirms the value of RTX maintenance therapy in pemphigus in real life.

miRNA implication in the pathogenesis and the outcome of Tunisian endemic pemphigus foliaceus.

Pemphigus foliaceus (PF) is a bullous autoimmune skin disease diagnosed through sera and skin analyses. PF severity is associated with maintained anti-Dsg1 sera levels and its prognosis is unpredictable. MicroRNA (miRNA), dynamic regulators of immune function, have been identified as potential biomarkers for some autoimmune diseases. This study aimed to assess the miRNA expression of miR-17-5p, miR-21-5p, miR-146a-5p, miR-155-5p and miR-338-3p using quantitative real-time PCR in peripheral blood mononuclear cells (PBMC) and lesional skin samples from untreated and treated PF patients (both remittent and chronic) over 3 months. Overall, miRNA expression was significantly higher in PBMC than in biopsy samples. Blood miR-21 expression was increased in untreated patients compared to controls and had a diagnostic value with an AUC of 0.78. After 6 weeks, it decreased significantly, similar to anti-Dsg1 antibodies and the PDAI score. In addition, a positive correlation was observed between cutaneous miR-21 expression and the disease activity score. Conversely, cutaneous expressions of miR-17, miR-146a and miR-155 were significantly higher in treated chronic patients compared to remittent ones. The cutaneous level of miR-155 positively correlated with pemphigus activity, making it a potential predictive marker for patients' clinical stratification with an AUC of 0.86.These findings suggest that blood miR-21 and cutaneous miR-155 can be used as supplemental markers for PF diagnosis and activity, respectively in addition to classical parameters.

Correlation of desmoglein 1 and 3 immunohistochemistry with autoantibody levels and clinical severity in pemphigus.

BACKGROUND: Pemphigus is a chronic potentially fatal autoimmune bullous disorder. Pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are the two common subtypes. PV is the most common and aggressive type characterized by oral mucosal erosions and cutaneous lesions. PF presents with blisters on the scalp, face, and upper trunk, and spares the mucosae. Direct immunofluorescence (DIF) is the gold standard for diagnosis. Immunohistochemistry (IHC) is an emerging alternate diagnostic tool. In this study, our objectives were to identify the staining patterns of desmoglein 1 (dsg 1) and desmoglein 3 (dsg 3) IHC and to correlate the same with autoantibody levels and clinical severity in patients with PV and PF. METHODS: Forty-nine clinically, histologically, and DIF-confirmed cases of pemphigus were included in the study. The IHC patterns were scored from 0 to 3+ with 3+ dsg 1 IHC exhibiting intense membranous staining in the upper layers of the epidermis and 3+ dsg 3 IHC showing intense basal layer staining. Enzyme-linked immunosorbent assay (ELISA) for anti-dsg 1 and 3 antibodies was performed in 38 cases where serum samples were available. The pemphigus disease activity index system was utilized for clinical scoring. RESULTS: A 0 to 1+ score was observed for dsg 1 IHC in 100% of PF cases. A score of 0 to 1+ was observed for dsg 3 IHC in 97.3% of PV cases. One hundred percent of cases with PF and 83.9% of patients with PV tested positive for ELISA anti-dsg 1 and 3 antibody titers, respectively. Anti-dsg 1 and 3 ELISA titers significantly correlated with the dsg 1 and dsg 3 IHC scores. The mucosal scores showed a significant association with both dsg 1 and 3 IHC (p < 0.001). The cutaneous scores showed a significant association with the dsg 3 IHC (p < 0.001). CONCLUSION: The IHC patterns for dsg 1 and 3 proved reliable in giving concordant results with the ELISA antibody titers and clinical severity.

Red crusty plaques in a young man.

Pemphigus foliaceus is a superficial blistering disorder characterized by erosions and scaling in a seborrheic distribution. The condition typically occurs in healthy individuals but issues arise from delayed diagnosis. Many cases remain undiagnosed or misdiagnosed due to the lack of awareness of the condition. With use of common diagnostic tools, pemphigus foliaceus can be easily identified and monitored. Histological analysis exhibits "chicken wire" patterning along keratinocytes in the upper epidermis, whereas immunofluorescence study displays subcorneal acantholysis. Pemphigus foliaceus is confirmed via ELISA studies revealing the presence of autoantibodies against desmoglein 1. Once correctly diagnosed, typically the condition is responsive to corticosteroid therapy. However in recalcitrant cases such as in ours, adjunctive immunosuppressive therapy with dapsone or rituximab may be indicated.

