Point-of-care coagulation monitors calibrated for the international normalized ratio for cirrhosis (INRliver) can help to implement the INRliver for the calculation of the MELD score.
OBJECTIVE
The MELD defines a score used to prioritize patients awaiting liver transplantation and includes results for bilirubin, creatinine and PT expressed as INR. It is assumed that the MELD for individual patients is the same regardless of the laboratory method used for testing, thus ensuring parity of organ allocation. Previous studies showed that the INR calibrated for patients on vitamin K antagonists (INR(vka)) does not normalize results across thromboplastins, whereas an alternative calibration called INR(liver) does. However, implementation of INR(liver) calibration for thromboplastins is difficult in practice. This study aimed to assess whether easy-to-run whole-blood coagulation monitors (widely used for patients on VKA) can be calibrated to measure efficiently the INR(liver) and minimize the interlaboratory variability.


METHODS
PT values for 61 cirrhotic patients were measured on native-blood with 2 monitors calibrated in terms of INR(vka). PTs for these subjects were also measured with a WHO-standard for thromboplastin. Paired-PTs with the monitors and the standard were subsequently used to calibrate the monitors in terms of INR(liver). INR(vka) and INR(liver) were then compared to assess for statistical significance.


RESULTS
The mean INR(vka) obtained with the monitors and the standard were significantly different (p<0.001). Conversely, the corresponding INR(liver) were not.


CONCLUSIONS
The INR(liver) calibration as previously described for thromboplastins works also for the easy-to-run whole-blood coagulation monitors. Once the monitors are calibrated by the manufacturer in terms of INR(liver) they could be used as near-patient-testing devices directly by the personnel of liver units making the determination of the INR for patients awaiting liver transplantation much easier and standardized.
Tripodi
Armando
A
Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Department of Internal Medicine and Medical Specialties, University and IRCCS Ospedale Maggiore, Mangiagalli and Regina Elena Foundation, Via Pace 9, 20122 Milan, Italy. armando.tripodi@unimi.it
Chantarangkul
Veena
V
Primignani
Massimo
M
Dell'Era
Alessandra
A
Clerici
Marigrazia
M
Iannuzzi
Francesca
F
Aghemo
Alessio
A
Cazzaniga
Massimo
M
Salerno
Francesco
F
Mannucci
Pier Mannuccio
PM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D019934:International Normalized Ratio / Q000592:standards / Q000706:statistics & numerical data; D008103:Liver Cirrhosis / Q000097:blood* / Q000188:drug therapy / Q000601:surgery; D016031:Liver Transplantation; D008297:Male; D008875:Middle Aged; D019095:Point-of-Care Systems / Q000592:standards / Q000706:statistics & numerical data; D011379:Prognosis; D014812:Vitamin K / Q000037:antagonists & inhibitors; D055815:Young Adult
D014812:Vitamin K