Conlan M G, Haire W D
Department of Medicine, University of Nebraska Medical Center, Omaha.
Am J Hematol. 1989 Oct;32(2):88-93. doi: 10.1002/ajh.2830320203.
Patients with essential thrombocythemia (ET) are at increased risk for large-vessel and microvascular thrombosis, presumably because of abnormal platelet number and function. To determine if another hemostatic abnormality might contribute to this thrombotic risk, we investigated protein C and protein S and the fibrinolytic system in four patients with ET. The patients segregated into two distinct groups. The first group consisted of two patients with moderate thrombocytosis who were without thrombotic symptoms and who had normal protein S and protein C and normal fibrinolysis. The second group consisted of two patients with mild to moderate thrombocytosis and thrombosis. Both these latter two patients had abnormalities in protein S. The first patient had only 31% free protein S and 67% total protein S, with normal protein C and normal fibrinolysis. Following treatment, vasoocclusive symptoms resolved and platelet count decreased, but protein S remained low (28% free protein S). The second patient in this group had only 35% total protein S at initial study. Other hemostatic abnormalities were also present. Following treatment, symptoms resolved and protein S returned to normal. Based on this limited series, it appears that, in some patients with ET, thrombotic phenomena may be due to the presence of a second hemostatic abnormality in addition to the high platelet count and abnormal platelet function. This abnormality may be acquired as part of the disease process. Some of these abnormalities may be corrected following treatment.
真性红细胞增多症（ET）患者发生大血管和微血管血栓形成的风险增加，推测是由于血小板数量和功能异常。为了确定是否存在其他止血异常可能导致这种血栓形成风险，我们对4例ET患者的蛋白C、蛋白S和纤溶系统进行了研究。患者分为两个不同的组。第一组由2例中度血小板增多症患者组成，他们没有血栓形成症状，蛋白S和蛋白C正常，纤溶功能正常。第二组由2例轻度至中度血小板增多症并伴有血栓形成的患者组成。后两名患者的蛋白S均有异常。第一名患者的游离蛋白S仅为31%，总蛋白S为67%，蛋白C正常，纤溶功能正常。治疗后，血管闭塞症状缓解，血小板计数下降，但蛋白S仍较低（游离蛋白S为28%）。该组中的第二名患者在初始研究时总蛋白S仅为35%。还存在其他止血异常。治疗后，症状缓解，蛋白S恢复正常。基于这一有限的病例系列，似乎在一些ET患者中，血栓形成现象可能是由于除了血小板计数高和血小板功能异常外，还存在第二种止血异常。这种异常可能是作为疾病过程的一部分而获得的。其中一些异常在治疗后可能得到纠正。
