Department of Nephrology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
Department of Medical Psychology, Radboud University Medical Center, Nijmegen, The Netherlands.
Kidney360. 2020 Sep 21;1(12):1398-1406. doi: 10.34067/KID.0000272020. eCollection 2020 Dec 31.
Cognitive functions are altered in patients with CKD. However, it is suggested that cognitive functions improve after kidney transplantation, at least partially. A possible cause for this improvement could be the reduction of uremic retention solutes after transplantation. This study assessed the association between the changes in uremic toxin concentration with the changes in cognitive function in patients after kidney transplantation.
Ten recipients of kidney transplants were compared with 18 controls (nine patients on hemodialysis, and nine patients with CKD stage 4 or 5 [eGFR <30 ml/min per 1.73 m] who were not on dialysis). An extensive neuropsychological assessment, covering the five major cognitive domains (, memory, attention and concentration, information processing speed, abstract reasoning, and executive function), was done before transplantation, at 1 week post-transplant, and 3 months after transplantation. Similarly, assessments of the 18 matched, control patients were performed longitudinally over a period of 3-5 months. Concentrations of 16 uremic retention solutes (indoxyl glucuronide, -cresyl glucuronide, phenylglucuronide, 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid, indoxyl sulfate, -cresyl sulfate, hippuric acid, phenyl sulfate, kynurenine, tryptophan, kynurenic acid, tyrosine, indole-3-acetic acid, phenylalanine, trimethylamine -oxide, and phenylacetylglutamine) were measured in serum samples collected at the time of the neuropsychological assessments.
A significant improvement in cognitive function was only found in the processing-speed domain, and this was observed in both patients who received a transplant and patients with CKD. No significant differences between patients who received a transplant and the control groups were seen in the other cognitive domains. As expected, the serum concentration of most uremic toxins decreased significantly within 1 week after kidney transplantation.
There was no significant improvement in cognitive function that could be specifically related to kidney transplantation in the first 3 months after the procedure. These data do not support the notion that uremic toxins exert an immediate effect on cognitive function.
慢性肾脏病（CKD）患者的认知功能会发生改变。然而，有研究表明，在接受肾移植后，认知功能至少会部分改善。这种改善的一个可能原因是移植后尿毒症毒素的潴留减少。本研究评估了肾移植患者的尿毒症毒素浓度变化与认知功能变化之间的关系。
比较了 10 名肾移植受者与 18 名对照组患者（9 名血液透析患者和 9 名未透析的 CKD 4 或 5 期[eGFR<30 ml/min/1.73 m]患者）。在移植前、移植后 1 周和 3 个月进行了广泛的神经心理学评估，涵盖了五个主要的认知领域（记忆、注意力和集中力、信息处理速度、抽象推理和执行功能）。同样，对 18 名匹配的对照组患者进行了纵向评估，评估时间为 3-5 个月。在神经心理学评估时采集血清样本，检测 16 种尿毒症毒素（马尿酸、对甲酚硫酸盐、苯乙酰谷氨酰胺、吲哚乙酸、吲哚硫酸、苯磺酸、对羟苯乙酸、苯丙氨酸、3-羧基-4-甲基-5-丙基-2-呋喃丙酸、色氨酸、酪氨酸、-羟色氨酸、犬尿氨酸、吲哚-3-乙酸、-甲酚葡萄糖醛酸苷、苯葡萄糖醛酸苷）的浓度。
仅在处理速度域发现认知功能有显著改善，而且这种改善既发生在接受移植的患者中，也发生在 CKD 患者中。在其他认知领域，移植患者与对照组患者之间没有显著差异。正如预期的那样，肾移植后 1 周内大多数尿毒症毒素的血清浓度显著下降。
在手术后的前 3 个月，没有发现与肾移植相关的认知功能的显著改善。这些数据不支持尿毒症毒素对认知功能有直接影响的观点。
