Correlation between Cerebrospinal Fluid Core Alzheimer's Disease Biomarkers and β-Amyloid PET in Chinese Dementia Population

The current diagnoses of Alzheimer's disease (AD) mainly rely on such measures as amyloid-β (Aβ) and tau neuropathology biomarkers in vivo via cerebrospinal fluid (CSF) and positron emission tomography (PET) imaging, which had been systematically studied in Caucasian individuals, whereas diagnostic performances of these approaches in Chinese dementia population still remain unclear. This study investigated the associations between the levels of CSF core AD biomarkers, including phosphorylated tau (p-Tau181), total tau (t-Tau), Aβ42, and Aβ40 measured by the single-molecule array (Simoa) and cerebral Aβ deposition status assessed by ¹⁸F-Florbetapir PET (Aβ PET), and evaluated the predictive values of CSF core AD biomarkers in discriminating Aβ PET status in a clinical dementia cohort of the Chinese population, which consisted of patients with mild cognitive impairment (MCI), AD dementia, and non-Alzheimer's dementia disease (Non-ADD). Global standard uptake value ratios (SUVRs) were calculated by Aβ PET, which was divided into positive (Aβ+) and negative (Aβ-) through visual analysis. CSF p-Tau181 and p-Tau181/t-Tau ratio were positively correlated with the global SUVR, while CSF Aβ42 and Aβ42/Aβ40 ratio were negatively correlated with the global SUVR. CSF Aβ40 has the highest predictive value in discriminating the MCI group from the AD group, while CSF p-Tau181 was applied to discriminate the AD group from the non-ADD group. CSF Aβ42/Aβ40 ratio, as the optimal predictive factor, was combined with APOE ε4 status rather than age and education, which could improve the predictive ability in differentiating the Aβ+ group from the Aβ- group. The results reveal the universal applicability of CSF core AD biomarkers and Aβ PET imaging in Chinese dementia population, which is helpful in clinical practice and drug trials in China.