Graduate School of the Chinese PLA General Hospital, Beijing, People's Republic of China.
J Thromb Thrombolysis. 2010 Jul;30(1):84-9. doi: 10.1007/s11239-009-0423-2.
International Normalized Ratio (INR), which standardizes prothrombin time (PT) during oral anticoagulation, has been extended to standardize PT in liver diseases and is included in all prognostic models of survival, the classification of CHILD-Pugh or Meld. However, the mechanisms of PT prolongation in liver diseases differ from those involved in oral anticoagulation. Our aim was to assess the validity of the INR system for patients with liver disease associated with viral hepatitis. We prospectively collected blood samples from 61 patients with liver disease associated with viral hepatitis; control patients were on warfarin (n = 20). PTs were measured on a STA-R coagulometer with six thromboplastin reagents, and INRs were calculated using instrument-specific ISIs. Simultaneously, we selected 15 pairs of patients in the study population and in the control population such that INR values for each patient pair are almost equal. For these 15 pairs of patients, we performed factor assays and measured the coagulant activities of factors II, V, VI, and X and fibrinogen. Analysis of results for the control population confirms the validity of the INR system for patients on oral anticoagulants in that there was no significant difference between the reported INRs for the six different thromboplastin reagents. Conversely, for the study population, there was a significant difference between the INR results using the different reagents. Results for fibrinogen and factors V, VII, and X showed significant differences between the two groups; however, control and patient results for factor II were not statistically different. The INR system is not valid for comparison of patients with liver disease associated with viral hepatitis because different reagents do not yield the same INR for the same sample.
国际标准化比值（INR）可标准化口服抗凝治疗期间的凝血酶原时间（PT），现已扩展至标准化肝病中的 PT，并包含在所有生存预后模型、CHILD-Pugh 分级或 MELD 评分中。然而，肝病中 PT 延长的机制与口服抗凝治疗中不同。我们的目的是评估 INR 系统在病毒性肝炎相关肝病患者中的有效性。我们前瞻性地收集了 61 例病毒性肝炎相关肝病患者的血液样本；对照组患者服用华法林（n = 20）。PT 使用 STA-R 凝血仪和六种组织凝血活酶试剂进行测量，并使用仪器特定的 ISI 计算 INR。同时，我们从研究人群和对照组中选择了 15 对患者，使得每对患者的 INR 值几乎相等。对于这 15 对患者，我们进行了因子测定，并测量了因子 II、V、VI 和 X 以及纤维蛋白原的凝血活性。对照组的结果分析证实了 INR 系统在口服抗凝剂患者中的有效性，即六种不同组织凝血活酶试剂报告的 INR 之间没有显著差异。相反，对于研究人群，不同试剂的 INR 结果之间存在显著差异。纤维蛋白原和因子 V、VII 和 X 的结果显示两组之间存在显著差异；然而，对照组和患者组的因子 II 结果没有统计学差异。INR 系统不适用于比较病毒性肝炎相关肝病患者，因为不同的试剂不能为相同的样本提供相同的 INR。
