Serum p-Tau217 and apolipoprotein E as potential biomarkers for Alzheimer's disease severity: a case-control study
TL;DR
Increased serum p-tau217 and decreased ApoE levels were significantly associated with greater AD severity, suggesting that both biomarkers may serve as complementary noninvasive indicators of disease severity in Alzheimer’s disease.
Abstract
Introduction: Alzheimer's disease (AD) is a chronic neurodegenerative illness characterised by aberrant protein accumulation and progressive cognitive decline. One of the most researched blood indicators of tau pathology is phosphorylated tau 217 (p-tau217), and apolipoprotein E (ApoE) is essential for lipid metabolism, amyloid removal, and neuronal maintenance. The severity of AD may be correlated with changes in these biomarkers. Objective: To compare serum levels of p-tau217 and ApoE in individuals with different severities of Alzheimer's Disease. Methods: The present case–control study consisted of 156 subjects aged between 55 and 85 years:106 patients with ad (and balanced frequency matched to healthy controls on age, international classification of diseases t63 diagnosis). The DSM-5 criteria classified the patients as mild (n = 12), moderate (n = 50), or severe (n = 44). Using the sandwich enzyme-linked immunosorbent assay (ELISA), the levels of circulating ApoE and p-tau217 were determined. The receiver operating characteristics (ROC) curve examination, Spearman's correlation, and the Kruskal-Wallis test were used in the statistical studies. Results: The mean serum p-tau217 and ApoE level were 165 ± 84.2 pg/mL and 75.5 ± 55.6 ng/mL, respectively. While serum p-tau217 significantly increased with severity of disease, ApoE levels decreased. We found a significant positive association of p-tau217 (p<0.001) and a negative association of ApoE (p<0.001) with disease severity by DSM-5 criteria. ROC analysis showed high diagnostic accuracy of CSF p-tau217 (AUC=0.916, sensitivity: 87.18%, specificity: 90.00%) and ApoE (AUC=0.992, sensitivity: 100.00%, specificity:98.00%). Conclusion: Increased serum p-tau217 and decreased ApoE levels were significantly associated with greater AD severity. Both biomarkers may serve as complementary noninvasive indicators of disease severity in Alzheimer’s disease. Objectives: The study objective is to reveal biochemical way to diagnose and know Alzheimer's patients biochemically instead of using traditional Methods that used to diagnosis as an example using: Electroencephalography (EEG), computed tomography (CT), magnetic resonance imaging (MRI) and brain biopsy. Methods: A case control research design was applied to current study, 156 individuals and thy were as follows: 12 with mild symptoms ,50 with moderate,44 with sever progression and 50 apparently as healthy control with an age range of 55 to 85 years were included. Samples were collected in accordance with the consultant's diagnosis; disease severity was categorized according to DSM-5(Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition) staging, which was then demonstrated by laboratory tests. A Human p-tau217 (Phospho Tau 217) Catalogue No.: EH5067 Revision: V4.0 Size: 48T/96T ELISA Kit was used and rang test was (7.813-500pg/ml) which tested by instrument (human reader). Results: The baseline serum biomarkers analysis of whole Study Participants showed that the mean tau level was 165 ± 84.2 pg/mL, Tau levels increased markedly with disease severity, rising from 86.33 ± 34.40 pg/mL in the control group to 265.72 ± 50.91 pg/mL in the severe group. DSM-5 score also showed a strong positive correlation with Tau concentration, suggesting that higher clinical severity was associated with increased Tau levels. Tau showed very strong negative correlations with ApoE, the correlations' findings indicated that this effect size is substantial up to assay. ApoE demonstrated a mean value of 75.5 ± 55.6 ng/mL. of whole Study Participants. ApoE levels showed a pronounced and significant reduction across disease stages, with the lowest mean value observed in the severe group. While DSM-5 score also showed a negative association with ApoE was strong and significant. Conclusion: Serum Tau levels increased markedly with disease severity, indicating that Tau may serve as a reliable marker of progressive neuronal injury and neurodegeneration in Alzheimer’s disease. ApoE levels declined substantially with increasing disease severity and showed the highest diagnostic accuracy among the studied biomarkers, indicating its strong potential as a predictive biomarker for Alzheimer’s disease progression.