Congenital dystrophic epidermolysis bullosa (DEB) in Sprague Dawley rats: a case series

• Published in: Veterinary dermatology 2016-04, Vol.27 (2), p.122-e34
• Main Authors: Eden, Kristin B., Peterson, Ashley, Payne, Harold R., Corapi, Wayne V., Mansell, Joanne, Hoffman, Aline Rodrigues
• Format: Article
• Language: English
• Subjects: Animals; Epidermolysis Bullosa Dystrophica - genetics; Epidermolysis Bullosa Dystrophica - pathology; Epidermolysis Bullosa Dystrophica - veterinary; Genetic Predisposition to Disease; Rats; Rats, Sprague-Dawley; Rodent Diseases - congenital; Rodent Diseases - genetics; Rodent Diseases - pathology
• ISSN: 0959-4493; 1365-3164
• DOI: 10.1111/vde.12293

Background Epidermolysis bullosa is a rare skin disease caused by defects in the basement membrane and/or other dermoepidermal junction components. Hypothesis/Objectives We describe a series of spontaneous cases of dystrophic epidermolysis bullosa (DEB) in a colony of Sprague Dawley rats investigated with histopathology, transmission electron microscopy (TEM) and inheritance pattern. Animals Four, 4‐day‐old pups from a litter of Sprague Dawley rats developed blistering, haemorrhagic skin lesions and were euthanized. Age‐matched controls from the same litter were normal. Several months later two more litters presented with identical findings. All three litters had the same sire, suggesting a genetic component. Methods Skin from affected and control animals was evaluated histologically and with TEM. Unaffected sibling pairs from affected litters were bred in order to potentially reproduce the disease and determine the mode of inheritance. Results Histologically, there was significant dermoepidermal clefting below the basement membrane with variable amounts of haemorrhage and cellular debris within the clefts. Ultrastructurally, clefting occurred below the basement membrane with an intact lamina densa and normal hemidesmosomes. Anchoring filaments were strikingly absent. Litters produced from phenotypically unaffected sibling pairs resulted in a total of four more litters with approximately a quarter of pups affected. Conclusions and clinical importance Based on the gross lesions, histopathological features and TEM determination of separation below the lamina densa and lack of normal anchoring fibrils, these cases are most consistent with DEB. This is the first report of naturally occurring, localized and reproducible recessive DEB in Sprague Dawley rats. Résumé Contexte L’épidermolyse bulleuse est une dermatose rare liée à des défauts de la membrane basale et/ou d'autres composants de la jonction dermo‐épidermique. Hypothèses/Objectifs Nous décrivons une série de cas spontanés d’épidermolyse bulleuse dystrophique (DEB) au sein d'une colonie de rats Sprague Dawley explorée par histopathologie, microscopie électronique à transmission (TEM) et reproductions. Sujets Quatre rats âgés de 4 jours d'un groupe de Sprague dawley ont développé des lésions cutanées hémorragiques et ont été euthanasiés. Les sujets contrôles du même âge de la même portée étaient normaux. Plusieurs mois plus tard deux portées de plus présentaient des lésions identiques. Les trois portées p