CLarifying ABCB1's Role in Alzheimer's Disease

NCT07393113 | Completed

• 1 other identifier: APHP251732
• Study Type: observational
• Target: 510
• Locations: 1 country
• Sites: 1

Brief Summary

Alzheimer's disease is biologically defined by the accumulation of amyloid beta and tau protein, identified using cerebrospinal fluid biomarkers. The ABCB1 gene, which encodes P-glycoprotein involved in amyloid beta efflux across the blood-brain barrier, may influence Alzheimer's disease risk. We hypothesize that certain functional ABCB1 polymorphisms impair amyloid beta clearance, thereby promoting the development of biologically defined Alzheimer's disease.

Conditions

Alzheimer Disease

Keywords

Alzheimer Disease; P-glycoprotein

Outcome Measures

Primary Outcomes (1)

• Allele and genotype frequencies of ABCB1 single nucleotide polymorphisms (3435C>T, 2677G>T/A, and 1236C>T)

  Allele and genotype frequencies of the ABCB1 single nucleotide polymorphisms 3435C\>T, 2677G\>T/A, and 1236C\>T, determined by genotyping from genomic DNA, will be compared between: * patients with biologically defined Alzheimer's disease (A+T+Nx), and * neurological control participants with a negative biomarker profile (A-T-N-). Data will be summarized as allele frequencies and genotype distributions in each group.

  Baseline (at the time of biological sampling and clinical assessment)

Secondary Outcomes (2)

• Haplotype frequencies of ABCB1 polymorphisms (3435C>T, 2677G>T/A, and 1236C>T)

  Baseline (at the time of biological sampling and clinical assessment)

• Distribution of ABCB1 polymorphisms stratified by APOE ε4 carrier status

  Baseline (at the time of biological sampling and clinical assessment)

Study Arms (2)

Patients with cerebrospinal fluid amyloid and phosphorylated tau biomarkers (A+T+)

Genetic: ABCB1 genotyping

Patients without cerebrospinal fluid amyloid, phosphorylated tau and total tau biomarkers (A-T-N-)

Genetic: ABCB1 genotyping

Interventions

ABCB1 genotyping GENETIC

Genotyping of three single nucleotide polymorphisms (3435C\>T, 2677G\>T/A, and 1236C\>T) associated with variation in P-glycoprotein activity, using DNA samples stored in a biobank.

Patients with cerebrospinal fluid amyloid and phosphorylated tau biomarkers (A+T+); Patients without cerebrospinal fluid amyloid, phosphorylated tau and total tau biomarkers (A-T-N-)

Eligibility Criteria

• Age: 50 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients followed in a memory clinic who underwent a comprehensive clinical and paraclinical assessment, including cerebrospinal fluid biomarkers.

You may qualify if:

• age ≥ 50 years,
• available cerebrospinal fluid biomarker results,
• an available and usable DNA sample,
• and consent for future research use within the biobank.

You may not qualify if:

• the presence of an active non-degenerative neurological disorder (for example, multiple sclerosis, infections, or tumors),
• and missing data regarding APOE genotyping or cardiovascular risk factors

Sponsors & Collaborators

• Assistance Publique - Hôpitaux de Paris: lead

Study Sites (1)

Hôpital Lariboisière - Fernand Widal (AP - HP)

Paris, France

Location

Biospecimen

Retention: SAMPLES WITH DNA

DNA samples stored in a biobank from patients followed in a memory clinic who underwent a lumbar puncture.

MeSH Terms

Conditions

Alzheimer Disease

Condition Hierarchy (Ancestors)

Dementia; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Tauopathies; Neurodegenerative Diseases; Neurocognitive Disorders; Mental Disorders

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 19, 2026
• First Posted: February 6, 2026
• Study Start: October 25, 2023
• Primary Completion: December 31, 2025
• Study Completion: December 31, 2025
• Last Updated: February 6, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

FR (1)