Decreased FABP5 and DSG1 protein expression following PAX6 knockdown of differentiated human limbal epithelial cells.

PAX6 haploinsufficiency related aniridia is characterized by disorder of limbal epithelial cells (LECs) and aniridia related keratopathy. In the limbal epithelial cells of aniridia patients, deregulated retinoic acid (RA) signaling components were identified. We aimed to visualize differentiation marker and RA signaling component expression in LECs, combining a differentiation triggering growth condition with a small interfering RNA (siRNA) based aniridia cell model (PAX6 knock down). Primary LECs were isolated from corneoscleral rims of healthy donors and cultured in serum free low Ca2+ medium (KSFM) and in KSFM supplemented with 0.9 mmol/L Ca2+. In addition, LECs were treated with siRNA against PAX6. DSG1, PAX6, KRT12, KRT 3, ADH7, RDH10, ALDH1A1, ALDH3A1, STRA6, CYP1B1, RBP1, CRABP2, FABP5, PPARG, VEGFA and ELOVL7 expression was determined using qPCR and western blot. DSG1, FABP5, ADH7, ALDH1A1, RBP1, CRABP2 and PAX6 mRNA and FABP5 protein expression increased (p ≤ 0.03), PPARG, CYP1B1 mRNA expression decreased (p ≤ 0.0003) and DSG1 protein expression was only visible after Ca2+ supplementation. After PAX6 knock down and Ca2+ supplementation, ADH7 and ALDH1A1 mRNA and DSG1 and FABP5 protein expression decreased (p ≤ 0.04), compared to Ca2+ supplementation alone. Using our cell model, with Ca2+ supplementation and PAX6 knockdown with siRNA treatment against PAX6, we provide evidence that haploinsufficiency of the master regulatory gene PAX6 contributes to differentiation defect in the corneal epithelium through alterations of RA signalling. Upon PAX6 knockdown, DSG1 differentiation marker and FABP5 RA signaling component mRNA expression decreases. A similar effect becomes apparent at protein level though differentiation triggering Ca2+ supplementation in the siRNA-based aniridia cell model. Expression data from this cell model and from our siRNA aniridia cell model strongly indicate that FABP5 expression is PAX6 dependent. These new findings may lead to a better understanding of differentiation processes in LECs and are able to explain the insufficient cell function in AAK.

Treatment of pemphigus vulgaris and foliaceus with efgartigimod, a neonatal Fc receptor inhibitor: a phase II multicentre, open-label feasibility trial.

BACKGROUND: Pemphigus vulgaris and pemphigus foliaceus are potentially life-threatening autoimmune disorders triggered by IgG autoantibodies against mucosal and epidermal desmogleins. There is an unmet need for fast-acting drugs that enable patients to achieve early sustained remission with reduced corticosteroid reliance. OBJECTIVES: To investigate efgartigimod, an engineered Fc fragment that inhibits the activity of the neonatal Fc receptor, thereby reducing serum IgG levels, for treating pemphigus. METHODS: Thirty-four patients with mild-to-moderate pemphigus vulgaris or foliaceus were enrolled in an open-label phase II adaptive trial. In sequential cohorts, efgartigimod was dosed at 10 or 25 mg kg-1 intravenously with various dosing frequencies, as monotherapy or as add-on therapy to low-dose oral prednisone. Safety endpoints comprised the primary outcome. The study is registered at ClinicalTrials.gov (identifier NCT03334058). RESULTS: Adverse events were mostly mild and were reported by 16 of 19 (84%) patients receiving efgartigimod 10 mg kg-1 and 13 of 15 (87%) patients receiving 25 mg kg-1 , with similar adverse event profiles between dose groups. A major decrease in serum total IgG and anti-desmoglein autoantibodies was observed and correlated with improved Pemphigus Disease Area Index scores. Efgartigimod, as monotherapy or combined with prednisone, demonstrated early disease control in 28 of 31 (90%) patients after a median of 17 days. Optimized, prolonged treatment with efgartigimod in combination with a median dose of prednisone 0·26 mg kg-1 per day (range 0·06-0·48) led to complete clinical remission in 14 of 22 (64%) patients within 2-41 weeks. CONCLUSIONS: Efgartigimod was well tolerated and exhibited an early effect on disease activity and outcome parameters, providing support for further evaluation as a therapy for pemphigus.

