Impact of vesicoureteral reflux post pediatric kidney transplant: A pediatric nephrology research consortium study
Namrata G Jain1, Elizabeth Benoit2, Rachel Engen3, Caitlin Peterson4, George Moran5, Benjamin Steinman6, Clare Lindner7, Saritha Ranabothu8, Asha Moudgil9, Michael Seifert10, Amrish Jain11, Samhar Al-Akash12, Julia Finkelstein13, Michael JG Somers3.
1Pediatrics, Hackensack University Medical Center , Hackensack, NJ, United States; 2Pediatrics, Boston Children's Hospital, Boston, MA, United States; 3Pediatrics, University of Wisconsin, Madison, Madison, WI, United States; 4Pediatrics, University of Utah, Salt Lake City, UT, United States; 5Urology, Columbia University Medical Center, New York, NY, United States; 6Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ, United States; 7Pediatrics, University of Michigan, Ann Arbor, MI, United States; 8Pediatrics, Arkansas Children's Hospital, Little Rock, AR, United States; 9Pediatrics, Children's National Medical Center, Washington , DC, United States; 10Pediatrics, Children's Hospital of Alabama, Birmingham, AL, United States; 11Pediatrics , Children's Hospital of Michigan, Detroit, MI, United States; 12Pediatrics, University of Texas Health Science Center at Houston, Houston, TX, United States; 13Pediatric Urology, Boston Children's Hospital, Boston, MA, United States
Pediatric Nephrology Research Consortium.
Purpose: Evaluate pediatric kidney allograft outcomes in the setting of asymptomatic or symptomatic vesicoureteral reflux (VUR) after transplant (Tx).
Methods: IRB approved study inclusive of 12 participating centers of the Pediatric Nephrology Research Consortium. Children up to 18 years old, receiving 1st transplants between 2014-2023, with post-transplant VUR on diagnostic imaging, were retrospectively reviewed and placed into two cohorts: Group 1, those with “normal” bladders pre-Tx, and Group 2, those with “abnormal” bladders pre-Tx. Estimated Glomerular Filtration Rate (eGFR), via the modified Schwartz equation, at 1 and 3 years post-Tx served as the primary outcome. Analysis was performed by paired t-tests and logistic regression.
Results: 86 children in total, 43 in Group 1 (51% boys), and 43 in Group 2 (86% boys; 74% congenital kidney and urinary tract anomalies). 98% had full 3 year follow up data. Overall, 41% had history of urinary tract infections (UTIs) pre-Tx, with 60% undergoing voiding cystourethrogram (VCUG) pre-Tx. At Tx, 57% had a non-refluxing extra-vesicle ureteral anastomosis, with 57% performed by pediatric urologists. Post-Tx, 49% had hydronephrosis within 1 year. Time to UTI was 3.5 months, with average 1.8 UTIs by 1 year. Group 2 had UTIs sooner (3.1 vs 3.5 months, p<0.001) and more often (2.5 vs 1, p<0.001). Logistic regression demonstrated that post-Tx Group 2 were more likely to have hydronephrosis and UTI, but less likely to have ureteral anastomosis done by pediatric urologists (see Table). Overall eGFR decreased from 114 mL/min1.73m2 at hospital discharge post-Tx to 84 and 72 at 1 and 3 years post Tx. Group 2 eGFRs were significantly lower at 1 and 3 years vs Group 1 (81 vs 86 (p<0.001)) at 1 year; 69 vs 74 (p<0.001) at 3 years.
Conclusions: VUR post-pediatric kidney Tx is common and manifested by hydronephrosis and UTI in the first post-Tx year. Children with pre-Tx abnormal bladders are more likely to have VUR, hydronephrosis, and UTI both pre- and post-Tx; they demonstrated more rapid decline in eGFR by 1 year post-Tx, and this persisted. Tx care in these children needs to be improved to mitigate post-Tx allograft injury.