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

Article type: Research Article

Authors: Schwinne, Megan^{a; b} | Alonso, Alvaro^b | Roberts, Blaine R.^c | Hickle, Sabrina^d | Verberk, Inge M.W.^e | Epenge, Emmanuel^{f; g} | Gikelekele, Guy^h | Tsengele, Nathan^{h; i} | Kavugho, Immaculee^j | Mampunza, Samuel^h | Yarasheski, Kevin E.^k | Teunissen, Charlotte E.^e | Stringer, Anthony^d | Levey, Allan^l | Ikanga, Jean^{d; g; *}

Affiliations: [a] Department of Biomedical Informatics, Emory University School of Medicine, Atlanta, GA, USA | [b] Department of Epidemiology, Emory University Rollins School of Public Health, Atlanta, GA, USA | [c] Department of Biochemistry, Department of Neurology, School of Medicine, Emory University, Atlanta, GA, USA | [d] Department of Rehabilitation Medicine, Emory University School of Medicine, Atlanta, GA, USA | [e] Department of Clinical Chemistry, Amsterdam Neuroscience, Neurodegeneration, Neurochemistry Laboratory, Amsterdam University Medical Centers, Vrije Universiteit, Amsterdam, The Netherlands | [f] Department of Psychiatry, School of Medicine, University of Kinshasa and Catholic University of Congo, Kinshasa, Kinshasa I, Democratic Republic of Congo | [g] Protestant University of Congo, Kinshasa, Kinshasa II, Democratic Republic of Congo | [h] Department of Psychiatry, University of Kinshasa, Kinshasa, Kinshasa I, Democratic Republic of Congo | [i] Faculty of Medicine, University of Kikwit, Democratic Republic of Congo | [j] Memory Clinic of Kinshasa, Kinshasa, Kinshasa I, Democratic Republic of Congo | [k] C₂N Diagnostics, Saint Louis, MO, USA | [l] Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA

Correspondence: [*] Correspondence to: Jean N. Ikanga, PhD, Department of Rehabilitation Medicine, Emory University, 1441 Clifton Rd NE, Atlanta, GA 30322, USA. Tel.: +1 404 712 5667; E-mail: [email protected].

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 ɛ4 allele, did not alter these relationships. Conclusions: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.

Keywords: Alzheimer’s disease, amyloid-β protein, biomarkers, blood-based biomarkers, cognitive test, dementia, tau proteins

DOI: 10.3233/JAD-230976

Journal: Journal of Alzheimer's Disease, vol. 97, no. 3, pp. 1353-1363, 2024