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Lancet (London, England) Sep 2019Pemphigus consists of a group of rare and severe autoimmune blistering diseases mediated by pathogenic autoantibodies mainly directed against two desmosomal adhesion... (Review)
Review
Pemphigus consists of a group of rare and severe autoimmune blistering diseases mediated by pathogenic autoantibodies mainly directed against two desmosomal adhesion proteins, desmoglein (Dsg)1 and Dsg3 (also known as DG1 and DG3), which are present in the skin and surface-close mucosae. The binding of autoantibodies to Dsg proteins induces a separation of neighbouring keratinocytes, in a process known as acantholysis. The two main pemphigus variants are pemphigus vulgaris, which often originates with painful oral erosions, and pemphigus foliaceus, which is characterised by exclusive skin lesions. Pemphigus is diagnosed on the basis of either IgG or complement component 3 deposits (or both) at the keratinocyte cell membrane, detected by direct immunofluorescence microscopy of a perilesional biopsy, with serum anti-Dsg1 or anti-Dsg3 antibodies (or both) detected by ELISA. Corticosteroids are the therapeutic mainstay, which have recently been complemented by the anti-CD20 antibody rituximab in moderate and severe disease. Rituximab induces complete remission off therapy in 90% of patients, despite rapid tapering of corticosteroids, thus allowing for a major corticosteroid-sparing effect and a halved number of adverse events related to corticosteroids.
Topics: Adrenal Cortex Hormones; Azathioprine; Desmoglein 1; Enzyme-Linked Immunosorbent Assay; Humans; Immunoglobulin G; Immunosuppressive Agents; Pemphigus; Rituximab; Treatment Outcome
PubMed: 31498102
DOI: 10.1016/S0140-6736(19)31778-7 -
Journal of the American Academy of... Oct 2020Antineoplastic agents that use the immune system have revolutionized cancer treatment. Specifically, implementation of immune checkpoint inhibitors, monoclonal... (Review)
Review
Antineoplastic agents that use the immune system have revolutionized cancer treatment. Specifically, implementation of immune checkpoint inhibitors, monoclonal antibodies that block cytotoxic T-lymphocyte-associated antigen-4, programmed cell death protein 1, or programmed cell death ligand 1 show improved and sustained responses in patients with cancer. However, these agents are associated with a plethora of adverse events, many manifesting in the skin. As the clinical application of cancer immunotherapies expands, understanding the clinical and histopathologic features of associated cutaneous toxicities becomes increasingly important to dermatologists, oncologists, and pathologists to ensure timely diagnosis and appropriate care. This review discusses cutaneous reactions to immune checkpoint inhibitors, focusing on histopathologic features.
Topics: Acantholysis; Alopecia; Drug Eruptions; Humans; Immune Checkpoint Inhibitors; Keratinocytes; Lichenoid Eruptions; Nevus, Pigmented; Panniculitis; Pemphigoid, Bullous; Pruritus; Psoriasis; Stevens-Johnson Syndrome; Vitiligo
PubMed: 32360716
DOI: 10.1016/j.jaad.2020.04.105 -
Dermatology Practical & Conceptual Jul 2020Autoimmune bullous disorders are a heterogeneous spectrum of skin disorders characterized by the production of autoantibodies against adhesion molecules of the skin. The... (Review)
Review
Autoimmune bullous disorders are a heterogeneous spectrum of skin disorders characterized by the production of autoantibodies against adhesion molecules of the skin. The 2 major groups of diseases are "pemphigus diseases" and "autoimmune bullous diseases of the pemphigoid type." Pemphigus diseases are a group of autoimmune blistering diseases of the skin and mucous membranes characterized by intraepithelial cleft and acantholysis. The main subtypes of pemphigus include pemphigus vulgaris, pemphigus foliaceus, and paraneoplastic pemphigus. Diagnosis is based on clinical manifestations and confirmed with histological, immunofluorescence, and serological testing. Recently multivariant enzyme-linked immunosorbent assay systems have been developed as practical screening tools for patients with suspected autoimmune bullous dermatoses. The current first-line treatment of pemphigus is based on systemic corticosteroids that are often combined with immunosuppressive adjuvants, such as azathioprine, mycophenolate mofetil, and the anti-CD20 monoclonal antibody rituximab, usually at initiation of treatment. Rituximab efficacy is higher when it is administered early in the course of the disease. Therefore, it should be used as first-line treatment to improve efficacy and reduce cumulative doses of corticosteroids and their side effects. Treatment of bullous pemphigoid is based on disease extension. Localized and mild forms can be treated with superpotent topical corticosteroids or with nonimmunosuppressive agents. In patients with generalized disease or whose disease is resistant to the treatments described above, systemic corticosteroids are preferred and effective. Adjuvant immunosuppressants are often combined with steroids for their steroid-sparing effect.
