Outcome of Desensitization in HLA and ABO Incompatible Living Donor Kidney Transplantation: A Single Center Experience of More than 100 Patients

Abstract

Introduction: Antibody mediated rejection (AMR) and inferior graft outcome remain the two most important obstacles to successful kidney transplantation in HLA and ABO incompatible recipients. We report a single center experience in the outcome of desensitized living donor HLA and ABO incompatible kidney transplantation. Methods: Since 2007, we included all HLA incompatible living donor kidney transplant candidates with T cell IgG AHG CDC crossmatch (CXM) titer of £1:8 and all ABO incompatible living donor kidney transplant candidates with IgM isoagglutinins titer of £ 256 in our desensitization program. All candidates were risk stratified for AMR and were subjected to an individualized desensitization protocols as follows: ABO incompatible and HLA incompatible candidates with positive AHG CDC CXM and positive donor specific antibody (DSA) by solid phase immunoassay (SPI) were deemed as high risk and received single dose Rituximab®, therapeutic plasma exchange (TPE) and high dose IVIG (2 gm/kg of body weight). HLA incompatible candidates with negative CDC and positive T and/or B IgG flow CXM and positive DSA by SPI were deemed as intermediate risk and received Rituximab® and high dose IVIG. HLA incompatible candidates with negative CDC and flow CXM and positive DSA by SPI were deemed as low risk and received small dose IVIG (1 gm/kg body weight). At transplant, all patients received induction with Thymoglobulin® and were maintained on Tacrolimus based immunosuppressive regimen. Results: There were 108 incompatible recipients; 33 received ABO incompatible and 75 received HLA incompatible living donor kidney transplantation after desensitization. Risk stratification for HLA incompatible transplant revealed 24 patients as high risk, 34 as intermediate risk, and 17 as low risk. 57 (53%) of the study population were females; average age was 43 (range: 15-83) years; 15 (14%) received pre-emptive kidney transplantation and 85 (79%) were primary transplants. Over a median follow up of 652 (range: 8-1444) days, patient survival was 98% and death censored graft survival was 96%. Average serum creatinine was 85 (32-160) mmol/L. Clinical and subclinical ACR was observed in 14 (13%) patients and clinical and subclinical AMR in 4 (3.7%) patients. All rejection episodes responded to treatment except one AMR in ABO incompatible transplant which led to graft failure. Conclusion: Within our inclusion criteria, risk stratification scheme and desensitization strategy, the short and intermediate outcome of HLA and ABO incompatible living donor kidney transplantation appears not to be different from those reported in HLA and ABO compatible transplantation. These excellent results are likely to positively impact the long term outcome.