Retrospective study of gingival involvement in pemphigus: A difficult to treat phenomenon.

Pemphigus is a group of autoimmune diseases characterized by flaccid lesions on the skin and mucous membranes. In pemphigus vulgaris, the most common subtype of pemphigus, lesions might be appeared anywhere on the oral mucosa, mostly in the buccal mucosa. However, the gingiva is a less frequently affected site. Here, we performed a retrospective study at Tehran University of Medical Sciences, covering a two-year period to identify pemphigus patients with active lesions confined to the gingiva. Considering 1787 initially evaluated pemphigus cases, 512 (28.6%) were found to have a history of gingival involvement. Among them, 31 patients had only gingival involvement during their last visit, including 29 (93.5%) women and only two (6.5%) men. The mean of disease duration in this group was 5.29 ± 3.46 years, and they had gingival involvement for a mean of 23.9 ± 19.3 months. Of 28 patients, nine were negative for anti-Dsg3 and 24 were negative for anti-Dsg1. In 24 patients, who received rituximab, the mean pemphigus disease area index specifically for gingiva was 4.76 ± 0.74 at baseline, which had changed to 4.13 ± 0.75 and 3.26 ± 0.63 three and 6 months after rituximab administration, respectively. After 3 months, gingival lesions were either entirely resolved (n = 3), partially resolved (n = 11), remained unchanged (n = 2), or progressed (n = 7). Gingiva-confined presentation of lesions in pemphigus could be non-anti-Dsg1/3 dependent in some patients. Such patients do not respond well to conventional treatments and rituximab therapy. More studies on the pathogenesis of gingiva-confined presentation of pemphigus are required.

Pemphigus patients with initial negative levels of anti-desmoglein: A subtype with different profile?

Pemphigus is a blistering autoimmune disease that is characterized by autoantibodies against desmogleins (Dsg), including anti-Dsg1 and anti-Dsg3. Despite the diagnosis of diseases, the anti-Dsg test by enzyme-linked immunosorbent assay (ELISA) is negative in a small group of pemphigus patients. The aim of this study was to evaluate the clinical course, clinical symptoms, and response to treatment in pemphigus patients with negative levels of anti-Dsg1 and anti-Dsg3. In this study, the data of pemphigus patients referred to Razi Hospital were retrospectively collected from the medical records from 2016 to 2020. Eight patients, whose initial anti-Dsg1/anti-Dsg3 was negative by the ELISA test, were enrolled and their clinical course, clinical signs, and response to treatment were evaluated. The mean age of the subjects (8 females) was 38.75 ± 12.09. The most common phenotype of the subjects was pemphigus vulgaris (PV) with mucosal involvement. Additionally, the common site of blister inception was mouth of the patients. The mean prednisolone dose received by the patients at the initiation was 32.5 ± 13.62 mg/day. According to Pemphigus disease area index (PDAI), six patients had mild severity, while two cases had moderate severity. Among the patients, six subjects received rituximab (RTX). Also, five patients experienced remission after 6.2 ± 5.21 months. PV is the most common phenotype of the disease and mucosal involvement is more common in patients with negative anti-Dsg-1/3 results. The severity of the lesions in most of the patients is mild at baseline and most patients seems to respond to RTX therapy and reach remission.

ELISA detection of anti-desmoglein 1 and anti-desmoglein 3 and indirect immunofluorescence in oral pemphigus: A retrospective study.

OBJECTIVE: The aim of this study was to test the efficacy of autoantibodies to desmoglein 1 and desmoglein 3 detected by ELISA and indirect immunofluorescence in the diagnosis of oral pemphigus and to correlate the antibody titres with the severity of the disease. MATERIALS AND METHODS: We report a retrospective cohort study of 22 patients with oral pemphigus and 64 controls from a single tertiary centre. Data about histopathological examination, direct immunofluorescence, indirect immunofluorescence and ELISA were analysed. Global validation of ELISA and IIF both alone and combined was established by calculating sensitivity, specificity, accuracy and both positive predictive value and negative predictive value. The relationship between Oral Disease Severity Score values and ELISA titres was analysed using Pearson's coefficient. RESULTS: The best diagnostic performance was observed for anti-desmoglein 3 ELISA. The sensitivity was 75% and specificity 100% and positive predictive value and negative predictive value were 92.5% and accuracy 93.9%. The level of agreement with histopathology + direct immunofluorescence was substantial (k = .758). Anti-desmoglein 3 titres showed a significant correlation with Oral Disease Severity Score (p < .05). CONCLUSIONS: Serological tests are commonly employed during clinical practice as adjunctive tools. Anti-desmoglein 3 ELISA should be considered as a first-instance diagnostic test for oral pemphigus early detection.

