#29-OR
THE LACK OF CLINICAL CORRELATION IN MEASURING CELL MEDIATED RESPONSIVENESS IN HEART TRANSPLANT RECIPIENTS.
Ronald Kerman Ph.D. 1, Eva McKissick B.S. 1, Noriel Acorda B.S. 1, Evelin Young B.S. 1, Natalie Guidry B.S. 1, Stan Stepkowski Ph.D. 1, Barry Kahan Ph.D., M.D. 1, Deirdre Smith R.N. 2, Lisa Nemeth R.N. 2, Rajko Radovancevic M.D. 2 and Branislav Radovancevic M.D. 2. 1 Surgery, University of Texas Medical School-Houston, Houston, TX, USA and 2 Transplant Research, Texas Heart Institute, Houston, TX, USA .
We evaluated twenty three end stage heart disease patients before and after cardiac transplantation (Tx) for Flow PRA detected HLA antibody (Ab) and their cell mediated responsiveness (CMR). HLA Ab and CMR were correlated to a stable or critical condition, rejection and heart biopsy (Bx) status. CMR was determined by an Immune Function Assay (Cylex, Inc., Columbia, MD) which measures ATP released from CD4+ T cells after PHA stimulation. The amount of ATP (ng/ml) may represent a surrogate of patient cellular immunity and be reflective of clinical events. The mean ng/ml of ATP for stable patients was 331 
176 which was comparable to the 367 258 for critically ill recipients. Seven patients had rejections, however, in only 2/7 rejections was the ATP data predictive of a clinical event. Moreover, when biopsy scores were compared to ng/ml ATP no statistically significant correlation was seen. Thirty-one percent of patients with a 0-biopsy score displayed > than 500 ng/ml ATP which was comparable and not statistically different from the 44% of patients with a grade 3A biopsy score. Finally, there was no correlation between patients with HLA Ab and quantity of ATP. Whether patients presented with <300, 301-500 or >500 ng/ml ATP no more than 25% of each group had HLA Ab. These data do not confirm a clinically correlative or predicative role for this Immune Function Assay in heart Tx recips.