Membrane attack complex (C5b‐9 complex or Mac), is strongly present in lesional skin from patients with endemic pemphigus foliaceus in El Bagre, Colombia

Abstract

Background El Bagre endemic pemphigus foliaceus (El Bagre‐EPF) is a new variant of endemic pemphigus foliaceus present in the El Bagre area of Colombia, South America. Here, we investigate the presence of complement/C5‐b9 in lesional skin of patients and matched controls from the endemic area. We also aim to compare the patient's autoantibody levels using indirect immunofluorescent titers (IIF) and correlate with the lesional presence of complement/C5b‐9. Methods A case‐control study was carried out by testing for the presence of complement/C5b‐9 in lesional skin in 43 patients affected by El Bagre‐EPF, as well as 43 matched, healthy controls from the endemic area. Skin biopsies were obtained and evaluated via hematoxylin and eosin staining, and immunohistochemistry. Results The presence of complement/C5b‐9 was observed in all cases of the patients affected by El Bagre‐EPF and was not observed in the controls from the endemic area (P < 0.001). The patients' autoantibody titers utilizing IIF for IgG and IgM showed correlation between higher autoantibody titers and stronger intensity of staining with complement/C5‐b9 staining (P < 0.001). Conclusion Patients affected by El Bagre‐EPF have lesional deposition of complement/C5b, which correlates with disease severity and previously established serologies.

Recurrent herpes zoster with IgD deposits, multinucleated keratinocytes and overexpression of galectin and glypican 3 in a patient with SARS-COVID-19 infection

“…Skin rashes associated with COVID-19 have primarily presented with erythematous, urticarial, and vesicular (chicken pox-like or varicelliform) manifestations [3][4][5]. Vascular manifestations such as petechiae and livedo reticularis have been noted.…”

“…A skin biopsy of the affected area from the left abdomen was examined with hematoxylin and eosin USA). The IHC stains were performed as previously described [4]. The H&E sections displayed areas in the epidermis with blistering at multiple levels and with reepithelization (Fig.…”

Complement Receptor 1 (CR1, CD35) Polymorphisms and Soluble CR1: A Proposed Anti-inflammatory Role to Quench the Fire of “Fogo Selvagem” Pemphigus Foliaceus

“…Altered cell-associated molecular patterns activate the complement system, and this is responsible for the recurrent observation of C3 component deposits along the basement membrane zone and in intercellular spaces of the perilesional and lesional epidermis of FS patients (13–16). Deposits of complement membrane attack complexes, in contrast, were only found in injured skin, whereas pathogenic IgG4 anti-desmoglein 1 autoantibodies—which cannot activate complement—were also abundant in apparently healthy tissue in FS patients (14, 17).…”