PubMed: 32642305
DOI: 10.5826/dpc.1003a50 -
Modern Pathology : An Official Journal... Jul 2023The diagnosis of oral epithelial dysplasia is based on the degree of architectural and cytologic atypia in the squamous epithelium. The conventional grading system of...
The diagnosis of oral epithelial dysplasia is based on the degree of architectural and cytologic atypia in the squamous epithelium. The conventional grading system of mild, moderate, and severe dysplasia is considered by many the gold standard in predicting the risk of malignant transformation. Unfortunately, some low-grade lesions, with or without dysplasia, progress to squamous cell carcinoma (SCC) in short periods. As a result, we are proposing a new approach to characterize oral dysplastic lesions that will help identify lesions at high risk for malignant transformation. We included a total of 203 cases of oral epithelial dysplasia, proliferative verrucous leukoplakia, lichenoid, and commonly observed mucosal reactive lesions to evaluate their p53 immunohistochemical (IHC) staining patterns. We identified 4 wild-type patterns, including scattered basal, patchy basal/parabasal, null-like/basal sparing, mid-epithelial/basal sparing, and 3 abnormal p53 patterns, including overexpression basal/parabasal only, overexpression basal/parabasal to diffuse, and null. All cases of lichenoid and reactive lesions exhibited scattered basal or patchy basal/parabasal patterns, whereas human papillomavirus-associated oral epithelial dysplasia demonstrated null-like/basal sparing or mid-epithelial/basal sparing patterns. Of the oral epithelial dysplasia cases, 42.5% (51/120) demonstrated an abnormal p53 IHC pattern. p53 abnormal oral epithelial dysplasia was significantly more likely to progress to invasive SCC when compared to p53 wild-type oral epithelial dysplasia (21.6% vs 0%, P < .0001). Furthermore, p53 abnormal oral epithelial dysplasia was more likely to have dyskeratosis and/or acantholysis (98.0% vs 43.5%, P < .0001). We propose the term p53 abnormal oral epithelial dysplasia to highlight the importance of utilizing p53 IHC stain to recognize lesions that are at high risk of progression to invasive disease, irrespective of the histologic grade, and propose that these lesions should not be graded using the conventional grading system to avoid delayed management.
Topics: Humans; Tumor Suppressor Protein p53; Mouth Neoplasms; Immunohistochemistry; Leukoplakia, Oral; Carcinoma, Squamous Cell; Hyperplasia; Cell Transformation, Neoplastic
PubMed: 36906072
DOI: 10.1016/j.modpat.2023.100153 -
International Journal of Dermatology Aug 2021Dowling-Degos disease is a rare autosomal dominant genodermatosis. It is characterized by acquired reticulate hyperpigmentation over the flexures, comedone-like... (Review)
Review
Dowling-Degos disease is a rare autosomal dominant genodermatosis. It is characterized by acquired reticulate hyperpigmentation over the flexures, comedone-like follicular papules, and pitted perioral scars that usually develop during adulthood. Mutations in genes affecting melanosome transfer, and melanocyte and keratinocyte differentiation have been implicated in the pathogenesis of this disease. These genes include KRT5, POFUT1, POGLUT1 and, most recently, PSENEN. Dowling-Degos disease can be found in isolation or with other associated findings, most notably hidradenitis suppurativa. This condition belongs to a spectrum of conditions that all result in reticulate hyperpigmentation that at times are hard to distinguish from each other. The most closely linked entity is Galli-Galli, which is clinically indistinguishable from Dowling-Degos disease and can only be distinguished by the presence of acantholysis on microscopy. Unfortunately, Dowling-Degos disease is generally progressive and recalcitrant to treatment.
