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

Not Applicable
Not yet recruiting
Conditions
Alzheimer Disease
Registration Number
NCT06661564
Lead Sponsor
University Hospital, Tours
Brief 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.

Detailed Description

Not available

Recruitment & Eligibility

Status
NOT_YET_RECRUITING
Sex
All
Target Recruitment
90
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

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Primary Outcome Measures
NameTimeMethod
Concentration of total Tau proteins in basal tears of patients with AD vs healthy volunteersAt inclusion

12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

Concentration of phosphorylated Tau proteins in basal tears of patients with AD vs healthy volunteersAt inclusion

12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

Concentration of Amyloid β 1-40 proteins in basal tears of patients with AD vs healthy volunteersAt inclusion

12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

Concentration of Amyloid β 1-42 in basal tears of patients with AD vs healthy volunteersAt inclusion

12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

Lipids in basal tears of patients with AD vs healthy volunteersAt inclusion

Collection of tears (5μL) using a glass micropipette without local anaesthetic. Lipids in tears of patients with AD vs healthy volunteers

Metabolites in basal tears of patients with AD vs healthy volunteersAt inclusion

Collection of tears (5μL) using a glass micropipette without local anaesthetic. Metabolites in tears of patients with AD vs healthy volunteers

Secondary Outcome Measures
NameTimeMethod
Concentration of total Tau proteins in tears vs plasma and Cerebral spinal fluid (CSF) within patients with AD-MCIAt inclusion

12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

Concentration of phosphylated Tau proteins in tears vs plasma and Cerebral spinal fluid (CSF) within patients with AD-MCIA inclusion

12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

Concentration of Amyloid β 1-40 proteins in tears vs plasma and Cerebral spinal fluid (CSF) within patients with AD-MCIA inclusion

12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

Concentration of Amyloid β 1-42 proteins in tears vs plasma and Cerebral spinal fluid (CSF) within patients with AD-MCIA inclusion

12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

Lipids in tears vs plasma and Cerebral spinal fluid (CSF) within patients with AD-MCIAt inclusion

Collection of tears (5μL) using a glass micropipette without local anaesthetic. Identification of lipids in basal tears using liquid chromatography-mass spectrometry.

Metabolites in tears vs plasma and Cerebral spinal fluid (CSF) within patients with AD-MCIAt inclusion

Collection of tears (5μL) using a glass micropipette without local anaesthetic. Identification of metabolites in basal tears using liquid chromatography-mass spectrometry.

Concentration of total Tau proteins in basal tears of patients with AD-dementia vs patients with AD-MCIAt inclusion

12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

Concentration of phosphorylated Tau proteins in basal tears of patients with AD-dementia vs patients with AD-MCIAt inclusion

12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

Concentration of Amyloid β 1-40 proteins in basal tears of patients with AD-dementia vs patients with AD-MCIAt inclusion

12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

Concentration of Amyloid β 1-42 proteins in basal tears of patients with AD-dementia vs patients with AD-MCIAt inclusion

12μL of tears will be collected using Schirmer strips after instillation of an anaesthetic eye drop. A multiplex analysis for the detection of protein of interest

Lipids in basal tears of patients with AD-dementia vs patients with AD-MCIAt inclusion

Collection of tears (5μL) using a glass micropipette without local anaesthetic. Identification of lipids in basal tears using liquid chromatography-mass spectrometry.

Metabolites in basal tears of patients with AD-dementia vs patients with AD-MCIAt inclusion

Collection of tears (5μL) using a glass micropipette without local anaesthetic. Identification of metabolites in basal tears using liquid chromatography-mass spectrometry.

Trial Locations

Locations (1)

CHRU de Tours

🇫🇷

Tours, France

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