Authors: Sousa JX, Diaz LA, Eaton DP, Hans-Filho G, Lanzani de Freitas E, Delgado L, Ichimura LM, Cristaldi F, Orlandi R, Kesper N, Umezawa ES, Rivitti EA, Aoki V, The Cooperative Group on Fogo Selvagem Research Abstract Fogo Selvagem (FS) is an autoimmune bullous disease with pathogenic IgG autoantibodies recognizing desmoglein 1 (Dsg1), a desmosomal glycoprotein. In certain settlements of Brazil, a high prevalence of FS (3%) is reported, suggesting environmental factors as triggers of the autoimmune response. Healthy individuals from endemic areas recognize nonpathogenic epitopes of Dsg1, and exposure to hematophagous insects is a risk factor for FS. Fogo selvagem and Chagas disease share some geographic sites, and anti-Dsg1 has been detected in Chagas patients. Indeterminate Cha…
Background Pemphigus foliaceus (PF) is a chronic cutaneous autoimmune blistering disease that is characterized by superficial blistering of the skin, and according to the current perspective is caused by autoantibodies directed against desmoglein 1 (Dsg1).
Objectives To examine early acantholysis in skin of PF patients at an ultrastructural level.
Methods Two Nikolsky negative (N-), five Nikolsky positive (N+) and two lesional skin biopsies of immunoserological defined PF patients were studied by light and electron microscopy.
Results We found no abnormalities in N- PF skin, whereas all N+ skin biopsies displayed intercellular widening between desmosomes, a decreased number of desmosomes, and hypoplastic desmosomes in the lower epidermal layers. Acantholysis was present in two of five N+ biopsies, but only in the upper epidermal layers. The lesional skin biopsies displayed acantholysis in the higher epidermal layers. Hypoplastic desmosomes were partially (pseudo-half-desmosomes) or completely torn off from the opposing cell.
Conclusion We propose the following mechanism for acantholysis in PF: initially PF IgG causes a depletion of non-junctional Dsg1, leading to intercellular widening between desmosomes starting in the lower layers and spreading upwards. Depletion of non-junctional Dsg1 impairs the assembly of desmosomes, resulting in hypoplastic and a decreased number of desmosomes. In addition antibodies might promote disassembly of desmosomes. In the upper layers of the epidermis, where Dsg3 is not expressed and cannot compensate for Dsg1 loss, ongoing depletion of Dsg1 will finally result in a total disappearance of desmosomes and subsequent acantholysis.
Background: Pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are potentially fatal blistering diseases caused by autoantibodies targeting desmoglein adhesion proteins. Previous studies have shown an IgG4>IgG1 predominance of anti-desmoglein antibodies in pemphigus; however, no studies have examined total serum IgG4 levels in pemphigus. IgG4 is induced by chronic antigen stimulation, which could occur with persistent skin blistering and potentially elevate the total serum IgG4 relative to other IgG subclasses in pemphigus patients.
Objectives: The primary aim of the study was to quantitate total and desmoglein-specific IgG subclasses in pemphigus patients.
Methods: IgG subclasses and desmoglein-specific IgG1 and IgG4 were quantitated in PV, PF, and age-matched normal sera using a subclass ELISA. The effectiveness of IgG4 depletion in blocking PV IgG pathogenicity was determined using a keratinocyte dissociation assay.
Results: Desmoglein-specific antibodies comprised a median of 7.1% and 4.2% of total IgG4 in PV and PF patients, with 8-fold and 4-fold enrichment in IgG4 versus IgG1. Total serum IgG4, but not other IgG subclasses, was enriched in PV and PF patients compared to age-matched controls (p=0.004 and p=0.005, respectively). IgG4 depletion of PV sera reduced pathogenicity in a keratinocyte dissociation assay and showed that affinity-purified IgG4 is more pathogenic than other serum IgG fractions.
Conclusions: Desmoglein-specific autoantibodies are significantly enriched in IgG4, which may explain the enrichment of total serum IgG4 in some pemphigus patients. By preferentially targeting autoimmune rather than beneficial immune antibodies, IgG4-targeted therapies may offer safer treatment options for pemphigus.
Herpes virus infections are well known infectious complications of pemphigus and bullous pemphigoid. We describe pathologic findings utilizing autopsy tissue from several organs from a patient affected by a new variant of endemic pemphigus in El Bagre, Colombia, South America.
We describe a patient by a new variant of endemic pemphigus foliaceus from El Bagre that was receiving high-dosage immunosuppressants when hospitalized and died suddenly following contact with a second patient affected by chicken pox.
We detected the presence of varicella zoster virus, as well as strong positivity for α-1 antitrypsin in the heart, kidneys, spleen, liver, skin, brain, lungs, pancreas, small and large intestines, and skeletal muscle. In regard to structural damage in the kidney and heart, we believe the observed damage is associated with the presence of autoantibodies to these organs, since both of them are rich in plakins and El Bagre-EPF patients present significant antibodies to plakin molecules.
In patients with endemic pemphigus foliaceus, we recommend complete isolation of the patient when receiving high dosages of systemic immunosuppressive agents. We further suggest the clinical possibility of a synergistic, fatal interaction between active pemphigus foliaceus, varicella zoster virus, herpes simplex virus, immunosuppressive agents, and a systemic activation of α-1 antitrypsin. Thus, we suggest adequate bed spacing, barrier nursing, and preventative testing for α-1 antitrypsin activation are warranted in these patients to address these complications.
Background: Pemphigus vulgaris (PV) is an autoimmune blistering skin disorder characterized by the presence of suprabasal acantholysis and autoantibodies against desmoglein 3. There are two different clinical forms: mucocutaneous (MCPV) or mucosal (MPV). However, it is not clear how PV lesions in oral, ear, nose and throat (OENT) areas produced by the very dynamic of the anatomical structures involved in the functions of the aerodigestive tract.
Patients: A prospective analysis of 40 patients diagnosed with MCPV (22 patients) or MPV (18 patients) was carried out in the University Clinic of Navarra. OENT manifestations were evaluated in all patients endoscopically. OENT involvement was divided into anatomical areas.
Results: The most frequent symptom was pain, mainly on oral mucosa (87,5%). Buccal mucosa (90%), posterior wall of pharynx (67.5%), upper edge of epiglottis (85%) and nasal vestibule (70%) were the areas most frequently affected in the OENT mucosa. These localizations were related to physiological traumatic mechanisms in polystratified squamous epithelium structures.
Conclusions: OENT endoscopy should be included in the examination of all PV patients. To know the most frequent localizations of active lesions on OENT mucosa in PV will help us to interpreter more efficiently the findings from OENT endoscopy. Also, information related to traumatic physiological mechanisms on OENT areas must be offered to patients in order to avoid the appearance of new active PV lesions.
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