Punctate Pattern and Pemphigus: Is There Any Evidence of Punctate Pattern Among Iranian Patients?

AIM: To examine the prevalence of this novel pattern among Iranian patients with pemphigus and peruse the relationship between the presence of a punctate pattern with clinical severity of disease and histopathological findings. METHODS: One hundred recently diagnosed patients with pemphigus were enrolled. DIF evaluation and routine light microscopy were performed on their biopsy specimens. Disease severity was determined using the Pemphigus Disease Area Index. Serum samples were collected to measure autoantibody titers using enzyme-linked immunosorbent assay. RESULTS: All the samples evaluated by DIF showed a continuous linear pattern of intercellular IgG deposition, whereas none of them had a punctate pattern. Despite a significant correlation between the Pemphigus Disease Area Index score and autoantibody values, no association between histopathological findings and disease severity has been found. CONCLUSION: We could not detect any punctate pattern among Iranian patients with pemphigus. The importance of this pattern in the diagnosis of pemphigus might be different among patients with different ethnic and genetic factors.

Analysis of clinical characteristics, prognosis and antibody pathogenicity of pemphigus patients positive for anti-desmoglein IgG autoantibodies in remission: a retrospective cohort study.

BACKGROUND: The detection of serum anti-desmoglein (Dsg) IgG autoantibodies has been reported to be useful for assessment of disease activity in pemphigus. However, previous studies have reported that anti-Dsg autoantibodies remain detectable in some patients without active pemphigus lesions. OBJECTIVES: To investigate the clinical characteristics and antibody pathogenicity of pemphigus patients positive for anti-Dsg IgG autoantibodies in remission. METHODS: We retrospectively investigated pemphigus patients with a history of clinical remission who visited the Department of Dermatology of Keio University during 2019 and 2020. The antibody pathogenicity was assessed by bead aggregation assay. RESULTS: When patients were recognized as having entered remission (PDAI = 0 and PSL ≦ 10 mg/day for 2 months), serum autoantibodies against Dsg were detected in 72 of 132 patients (54.5%, positive group; PG), but were not detected in 60 patients (45.5%, negative group; NG). Anti-Dsg antibody titres in remission declined from the active phase in 33 patients in the PG for whom data were available. There were no differences in the chance of reducing PSL to 5 mg/day (P = 0.885) and rate of relapse (P = 0.279) between PG and NG, but fewer patients in PG discontinued corticosteroids (P = 0.004). The ability of patients' sera to block aggregation of Dsg/desmocollin beads was significantly reduced in remission compared to the active phase. However, our results revealed that whole sera in remission still had pathogenic activity in seven of nine patients, and the approximately equal amounts of anti-Dsg antibodies in active phase and remission showed similar pathogenicity. CONCLUSIONS: This study will provide guidance in cases where autoantibodies are found to be positive in pemphigus patients during remission or steroid reduction.

Staphylococcus epidermidis protease EcpA can be a deleterious component of the skin microbiome in atopic dermatitis.

BACKGROUND: Staphylococcus aureus and Staphylococcus epidermidis are the most abundant bacteria found on the skin of patients with atopic dermatitis (AD). S aureus is known to exacerbate AD, whereas S epidermidis has been considered a beneficial commensal organism. OBJECTIVE: In this study, we hypothesized that S epidermidis could promote skin damage in AD by the production of a protease that damages the epidermal barrier. METHODS: The protease activity of S epidermidis isolates was compared with that of other staphylococcal species. The capacity of S epidermidis to degrade the barrier and induce inflammation was examined by using human keratinocyte tissue culture and mouse models. Skin swabs from atopic and healthy adult subjects were analyzed for the presence of S epidermidis genomic DNA and mRNA. RESULTS: S epidermidis strains were observed to produce strong cysteine protease activity when grown at high density. The enzyme responsible for this activity was identified as EcpA, a cysteine protease under quorum sensing control. EcpA was shown to degrade desmoglein-1 and LL-37 in vitro, disrupt the physical barrier, and induce skin inflammation in mice. The abundance of S epidermidis and expression of ecpA mRNA were increased on the skin of some patients with AD, and this correlated with disease severity. Another commensal skin bacterial species, Staphylococcus hominis, can inhibit EcpA production by S epidermidis. CONCLUSION: S epidermidis has commonly been regarded as a beneficial skin microbe, whereas S aureus has been considered deleterious. This study suggests that the overabundance of S epidermidis found on some atopic patients can act similarly to S aureus and damage the skin by expression of a cysteine protease.

