P-77: Effectiveness of Desensitization Therapy in Pediatric Intestinal Transplant Recipients

Abstract

Introduction: Donor specific anti-HLA antibodies (DSA) impact negatively on the outcome of the intestinal graft. Although the use of desensitization therapies is becoming more frequent in the last years, issues as “when and how” still remain under discussion. The objective of this study was to evaluate the effectiveness of DSA desensitization in a pediatric intestinal transplant cohort. Methods: We studied retrospectively a cohort of 112 transplants. 14 desensitization procedures in 11 transplants were carried out (figure 1A). Desensitization was performed with different combinations of intravenous immunoglobulin, plasmapheresis and rituximab. Anti-HLA antibodies were tested by Luminex assay. Results: DSA were confirmed in 21 transplants. Desensitization was performed in 10 of them, plus one more retransplant of one of the recipients in the adulthood (figure 1A). Three recipients were desensitized peritransplant because of preformed DSA. Another 3 were desensitized in the context of rejection while 4 more were desensitized when DSA appearance without rejection. In two cases rituximab was used for other purposes (figure 1B). DSA removal was observed in 8 procedures, while in another 2 only class I DSA were cleared. Anti-HLA levels decreased in 2 more patients although DSA persisted. In 2 procedures (corresponding to the same recipient) no changes were observed. Patients with higher antibody levels and class II DSA did not negativize or needed more than one desensitization procedure to do it. No additional rejection episodes were observed in recipients with cleared DSA, who showed same graft survival rates than DSA negative patients. Conclusions: Desensitization treatment in intestinal paediatric recipients was effective in 82% of the transplants (9/11). Class I DSA and those with lower levels were more likely to clear up, which encourages an early desensitization even without any rejection sign.