Identification of Diagnosis Biomarkers in the Tears of Alzheimer's Disease Patients: The COG-EYE Pilot Study

Regional University Hospital Center (CHRU)

Status: Enrolling

Conditions: Alzheimer Disease

Treatments: Other: Basal tear collection for the analysis of metabo-lipidomic profiles and concentrations of protein biomarkers (Tau, phosphorylated Tau, Aβ 1-40, and Aβ 1-42); Other: Collection of a blood sample (5 mL) for blood biomarkers analysis

Study type: Interventional

Funder types: Other

Identifiers

NCT06661564

DR240140

Details and patient eligibility

About

The diagnosis of Alzheimer's disease (AD) relies on the detection of protein biomarkers, particularly in cerebrospinal fluid (e.g., Aβ and phosphorylated Tau) or through brain imaging. The invasive nature of lumbar puncture and the numerous contraindications have driven the search for early and reliable diagnostic biomarkers for AD.

Human tears are an accessible biological fluid that has proven relevant in the biomarker search strategy for both ophthalmological and systemic diseases, especially neurodegenerative conditions. Advances in methods for low-volume analysis have facilitated the identification of tear biomarkers. Total tau has been reported as elevated in the tears of patients with AD compared to controls (n=65). Additionally, metabo-lipidomic analyses offer several advantages (accessibility, non-invasiveness, reproducibility) and also appear promising as a diagnostic tool for systemic and neurodegenerative diseases, such as amyotrophic lateral sclerosis. This supports the relevance of comparing both AD proteins biomarkers and metabo-lipidomic signatures in the tears of patients with AD (Mild Cognitive Impairement (MCI) and dementia) with healthy controls.

Enrollment: 90 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Age ≥18 years
• Participant affiliated in French Social Security scheme
• Informed and written consent from the participant

Exclusion criteria

• Pregnant or breastfeeding woman
• Participant under judicial protection measures
• Participant under guardianship or curatorship
• Contraindications to participation in the research:

Other neurodegenerative disease Any eye drops or treatment that may interfere with tear production Occasional or permanent contact lens use within the last 3 months Eye surgery ≤3 months Any ocular pathology other than refractive errors, oculomotor disorders, amblyopia Any general pathology other than AD with ocular implications

-Inability to perform tear collection

Trial design

Primary purpose: Diagnostic

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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90 participants in 3 patient groups

Patients with AD dementia

Active Comparator group

Description:

Patient ≥ 18 years old with AD at a major stage according to the 2018 NIA-AA criteria (dementia)

Treatment:

Other: Basal tear collection for the analysis of metabo-lipidomic profiles and concentrations of protein biomarkers (Tau, phosphorylated Tau, Aβ 1-40, and Aβ 1-42)

Patients with AD Mild Cognitive Impaiment (MCI)

Active Comparator group

Description:

Patient ≥ 18 years old with AD at a minor stage according to the 2018 NIA-AA criteria (Mild Cognitive Impairment)

Treatment:

Other: Collection of a blood sample (5 mL) for blood biomarkers analysis

Other: Basal tear collection for the analysis of metabo-lipidomic profiles and concentrations of protein biomarkers (Tau, phosphorylated Tau, Aβ 1-40, and Aβ 1-42)

Healthy controls

Sham Comparator group

Description:

Participants ≥ 18 years old with no known central neurological pathology, no cognitive decline, and matched by age (± 2 years) and sex with a patient from AD-MCI group

Treatment:

Other: Basal tear collection for the analysis of metabo-lipidomic profiles and concentrations of protein biomarkers (Tau, phosphorylated Tau, Aβ 1-40, and Aβ 1-42)