Marlar R A, Neumann A
Laboratory Services, Denver VA Medical Center, CO 80220.
Semin Thromb Hemost. 1990 Oct;16(4):299-309. doi: 10.1055/s-2007-1002683.
Homozygous protein C deficiency or homozygous protein S deficiency are rare genetic diseases with catastrophic and fatal purpura fulminans-like or thrombotic complications occurring during the neonatal period. These diseases can now be successfully treated. Purpura fulminans is at least in part a cutaneous manifestation of the syndrome of systemic DIC. It is characterized by microvascular thrombosis in the dermis followed by perivascular hemorrhage, necrosis, and minimal inflammation. Laboratory findings are consistent with DIC. Although the pathogenesis is not fully understood, the DIC in purpura fulminans appears to involve the skin selectively. The development of purpura fulminans from homozygous protein C or protein S deficiencies can be separated into the two distinct phases. The first phase is the time period when the initial reversible lesions develop and grow. This reversible progression can be halted and reversed with the administration of protein C or protein S. The second phase is the irreversible stage in which the lesion continues to develop into a necrotic lesion, whether or not treated with protein C. This irreversible lesion will ultimately develop into a large full-thickness necrotic injury of the skin. It is very similar to the lesions seen in idiopathic purpura fulminans, warfarin-induced skin necrosis, and acute infectious purpura fulminans. Unfortunately, our current understanding of the mechanism or mechanisms of the induction and propagation of the purpura fulminans-like lesions in homozygous protein C or protein S deficiencies is minimal, since it has never been studied. We can only speculate on the mechanism based on laboratory data and comparison with the little that is known about the other similar types of lesions.
纯合子蛋白C缺乏症或纯合子蛋白S缺乏症是罕见的遗传性疾病，在新生儿期会出现灾难性的、致命的暴发性紫癜样或血栓形成并发症。这些疾病现在可以得到成功治疗。暴发性紫癜至少部分是系统性弥散性血管内凝血（DIC）综合征的皮肤表现。其特征是真皮微血管血栓形成，随后出现血管周围出血、坏死，炎症轻微。实验室检查结果与DIC一致。虽然发病机制尚未完全明确，但暴发性紫癜中的DIC似乎选择性地累及皮肤。纯合子蛋白C或蛋白S缺乏导致暴发性紫癜的发展可分为两个不同阶段。第一阶段是初始可逆性病变发生和发展的时期。给予蛋白C或蛋白S可阻止并逆转这种可逆性进展。第二阶段是不可逆阶段，无论是否用蛋白C治疗，病变都会继续发展为坏死性病变。这种不可逆病变最终会发展为皮肤全层大面积坏死性损伤。它与特发性暴发性紫癜、华法林诱导的皮肤坏死和急性感染性暴发性紫癜中所见的病变非常相似。不幸的是，我们目前对纯合子蛋白C或蛋白S缺乏症中暴发性紫癜样病变的诱导和传播机制的了解极少，因为从未对此进行过研究。我们只能根据实验室数据并与对其他类似病变类型的少量已知信息进行比较来推测其机制。
