lated to histological grade of rejection (ISHLT) and time-point of rejection. Results: A strong correlation was found between CTLA-4 gene expression and histologically proven rejection. Also increased mRNA levels were detected in biopsies with acute rejection for granzyme B and FasL respectively. In addition, TGF- which is involved in repair responses after tissue damage showed higher expression patterns after episodes of acute rejection. Throughout the biopsies IL-6 levels were lower compared to other measured genes but also displayed a good correlation with allograft rejection. Conclusions: Our results provide strong evidence that monitoring expression of CTLA-4, FasL and Granzyme B is an additive method in diagnosing and observing allograft rejection during human heart transplantation. 68 Historical Trends of Primary Graft Failure after Heart Transplantation M. Gomez-Bueno, J.M. Barcelo, J. Segovia, M. Cobo, J. Mirelis, E. Sufrate, P. Garcia-Pavia, L. Alonso-Pulpon Hospital Universitario Puerta de Hierro, Majadahonda, Madrid, Spain Purpose: Primary graft failure (PGF) remains the leading cause of early mortality in heart transplantation (HTx). Little is known about the changes of this syndrome along a considerable period of time. The aim of this study was to analyze the incidence, mortality and risk factors of PGF during a period of 22 years. Methods and Materials: PGF is defined as a severe impairment of systolic graft function affecting the right, left or both ventricles, within the first 24 hours after transplantation and without any other obvious cause for the graft dysfunction. Data of 621 HTx performed in our institution were reviewed and classified in four groups according the following dates: between 1984 and 1989 Group 1 (n=78), 1990-1994 Group 2 (n=180), 1995-1999 Group 3 (n=194), 2000-2006 Group 4 (n=169). Results: The overall incidence of PGF was 9% with a 30-day mortality of 80.4%. PGF characteristics and relating risk factors for each group are show in Table 1. Conclusions: Despite of technical progresses in HTx, the incidence of PGF has not diminished over time. A trend to higher incidence in recent years could be associated with less favorable characteristic of recipients and donors. The early mortality of PGF has decreased with experience, probably because of an earlier and more aggressive treatment, as reflected by the increasing use of mechanical circulatory support devices. Table 1. Period 1 Period 2 Period 3 Period 4 p for trend PGF Incidence 7(9%) 9(5%) 19(9.8%) 21(12.4%) 0.05 PGF 30-Day Mortality 7(100%) 8(88.9%) 16(84%) 14(66.7%) 0.03 VAD or IABP 3(42.9%) 5(55.6%) 11(57.9%) 18(85.7%) 0.004 Recipient age60 years 2(2.5%) 21(11.65) 57(29.3%) 46(27.2%) 0.001 Recipient diabetes 4(5.1%) 13(7.2%) 26(13.4%) 32(18.9%) 0.001 Recipient inotropic dependence 22(28.2%) 61(33.9%) 70(36.1%) 85(50.3%) 0.001 Recipient RAP10 mmHg 25(32%) 58(32.2%) 83(42.8%) 88(52.1%) 0.001 Donor age30 years 12(15.4%) 52(28.9%) 90(46.4%) 90(53.3%) 0.001 69 Do MICA Antibodies Prior to Heart Transplantation Influence Development of Acute Rejection? S. Gupta, A. Medhat, A. Sabe, N. Ed, B. Eugene, G. Gonzalez-Stawinski Cleveland Clinic, Cleveland, OH Purpose: To determine if pre-transplant MHCclass I-related chain A (MICA) antibodies in heart transplant recipients are responsible for acute rejection. Methods and Materials: Available serum of patients undergoing heart transplant between 2003 and 2008 was screened for HLA antibodies, and these were absent in 152. These 152 recipients were tested for MICA antibodies using flow cytometry and bead assay. Their respective donors were genotyped with respect to MICA. Recipient MICA specificities were compared with those of their respective donor to determine presence of donor-specific antibodies. 1,493 post-transplant right heart biopsies were graded for acute cellular and antibody-mediated rejection (0=none, 1=mild, 2=moderate, 3=severe) up to 1 year in 140 of the 152 patients. Acute rejection grade was compared between patients with and without pre-transplant MICA antibodies using repeated-mea- sures nonlinear cumulative logit mixed modeling with temporal decom- position. Results: Of the 152 patients having pre-transplant serum tested for MICA antibodies, 34 (22%) tested positive (MICA+). Of the 140 patients having biopsy data, 31 had MICA antibodies (22%). MICA+ and MICA- groups had similar demographics, UNOS status, and cold ischemia times. They also had similar prevalence of rejection by severity during the first postoperative year (P=.6): Only 3 patients had donor-specific MICA antibodies (2.0%). Conclusions: Although etiology of MICA sensitivity in heart trans- plant recipients is unknown, 22% of our population tested positive for MICA antibodies prior to transplantation. The presence of pre- transplant MICA antibodies did not influence development of acute rejection during the first postoperative year. 70 Rabbit Antithymocyte Globulin Dosing and Complications in Heart Transplant Induction and Rejection J. Lindsley, K. Pickworth, D. Blais, A.K. Hasan, D. Feldman Ohio State University, Columbus, OH Purpose: Many centers utilize antithymocyte globulin (ATG) for induction therapy or for treatment of rejection. The purpose of this retrospective review was to determine if dosing based on CD3 count response reduced ATG doses, while effectively treating patients. Methods and Materials: A review was performed on heart trans- plant patients requiring ATG therapy over 4 years. ATG dose with acquisition costs, CD3 counts and outcomes were collected. ATG complications were based on readmission diagnosis and classified as infectious, hematologic, rejection, or non-transplant related. With initial dosing, 1 mg/kg was administered. Subsequently, based on a CD3 count 25 cells/mm3, the patient was redosed with 0.25 mg/kg to 1 mg/kg in order to achieve CD3 counts of less than 25 cells/mm 3 The Journal of Heart and Lung Transplantation Abstracts S89 Volume 28, Number 2S