Sepp N, Zelger B, Schuler G, Romani N, Fritsch P
Department of Dermatology, University of Innsbruck, Austria.
Am J Surg Pathol. 1995 Apr;19(4):448-53. doi: 10.1097/00000478-199504000-00006.
Sneddon's syndrome is a rare, but potentially severe, arterioocclusive disorder characterized by generalized livedo racemosa of the skin and various central nervous symptoms due to occlusion of medium-sized arteries of unknown cause. We have recently shown that, in skin, small to medium-sized arteries of the dermis-subcutis boundary are affected in a stage-specific sequence. An initial phase (stage I), characterized by the attachment of lymphohistiocytic cells and detachment of endothelial cells (endothelitis), is followed by an early phase (stage II), which displays partial or complete occlusion of the lumen by a plug of lymphohistiocytic cells and fibrin. In an intermediate phase (stage III), the occluding plug is replaced by proliferating subendothelial cells accompanied by the occurrence of dilated capillaries in the adventitia of the occluded vessel. The late phase (stage IV) shows fibrosis and shrinkage of the affected vessels. We investigated sections of paraffin-embedded specimens of 18 patients by immunohistochemistry using a panel of antibodies to detect endothelial cells, macrophages, T cells, smooth muscle-specific actin, and intermediate filaments (vimentin, desmin). We found that the cells involved in subendothelial proliferation were vimentin and actin positive (smooth-muscle-specific), but desmin negative and thus displayed the phenotype characteristic of smooth muscle cells, which was confirmed by ultrastructural studies. CD3+, UCHL-1+, and HLA-DR+ cells constituted a significant proportion of the inflammatory infiltrate in the early stages. The endothelial cells in the dilated capillaries of the adventitia were strongly HLA-DR positive. In later stages, endothelial cells and leukocytes were scarce. The data confirm the hypothesis that Sneddon's syndrome starts as an inflammatory and possibly immunologically mediated disorder, leading to a migration and proliferation of smooth cells of small arteries, resulting in a partial or complete narrowing of the vessel lumen.
斯内登综合征是一种罕见但可能严重的动脉闭塞性疾病，其特征为皮肤出现全身性网状青斑以及因不明原因的中等大小动脉闭塞而导致的各种中枢神经症状。我们最近发现，在皮肤中，真皮 - 皮下组织交界处的中小动脉按特定阶段顺序受到影响。初始阶段（I期）的特征是淋巴细胞和组织细胞附着以及内皮细胞脱离（内皮炎），随后是早期阶段（II期），此阶段显示管腔被淋巴细胞和组织细胞以及纤维蛋白形成的栓子部分或完全阻塞。在中间阶段（III期），阻塞栓子被增生的内皮下细胞替代，同时在阻塞血管的外膜出现扩张的毛细血管。晚期阶段（IV期）表现为受累血管的纤维化和萎缩。我们使用一组抗体通过免疫组织化学方法研究了18例患者石蜡包埋标本的切片，以检测内皮细胞、巨噬细胞、T细胞、平滑肌特异性肌动蛋白和中间丝（波形蛋白、结蛋白）。我们发现参与内皮下增殖的细胞波形蛋白和肌动蛋白呈阳性（平滑肌特异性），但结蛋白呈阴性，因此显示出平滑肌细胞的表型特征，超微结构研究证实了这一点。CD3 +、UCHL - 1 +和HLA - DR +细胞在早期炎症浸润中占相当比例。外膜扩张毛细血管中的内皮细胞HLA - DR呈强阳性。在后期，内皮细胞和白细胞稀少。这些数据证实了以下假说：斯内登综合征起始为一种炎症性且可能由免疫介导的疾病，导致小动脉平滑肌细胞迁移和增殖，从而使血管腔部分或完全狭窄。
