Attitudes of Swedish primary care physicians toward GLP-1 receptor agonists for overweight and obesity: a cross-sectional survey.

Amyloid beta (Aβ) pathology biomarkers are often classified in a binary manner, typically based on a threshold at which abnormality can be reliably detected. However, quantifying the severity of Aβ accumulation in a continuous manner provides additional clinically relevant information., , For instance, amyloid positron emission tomography (PET) staging is increasingly used to guide inclusion criteria in clinical trials., Continuous values also enable more precise monitoring of disease progression over time, which is particularly valuable in both observational studies and interventional trials. However, PET imaging is costly and not widely available, which limits its use in large‐scale or repeated assessments. Conventional phosphorylated tau (p‐tau) 217, measured in both cerebrospinal fluid (CSF) and plasma, reliably identifies individuals with abnormal Aβ, particularly among cognitively impaired (CI) participants, confirming its value as a biomarker for binary classification., , , , , However, limited evidence shows that it captures the full continuum of Aβ accumulation measured by PET Centiloids (CL),, highlighting the need for more precise characterization of p‐tau217 performance across the Aβ continuum, and for biomarkers that may further improve staging across its full spectrum. Moreover, comparing CSF and plasma performance is important to determine whether minimally invasive plasma measures can approximate CSF‐derived signals while maintaining accuracy across disease stages. Recently, brain‐derived (BD) p‐tau assays have been developed to improve specificity for AD‐related pathology by enriching for tau species originating from the central nervous system. These assays reduce potential confounding from peripheral sources of tau and, when combined with ultrasensitive proteomic platforms, allow precise measurement of low‐abundance central nervous system (CNS)‐relevant proteins in both plasma and CSF., BD p‐tau217 has shown promise in predicting amyloid PET positivity and may offer a minimally invasive approach to estimate Aβ accumulation. In addition, comparing BD p‐tau217 to conventional p‐tau217 enables assessment of whether CNS‐enriched signal improves prediction performance. In this study, we evaluated the ability of CSF and plasma BD p‐tau217 to reflect Aβ accumulation across the full continuum of PET CL values.