Castaman G, Lattuada A, Ruggeri M, Tosetto A, Mannucci P M, Rodeghiero F
Department of Hematology and Hemophilia, San Bortolo Hospital, Vicenza, Italy.
Am J Hematol. 1995 Aug;49(4):289-93. doi: 10.1002/ajh.2830490406.
Plasma and platelet von Willebrand factor (vWF) measurements, multimeric pattern and subunit composition of plasma vWF were obtained in 29 consecutive patients with chronic myeloproliferative syndromes. In the 8 patients with chronic myelogenous leukemia (CML), plasma vWF was significantly higher than in the 11 patients with essential thrombocythemia (ET) and in the 10 patients with polycythemia vera (PV). The RiCof/vWF:Ag ratio was low in all these groups of patients (mean 0.64 +/- 0.1, 0.66 +/- 0.2, and 0.61 +/- 0.2; normal 0.97 +/- 0.2). Bleeding time was prolonged (> 7.5 min) in 1/8 CML patients, 1/10 with PV, and 3/11 with ET. Plasma vWF multimers showed a minor loss of the largest multimers in 3/8 patients with CML, 4/10 with PV, and a more severe reduction in 9/11 ET patients. The latter pattern correlated with an abnormal proteolysis of vWF, expressed by a major increase of the 140-Kd fragment and decrease of the intact 225-Kd subunit in ET patients, whereas the 176-Kd fragment was significantly increased in all the subgroups of patients. Platelet vWF was significantly higher in CML patients in comparison to ET and normal controls. However, minor losses of the larger multimers were evident in all the subsets of patients. In ET patients also the intermediate forms were lacking in platelets, accompanied by a significant decrease of platelet RiCof. This abnormality was significantly correlated with the occurrence of bleeding symptoms in PV and ET patients (P = 0.007; Fisher's exact test). In conclusion, plasma and platelet vWF abnormalities are common findings in myeloproliferative syndromes and are more severe in ET. The more pronounced platelet vWF abnormalities in ET may reflect the more frequent bleeding symptoms observed in this disorder.
对29例连续性慢性骨髓增殖性综合征患者进行了血浆和血小板血管性血友病因子（vWF）测定、血浆vWF的多聚体模式及亚基组成分析。在8例慢性粒细胞白血病（CML）患者中，血浆vWF显著高于11例原发性血小板增多症（ET）患者和10例真性红细胞增多症（PV）患者。所有这些患者组的瑞斯托霉素辅因子/血管性血友病因子抗原（RiCof/vWF:Ag）比值均较低（平均值分别为0.64±0.1、0.66±0.2和0.61±0.2；正常为0.97±0.2）。1/8的CML患者、1/10的PV患者和3/11的ET患者出血时间延长（>7.5分钟）。血浆vWF多聚体显示，3/8的CML患者、4/10的PV患者最大多聚体轻度丢失，而9/11的ET患者丢失更为严重。后一种模式与vWF异常蛋白水解相关，表现为ET患者140-Kd片段大幅增加，完整的225-Kd亚基减少，而176-Kd片段在所有患者亚组中均显著增加。与ET患者和正常对照相比，CML患者的血小板vWF显著更高。然而，在所有患者亚组中均可见较大多聚体轻度丢失。在ET患者中，血小板也缺乏中间形式，同时血小板RiCof显著降低。这种异常与PV和ET患者出血症状的发生显著相关（P = 0.007；Fisher精确检验）。总之，血浆和血小板vWF异常是骨髓增殖性综合征中的常见表现，在ET中更为严重。ET中更明显的血小板vWF异常可能反映了该疾病中更频繁出现的出血症状。
