The Association of Alzheimer’s Disease-related Blood-based Biomarkers with Cognitive Screening Test Performance in the Congolese Population in Kinshasa

• Authors: Megan Schwinne, Emory University; Alvaro Alonso, Emory University; Blaine Russell Roberts, Emory University; Sabrina Hickle, Emory University; Inge MW Verberk, Amsterdam University; Emmanuel Epenge, University of Kinshasa; Guy Gikelekele, University of Kinshasa; Nathan Tsengele, University of Kinshasa; Immaculee Kavugho, Memory Clinic of Kinshasa; Samuel Mampunza, University of Kinshasa; Kevin E. Yarasheski, C2N Diagnostics; Charlotte E. Teunissen, Amsterdam University; Anthony Stringer, Emory University; Allan I Levey, Emory University; Jean N. Ikanga, Emory University
• Journal Title: medRxiv
• Publisher: NIH | 2023-08-31
• Type of Work: Article | Preprint: Prior to Peer Review
• Publisher DOI: http://doi.org/10.1101/2023.08.28.23294740
• Subjects: Health Sciences, Public Health
• Keywords: Alzheimer's disease; amyloid-beta protein; biomarkers; blood-based biomarkers; cognitive test; dementia; tau proteins

Abstract

Background: Alzheimer’s Disease (AD), the most common cause of dementia, poses a significant global burden. Diagnosis typically involves invasive and costly methods like neuroimaging or cerebrospinal fluid (CSF) biomarker testing of phosphorylated tau (p-tau) and amyloid-β42/40 (Aβ42/40). Such procedures are especially impractical in resource-constrained regions, such as the Democratic Republic of Congo (DRC). Blood-based biomarker testing may provide a more accessible screening opportunity. Objective: This study aims to examine if AD-related blood-based biomarkers are associated with cognitive test performance in the Congolese population, where limited research has been conducted. Methods: In this cross-sectional study of 81 Congolese individuals, cognitive assessments (Alzheimer’s Questionnaire (AQ) and Community Screening Interview for Dementia (CSID)) distinguished dementia cases from controls. Blood draws were taken to assess p-tau 181 and Aβ42/40 biomarkers. Relationships between the biomarkers and cognitive performance were analyzed using multiple linear regression models. Results: Lower plasma Aβ42/40 was significantly associated with lower CSID scores and higher AQ scores, indicative of AD (p<0.001). These relationships were observed in healthy controls (CSID p=0.01, AQ p=0.03), but not in dementia cases. However, p-tau 181 did not exhibit significant associations with either measure. Factors such as age, sex, education, presence of APOE e4 allele, did not alter these relationships. Conclusion: Understanding relationships between AD-related screening tests and blood-biomarkers is a step towards utilization of blood-based biomarker tests as a screening tool for AD, especially in resource-limited regions. Further research should be conducted to evaluate blood biomarker test efficacy in larger samples and other populations.