Clinical Characteristics and Outcomes of Kidney Transplantation under Urgency Priority Condition

Abstract

Background: In several countries, patients with end-stage renal disease who are ineligible for dialysis are considered urgency priority (UP) for kidney transplantation (KT) through distinct allocation rules. There are scarce published data on clinical features and outcomes after KT of these patients.

Methods: We retrospectively reviewed and compared demographic and clinical pretransplant characteristics and outcomes after KT of all patients transplanted under UP allocation in a single Brazilian transplant center from January 10 to March 16 (n = 74) and 1: 1 patients transplanted under standard allocation in the same period (n = 74). A propensity score (PS) matching analysis was performed to evaluate risk factors for death-censored graft loss.

Results: UP KT group presented higher percentage of women (58.1 vs. 33.8%, p = 0.005), higher class I (22.2 ± 32.9 vs. 13.1 ± 25.3%, p = 0.027) and class II panel reactive antibodies (11.5 ± 24 vs. 5.2 ± 19.1%, p = 0.002), higher HLA mismatches (4.9 ± 0.9 vs. 3.7 ± 1.2, p < 0.001), higher percentage of retransplants (27 vs. 4.1%, p < 0.001), and spent longer time on dialysis off the waiting list (WL; 54.5 ± 52.5 vs. 31.2 ± 29.0 months, p = 0.03). After transplantation, UP KT patients presented longer hospital stay (29.3 ± 35.7 vs. 18.5 ± 19.5 days, p = 0.003) and inferior death-censored graft survival at 3 years (82 vs. 95.8%, log rank = 0.016), with 33.3% of graft losses due to vascular thrombosis. In PS-matched multivariable analysis, UP status hazard ratios (HR 4.791, 95% CI 1.052-21.722, p = 0.042) and donor age (HR 1.071, 95% CI 1.003-1.145, p = 0.041) were independent risk factors for death-censored graft loss.

Conclusion: Patients transplanted under UP status remained a longer time on dialysis off the WL, suggesting that long-term dialysis led to exhaustion of accesses. After transplantation, outcomes are inferior and UP status was a risk factor for graft loss. These results point to the need for local policies to encourage and monitor the early referral to KT.

Keywords: End-stage vascular access; High-urgency; Kidney transplantation; Prioritized renal allocation; Urgency priority.