Previous reports have suggested that CKD might influence plasma p-tau217 and p-tau181 concentrations determined using immunoassays.2,16 Here we corroborated these findings in cognitively unimpaired participants and 2 independent cohorts of patients with cognitive impairment using the IP-MS approach, which typically offers more accurate and reliable quantification of AD biomarkers in blood.4,7 We found that lower eGFR was associated with increased plasma levels of phosphorylated and unphosphorylated tau peptides that are measured simultaneously in the tau IP-MS assay. Here, MAPT is linked to Alzheimer disease.