Immunophenotyping in pemphigus reveals a TH17/TFH17 cell-dominated immune response promoting desmoglein1/3-specific autoantibody production.

BACKGROUND: TH2 cells were thought to be a pivotal factor for initiation of the autoimmune blistering disease pemphigus. However, the role of other T-cell subsets in pemphigus pathogenesis remained unclear. OBJECTIVE: We aimed to characterize the exact phenotype of T cells responsible for the development of pemphigus. METHODS: Whole transcriptome shotgun sequencing was performed to determine differential gene expression in pemphigus lesions and skin of healthy individuals. The cutaneous cytokine signature was further evaluated by real-time quantitative PCR. In peripheral blood, the distribution of TH cell and folliclular helper (TFH) cell subsets was analyzed by flow cytometry. Finally, the capacity of TH and TFH cell subsets to induce desmoglein (Dsg)-specific autoantibodies by memory B cells was evaluated in coculture experiments. RESULTS: Transcriptome analysis of skin samples identified an IL-17A-dominated immune signature in patients with pemphigus, and Kyoto Encyclopedia of Genes and Genomes pathway analysis confirmed the dominance of the IL-17A signaling pathway. Increased expression of IL17A and associated cytokines was also detected by real-time quantitative PCR comparing lesional with perilesional or healthy skin. Interestingly, utilization of flow cytometry showed that patients with active pemphigus had elevated levels of circulating IL-17+, TH17, TFH17, and TFH17.1 cells. Notably, levels of TH17 and TFH17 cells correlated with levels of Dsg-specific CD19+CD27+ memory B cells, and patients with acute pemphigus showed higher levels of Dsg3-autoreactive TFH17 cells. Coculture experiments revealed TFH17 cells as primarily responsible for inducing Dsg-specific autoantibody production by B cells. CONCLUSION: Our findings show that TFH17 cells are critically involved in the pathogenesis of pemphigus and offer novel targets for therapeutic intervention.

Trunk-dominant and classic facial pemphigus foliaceus in dogs - comparison of anti-desmocollin-1 and anti-desmoglein-1 autoantibodies and clinical presentations.

BACKGROUND: Canine trunk-dominant pemphigus foliaceus (PF) is mentioned rarely in the literature. HYPOTHESIS/OBJECTIVES: The goal of this study was to provide clinical description of trunk-dominant PF and to demonstrate the prevalence of serum antikeratinocyte, anti-desmocollin-1 (DSC1) and anti-desmoglein-1 (DSG1) antibodies, and determine their diagnostic value in this particular PF phenotype. MATERIALS AND METHODS: Clinically relevant information was collected from 31, 25 and 34 dogs with trunk-dominant and facial PF and superficial pyoderma (SP), respectively. Sera from these dogs were tested for antikeratinocyte, anti-DSC1 and anti-DSG1 antibodies using indirect immunofluorescence on canine tissues and DSC1- and DSG1-transfected cells. Sera from healthy dogs and dogs with clinically irrelevant diseases served as controls. RESULTS: Footpad involvement and grouped/polycyclic lesion organisation were identified as features of both PF phenotypes, and not of SP. Antikeratinocyte immunoglobulin (Ig)G was not specific for canine PF. By contrast, antigen-specific IgG was detected only in PF sera; anti-DSC1 IgG in 100% and 58% of dogs with facial and trunk-dominant PF, respectively, and anti-DSG1 IgG in 7% of dogs with trunk-dominant PF only. CONCLUSIONS: Trunk-dominant PF shares DSC1 as a major autoantigen with facial PF. The ability to detect anti-DSC1 IgG is lower in trunk-dominant PF, yet despite the lower sensitivity, the positive predictive value and accuracy of this particular anti-DSC1 IgG test are high. A negative test result, however, cannot exclude the diagnosis, and characteristic clinical features such as footpad involvement and/or grouped/polycyclic lesions must be considered when distinguishing trunk-dominant PF from its most relevant differential diagnosis: SP.

