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The American Journal of Dermatopathology Sep 2023Acantholysis is a microscopic finding describing the breakdown of desmosomes of keratinocytes and the formation of intraepithelial clefts after the loss of cohesion of...
Acantholysis is a microscopic finding describing the breakdown of desmosomes of keratinocytes and the formation of intraepithelial clefts after the loss of cohesion of keratinocytes. It can be observed in keratinocytic neoplasms, typically actinic keratoses and squamous cell carcinomas, and defines the acantholytic variants of these entities. Acantholysis has so far been reported in only 4 cases of basal cell carcinomas (BCCs), mainly of the superficial type. A case of an otherwise typical nodular BCC showing features of acantholysis is presented here. Because BCCs are keratinocytic neoplasms, the finding of acantholysis in them is not totally surprising; however, the reason why it is only very exceptionally observed in BCCs is unclear.
Topics: Humans; Acantholysis; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Keratinocytes; Skin Neoplasms
PubMed: 37506275
DOI: 10.1097/DAD.0000000000002499 -
Journal of Cellular Physiology Jul 2022Pemphigus vulgaris (PV) is a potentially fatal autoimmune blistering disease characterized by cell-cell detachment (or acantholysis) and blister formation. While the... (Review)
Review
Pemphigus vulgaris (PV) is a potentially fatal autoimmune blistering disease characterized by cell-cell detachment (or acantholysis) and blister formation. While the signaling mechanisms that associate with skin/mucosal blistering are being elucidated, specific treatment strategies targeting PV-specific pathomechanisms, particularly kinase signaling, have yet to be established. Hence, the aim of this review was to systematically evaluate molecules in the class of kinases that are essential for acantholysis and blister formation and are therefore candidates for targeted therapy. English articles from PubMed and Scopus databases were searched, and included in vitro, in vivo, and human studies that investigated the role of kinases in PV. We selected studies, extracted data and assessed risk of bias in duplicates and the results were reported according to the methodology outlined by the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). The risk of bias assessment was performed on in vivo studies utilizing SYRCLE's risk of bias tool. Thirty-five studies were included that satisfied the pathogenicity criterion of kinases in PV, the vast majority being experimental models that used PV sera (n = 13) and PV-IgG (n = 22). Inhibition of kinase activity (p38MAPK, PKC, TK, c-Src, EGFR, ERK, mTOR, BTK, and CDK2) was achieved mostly by pharmacological means. Overall, we found substantial evidence that kinase inhibition reduced PV-associated phosphorylation events and keratinocyte disassociation, prevented acantholysis, and blocked blister formation. However, the scarce adherence to standardized reporting systems and the experimental protocols/models used did limit the internal and external validity of these studies. In summary, this systematic review highlighted the pathogenic intracellular events mediated by kinases in PV acantholysis and presented kinase signaling as a promising avenue for translational research. In particular, the molecules identified and discussed in this study represent potential candidates for the development of mechanism-based interventions in PV.
Topics: Acantholysis; Autoantibodies; Blister; Humans; Immunoglobulin G; Keratinocytes; Pemphigus; Phosphorylation
PubMed: 35616233
DOI: 10.1002/jcp.30784 -
Journal of Autoimmunity Sep 2021Pemphigus is a group of bullous diseases characterized by acantholysis and skin blisters. As for other autoimmune diseases, the strongest genetic associations found so...
BACKGROUND
Pemphigus is a group of bullous diseases characterized by acantholysis and skin blisters. As for other autoimmune diseases, the strongest genetic associations found so far for pemphigus foliaceus (PF) and vulgaris (PV) are with alleles of HLA genes. However, apart from protein-coding genes, the MHC region includes a set of poorly explored long non-coding RNA (lncRNA) genes, the HLA complex group (HCG).
OBJECTIVES
To investigate if HCG lncRNA alleles are associated with pemphigus susceptibility.
METHODS AND RESULTS
We analyzed SNPs in 13 HCG lncRNA genes, both in PV (Germany: 241 patients; 1,188 controls) and endemic PF (Brazil: 227 patients; 194 controls), applying multivariate logistic regression. We found 55 associations with PV (p < 0.01) and nine with endemic PF (p < 0.05), the majority located in TSBP1-AS1 (which includes HCG23) and HCG27 lncRNA genes, independently of HLA alleles previously associated with pemphigus. The association of TSBP1-AS1 rs3129949*A allele was further replicated in sporadic PF (p = 0.027, OR = 0.054; 75 patients and 150 controls, all from Germany). Next, we evaluated the expression levels of TSBP1-AS1, TSBP1, HCG23, and HCG27 in blood mononuclear cells of Brazilian patients and controls. HCG27 was upregulated in endemic PF (p = 0.035, log FC = 1.3), while TSBP1-AS1 was downregulated in PV (p = 0.029, log FC = -1.29). The same expression patterns were also seen in cultured keratinocytes stimulated with IgG antibodies from patients and controls from Germany. TSBP1 mRNA levels were also decreased in endemic PF blood cells (p = 0.042, log FC = -2.14). TSBP1-AS1 and HCG27 were also observed downregulated in CD19 cells of endemic PF (p < 0.01, log FC = -0.226 and -0.46 respectively).
