title: Impact of different creatinine measurement methods on liver transplant allocation.
abstract: BACKGROUND
  The model for end-stage liver disease (MELD) score is used in many countries to prioritize organ allocation for the majority of patients who require orthotopic liver transplantation. This score is calculated based on the following laboratory parameters: creatinine, bilirubin and the international normalized ratio (INR). Consequently, high measurement accuracy is essential for equitable and fair organ allocation. For serum creatinine measurements, the Jaffé method and enzymatic detection are well-established routine diagnostic tests.
  
  
  METHODS
  A total of 1,013 samples from 445 patients on the waiting list or in evaluation for liver transplantation were measured using both creatinine methods from November 2012 to September 2013 at the university hospital Leipzig, Germany. The measurements were performed in parallel according to the manufacturer's instructions after the samples arrived at the institute of laboratory medicine. Patients who had required renal replacement therapy twice in the previous week were excluded from analyses.
  
  
  RESULTS
  Despite the good correlation between the results of both creatinine quantification methods, relevant differences were observed, which led to different MELD scores. The Jaffé measurement led to greater MELD score in 163/1,013 (16.1%) samples with differences of up to 4 points in one patient, whereas differences of up to 2 points were identified in 15/1,013 (1.5%) samples using the enzymatic assay. Overall, 50/152 (32.9%) patients with MELD scores >20 had higher scores when the Jaffé method was used.
  
  
  CONCLUSIONS
  Using the Jaffé method to measure creatinine levels in samples from patients who require liver transplantation may lead to a systematic preference in organ allocation. In this study, the differences were particularly pronounced in samples with MELD scores >20, which has clinical relevance in the context of urgency of transplantation. These data suggest that official recommendations are needed to determine which laboratory diagnostic methods should be used when calculating MELD scores.
authors.affiliation: Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Kaiser
authors.affiliation: Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Benedict
authors.initials: B
authors.lastname: Kinny-Köster
authors.affiliation: Department of Visceral, Vascular, Thoracic and Transplant Surgery, University Hospital of Leipzig, Leipzig, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Bartels
authors.affiliation: Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Tanja
authors.initials: T
authors.lastname: Parthaune
authors.affiliation: Reference Institute for Bioanalytics, Bonn, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Schmidt
authors.affiliation: Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Thiery
mesh_terms: D000328:Adult; D000368:Aged; D003404:Creatinine / Q000378:metabolism*; D058625:End Stage Liver Disease / Q000601:surgery; D005260:Female; D005858:Germany; D006801:Humans; D016031:Liver Transplantation; D008297:Male; D008875:Middle Aged; D019737:Transplants / Q000378:metabolism*; D055815:Young Adult
chemical_list: D003404:Creatinine