Outcome of Desensitization in Human Leukocyte Antigen– and ABO-Incompatible Living Donor Kidney Transplantation: A Single-Center Experience in More Than 100 Patients

Abstract

BackgroundAntibody-mediated rejection (AMR) and inferior graft outcome remain the 2 most important obstacles to successful kidney transplantation in human leukocyte antigen (HLA)- and ABO-incompatible recipients. We report a single-center experience in the outcome of desensitized living donor HLA- and ABO-incompatible kidney transplantation. MethodsSince 2007 we included 2 groups in our desensitization program. HLA-incompatible living donor kidney transplant candidates displaying donor-specific antibodies (DSA) with or without a positive T-cell and/or B-cell flow crossmatch (FCXM). Second, those displaying DSA with positive T-cell immunoglobulin (Ig)G AHG CDC CXM with a titer of ≤1:8, as well as all ABO-incompatible living donor kidney transplant candidates with an IgM isoagglutinin titer ≤ 256. They were risk stratified for AMR and underwent individualized desensitization protocol: ABO-incompatible and HLA-incompatible candidates with either positive AHG CDC CXM or positive T and/or B IgG flow CXM with repeat HLA mismatch from a previous transplantation were deemed to be high risk and received a single dose of Rituximab, therapeutic plasma exchange and high-dose intravenous immunoglobulin (IVIG) (2 g/kg). HLA-incompatible candidates with negative CDC but positive T and/or B IgG FCXM were deemed intermediate risk, receiving rituximab and high-dose IVIG. Those with positive DSA but negative flow and CDC CXM were deemed low risk, receiving low-dose IVIG (1 g/kg). All patients received induction with thymoglobulin and were maintained on a tacrolimus-based immunosuppressive regimen. ResultsAmong 124 incompatible recipients, 85 received HLA-incompatible and 39 ABO-incompatible living donor kidney transplantations after desensitization. Risk stratification for HLA-incompatible transplants revealed 61 high-risk, 42 intermediate-risk, and 21 low-risk cases. Ninety-nine (80%) were primary transplants. At a median follow-up of 23 (range 1–53) months, patient survival was 98% and death censored graft survival 96%. Mean serum creatinine was 84 μmol/L (range 41–169). Acute cellular rejection was observed in 15 (12%) and AMR in 5 (4%) patients. All rejection episodes responded to treatment except 1 AMR in an ABO-incompatible transplant that led to graft failure. ConclusionOur risk stratification for desensitization strategy achieved a low incidence of AMR among HLA- and ABO-incompatible kidney transplant recipients. Their 2-year data appear to be comparable to HLA- and ABO-compatible transplantations.