#4251 KIDNEY TRANSPLANTATION WITH DONOR-SPECIFIC ANTIBODIES: A GROWING NEED

Abstract

Abstract Background and Aims Preformed donor specific antibodies in kidney transplant (KT) recipients are associated with higher risk of antibody mediated rejection (ABMR) and poorer graft survival. However, remaining a long time on the waiting list is strongly related to worse patient outcomes. We aimed to analyze KT recipients with preformed DSA with mean intensity fluorescence (MFI) who received induction therapy adapted to their higher immunological risk. Method We conducted a cohort retrospective study. All KT with preformed DSA performed in our center since May 2010 until March 2021 were included in the analysis. The presence of DSA was evaluated through Luminex Single Antigen (SA®) technology. All KT were performed with cadaveric kidney donor and with previous negative test by CDC crossmatch. The induction therapy in the presence of DSA included steroids, thymoglobulin, rituximab, plasmapheresis and standard treatment with tacrolimus and mycophenolate. Results During the study period 27 KT with preformed DSA were carried out. Recipient median age was 49 (IQR 40-62) years and 70,2% were women. Dialysis vintage was 5.8 (IQR 2.3-10.2) years. 63% were blood group A and 29,5% blood group 0. 29.6% were also included in the Hypersensitized National Programme (PATHI). The main causes of sensitization were previous KT (55.6%), pregnancy (29.6%) and blood transfusions (3.7%). 63% received KT with preformed DSA class I (median MFI 2218) and 37% with preformed DSA class II (median MFI 1900). Median calculated PRA was 90.5% (IQR 80.6-98.3). Median follow up time was 32.5 (IQR 12.3-61.2) months. Seventeen kidney biopsies were carried out. The most frequent findings were acute tubular necrosis (35.3%) and active ABMR (23.5%). DSA disappeared in most of the cases in successive analysis (81%) without any differences between both DSA classes. Median serum creatinine was 1.25 (IQR 0.97-1.75) mg/dl at 12 months and 1.65 (IQR 1.1-1.81) mg/dl at 24 months. In the post-transplantation period 2 patients were diagnosed with malignant solid organ tumors, 3 developed BK nephropathy, 5 CMV asymptomatic reinfection, and 9 recurrent urinary tract infections. During the observation time, 8 grafts were lost (29.6%): 3 due to patient deaths with functioning grafts and 5 due to graft failure (3 chronic ABMR, 1 active ABMR and 1 BKV nephropathy). Graft survival was 98% and 12 months and 92% at 24 months, respectively. Conclusion DSA with MFI low levels must be considered as a risk factor of ABMR and not as a contraindication to perform KT. A reinforced induction immunosuppression therapy enables KT to patients with high immunological risk and avoid prolonged time on the waiting list.