1.3000
#36
IMMUNE PARAMETERS USED TO IDENTIFY HIGH RISK RECIPIENTS IN A STEROID AVOIDANCE CLINICAL TRIAL.
Karen Mohler, Angela Burnette, Kay Savik, Arthur Matas, Lois McHugh and Nancy Reinsmoen. Durham NC, USA, Duke University Medical Center, 27710, Pathology and Minneapolis MN, USA, University of Minnesota, 55455, Surgery.

---

Steroid avoidance immunosuppression (IS) protocols have been implemented recently to decrease posttransplant (posttx) side effects of steroids. A randomized three-arm clinical trial with a rapid discontinuation of prednisone is being conducted to determine the best long-term protocol. Gp1 receives hi tacrolimus(Tac)/lo sirolimus(Sir), Gp2: lo Tac/hi Sir, and Gp3: cyclosporine(CSA) and mycophenolate mofetil(MMF). We have designed a battery of assays to test immune responses and determine if these assays can identify recipients(recips) at high risk for developing AR. 37 specimens were obtained pretx and 28 posttx from recips in the trial. Data has shown that high prettx whole blood intracellular iATP levels(>450 ng/ml) from CD4+ cells, frequency of donor-reactive γ -IFN memory T cells by ELISpot (>50 spots/2x10 cells) and flow detectable HLA antibody correlate with increased risk of early AR. 2 or more of these risk factors were classified as high risk(HR). In Gpl, 4 of 13 were HR, one had biopsy-proven AR. When comparing pre vs. 1-6 mo posttx iATP whole blood levels, recips in Gp1 showed a decrease of 271 to190ng/ml (p = .003; Wilcoxon-Matched Pairs signed-rank test). In Gp2, 2 of 13 were HR, one had AR. Gp2 decreased from 330 to192ng/ml (p = .03). 2 of 9 in Gp3 were HR. One of the two, and one recip with one risk factor had AR. Gp3 had a statistically insignificant decrease of 269 vs. 196 ng/ml ATP (p = .07), suggesting the drug regime in Gp3 was least effective. Our results show pre and posttx parameters identify recips at risk for immune complication and may benefit from individualized IS and identify potential points for intervention.