Introduction: The in situ immune response within skin biopsies from patients affected by autoimmune skin blistering diseases (ABDs) is not well characterized. Aim: Based on the fact that the ABD immune response is considered an adaptive immune response, both an innate immune response and inflammation would be expected in these diseases. Our investigation investigates the presence of cyclo-oxygenase-2 (COX-2), since this enzyme is commonly involved in innate immune responses. Methods: We utilized immunohistochemistry (IHC) to evaluate the presence of COX-2 in lesional skin biopsies of patients affected by ABDs. We tested 30 patients with endemic pemphigus foliaceus (EPF), 15 controls from the endemic area, and 15 biopsies from healthy controls from the USA. We also tested archival biopsies from patients with selected ABDs, including 20 patients with bullous pemphigoid, 20 with pemphigus vulgaris, 8 with pemphigus foliaceus and 12 with dermatitis herpetiformis. Results: Most ABD biopsies stained positive for COX-2 in the lesional blister and/or the dermal inflammatory infiltrate, accentuated in the upper neurovascular plexus. In BP and EPF, the COX-2 staining was also seen in the sweat glands. All controls were negative. Conclusions: We document that COX-2 is expressed in lesional skin of patients with ABDs.

En muchas enfermedades dermatológicas se presentan ampollas, pero no todas son de etiología autoinmune. Para el estudio de las enfermedades ampollosas se deben tener en cuenta las manifestaciones clínicas, la historia de cómo y cuándo empezaron las ampollas, las características epidemiológicas e histológicas (por ejemplo, el nivel de la piel en el que se producen las ampollas) y la presencia o no de infiltrados inflamatorios. Para corroborar la etiología autoinmune de la enfermedad ampollosa es importante contar con los resultados de pruebas como la inmunofluorescencia directa e indirecta, el inmunoblotting, el ensayo inmunoenzimático (ELISA), la inmunoprecipitación y la microscopía electrónica. La información sobre los títulos séricos de autoanticuerpos ayuda a orientar mejor el tratamiento inmunosupresor.