Long-term cognitive effects of kidney transplantation

A.L. Ziengs, S.J.L. Bakker, A.M. Buunk, M.F. Eisenga, A.W. Gomes Neto, J.H. Annema - de Jong, J.M. Spikman

Friday 16 march 2018

14:50 - 15:00h at Willem Burger Zaal

Categories: Clinical, Session (parallel)

Parallel session: Parallel session 18: Clinical

Objective

Patients with end-stage renal disease (ESRD) depend on kidney transplantation to increase survival chance. Although patients’ health condition often improves after transplantation, many renal recipients still experience cognitive impairments such as memory-loss and deficits in attention and concentration. However, it is yet unknown whether cognitive impairments in renal recipients remain chronic over time and to what extent they affect daily life functioning. Therefore, the aim of the present study is to investigate cognitive functioning in renal transplant recipients (RTR) and their impact on participation several years after transplantation.

Method

This study was conducted in the TransplantLines Biobank & Cohort Study. We included 115 RTR, as well as 55 matched healthy controls. RTR and controls were assessed with neuropsychological tests measuring executive functioning (Trail Making Test B, Dutch version of the Controlled Word Association Test, Semantic Fluency), attention (Symbol Digit Modalities Test, Trail Making Test A) and memory (Wechsler Adult Intelligence Scale subtest Digit Span, Rey Auditory Verbal Learning Test), and a questionnaire examining daily life participation (Utrecht Scale for Evaluation of Rehabilitation – Participation).

Results

Mean time after transplantation was 10.7±8.5 years. Our results show that RTR performed significantly worse on tasks for executive functioning, attention, processing speed, verbal fluency & memory, compared to controls. Time after transplantation was significantly correlated to poor performance on the test for processing speed (Trail Making Test A; r = .20, p < .03) and to poor performance on the test for mental flexibility (Trail Making Test B; r = .23, p < .02). Also, participation was significantly inversely correlated to poor performance on the test for processing speed (Trail Making Test A; r = - .336, p < .002) and poor performance on the test for mental flexibility (Trail Making Test B; r = -.236, p < .034).

Conclusion

This study shows cognitive deficits in multiple domains in RTR several years after transplantation, in particular regarding executive functioning. Based on correlations with time after transplantation we conclude that cognitive deficits post-transplant are persistent and there is limited recovery over time. Consequently, neuropsychological tests should be used in clinical practice to improve the detection and treatment of cognitive deficits after kidney transplantation.