#3349 Experiences of performing ABO-incompatible kidney transplantation in Argentina

Abstract Background and Aims Living donor kidney transplantation is the best renal replacement therapy for patients with end-stage renal disease (ESRD). Thirty percent of potential living donors are rejected due to human leukocyte antigen (HLA) antibodies of ABO incompatibility. In Latin America, few centers, including ours, have initiated this type of transplantation. This study reviews our experience with a case series of ABOi transplantation. Method Retrospective, observational and descriptive cross-sectional study conducted between 2015 and 2023 in patients with ABO incompatible kidney transplantation. Immunological risk was classified according to isoagglutinin titer as low <1/8, moderate 1/16–1/64 and high 1/128–1/256. Isoagglutinin titration was performed according to haemotherapy service standards (semi-quantitative titration technique). The desensitization protocol included rituximab, plasma exchange (PEX) and intravenous immunoglobulin. All patients were monitored post-renal transplantation with isoagglutinins daily during hospitalization and weekly on an outpatient basis until day +15. Data are presented as absolute and relative frequencies for categorical variables and as medians (IQR) or means ± SD for continuous variables. Results Baseline donor and recipient characteristics are summarized in Table 1. The mean baseline anti-ABO IgM/IgG antibody titres were 1:32 and 1:64, respectively (range, 1:4–1:128). Our patients received an average of six pre-transplant PEX sessions and one post-transplant session (Table 2). Overall patient and graft survival at 1 year was 90%. The mean GFR was 74 ± 18 ml/min/1.73 m2. Two out of ten patients had acute post-transplant rejection (+14 days and +7 months post-transplant). Infection was the most common complication in ABOi kidney transplant patients. One patient died and lost the graft due to human herpesvirus 6 (Table 3). Conclusion ABOi kidney transplantation is a viable option in our setting for those who do not have a compatible donor. Strengthening these non-conventional modalities of kidney transplantation will increase the number of living donors, organ self-sufficiency, reduce the waiting list and decrease mortality in chronic kidney patients. However, high costs and infections remain major concerns. It is of common interest to promote the development of crossed kidney transplants to limit incompatible transplants.