Introduction: KDIGO 2009 guidelines recommend interleukin-2 receptor antagonist (IL2-RA) as a 1st-line induction therapy for living donor renal transplantation. The relatively-more-potent immunosuppressant rabbit antithymocyte globulin (rATG) has been associated with a lower risk of acute rejection and higher rate of infection compared with IL2-RA, and is recommended for high-risk donor recipients. This retrospective study compared the efficacy and safety of rATG with IL-2RA in Chinese patients who underwent living donor renal transplant over a 10-year period.

Materials and Methods: This retrospective analysis included 188 adult (≥18 years) patients who received induction immunosuppression and underwent living donor renal transplantation at our institution from Feb 2004–Dec 2013. Patients were stratified based on induction therapy received; rATG (thymoglobulin) 1 mg/kg/day at Day 0–Day 2 after transplantation (n=41), or IL2-RA (basiliximab) 20 mg/day at Day 0–Day 3 after transplantation (n=147). The main outcome was incidence of acute rejection. Other outcomes included detection of de novo donor-specific antigen (dn-DSA), graft survival, and rate of infection.

Results and Discussion: The rATG group had a higher mean panel reactive antigen (PRA) score, and more complete human leukocyte antigen (HLA) mismatches, compared with the IL2-RA group (Table). There was no significant difference in the incidence of acute rejection between the rATG and IL2-RA groups (9.8% vs. 8.8%), although patients in the rATG group had a significantly lower rate of biopsy-proven acute rejection (BPAR) (p=0.01) (Table). There was no significant difference in 1, 3 or 5-year graft (Figure 1) or recipient (data not shown) survival between the two groups. The safety profile in both treatment groups was comparable, which is contrary to current treatment guidelines and previous research that showed a relatively lower rate of infection with IL-2RA versus rATG (Table). Given that dn-DSAs directed against HLA are one of the major risk factors for allograft failure, it is interesting that this study found the incidence of dn-DSA was comparable in the rATG (two cases [4.9%]) and IL2-RA (seven cases [5.4%]) groups.

Conclusion: It may be beneficial to stratify high-risk renal donor recipients to induction with rATG; similar efficacy and safety outcomes were achieved for higher-risk patients following rATG, with a lower rate of BPAR, compared with relatively lower-risk patients treated with IL-2RA.