Elghetany M T, Walker D H
University of Texas Medical Branch, Galveston 77555-0609, USA.
Am J Clin Pathol. 1999 Aug;112(2):159-68. doi: 10.1093/ajcp/112.2.159.
Rocky Mountain spotted fever and Mediterranean spotted fever are rickettsial infections primarily of endothelial cells that normally have a potent anticoagulant function. As a result of endothelial cell infection and injury, the hemostatic system is perturbed and shows changes that vary widely from a minor reduction in the platelet count (frequently) to severe coagulopathies, such as deep venous thrombosis and disseminated intravascular coagulation (rarely). Changes favoring a hypercoagulable state include endothelial injury and release of procoagulant components, activation of the coagulation cascade with thrombin generation, platelet activation, increased antifibrinolytic factors, consumption of natural anticoagulants, and possibly high levels of coagulation-promoting cytokines. Yet, most studies have been performed on endothelial cell cultures that provide nonphysiologic, reductionistic, experimental conditions. The lack of flow, platelets, and WBCs makes these experiments far from simulating the response of endothelial cells in the human body. Coagulopathies and thrombotic events should be considered as potential complications of severe Rocky Mountain spotted fever and Mediterranean spotted fever.
落基山斑疹热和地中海斑疹热是主要累及内皮细胞的立克次体感染，内皮细胞通常具有强大的抗凝功能。由于内皮细胞感染和损伤，止血系统受到干扰，表现出的变化差异很大，从血小板计数轻度降低（常见）到严重的凝血病，如深静脉血栓形成和弥散性血管内凝血（罕见）。有利于高凝状态的变化包括内皮损伤和促凝成分释放、凝血级联激活伴凝血酶生成、血小板激活、抗纤溶因子增加、天然抗凝剂消耗以及可能高水平的促凝血细胞因子。然而，大多数研究是在内皮细胞培养中进行的，这些培养提供了非生理、简化的实验条件。缺乏血流、血小板和白细胞使得这些实验远不能模拟人体内皮细胞的反应。凝血病和血栓形成事件应被视为重症落基山斑疹热和地中海斑疹热的潜在并发症。
