Gordon B G, Haire W D, Stephens L C, Kotulak G D, Kessinger A
Department of Pediatrics, University of Nebraska Medical Center, Omaha 68198-2168.
Bone Marrow Transplant. 1993 Jul;12(1):73-6.
Patients undergoing hematopoietic stem cell transplantation (HSCT) are dependent on i.v. vitamin K supplementation to prevent deficiency. Vitamin K deficiency may contribute to the development of a hypercoagulable state by limiting hepatic synthesis of fully functional carboxylated anticoagulant protein C (PC). The ratio of PC antigen (CAg) to PC measured in a clot-based functional assay (CFx) reflects the degree to which PC is carboxylated. The 133 patients undergoing HSCT received vitamin K 10 mg per week (low dose, 101 patients) or 5 mg per day (high dose, 32 patients) i.v. as their sole exogenous source of vitamin K. CAg and CFx were assayed before HSCT preparative regimen and again 14 days later. CAg and CFx fell significantly in both groups from day 0 to day 14 but there were no differences between the low-dose and high-dose vitamin K groups. For both groups, CAg correlated strongly with CFx at day 14 (p = 0.0001). At day 14, the CAg/CFx ratio for the low-dose group was significantly greater than for the high-dose group (1.26 +/- 0.4 vs 1.09 +/- 0.1, p < 0.0002), suggesting that low-dose patients had a higher proportion of incompletely carboxylated PC. The CAg/CFx ratio at day 14 correlated with serum albumin for the high-dose group (p = 0.05), but not the low-dose group (p = 0.09), suggesting that the change in ratio in the low-dose group was not simply due to a lack of protein synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)
接受造血干细胞移植（HSCT）的患者依赖静脉补充维生素K以预防缺乏。维生素K缺乏可能通过限制肝脏合成功能完全正常的羧化抗凝蛋白C（PC）而导致高凝状态的发生。在基于凝血的功能测定（CFx）中测得的PC抗原（CAg）与PC的比值反映了PC的羧化程度。133例接受HSCT的患者静脉注射维生素K，低剂量组（101例）每周10mg，高剂量组（32例）每天5mg，作为其唯一的外源性维生素K来源。在HSCT预处理方案前及14天后再次测定CAg和CFx。从第0天到第14天，两组的CAg和CFx均显著下降，但低剂量和高剂量维生素K组之间无差异。两组在第14天时，CAg与CFx均呈强相关（p = 0.0001）。第14天时，低剂量组的CAg/CFx比值显著高于高剂量组（1.26±0.4 vs 1.09±0.1，p < 0.0002），提示低剂量组未完全羧化的PC比例更高。高剂量组第14天的CAg/CFx比值与血清白蛋白相关（p = 0.05），而低剂量组则无相关性（p = 0.09），这表明低剂量组比值的变化并非仅仅由于蛋白质合成不足所致。（摘要截选至250字）
