Changes in Alzheimer's disease blood biomarkers in kidney failure before and after kidney transplant

Abstract INTRODUCTION Alzheimer's disease (AD) blood biomarkers show promise for clinical diagnosis but their reliability in chronic kidney disease (CKD) is debated. This study investigates the impact of kidney transplant (KT) on AD biomarkers in CKD. METHODS We assessed AD biomarkers in 46 CKD patients pre‐KT, at 12 weeks and 12 months post‐KT, with baseline measures from 13 non‐CKD controls. Using linear mixed models, we examined associations with participant groups, estimated glomerular filtration rate (eGFR) and cognition. RESULTS CKD patients showed elevated levels of neurofilament light (117 ± 72 vs. 11 ± 5 pg/mL), phosphorylated tau 181 (75 ± 42 vs. 13 ± 8 pg/mL), glial fibrillary acidic protein (193 ± 127 vs. 94 ± 39 pg/mL), amyloid β 42 (17 ± 5 vs. 5 ± 1 pg/mL), and amyloid β 40 (259 ± 96 vs. 72 ± 17 pg/mL) compared to controls. Post‐KT, biomarker levels approached normal with improved eGFR, paralleled by enhanced cognitive function. DISCUSSION AD blood biomarker elevations in CKD are reversible with improved kidney function through KT. Highlights AD biomarker levels are extremely high in severe CKD. AD biomarker levels are higher in patients with kidney failure on dialysis when compared to CKD patients not on dialysis. These elevations in AD biomarker levels in kidney failure are reversable and decrease dramatically after kidney transplantation. The change in biomarker levels after transplantation align with changes in kidney function. The change in biomarker levels after transplantation align with changes in cognitive function.