33 - Cognitive deficits may not fully resolve following pediatric kidney transplantation
Saturday, April 23, 2022
3:30 PM – 6:00 PM US MT
Poster Number: 33 Publication Number: 33.235
Olivia Lullmann, University of Iowa Stead Family Children's Hospital, Iowa City, IA, United States; Amy L. Conrad, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA, United States; Tammy Wilgenbusch, University of Iowa Stead Family Children's Hospital, Iowa City, IA, United States; Ellen van der Plas, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA, United States; Lyndsay Harshman, University of Iowa Stead Family Children's Hospital, Iowa City, IA, United States
Undergraduate Research Assistant University of Iowa Stead Family Children's Hospital Iowa City, Iowa, United States
Background: Pediatric chronic kidney disease (CKD) patients are at risk for cognitive deficits. These deficits are observed prior to dialysis and may worsen with disease duration and severity. Cognitive deficits are generally thought to improve after kidney transplantation; however, published data shows conflicting results.
Objective: Assess cognitive performance in relation to kidney transplantation and CKD-specific medical variables.
Design/Methods: This was a retrospective review of clinical data on pediatric kidney transplant patients who completed pre- and/or post-transplant cognitive testing at the University of Iowa from 2015-2021. Developmentally appropriate evaluations were performed with full-scale intelligence (FSIQ) and sub-domains as variables of interest. Outcomes were expressed as Z-scores. Mixed linear models with random effects were used to estimate the impact of transplant status across the sample. Mixed models specific to the post-transplant group explored transplant-specific risk factors for cognitive deficits.
Results: 38 patients (84% of potentially eligible pool) provided 50 observations: 10 individuals had pre- and post-transplant cognitive assessments, 11 had pre-transplant assessment only, and 17 had post-transplant data only. 66% of participants was male, congenital kidney anomalies was the primary etiology (48% of sample), and 30% required dialysis prior to transplantation. The median age at kidney transplant was 110 months (range:12.0-218). Patients scored significantly lower than the normative mean across all cognitive measures and time points (Figure 1). Post-transplant status was associated with significantly lower full-scale IQ and slower processing speed (estimate=-0.32, 95% confidence interval [CI]=-0.52:-0.12; estimate=-0.86, CI=-1.17:-0.55, respectively). Post-hoc analyses within a subsample who had repeated measures supported the findings across the entire sample (FSIQ change score= -0.34, 95% CI= -0.56:-0.12; processing speed change score=-0.98, CI=-1.28:-0.68). Transplantation at or after 75 months of age was associated with substantially lower FSIQ (estimate=-1.25, 95% CI=-1.94:-0.56).Conclusion(s): There was no improvement of cognitive function following transplant in pediatric patients. Older transplant age is a risk factor for cognitive deficit following transplantation. Our findings highlight the need for further longitudinal studies to understand the non-normalization of cognition following pediatric kidney transplantation. Impact of transplant status on cognitive performance in pediatric patientsZ-scores were plotted across cognitive measures (y-axis) for each group. Means and 95% confidence limits (CI) are shown. The vertical line at Z=0 marks normal performance.