Induction and Donor Specific Antibodies in Low Immunologic Risk Kidney Transplant Recipients

Background Optimal induction for patients without pretransplant donor-specific antibodies (DSAs) is poorly defined. The goal of this study was to compare the incidence of de novo DSA (dnDSA) and graft outcomes between induction therapies in patients with a negative virtual crossmatch (VXM). Methods A retrospective chart review was performed, identifying 782 patients with a negative VXM who underwent kidney transplantation at a single, high-volume institution between January 2013 and May 2017. Kaplan-Meier analysis was used to assess the incidence of dnDSA and allograft survival between induction therapies in this group. dnDSA is defined as the development of new post-transplant DSA, at any MFI level. Results Induction therapy included alemtuzumab (N=87, 11%), basiliximab (N=522, 67%), and anti-thymocyte globulin (ATG; N=173, 22%). One-year graft survival was similar between groups (alemtuzumab, 100%; basiliximab, 98%; ATG, 99%). Incidence of acute rejection at 1 year was < 2% and not different between the three groups. Alemtuzumab was associated with the highest incidence of dnDSA at 14%, compared with 5% and 8% in basiliximab and ATG groups, respectively, at 1 year (P=0.009). In multivariate regression analyses, alemtuzumab retained its significant association with a dnDSA HR of 2.5 (95% CI, 1.51 to 4.25; P=0.0004). Conclusions In summary, alemtuzumab was associated with a higher rate of dnDSA development in patients with a negative VXM; however, this finding was not associated with rejection or graft failure.