Plasma Levels of Amyloid-β Peptides and Tau Protein in Mexican Patients with Alzheimer’s Disease

Issue title: Translational Research and Drug Discovery for Neurodegeneration: Challenges for Latin America

Guest editors: K.S. Jagannatha Rao, Gabrielle B. Britton, Luisa Lilia Rocha Arrieta, Norberto Garcia-Cairasco, Alberto Lazarowski, Adrián Palacios, Antoni Camins Espuny and Ricardo B. Maccioni

Article type: Research Article

Authors: Castillo-Mendieta, Tzayaka^{a; b} | Arana-Lechuga, Yoaly^c | Campos-Peña, Victoria^d | Sosa, Ana Luisa^e | Orozco-Suarez, Sandra^f | Pinto-Almazán, Rodolfo^g | Segura-Uribe, Julia^h | Javier Rodríguez-Sánchez de Tagle, Aldo^{a; i} | Ruiz-Sánchez, Elizabeth^j | Guerra-Araiza, Christian^{a; *}

Affiliations: [a] Unidad de Investigación Médica en Farmacología, Hospital de Especialidades Bernardo Sepúlveda, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico | [b] Doctorado en Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana, Mexico City, Mexico | [c] Sleep Disorders Clinic, Universidad Autónoma Metropolitana-Iztapalapa, Mexico City, Mexico | [d] Laboratorio Experimental de Enfermedades Neurodegenerativas, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, Mexico City, Mexico | [e] Clínica de Demencia, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, Mexico City, Mexico | [f] Unidad de Investigación Médica en Enfermedades Neurológicas, Hospital de Especialidades Bernardo Sepúlveda, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico | [g] Laboratorio de Biología Molecular en Enfermedades Metabólicas y Neurodegenerativas, Unidad de Investigación, Hospital Regional de Alta Especialidad de Ixtapaluca, Ixtapaluca, State of Mexico, Mexico | [h] Subdirección de Gestión de la Investigación, Hospital Infantil de México Federico Gómez, Secretaría de Salud, Mexico City, Mexico | [i] Coordinación de QFBT, Universidad del Valle de México-Chapultepec, México City, México | [j] Laboratorio de Neurotoxicología, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, Mexico City, Mexico

Correspondence: [*] Correspondence to: Christian Guerra-Araiza, Unidad de Investigación Médica en Enfermedades Neurológicas, Hospital de Especialidades, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Av. Cuauhtémoc 330, Doctores, Cuauhtémoc, 06720, Mexico City, Mexico. Tel.: +52 1 55 56 27 69 00; E-mail: [email protected].

Abstract: Background:Alzheimer’s disease (AD) causes memory deficit and alterations in other cognitive functions, mainly in adults over 60 years of age. As the diagnosis confirmation is performed by a postmortem neuropathological examination of the brain, this disease can be confused with other types of dementia at early stages. About 860,000 Mexicans are affected by dementia, most of them with insufficient access to adequate comprehensive health care services. Plasma biomarkers could be a rapid option for early diagnosis of the disease. Objective:This study aimed to analyze some plasma biomarkers (amyloid-β, tau, and lipids) in Mexican AD patients and control subjects with no associated neurodegenerative diseases. Methods:Plasma amyloid-β peptides (Aβ40 and Aβ42), total and phosphorylated tau protein (T-tau and P-tau), and cholesterol and triglyceride levels were quantified by enzyme-linked immunosorbent assay in AD patients and control subjects. Results:In Mexican AD patients, we found significantly lower levels of Aβ42 (p < 0.05) compared to the control group. In contrast, significantly higher levels of P-tau (p < 0.05) and triglycerides (p < 0.05) were observed in AD patients compared to controls. Furthermore, a significant correlation was found between the severity of dementia and plasma P-tau levels, Aβ42/Aβ40 and P-tau/T-tau ratios, and triglycerides concentrations. This correlation increased gradually with cognitive decline. Conclusion:The detection of these plasma biomarkers is an initial step in searching for a timely, less invasive, and cost-efficient diagnosis in Mexicans.

Keywords: Alzheimer’s disease, amyloid-β, early diagnosis, Mexican patients, tau protein

DOI: 10.3233/JAD-200912

Journal: Journal of Alzheimer's Disease, vol. 82, no. s1, pp. S271-S281, 2021