New simultaneous lung-kidney allocation policy benefits adult recipients of lung transplant with chronic renal dysfunction.

OBJECTIVE: The United Network for Organ Sharing defined allocation policies for Simultaneous Lung-Kidney transplantation (SLK) in 2023. However, SLK has rarely been performed, and the benefit for lung transplant candidates remains unclear. We sought to determine the outcomes for lung transplant recipients (LTRs) with pretransplant renal dysfunction and estimate the potential impact of the policy. METHODS: Using Organ Procurement and Transplantation Network data, we categorized adult LTRs from 2005 to 2022 by pretransplant renal dysfunction. We then retrospectively applied the 2023 SLK eligibility criteria to identify LTRs with kidney dysfunction who would have been eligible for SLK. Next, we evaluated the outcomes for SLK-eligible LTRs who received SLK or lung transplant using adjusted Cox regression. RESULTS: Among 17,954 LTRs, 1913 (10.7%) had pretransplant renal dysfunction. Applying the new OPTN SLK allocation policy to the retrospective cohort, 292 (16.2%) LTRs would have been eligible for SLK, and 39 LTRs received SLK. SLK recipients had significantly greater pretransplant dialysis use (69% vs 34%, P < .01) and greater lung allocation score (85 vs 51, P < .001). Yet, 3-year overall (81% vs 58%, P < .001) and adjusted (adjusted hazard ratio, 0.30; 95% CI, 0.13-0.68; P = .004) survival was significantly improved among SLK versus LT-only recipients. The risk of all-cause graft loss for SLK recipients was 76% lower compared with lung-only recipients (adjusted hazard ratio, 0.24; 95% CI, 0.11-0.54; P = .001). CONCLUSIONS: In the historical cohort, a minority of LTRs who were eligible for SLK by contemporary Organ Procurement and Transplantation Network criteria received a multiorgan transplant. However, despite being sicker, recipients of SLK had significantly improved survival compared with candidates eligible for SLK who received lung-only transplants.