C. Eymard1, W. Ally1, K. L. Brayman1, A. Agarwal1 1University Of Virginia,Charlottesville, VA, Virgin Islands, U.S.
Introduction: Modern induction immunosuppression protocols for renal transplantation balance the risks of over-immunosuppression, namely drug toxicity and infection, against graft rejection. There is limited literature on induction therapy optimization with polyclonal antibodies in the elderly population (≥ 65 years). Rising health care costs and fixed payment are pressuring transplant programs to balance quality and fiscal management. Beyond the surgery, medications such as anti-thymocyte globulin (ATG) are the largest expense in transplantation. The aim of this study is to evaluate graft outcomes and associated cost savings of reduced immunosuppression in elderly renal transplant patients as part of a risk stratified immunosuppression protocol.
Methods: This is a retrospective cohort study of elderly patients undergoing solitary renal transplants from 2011 to 2014. Risk-stratification (RS) was based on immunological risk (sensitization and age) with varying ATG dosing utilizing adjusted body weight as opposed to total body weight. All patients were maintained on tacrolimus, mycophenolate mofetil (MMF), and prednisone. MMF target dosage was reduced from 2 g/day to 1.5 g/day. Patient (PS) and graft survival (GS), acute rejection (AR), total dosage (TD) and ATG cost are reported. Univariate analysis was performed and p<0.05 was considered significant.
Results:21 elderly patients underwent transplantation: 4 in the historical (HT) and 17 in the RS group. Mean follow up was 34±3 months in the HT and 23±8 months in the RS group. One year patient and graft survival were comparable (HT: 100 vs. RS: 100%; p=ns). Demographics were similar between groups, including mean age (67±2 years vs. 69±1; p=ns), % patients undergoing living donor transplants (0 vs. 6%; p=ns) and % patients with delayed graft function (25% vs. 31% p=ns). The HT group received two-fold total ATG dosage per patient vs. the RS group (450±92 mg (5.3 mg/kg) vs. 209±57 mg (2.6 mg/kg), p<0.05). MMF dosage was reduced in RS by 30% (1875±216 mg/day vs. 1312±258 mg/day; p=0.01). Renal function, as determined by eGFR, remained excellent at 3 and 6 months (52±13 ml/min/1.73m2 vs. 65±23; 46±16 vs. 62±21; p=ns). Acute cellular and humoral rejection was similar between groups at 6 months (25% vs. 6% p=ns; and 0%vs. 12%; p=ns). Overall 6 month infection rates were similar between cohorts (75% vs. 58%) with urinary tract infections as most common infection. The 53% reduction of ATG use in the RS cohort translated to a savings of $5825 per patient.
Conclusion:
The data would suggest that future modifications with immune monitoring could allow further optimization of immunosuppression. These data demonstrate that an individualized approach to immunosuppression with reduced dose ATG appears to maintain excellent clinical outcomes with low rejection rates and improved value of care with quantifiable cost savings.