Intro: Kidney Transplant Recipients (KTRs) taking calcineurin inhibitors (CNIs) can experience varying drug toxicities. Less well studied compared to the metabolic consequences, many patients report neurocognitive impairment with tacrolimus. Disturbances in short-term memory (STM), calculation difficulty, and word finding, among others, have been attributed to the CNIs. And while these symptoms can be profound in some cases, they are likely to manifest more subtly in others. Belatacept (Bela) is unlikely to significantly cross the blood brain barrier. Therefore, we hypothesized that patients converted from CNIs to bela experienced less neurotoxicity.

Traditional methods to quantify changes in neurocognition involve testing that is time intensive, and require a specialist trained in the performance of cognitive assessments. However, simpler assessments have been designed for use as screening tools by providers in the office setting. Our pre-study data indicated that the Mini-Mental State Examination (MMSE) lacked sufficient granularity to test our hypothesis (all patients scored high). Therefore, we selected the NIH Toolbox Cognition Battery (NIHT-CB), a more detailed measure of neurocognition that has been normalized to the general population.

We report our preliminary results on cognition after bela conversion utilizing the NIHT-CB. And, we compare these with those obtained using the Montreal Cognitive Assessment (MoCA), which has been validated in the setting of mild cognitive impairment.

Methods: KTRs who met indications for conversion to bela were studied. During their monthly bela infusion, they were evaluated using the MoCA followed by the NIHT-CB administered on an iPad. Patients with history of dementia, concomitant use of sedative medications, and language barriers were excluded. Charts were reviewed for potential confounders.

Results: We assessed 33 patients converted to bela. The composite results of the NIHT-CB did not strongly correlate with the MoCA (R² = 0.303). However, patients who reported STM loss did score lower on the NIHT-CB Flanker Inhibitory Control and Attention Test compared to patients converted for another indication (p = 0.02), a finding not detected by the MoCA.

Conclusions: The NIHT-CB may be able to substantiate STM loss in KTRs, while the MoCA has limitations assessing neurocognition in a domain specific manner. Our preliminary data confirm that KTRs experiencing STM impairment on CNIs score lower on neurocognitive assessment than patients on bela, as well controls in the general population after full adjustment.

CITATION INFORMATION: Ogbejesi C., Cohen E., Belfield K., Asch W. Cognition after Belatacept Conversion Am J Transplant. 2017;17 (suppl 3).

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