P1760EXTRACORPOREAL PHOTOPHERESIS AND KIDNEY ALLOGRAFT REJECTION

Background and Aims Extracorporeal photopheresis (ECP) is an apheresis modality that in the field of solid organ transplantation (SOT) has an indication in the treatment or prophylaxis of pulmonary, cardiac or hepatic graft rejection. The usefulness of ECP in renal transplantation (RTx) remains contradictory because of the few studies that evaluate the effectiveness and safety of this technique. Method Case series study of kidney transplant patients with histological diagnosis of rejection who have been treated with ECP during the 2013-2018 period (n = 8 patients). The technical characteristics of the ECP sessions (n = 89) were studied, including tolerance and complications in each of them. Results Demographic and clinical characteristics are shown in Table 1. The indication of FEC was the contraindication to conventional treatment (n = 4), mainly due to concomitant infection (50%), or refractoriness (n = 4) to the treatment prescribed in each case and it is specified in Table 1. The initial schedule was 2 consecutive weekly sessions for 5 weeks, with additional sessions depending on the evolution at the end of the first batch. The scheduled sessions could be completed in most patients (n = 5). The 3 reasons for discontinuation were the lack of response to treatment, hospital admission and thrombosis of the arteriovenous fistula (AVF). The improvement of graft function in terms of creatinine reduction at the end of therapy occurred among patients presenting with acute cellular rejection (ACR) (n = 4) and it remained 3 months after the end of the treatment. The only late ACR (> 3 months post-transplant) could not complete the initial programming. No graft with humoral component showed improvement in renal function. Graft loss and dialysis restart occurred in a patient with chronic active antibody-mediated rejection (cAMR). The other patient with cAMR is in a pre-dialysis situation. A total of 89 procedures were studied, all performed with the THERAKOS® CELLEX® Photopheresis System, with the administration of the methoxsalen solution (UVADEX®) and photoactivation with ultraviolet A light. Vascular access per session was the AVF (76% ) or the central vascular catheter (CVC) (24%), under no circumstances was peripheral access used. Each procedure lasted on average 112.72 +/- 13.85 minutes (range, 86-145). The volume of treatment (“buffy coat”) was 189.11 +/- 28.67 mL per session, and the total volume of fluids administered (NaCl and anticoagulation) was 559.40 +/- 41.17 mL. The complications observed during the sessions were fever (n = 2), thrombosis of the AVF (n = 1), coagulation of the extracorporeal system (n = 1) and anemization (n = 1). Interprocedure there was a case of urinary infection that conditioned hospital admission and discontinuation of therapy. One patient died of cardiovascular cause with a functioning graft 4 years after therapy. Conclusion The utility of the ECP seems to be in cases of cell rejection, probably related to the triggering of an immunomodulatory response of lymphocytes. It can be considered a well-tolerated and safe treatment. Special care should be taken with patients who require water restriction (infusion of 560 mL on average per session). We need more studies with a greater number of patients and a control group to be able to confirm the effectiveness and safety of PEC in RTx and to be considered a useful therapeutic tool as in other SOT.