An innocent bystander or a predisposing culprit? Kidney injury following pediatric liver transplantation.

Background: Survival after pediatric liver transplantation has increased dramatically over the years, revealing extra-hepatic complications including impaired kidney function. We conducted a large single-center retrospective study to evaluate kidney outcomes after pediatric liver transplantation.

Methods: From electronic charts of 121 children who underwent liver transplantation during 2007-2020, we collected pre- and post-transplant data. We investigated the presence of post-transplant permanent kidney injury, including proteinuria, hypertension, and decreased estimated glomerular filtration rate (eGFR). We excluded children who died, underwent liver-kidney transplantation, or had less than 1 year of follow-up.

Results: During a median follow-up of 5.1 (interquartile range 2.9-7.3) years, eGFR decreased, mostly in the first year post-transplant. In addition, 41% of the children presented with acute kidney injury. At their last follow-up, 35% showed permanent kidney injury (hypertension 13%, proteinuria 36%, and eGFR < 90 mL/min per 1.73 m² 7%). Kidney ultrasounds were abnormal for 44% of the children at the last visit, compared to 11% before transplant (p < 0.001). In multivariate analysis, abnormal kidney ultrasound before transplant (odds ratio = 4.53, 95% CI 1.1-18.7) and liver disease with potential risk of primary kidney involvement (odds ratio = 4.77, 95% CI 1.58-14.4) were predictors for hypertension or decreased eGFR at the last follow-up.

Conclusions: The high prevalence of kidney injury after pediatric liver transplantation and the pretransplant predictors for kidney injury highlight the importance of a thorough kidney pretransplant evaluation and follow-up.