Clinical effects of amyloid positivity upon positron emission tomography in an Asian cohort with Alzheimer’s disease and other dementias.

Background: Ethnic differences in amyloid‐β (Aβ) characteristics and cognitive trajectories should be considered, when designing Aβ‐targeted therapies. The clinical effects of co‐pathologies of Aβ have not been evaluated extensively across various dementias. We investigated the prevalence of Aβ+ and cognitive trajectories in Koreans and non‐Hispanic whites (NHWs) with Alzheimer’s clinical syndrome (ACS) and the clinical effects of Aβ+ in other dementias.

Association between focal amyloid deposition and cognitive impairment in individuals below the amyloid threshold.

Purpose: This study aimed to investigate the characteristics of individuals with amyloid levels below the threshold. To achieve this, we differentiated between two groups: those with global amyloid negativity but focal deposition [G(-)F(+)] and those without focal deposition [G(-)F(-)].

Materials And Methods: A total of 2,677 participants were diagnosed with cognitive unimpairment (CU) or mild cognitive impairment (MCI).

Plasma Alzheimer's disease biomarker variability: Amyloid-independent and amyloid-dependent factors.

Introduction: We aimed to investigate which factors affect plasma biomarker levels via amyloid beta (Aβ)-independent or Aβ-dependent effects and improve the predictive performance of these biomarkers for Aβ positivity on positron emission tomography (PET).

Methods: A total of 2935 participants underwent blood sampling for measurements of plasma Aβ42/40 ratio, phosphorylated tau 217 (p-tau217; ALZpath), glial fibrillary acidic protein (GFAP), and neurofilament light chain (NfL) levels using single-molecule array and Aβ PET. Laboratory findings were collected using a routine blood test battery.

Distinct effects of blood pressure parameters on Alzheimer's and vascular markers in 1,952 Asian individuals without dementia.

Background: Risk factors for cardiovascular disease, including elevated blood pressure, are known to increase risk of Alzheimer's disease. There has been increasing awareness of the relationship between long-term blood pressure (BP) patterns and their effects on the brain. We aimed to investigate the association of repeated BP measurements with Alzheimer's and vascular disease markers.

Prediction of Amyloid Positivity in Patients with Subcortical Vascular Cognitive Impairment.

Background: Amyloid-β (Aβ) commonly coexists and impacts prognosis in subcortical vascular cognitive impairment (SVCI).

Objective: This study aimed to examine the differences in clinical and neuroimaging variables between Aβ-positive and Aβ-negative SVCI and to propose a prediction model for Aβ positivity in clinically diagnosed SVCI patients.

Methods: A total of 130 patients with SVCI were included in model development, and a separate cohort of 70 SVCI patients was used in external validation.

Clinical and Pathological Validation of CT-Based Regional Harmonization Methods of Amyloid PET.

Purpose: The CT-based regional direct comparison Centiloid (dcCL) method was developed to harmonize and quantify regional β-amyloid (Aβ) burden. In the present study, we aimed to investigate correlations between the CT-based regional dcCL scales and Aβ pathological burdens and to validate the clinical utility using thresholds derived from pathological assessment.

Patients And Methods: We included a pathological cohort of 63 cases and a clinical cohort of 4062 participants, and obtained modified Consortium to Establish a Registry for Alzheimer's Disease criteria (mCERAD) scores by assessment of neuritic plaque burdens in multiple areas of each cortical region.

Distinct effects of cholesterol profile components on amyloid and vascular burdens.

Background: Cholesterol plays important roles in β-amyloid (Aβ) metabolism and atherosclerosis. However, the relationships of plasma cholesterol levels with Aβ and cerebral small vessel disease (CSVD) burdens are not fully understood in Asians. Herein, we investigated the relationships between plasma cholesterol profile components and Aβ and CSVD burdens in a large, non-demented Korean cohort.

Clinical effects of novel susceptibility genes for beta-amyloid: a gene-based association study in the Korean population.

Amyloid-beta (Aβ) is a pathological hallmark of Alzheimer's disease (AD). We aimed to identify genes related to Aβ uptake in the Korean population and investigate the effects of these novel genes on clinical outcomes, including neurodegeneration and cognitive impairments. We recruited a total of 759 Korean participants who underwent neuropsychological tests, brain magnetic resonance imaging, F-flutemetamol positron emission tomography, and microarray genotyping data.

Development and clinical validation of CT-based regional modified Centiloid method for amyloid PET.

Background: The standard Centiloid (CL) method was proposed to harmonize and quantify global F-labeled amyloid beta (Aβ) PET ligands using MRI as an anatomical reference. However, there is need for harmonizing and quantifying regional Aβ uptakes between ligands using CT as an anatomical reference. In the present study, we developed and validated a CT-based regional direct comparison of F-florbetaben (FBB) and F-flutemetamol (FMM) Centiloid (rdcCL).