BASIMA MUHAMMED
HAMZA AL.DUHAIMI
Hala Hammadi
Ameer B. Ali
Abstract :
Background:
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that leads to cognitive decline, dementia, and ultimately death. The neuropathological features such as amyloid-β (Aβ) plaques and phosphorylated tau (p-Tau) tangles. Blood based biomarkers of Aβ and p-Tau have emerged as promising tools for early diagnosis, monitoring, and risk stratification of AD.
Objective: This study aims to assess the role of blood-based amyloid-beta and phosphorylated tau biomarkers in monitoring Alzheimer’s disease progression and enhancing risk stratification among individuals
Martials& method: A study ′s case – control was conducted at Marjan Medical City from April 2025-March 2026.A total of 100 blood samples were obtained from individuals with age ≥ 60 years (male 40,Female 60) .They are seeing a neurologist, including 25 classified as healthy controls(non-carriers APOE ε4) (10M,15 F) and 75 diagnosed with Alzheimer’s disease(APOE ε4 carriers) through PCR analysis.. Aβ1-42, Aβ1-40, p-Tau181, and p-Tau217 were measured by ELISA using commercial kits: Elabscience E-EL-H0543 for Aβ1-42, Elabscience E-EL-H0542 for Aβ1-40, Abcam ab325078 for p-Tau181, and Abcam ab318936 for p-Tau217. The Aβ42/Aβ40 ratio was calculated by dividing Aβ1-42 by Aβ1-40. absorbance was measured with a Fisher Scientific ELISA plate reader.
Results: Conventional PCR analysis of 100 blood samples showed that 75 samples (75%) were positive for the APOE ε4 allele and were classified as APOE ε4 carriers, whereas 25 samples (25%) were negative and classified as non-carriers. ELISA analysis demonstrated significantly lower Aβ1-42 levels in Alzheimer’s disease patients (4.02 ± 8.031 pg/mL) compared with controls (9.07 ± 10.43 pg/mL) (p < 0.05). Similarly, Aβ1-40 levels were significantly reduced in Alzheimer’s disease patients (3.03 ± 6.01 pg/mL) compared with controls (7.08 ± 9.05 pg/mL) (p < 0.05).An Aβ42/Aβ40 ratio below 0.077 was considered amyloid-positive. And higher levels of p-Tau181 (4404.1 ± 5053 pg/mL) and p-Tau217 (44.02 ± 63.1 pg/mL) compare control(198.04±221,09),(20.12± 28.33)respectively, were observed. The results showed statistically significant differences between Alzheimer’s disease patients and controls (p < 0.05).
Conclusion:
The biomarker levels were significantly associated with Alzheimer’s disease. These findings suggest that combining APOE ε4 detection by PCR with ELISA-based blood biomarkers may support Alzheimer’s disease risk assessment and differentiation from healthy controls.