Research Article Peak Serum AST Is a Better Predictor of Acute Liver Graft Injury after Liver Transplantation When Adjusted for Donor/Recipient BSA Size Mismatch (ASTi) Kyota Fukazawa, 1 Seigo Nishida, 2 and Ernesto A. Pretto Jr. 3 1 Department of Anesthesiology, College of Physicians and Surgeons of Columbia University, 630 West 168th Street, New York, NY 10032-3784, USA 2 Division of Liver and Gastrointestinal Transplant, Department of Surgery, University of Miami Miller School of Medicine and Jackson Memorial Hospital, 1801 NW 9th Avenue, Miami, FL 33136, USA 3 Division of Solid Organ Transplantation, Department of Anesthesiology, Perioperative Medicine and Pain Management University of Miami Miller School of Medicine, 1611 NW 12th Avenue, D318, Miami, FL 33136, USA Correspondence should be addressed to Kyota Fukazawa; kyotaf@gmail.com Received 27 February 2014; Accepted 22 May 2014; Published 9 June 2014 Academic Editor: Giuseppe Tisone Copyright © 2014 Kyota Fukazawa et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background. Despite the marked advances in the perioperative management of the liver transplant recipient, an assessment of clinically signiicant grat injury following preservation and reperfusion remains diicult. In this study, we hypothesized that size- adjusted AST could better approximate real AST values and consequently provide a better relection of the extent of grat damage, with better sensitivity and speciicity than current criteria. Methods. We reviewed data on 930 orthotopic liver transplant recipients. Size-adjusted AST (ASTi) was calculated by dividing peak AST by our previously reported index for donor-recipient size mismatch, the BSAi. he predictive value of ASTi of primary nonfunction (PNF) and grat survival was assessed by receiver operating characteristic curve, logistic regression, Kaplan-Meier survival, and Cox proportional hazard model. Results. Size-adjusted peak AST (ASTi) was signiicantly associated with subsequent occurrence of PNF and grat failure. In our study cohort, the prediction of PNF by the combination of ASTi and PT-INR had a higher sensitivity and speciicity compared to current UNOS criteria. Conclusions. We conclude that size-adjusted AST (ASTi) is a simple, reproducible, and sensitive marker of clinically signiicant grat damage. 1. Introduction Despite the marked advances in the perioperative man- agement of the liver transplant recipient, an assessment of clinically signiicant grat injury following preservation and reperfusion remains diicult [1]. he lack of a sensitive clinical marker of acute liver injury has a profound impact on clinical practice and the success of translational research in liver transplantation. Such a clinical marker could aid the management of grat dysfunction in early identiication of recipients who will require retransplantation. Currently, posttransplant peak aspartate aminotransferase (AST) is a widely accepted clinical marker for grat damage in liver transplant practice [2–6]. In fact, the United Network for Organ Sharing (UNOS) suggests relisting criteria for the recipients with primary grat dysfunction (PNF) on the basis of the post-transplant peak AST [7]. AST is an enzyme that is involved in amino acid metabolism, primarily existing in hepatocytes. During transplantation grat hepatocytes are inevitably injured, and intracellular enzymes are subse- quently released into the systemic circulation of the recipient. We theorized that the recipient AST serum concentration is a function of the total amount of AST released by the grat liver diluted by the total circulating blood volume at the time of blood sampling. herefore, the AST value could be misleading or inaccurate, depending on the size of the grat (total mass of injured hepatocytes) and the volume of blood in the recipient’s circulation. Hindawi Publishing Corporation Journal of Transplantation Volume 2014, Article ID 351984, 7 pages http://dx.doi.org/10.1155/2014/351984