Contexte - Le pemphigus foliacé (PF) dominant le tronc chez le chien est rarement mentionné dans la littérature. Hypothèse/Objectifs - Le but de cette étude était de fournir une description clinique du PF dominant le tronc et de démontrer la prévalence des anticorps sériques anti-kératinocytes, anti-desmocolline-1 (DSC1) et anti-desmogléine-1 (DSG1), et de déterminer leur valeur diagnostique dans ce phénotype particulier de PF. Matériels et méthodes - Des informations cliniquement pertinentes ont été recueillies auprès de 31, 25 et 34 chiens atteints respectivement de PF à dominante tronculaire et faciale et de pyodermite superficielle (SP). Les sera de ces chiens ont été testés pour les anticorps anti-kératinocytes, anti-DSC1 et anti-DSG1 en utilisant l'immunofluorescence indirecte sur des tissus canins et des cellules transfectées avec DSC1 et DSG1. Des sera de chiens sains et de chiens atteints de maladies cliniquement non pertinentes ont servi de témoins. Résultats - L'implication du coussinet plantaire et l'organisation des lésions groupées / polycycliques ont été identifiées comme des caractéristiques des deux phénotypes PF, et non de SP. L'immunoglobuline antikératinocytaire (Ig)G n'était pas spécifique du PF canin. En revanche, l'IgG spécifique de l'antigène n'a été détectée que dans les sera de PF ; IgG anti-DSC1 chez 100 % et 58 % des chiens atteints de PF faciale et tronc-dominante, respectivement, et anti-DSG1 IgG chez 7 % des chiens avec PF tronc-dominant uniquement. Conclusions - Le PF à dominante tronculaire partage DSC1 comme auto-antigène majeur avec le PF facial. La capacité à détecter les IgG anti-DSC1 est plus faible chez les PF à dominante tronculaire, mais malgré la sensibilité plus faible, la valeur prédictive positive et la précision de ce test IgG anti-DSC1 particulier sont élevées. Cependant, un résultat de test négatif ne peut pas exclure le diagnostic, et les caractéristiques cliniques caractéristiques telles que l'atteinte du coussinet plantaire et/ou les lésions groupées/polycycliques doivent être prises en compte lors de la distinction entre la PF à dominante tronculaire et son diagnostic différentiel le plus pertinent : la SP.

Introducción- el pénfigo foliáceo (PF) de distribución truncal predominante se describe raramente n la literatura. Hipótesis/Objetivos- el objetivo de este estudio fue proporcionar una descripción clínica del PF truncal y demostrar la prevalencia de anticuerpos séricos antiqueratinocitos, antidesmocolina-1 (DSC1) y antidesmogleína-1 (DSG1), y determinar su valor diagnóstico en este fenotipo PF particular. Materiales y métodos- se recopiló información clínicamente relevante de 31, 25 y 34 perros con PF dominante truncal, PF dominante facial y pioderma superficial (PS), respectivamente. Los sueros de estos perros se analizaron en busca de anticuerpos antiqueratinocitos, anti-DSC1 y anti-DSG1 mediante inmunofluorescencia indirecta en tejidos caninos y células transfectadas con DSC1 y DSG1. Sueros de perros sanos y perros con enfermedades clínicamente irrelevantes sirvieron como controles. Resultados- la afectación de la almohadilla plantar y la organización de lesiones agrupadas/policíclicas se identificaron como características de ambos fenotipos de PF y no de SP. La inmunoglobulina (Ig)G antiqueratinocitos no fue específica para la PF canina. Por el contrario, la IgG específica de antígeno se detectó solo en sueros PF; IgG anti-DSC1 en el 100 % y el 58 % de los perros con PF predominante en la cara y el tronco, respectivamente, y IgG anti-DSG1 en el 7 % de los perros con PF predominante en el tronco solamente. Conclusiones- el PF dominante truncal comparte DSC1 como un autoantígeno importante con el PF facial. La capacidad para detectar IgG anti-DSC1 es menor en la PF dominante truncal; sin embargo, a pesar de la menor sensibilidad, el valor predictivo positivo y la precisión de esta prueba de IgG anti-DSC1 en particular son altos. Sin embargo, un resultado negativo de la prueba no puede excluir el diagnóstico, y deben tenerse en cuenta las características clínicas, como la afectación de las almohadillas plantares y/o las lesiones agrupadas/policíclicas, al distinguir la PF dominante truncal de su diagnóstico diferencial más relevante: SP.