CONCLUSIONS
HCG lncRNAs are associated with susceptibility to pemphigus, being TSBP1-AS1 and HCG27 also differentially expressed in distinct cell populations. These results suggest a role for HCG lncRNAs in pemphigus autoimmunity.
Topics: HLA Antigens; Humans; Keratinocytes; Pemphigus; Polymorphism, Genetic; Polymorphism, Single Nucleotide; RNA, Long Noncoding
PubMed: 34325306
DOI: 10.1016/j.jaut.2021.102705 -
Experimental Dermatology Jan 2024Pyodermatitis pyostomatitis vegetans is a rare inflammatory condition, affecting the skin and/or mucous membrane. Some cases include both skin and mucous involvement,... (Review)
Review
Pyodermatitis pyostomatitis vegetans is a rare inflammatory condition, affecting the skin and/or mucous membrane. Some cases include both skin and mucous involvement, whereas others develop either skin or mucous lesions only. The typically affected areas are the scalp, face, trunk and extremities, including the flexural areas and umbilicus. Clinical features show erosive granulomatous plaques, keratotic plaques with overlying crusts and pustular lesions. Among mucous lesions, oral mucosa is most frequently involved, and gingival erythema, shallow erosions, cobblestone-like papules on the buccal mucosa or upper hard palate of the oral cavity are also observed. Some of the lesions assume a 'snail track' appearance. Although there are several similarities between pyodermatitis pyostomatitis vegetans and other diseases, that is pyoderma gangrenosum, pemphigus vegetans and pemphigoid vegetans, the histopathological features of pyodermatitis pyostomatitis vegetans are unique in that epidermal hyperplasia, focal acantholysis and dense inflammatory infiltrates with intraepidermal and subepidermal eosinophilic microabscesses are observed. Direct immunofluorescence findings are principally negative. Activated neutrophils are supposed to play an important role in the pathogenesis of pyodermatitis pyostomatitis vegetans. The expression of IL-36 and neutrophil extracellular traps (NETs) was observed in the lesional skin, and additionally, eosinophil extracellular traps (EETs) was detected in pyodermatitis pyostomatitis vegetans. A possible pathogenic role of NETs and EETs in the innate immunity and autoinflammatory aspects of pyodermatitis pyostomatitis vegetans was discussed.
Topics: Humans; Pemphigus; Pyoderma; Stomatitis; Extracellular Traps; Neutrophils; Erythema; Organic Chemicals
PubMed: 37694984
DOI: 10.1111/exd.14931 -
Frontiers in Immunology 2021The presence of anti-desmocollin (Dsc) antibodies is rarely described in autoimmune blistering diseases patients. Moreover, several clinical phenotypes of pemphigus may...
The presence of anti-desmocollin (Dsc) antibodies is rarely described in autoimmune blistering diseases patients. Moreover, several clinical phenotypes of pemphigus may be associated with these antibodies. In this review we analyze clinicopathological, immunologic and outcome features of anti-Dsc autoimmune blistering diseases patients, to improve their diagnosis and management. We conducted a systematic search of PubMed and Embase (1990-present) for studies reporting cases of autoimmune blistering diseases with anti-Dsc antibodies. We classified the selected patients as patients with exclusively anti-Dsc autoantibodies, and patients with anti-Dsc and other autoantibodies. Of 93 cases with anti-Dsc autoantibodies included, 38 (41%) had exclusively these antibodies. Only 18% of patients presented with the typical clinicopathological phenotype of pemphigus vulgaris or pemphigus foliaceous. Mucosal involvement was seen in approximately half of the patients. Up to 18% of cases were associated with neoplasms. Acantholysis was described in 54% of cases with histopathological information. Treatments and outcomes vary in the different clinical phenotypes. The presence of anti-Dsc antibodies must be suspected mainly in those patients with either atypical pemphigus, in special with clinical pustules, or in cases showing intraepithelial or dermal neutrophilic/eosinophilic infiltrate on histological examination and dual pattern by direct immunofluorescence examination.
Topics: Acantholysis; Animals; Autoantibodies; Autoimmunity; Desmocollins; Desmogleins; Eosinophils; Humans; Neutrophils; Pemphigus; Phenotype; Skin
PubMed: 34567003
DOI: 10.3389/fimmu.2021.740820 -
Anais Brasileiros de Dermatologia 2022Anti-desmoglein 1 and 3 autoantibodies justify acantholysis in pemphigus; however, the pathogenesis of anti-desmoglein 2 is hypothetical.
BACKGROUND
Anti-desmoglein 1 and 3 autoantibodies justify acantholysis in pemphigus; however, the pathogenesis of anti-desmoglein 2 is hypothetical.
OBJECTIVE
To compare the participation of desmogleins 1, 2 and 3 through the production of serum autoantibodies, and protein and gene expression in the skin/mucosa of patients with pemphigus foliaceus and pemphigus vulgaris.
