title: 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.
abstract: 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.
authors.affiliation: 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
authors.forename: Armando
authors.initials: A
authors.lastname: Tripodi
authors.forename: Veena
authors.initials: V
authors.lastname: Chantarangkul
authors.forename: Massimo
authors.initials: M
authors.lastname: Primignani
authors.forename: Alessandra
authors.initials: A
authors.lastname: Dell'Era
authors.forename: Marigrazia
authors.initials: M
authors.lastname: Clerici
authors.forename: Francesca
authors.initials: F
authors.lastname: Iannuzzi
authors.forename: Alessio
authors.initials: A
authors.lastname: Aghemo
authors.forename: Massimo
authors.initials: M
authors.lastname: Cazzaniga
authors.forename: Francesco
authors.initials: F
authors.lastname: Salerno
authors.forename: Pier Mannuccio
authors.initials: PM
authors.lastname: Mannucci
mesh_terms: 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
chemical_list: D014812:Vitamin K