The Impact of Kidney Transplantation on Survival Outcomes for Lung Transplantation

L. Lester¹, S. M. Atay², G. M. Rosenberg², S. Wightman³, B. V. Udelsman², A. W. Kim², T. Harano^2
1University of Southern California, Los Angeles, California ²Keck School of Medicine, University of Southern California, Los Angeles, California ³University of Southern California, La Crescenta, California

Purpose: Kidney failure affects long-term outcomes after lung transplantation [1]. Some patients with chronic kidney disease (CKD) undergo kidney transplantation after lung transplantation, while others are offered simultaneous lung-kidney transplantation. This study aims to investigate the impact of kidney transplantation on lung transplantation outcomes using a national transplant database.

Methods: A retrospective cohort study was performed utilizing Organ Procurement and Transplantation Network/United Network for Organ Sharing data from May 2005 to December 2022. The study excluded pediatric patients, patients with a history of kidney transplantation prior to lung transplantation, patients without a serum creatinine level at time of waitlisting and multi-organ transplant recipients other than simultaneous lung-kidney recipients. For the remaining 35,038 patients, glomerular filtration rate (GFR) was calculated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation [2]. Patients were then assigned a CKD stage according to GFR. The primary outcome compared across groups was overall survival after lung transplantation.

Results: 35,038 patients underwent isolated lung transplantation or simultaneous lung-kidney transplantation. 526 of these recipients underwent kidney transplantation including 111 who underwent simultaneous lung-kidney transplantation. At the time of lung transplant waitlisting, 435 patients were CKD stage 3b, 81 were stage 4, and 57 were stage 5. A total of 2,608 patients required renal replacement therapy (RRT) after lung transplantation, during the index admission. Of these 2,608 patients, 113 patients underwent kidney transplantation. RRT patients who underwent kidney transplantation had improved survival compared to RRT patients who did not undergo kidney transplantation (n = 2,608; log-rank test p < 0.001, Figure 1A). Of 573 patients with CKD stage 3b-5 at waitlisting, 103 patients underwent kidney transplantation, including 79 who underwent simultaneous lung-kidney transplantation. Survival outcomes were significantly improved with kidney transplantation (n = 573; log-rank test p < 0.001, Figure 1B). Survival outcomes of simultaneous lung-kidney transplantation were comparable to outcomes of sequential lung and kidney transplantation (n = 103; log-rank test p = 0.24).

Conclusion: Kidney transplantation may improve survival outcomes for lung transplant recipients with CKD stage 3b-5 at the time of lung transplant waitlisting and for lung transplant recipients who require RRT immediately after lung transplantation.

Identify the source of the funding for this research project: None