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.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
90
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.
CHRU de Tours
Tours, France, France
RECRUITINGConcentration of total Tau proteins in basal tears of patients with AD vs healthy volunteers
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
Time frame: At inclusion
Concentration of phosphorylated Tau proteins in basal tears of patients with AD vs healthy volunteers
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
Time frame: At inclusion
Concentration of Amyloid β 1-40 proteins in basal tears of patients with AD vs healthy volunteers
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
Time frame: At inclusion
Concentration of Amyloid β 1-42 in basal tears of patients with AD vs healthy volunteers
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
Time frame: At inclusion
Lipids in basal tears of patients with AD vs healthy volunteers
Collection of tears (5μL) using a glass micropipette without local anaesthetic. Lipids in tears of patients with AD vs healthy volunteers
Time frame: At inclusion
Metabolites in basal tears of patients with AD vs healthy volunteers
Collection of tears (5μL) using a glass micropipette without local anaesthetic. Metabolites in tears of patients with AD vs healthy volunteers
Time frame: At inclusion
Concentration of total Tau proteins in tears vs plasma and Cerebral spinal fluid (CSF) within patients with AD-MCI
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
Time frame: At inclusion
Concentration of phosphylated Tau proteins in tears vs plasma and Cerebral spinal fluid (CSF) within patients with AD-MCI
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
Time frame: A inclusion
Concentration of Amyloid β 1-40 proteins in tears vs plasma and Cerebral spinal fluid (CSF) within patients with AD-MCI
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
Time frame: A inclusion
Concentration of Amyloid β 1-42 proteins in tears vs plasma and Cerebral spinal fluid (CSF) within patients with AD-MCI
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
Time frame: A inclusion
Lipids in tears vs plasma and Cerebral spinal fluid (CSF) within patients with AD-MCI
Collection of tears (5μL) using a glass micropipette without local anaesthetic. Identification of lipids in basal tears using liquid chromatography-mass spectrometry.
Time frame: At inclusion
Metabolites in tears vs plasma and Cerebral spinal fluid (CSF) within patients with AD-MCI
Collection of tears (5μL) using a glass micropipette without local anaesthetic. Identification of metabolites in basal tears using liquid chromatography-mass spectrometry.
Time frame: At inclusion
Concentration of total Tau proteins in basal tears of patients with AD-dementia vs patients with AD-MCI
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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
Time frame: At inclusion
Concentration of phosphorylated Tau proteins in basal tears of patients with AD-dementia vs patients with AD-MCI
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
Time frame: At inclusion
Concentration of Amyloid β 1-40 proteins in basal tears of patients with AD-dementia vs patients with AD-MCI
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
Time frame: At inclusion
Concentration of Amyloid β 1-42 proteins in basal tears of patients with AD-dementia vs patients with AD-MCI
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
Time frame: At inclusion
Lipids in basal tears of patients with AD-dementia vs patients with AD-MCI
Collection of tears (5μL) using a glass micropipette without local anaesthetic. Identification of lipids in basal tears using liquid chromatography-mass spectrometry.
Time frame: At inclusion
Metabolites in basal tears of patients with AD-dementia vs patients with AD-MCI
Collection of tears (5μL) using a glass micropipette without local anaesthetic. Identification of metabolites in basal tears using liquid chromatography-mass spectrometry.
Time frame: At inclusion