METHODS
The autoantibodies were titrated by ELISA in 202 samples of pemphigus foliaceus, 131 pemphigus vulgaris, 50 and 57 relatives of patients with pemphigus foliaceus and pemphigus vulgaris, respectively, and 114 controls. Protein and gene expressions were determined by immunohistochemistry and qPCR in the skin/mucosa of 3 patients with pemphigus foliaceus and 3 patients with pemphigus vulgaris.
RESULTS
Higher titers of anti-desmoglein 2 (optical density) resulted in pemphigus foliaceus and pemphigus vulgaris, when compared to controls (0.166; 0.180; 0.102; respectively; p < 0.0001). There was a correlation between anti-desmoglein 2 and anti-desmoglein 1 titers in pemphigus foliaceus (r = 0.1680; p = 0.0206). There was no cross-reaction of anti-desmoglein 2 with desmoglein 1 and 3. Protein overexpression of desmoglein 2 was observed in intact and lesional skin of patients with pemphigus compared to the skin of controls. Internalization granules of desmoglein 1 and 3, but not of desmoglein 2, were observed in lesions of pemphigus foliaceus and pemphigus vulgaris, respectively. Gene overexpression of desmoglein 2 was observed in the mucosa.
STUDY LIMITATIONS
Small sample size for the statistical analysis of protein and gene expression.
CONCLUSION
Autoantibodies against desmoglein 2 are not pathogenic in pemphigus; protein and gene overexpression of desmoglein 2 in the skin and mucosa may be involved in acantholysis repair.
Topics: Acantholysis; Autoantibodies; Desmoglein 1; Desmoglein 2; Desmoglein 3; Humans; Pemphigus
PubMed: 35058080
DOI: 10.1016/j.abd.2021.06.004 -
Veterinary Dermatology Dec 2021Autoimmune blistering diseases (AIBDs) are a heterogenous group of skin conditions, broadly classified into two categories depending on the location of blister... (Review)
Review
Autoimmune blistering diseases (AIBDs) are a heterogenous group of skin conditions, broadly classified into two categories depending on the location of blister formation: intraepidermal blistering in the pemphigus group and subepidermal blistering in the pemphigoid group. Although AIBDs occur in both humans and animals, the arsenal of data for human AIBDs far exceeds those of their animal counterpart. Therefore, the main purpose of this review is to highlight existing knowledge, and recent advances in the diagnosis and management of AIBDs in humans - to serve as a road map for veterinary dermatologists. AREAS COVERED: Recent findings include complement-independent pathways in the pathogenesis of bullous pemphigoid, as well as the role of desmoglein and desmocollin autoantibodies in inducing acantholysis. Systemic glucocorticoids are the mainstay of treatment for AIBDs in humans, yet their long-term use is associated with severe adverse effects and complications, thereby limiting their use. Therefore, researchers have been exploring new and safer alternative therapeutic options for human AIBDs such as anti-CD20 monoclonal antibodies (Rituximab), Bruton's tyrosine kinase inhibitors (BTKi) and neonatal Fc receptor (FcRn) blockers. EXPERT OPINION: Randomised controlled trial (RCT) level evidence show that Rituximab and short-course GC regimes are more effective and safer than traditional GC treatment for human AIBDs. FcRn blockers such as SYNT001 have shown positive results in preliminary phase 2 clinical trials for treatment of human pemphigus; further trials are required. Rilzabrutinib (PRN1008), an orally administered BTKi, has recently completed phase 2 trials in pemphigus and is in a phase 3 RCT in humans.
Topics: Animals; Antibodies, Monoclonal, Humanized; Autoantibodies; Autoimmune Diseases; Blister; Humans; Pemphigoid, Bullous; Pemphigus
PubMed: 34351020
DOI: 10.1111/vde.13008 -
International Journal of Molecular... Jun 2022Pemphigus is a life-threatening autoimmune disease. Several phenotypic variants are part of this family of bullous disorders. The disease is mainly mediated by... (Review)
Review
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.
Topics: Acantholysis; Animals; Autoantibodies; Autoantigens; Desmoglein 1; Desmoglein 3; Mice; Pemphigus
PubMed: 35806044
DOI: 10.3390/ijms23137044 -
SAGE Open Medical Case Reports 2023Segmental Darier's disease is an uncommon subtype of Darier's genodermatosis, resulting from a mutation in the ATPase type 2 during early embryogenesis. It typically...
Segmental Darier's disease is an uncommon subtype of Darier's genodermatosis, resulting from a mutation in the ATPase type 2 during early embryogenesis. It typically presents as a persistent, pruritic papular eruption following the lines of Blaschko. Histopathology of Darier's disease demonstrates acantholysis, dyskeratosis, and corps ronds. First-line treatment includes topical retinoids, calcineurin inhibitors, and synthetic vitamin D analogues. Severe disease may require systemic therapy with oral retinoids, immunomodulators, magnesium, and low-dose naltrexone. Segmental Darier's disease is important to recognize both clinically and histologically as it may resemble other acantholytic Blaschkolinear dermatoses and should be considered in individuals presenting with a chronic localized papular eruption in a Blaschkoid distribution. Herein, we present a case of a 48-year-old male with segmental Darier's disease who improved significantly following acitretin treatment.
PubMed: 37032996
DOI: 10.1177/2050313X231160938