Contexto - O pênfigo foliáceo (PF) canino predominante no tronco é raramente relatado na literatura. Hipótese/Objetivos - O objetivo deste estudo foi apresentar a descrição clínica do PF predominante no tronco e demonstrar a prevalência de anticorpos anti-queratinócitos, anti-desmocolina-1 (DSC1) e anti-desmogleína-1 (DSG1), e determinar o seu potencial diagnóstico neste tipo particular de PF. Materiais e métodos - Informações clinicamente relevantes foram coletadas de 31, 25 e 34 cães com PF predominante no tronco, PF facial e piodermite superficial (PS), respectivamente. Os soros destes cães foram testados para anticorpos anti-queratinócitos, anti-DSC1 e anti-DSG1 utilizando imunofluorescência indireta em tecidos caninos e em células DSC1 e DSG1 transfectadas. Os soros de cães saudáveis e cães com doenças clinicamente irrelevantes serviram de controle. Resultados - O acometimento dos coxins e a organização agrupada/policíclica das lesões foram identificadas como características de ambos os fenótipos de PF, não de PS. A imunoglobulina (Ig)G anti-queratinócitos não foi específica para PF. Em contraste, IgG antígeno-específica foi detectada apenas no soro de PF; IgG anti-DSC1 em 100% e 58% dos cães com PF facial e predominante no tronco, respectivamente, e IgG anti-DSG1 em 7% dos cães somente acometidos pelo PF predominante no tronco. Conclusões - O PF predominante no tronco compartilha DSC1 como um autoantígeno principal com PF facial. A capacidade de detectar IgG anti-DSC1 é menor no PF predominante no tronco, mas apesar da sensibilidade mais baixa, o valor preditivo positivo e a precisão do teste IgG anti-DSC1 específico são altos. Um resultado de teste negativo, no entanto, não pode excluir o diagnóstico, e características clínicas típicas, como envolvimento do coxim plantar e/ou lesões agrupadas/policíclicas, devem ser consideradas ao distinguir PF predominante no tronco de seu diagnóstico diferencial mais relevante: PS.

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.

Disease progression and response to therapy in pemphigus based on a registry.

BACKGROUND AND OBJECTIVES: Pemphigus diseases are potentially life-threatening and rare autoimmune bullous disorders characterized by blisters and erosions of the skin and mucous membranes. These disorders can be largely divided into two major subtypes: pemphigus vulgaris (PV) and pemphigus foliaceus (PF). The objective of this study was to evaluate the autoantibody profile and response to therapy of PV and PF patients by analyzing the clinicopathological data from a registry for bullous autoimmune dermatoses. PATIENTS AND METHODS: In a retrospective study, data from 69 patients with PV and PF were included in the analysis. The Autoimmune Bullous Skin Intensity Score (ABSIS) was used to assess the clinical course, remissions, relapses and severity of the disease at first manifestation and throughout the observation period. ELISA was performed to assess levels of anti-desmoglein (Dsg)-1 and anti-Dsg3 IgG serum autoantibodies. RESULTS: The mean remission time in PV and PF patients was 63 weeks. PV patients with mucosal involvement showed a more favorable healing process. In PV patients with a moderate/high anti-Dsg1 IgG serum level at baseline, anti-Dsg3 IgG levels decreased during the observation period. CONCLUSIONS: Our study provides additional insights into the clinical course of patients with PV and PF, revealing that a mucosal phenotype is associated with a higher tendency towards remission.

[A Case of Pemphigus Vulgaris Showing a Local Nose Erosion as the First Clinical Manifestation].

A 73-year-old male noticed a localized nose erosion that we thought was possibly an exacerbation of skin erosion due to the direct influence of friction from wearing a mask. Blood examination revealed a remarkable increase in serum anti-desmoglein-1 and anti-desmoglein-3 antibodies. A skin biopsy showed acantholysis in the epidermal granular layer. Based on the clinical manifestation and laboratory examination, we diagnosed his eruption as anti-desmoglein-1 and anti-desmoglein-3 antibody - positive pemphigus vulgaris. His skin eruption responded well to oral prednisolone and azathioprine and gradually improved. Pemphigus was a candidate as a differential diagnosis in this case, in which the direct mechanical friction from wearing a mask was thought to be an exacerbating factor of skin eruption.