Topics: Acantholysis; Adult; Amyloid Precursor Protein Secretases; Fucosyltransferases; Glucosyltransferases; Humans; Hyperpigmentation; Keratin-5; Membrane Proteins; Skin Diseases, Genetic; Skin Diseases, Papulosquamous
PubMed: 33368260
DOI: 10.1111/ijd.15385 -
Journal of Translational Autoimmunity Dec 2019Bullous skin diseases are a group of dermatoses characterized by blisters and bullae in the skin and mucous membranes. The etiology and pathogenesis of bullous skin... (Review)
Review
Bullous skin diseases are a group of dermatoses characterized by blisters and bullae in the skin and mucous membranes. The etiology and pathogenesis of bullous skin diseases are not completely clear. The most common are pemphigus and bullous pemphigoid (BP). Autoantibodies play critical roles in their pathogenesis. Abnormalities in the adhesion between keratinocytes in patients with pemphigus leads to acantholysis and formation of intra-epidermal blisters. Anti-desmoglein autoantibodies are present both in the circulation and skin lesions of patients with pemphigus. The deficient adhesion of keratinocytes to the basement membrane in BP patients gives rise to subepidermal blisters. Autoantibodies against the components of hemidesmosome can be detected in BP patients. Many novel therapeutics based on knowledge of the pathogenesis have emerged in recent years.
PubMed: 32743502
DOI: 10.1016/j.jtauto.2019.100014 -
American Journal of Clinical Dermatology Dec 2020Pemphigus vulgaris (PV) is a severe chronic autoimmune blistering disease that affects the skin and mucous membranes. It is characterized by suprabasal acantholysis due... (Review)
Review
Pemphigus vulgaris (PV) is a severe chronic autoimmune blistering disease that affects the skin and mucous membranes. It is characterized by suprabasal acantholysis due to disruption of desmosomal connections between keratinocytes. Autoantibodies against desmosomal cadherins, desmoglein 3 and 1, have been shown to induce disease. Certain human leukocyte antigen (HLA) types and non-HLA foci confer genetic susceptibility. Until the discovery of corticosteroids in the 1950s, PV was 75% fatal. Since then, multiple PV treatments, such as systemic corticosteroids and adjunctive therapy with immunosuppressive medications (mycophenolate mofetil, azathioprine, cyclophosphamide, cyclosporine, methotrexate, gold, and others) have been introduced; however, none have led to long-term remissions and many have undesired adverse effects. Our growing understanding of the pathophysiologic mechanisms in PV is leading to development of new targeted therapies, such as intravenous immunoglobulin, anti-CD20 monoclonal antibodies, inhibitors of Bruton tyrosine kinase and neonatal Fc receptors, and adoptive cellular transfer, that may result in lasting control of this life-threatening disease.
Topics: Agammaglobulinaemia Tyrosine Kinase; Antibodies, Monoclonal; Antigens, CD20; Autoantibodies; Combined Modality Therapy; Drug Therapy, Combination; Genetic Predisposition to Disease; HLA Antigens; Histocompatibility Antigens Class I; Humans; Immunoglobulins, Intravenous; Immunosuppressive Agents; Immunotherapy, Adoptive; Molecular Targeted Therapy; Pemphigus; Plasmapheresis; Receptors, Fc; Remission Induction; Signal Transduction; Treatment Outcome
PubMed: 32860200
DOI: 10.1007/s40257-020-00544-w