Rabbit antithymocyte induction and dosing in deceased donor renal transplant recipients over 60yr of age

Background: Antithymocyte globulin (rATG) is a commonly used induction agent in renal transplantation; however, data in older kidney recipients are limited. Methods: We reviewed charts of 301 deceased donor renal transplants who received a protocol consisting of 3-7 doses of rATG and triple maintenance therapy. Outcomes of patients >60yr of age (n=45) were compared to those aged 18-59yr (n=256). Results: Older recipients had more diabetics, were more likely to receive expanded criteria donor kidneys (p<0.01), and over 30% were sensitized. Recipients >60 received less cumulative rATG (4.6 vs. 5.1mg/kg; p<0.01). Three-yr acute rejection was lower in the >60 group (2% vs. 16%, p<0.01) although glomerular filtration rates were similar between groups. Actuarial graft survival was similar; however, patient survival in the >60 group at threeyr was lower (80% vs. 95%; p=0.02). Specifically, patients >60 with delayed graft function and rATG cumulative dosing >6mg/kg had a survival of <50% by twoyr. Conclusion: Recipients over 60yr receiving rATG induction have acceptable renal function and a low risk of rejection; however, reduced survival was noted among those receiving >6mg/kg. These data suggest that when used, lower cumulative dosages of rATG are preferable in the older recipient.