Identification of a primary antigenic target of epitope spreading in endemic pemphigus foliaceus.

Epitope spreading is an important mechanism for the development of autoantibodies (autoAbs) in autoimmune diseases. The study of epitope spreading in human autoimmune diseases is limited due to the major challenge of identifying the initial/primary target epitopes on autoantigens in autoimmune diseases. We have been studying the development of autoAbs in an endemic human autoimmune disease, Brazilian pemphigus foliaceus (or Fogo Selvagem (FS)). Our previous findings demonstrated that patients before (i.e. preclinical) and at the onset of FS have antibody (Ab) responses against other keratinocyte adhesion molecules in addition to the main target autoantigen of FS, desmoglein 1 (Dsg1), and anti-Dsg1 monoclonal Abs (mAbs) cross-reacted with an environmental antigen LJM11, a sand fly saliva protein. Since sand fly is prevalent in FS endemic regions, individuals in these regions could develop Abs against LJM11. The anti-LJM11 Abs could recognize different epitopes on LJM11, including an epitope that shares the structure similarity with an epitope on Dsg1 autoantigen. Thus, Ab response against this epitope on LJM11 could be the initial autoAb response detected in individuals in FS endemic regions, including those who eventually developed FS. Accordingly, this LJM11 and Dsg1 cross-reactive epitope on Dsg1 could be the primary target of the autoimmune response in FS. This investigation aimed to determine whether the autoAb responses against keratinocyte adhesion molecules are linked and originate from the immune response to LJM11. The anti-Dsg1 mAbs from preclinical FS and FS individuals were employed to determine their specificity or cross-reactivity to LJM11 and keratinocyte adhesion molecules. The cross-reactive epitopes on autoantigens were mapped. Our results indicate that all tested mAbs cross-reacted with LJM11 and keratinocyte adhesion molecules, and we identified an epitope on these keratinocyte adhesion molecules which is mimicked by LJM11. Thus, the cross-reactivity could be the mechanism by which the immune response against an environmental antigen triggers the initial autoAb responses. Epitope spreading leads to the pathogenic autoAb development and ensuing FS among genetically susceptible individuals.

Ca2+ signalling is critical for autoantibody-induced blistering of human epidermis in pemphigus.

BACKGROUND: Pemphigus is a severe bullous autoimmune skin disease. Pemphigus foliaceus (PF) is characterized by antidesmoglein (Dsg) 1 IgG causing epidermal blistering; mucosal pemphigus vulgaris (mPV) by anti-Dsg3 IgG inducing erosions in the mucosa; and mucocutaneous pemphigus vulgaris (PV) by affecting both, with autoantibodies targeting Dsg1 and Dsg3. OBJECTIVES: To characterize the Ca2+ flux pathway and delineate its importance in pemphigus pathogenesis and clinical phenotypes caused by different antibody profiles. METHODS: Immunoprecipitation, Ca2+ flux analysis, Western blotting, immunofluorescence staining, dissociation assays and a human skin ex vivo model were used. RESULTS: PV IgG and PF IgG, but neither Dsg3-specific monoclonal antibody (AK23) nor mPV IgG, caused Ca2+ influx in primary human keratinocytes. Phosphatidylinositol 4-kinase α interacts with Dsg1 but not with Dsg3. Its downstream target - phospholipase-C-γ1 (PLC) - was activated by PV IgG and PF IgG but not AK23 or mPV IgG. PLC releases inositol 1,4,5-trisphosphate (IP3) causing IP3 receptor (IP3R) activation and Ca2+ flux from the endoplasmic reticulum into the cytosol, which stimulates Ca2+ release-activated channels (CRAC)-mediated Ca2+ influx. Inhibitors against PLC, IP3R and CRAC effectively blocked PV IgG and PF IgG-induced Ca2+ influx; ameliorated alterations of Dsg1 and Dsg3 localization, and reorganization of keratin and actin filaments; and inhibited loss of cell adhesion in vitro. Finally, inhibiting PLC or IP3R was protective against PV IgG-induced blister formation and redistribution of Dsg1 and Dsg3 in human skin ex vivo. CONCLUSIONS: Ca2+ -mediated signalling is important for epidermal blistering and dependent on the autoantibody profile, which indicates different roles for signalling complexes organized by Dsg1 and Dsg3. Interfering with PLC and Ca2+ signalling may be a promising approach to treat epidermal manifestations of pemphigus.