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A NEW MODE OF PROTHROMBIN TIME (PT) REPORTING SPECIFIC FOR LIVER DISEASES
Abstract number: P-M-224
Eschwège1 V., Bellest1 L., Poupon2 R., Chazouillères2 O., Robert1 A.
11Unité d'hémostase 22Service d'hépatologie, AP-HP Hôpital Saint Antoine, Paris, FRANCE
How-to-cite Eschwège V, Bellest L, Poupon R, Chazouillères O, Robert A. A NEW MODE OF PROTHROMBIN TIME (PT) REPORTING SPECIFIC FOR LIVER DISEASES. J Thromb Haemost 2007; 5 Supplement 2: P-M-224
Abstract
Introduction: International Normalized Ratio (INR)/International Sensitivity Index (ISI) system developed to standardize PT reporting during oral anticoagulation (OA) has been extended in liver disease (LD) and even included in prognostic models such as the Model for End Stage Liver Disease (MELD) prioritizing liver transplant. We have previously reported that, in LD, INR fails to yield a PT reporting independent of the thromboplastin used. Our aim was to determine whether, in the thromboplastin calibration model proposed by the World Health Organization (WHO), the use of plasmas from LD patients instead of OA patients could lead to an INRLD/ISILD system achieving PT standardization in LD.
Methods: 1)Calibration. The ISILD of 5 thromboplastins (#1, 2, 3:rabbit, 4:human, 5:human recombinant) were determined by calibration, following WHO guidelines, against the reference preparation rTF/95 using 60 plasmas of patients covering the whole range of LD severity. 2)Validation. In 34 other LD patients, the differences between mean PT reported as seconds, ratio, INR and INRLD across the 5 thromboplastins were analysed by ANOVA and multiple comparison test. MELD score [9.57×loge(creatinine) + 3.78×loge(bilirubin) + 11.2×loge(INR) + 9.43] was calculated for each patient using the 5 different INR obtained with the 5 reagents.
Results: The ISILD/ISI were 0.98/1.67, 0.94/1.54, 0.70/1.05, 0.84/1.03 0.85/0.83 for thromboplastins 1 to 5 respectively, demonstrating the difference in reagents sensitivities to defects induced by LD and by OA. For the 2 most different reagents (1 and 5) and for the 5 patients with INR>3, the discrepancy between INR was >60% of the mean INR and consequently the difference between MELD scores (scale from 0 to 40) calculated with these INR was >7. Mean PT differed significantly for most pairs of reagents in all reporting modes except INRLD that eliminated all results variability.
Conclusions: Adoption of INRLD instead of INR as an international scale of PT reporting appears as an important goal in hepatology.
To cite this abstract use the following format:
Journal of Thrombosis and Haemostasis 2007; Volume 5, Supplement 2: abstract number
Session Details
| Date: |
01/08/2007
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| Time: |
00:00-00:00
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| Session name: |
XXIst ISTH Congress |
| Subject: |
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| Location: |
Oxford, UK |
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