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

Summary

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.

Interventions

• 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 tear volume of (i) 2 x 5µL using glass microcapillary tubes and (ii) 12µL using Schirmer strips after the instillation of anesthetic eye drops for metabo-lipidomic analysis and multiplexing of protein markers

• Collection of a blood sample (5 mL) for blood biomarkers analysis · OTHER

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

Published eligibility criteria

Verbatim from the registry. Only the site can decide how these apply to a specific patient.

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

Sites (1)

• CHRU de Tours, Tours, France, France · RECRUITING