Olivry Thierry, Linder Keith E
Department of Clinical Science, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA.
Vet Dermatol. 2009 Oct;20(5-6):313-26. doi: 10.1111/j.1365-3164.2009.00821.x.
Failure of desmosomal adhesion with ensuing keratinocyte separation - a phenomenon called acantholysis - can result from genetic, autoimmune or infectious proteolytic causes. Rare hereditary disorders of desmosomal formation have been identified in animals. Familial acantholysis of Angus calves and hereditary suprabasal acantholytic mechanobullous dermatosis of buffaloes appear to be similar to acantholytic epidermolysis bullosa of human beings. A genetic acantholytic dermatosis resembling human Darier disease has been rarely recognized in dogs. In autoimmune blistering dermatoses, circulating autoantibodies bind to the extracellular segments of desmosomal proteins and induce acantholysis. Autoantibodies against desmoglein-3 are found in canine pemphigus vulgaris and paraneoplastic pemphigus. Autoantibodies against desmoglein-1 have been rarely detected in dogs with pemphigus foliaceus. When circulating autoantibodies target desmogleins-1 and -3, mucocutaneous pemphigus vulgaris develops in dogs. Finally, several infectious agents can release proteases that cleave desmosomal bonds. In superficial pustular dermatophytosis of dogs and horses, Trichophyton hyphae colonize the stratum corneum, and acantholysis presumably develops because of proteases secreted by the dermatophytes. In exudative epidermitis of piglets, Staphylococcus bacteria - usually Staphylococcus hyicus- release exfoliatin toxins that bind to and specifically cleave desmoglein-1. Any of the above mechanisms can result in impairment of desmosomal function with subsequent acantholysis. The end point of adhesion failure is identical among these diseases: there is cleft formation where desmosomes are affected. The similarity of mechanisms explains why clinical and microscopic skin lesions overlap between entities, thus leaving clinicians and dermatopathologists with the conundrum of determining whether the acantholysis is of genetic, autoimmune or infectious origin.
桥粒黏附功能障碍及随之而来的角质形成细胞分离——一种称为棘层松解的现象——可由遗传、自身免疫或感染性蛋白水解原因引起。在动物中已发现罕见的桥粒形成遗传性疾病。安格斯犊牛的家族性棘层松解和水牛的遗传性基底层上棘层松解性机械性大疱性皮肤病似乎与人类的棘层松解性大疱性表皮松解症相似。一种类似于人类 Darier 病的遗传性棘层松解性皮肤病在犬中很少被认识到。在自身免疫性大疱性皮肤病中，循环自身抗体与桥粒蛋白的细胞外片段结合并诱导棘层松解。寻常型天疱疮和副肿瘤性天疱疮犬体内可发现抗桥粒芯糖蛋白-3 的自身抗体。在落叶型天疱疮犬中很少检测到抗桥粒芯糖蛋白-1 的自身抗体。当循环自身抗体靶向桥粒芯糖蛋白-1 和 -3 时，犬会发生黏膜皮肤寻常型天疱疮。最后，几种感染因子可释放裂解桥粒连接的蛋白酶。在犬和马的浅表脓疱性皮肤癣菌病中，毛癣菌菌丝定殖于角质层，可能由于皮肤癣菌分泌的蛋白酶而发生棘层松解。在仔猪渗出性皮炎中，葡萄球菌——通常是猪葡萄球菌——释放表皮剥脱毒素，该毒素与桥粒芯糖蛋白-1 结合并特异性裂解它。上述任何一种机制都可导致桥粒功能受损，随后发生棘层松解。这些疾病中黏附功能丧失的终点是相同的：在桥粒受影响的部位形成裂隙。机制的相似性解释了为什么不同疾病之间临床和微观皮肤病变会重叠，从而给临床医生和皮肤病理学家留下了确定棘层松解是遗传、自身免疫还是感染性起源的难题。
