Presence of Anti-RACH Antibodies and Neurocognitive Disorder in Myasthenic or Alzheimers's Patients. (ARN-MA)

Study of the Relationship Between the Presence of Anti-AChR Antibodies in the Cerebrospinal Fluid and the Presence of Neurocognitive Disorder in Myasthenic and Alzheimers's Patients.

The purpose of the study is to evaluate if there is a specific association between the presence of anti Rach antibodies in the CSF and the presence of a cogntive disorder in myasthenic patients. Moreover the investigator wants to study if there is a link between the presence of Anti RACH antibodies in myasthenia and Alzheimers's disease.

For that, the investigator will recruit myasthenic patient with cognitive disorder that has undergo a diagnostic process including lombar punction for memory trouble in Nice memory center as well as Alzheimer's patient having go through the same process.

The study will consist in one additionnal blood draw. Anti RACH antibodies will be analyzed in historical CSF stored in biocollection and serum collected for the study.

LCS of healthy control will also be analyzed.

Study Overview

• Status: Recruiting
• Conditions: Alzheimer Disease; Myasthenia
• Intervention / Treatment: Procedure: Adults with Alzheimer's disease; Procedure: Adults with Myasthenia; Other: Healhty controls

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: LEMAIRE JUSTINE; Phone Number: 33492034778; Email: lemaire.j@chu-nice.fr

Study Locations

• France
  • Alpes Maritimes
    • Nice, Alpes Maritimes, France, 06000
      • Recruiting
      • CHU de Nice
      • Principal Investigator: Guillaume SACCO, MD
      • Contact: Justine Lemaire; Phone Number: 33492034778; Email: lemaire.j@chu-nice.fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion criteria

For patient with myasthenia :

1. adult person,
2. Diagnosis of anti-AChR positive autoimmune myasthenia gravis, confirmed by clinical and biological data, and categorized in class I to IV according to the Myasthenia Gravis Foundation of America (MGFA) classification,
3. Mild or major neurocognitive disorder (DSM-5 criterion) having benefited from a diagnosis at the CMRR with CSF biomarker dosage and agreement to bio-collect residual CSF,
4. Agreeing to sign the free and informed consent,
5. Affiliate or beneficiary of a social security system.

For patient with Alzheimer Disease :

1. adult person,
2. Mild or major neurocognitive disorder (DSM-5 criterion) having benefited from a diagnosis at the CMRR with CSF biomarker dosage and agreement to bio-collect residual CSF,
3. Neurocognitive disorder only linked to Alzheimer's disease (IWG-2 criterion): typical or atypical clinical form with biomarkers of Alzheimer's disease in the CSF;
4. Agreeing to sign the free and informed consent,
5. Affiliate or beneficiary of a social security system.

For healty control :

1. absence of memory complaint,
2. absence of neurocognitive disorder,
3. Having agreed to carry out analyzes as part of research, on these CSF samples stored in the biobank of the Institute of Translational Neurology in Münster (Germany)

Exclusion Criteria:

For patient with myasthenia :

1. Person who does not have sufficient command of the French language to understand, read and write, to take neuropsychological tests;
2. Need to use the routine complementary CSF tube to carry out additional diagnostic explorations as part of routine care,
3. Vulnerable people are defined in articles L1121-5 to -8 ( Pregnant women, parturients and breastfeeding mothers, persons deprived of their liberty by a judicial or administrative decision, persons hospitalized without consent under articles L. 3212-1 and L. 3213-1 who do not fall under the provisions of article L. 1121-8, and persons admitted to a health or social establishment for purposes other than research/Adults who are subject to a legal protection measure or who are unable to express their consent.),

For patient with Alzheimer Disease :

1) vulnerable people are defined in articles L1121-5 to -8 ( Pregnant women, parturients and breastfeeding mothers, persons deprived of their liberty by a judicial or administrative decision, persons hospitalized without consent under articles L. 3212-1 and L. 3213-1 who do not fall under the provisions of article L. 1121-8, and persons admitted to a health or social establishment for purposes other than research/Adults who are subject to a legal protection measure or who are unable to express their consent.)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Adults with Alzheimer's disease	Procedure: Adults with Alzheimer's disease; Each patient will undergo a blood draw for the analysis of RACH antibodies in serum. Also an aliquot of frozen spinal fluid of patient kept in biobank ( spinal fluid taken during a puncture as part of routine care) will be used for the analysis of RACH antibodies.
Experimental: Adults with Myasthenia	Procedure: Adults with Myasthenia; Each patient will undergo a blood draw for the analysis of RACH antibodies in serum. Also an aliquot of frozen spinal fluid of patient kept in biobank ( spinal fluid taken during a puncture as part of routine care) will be used for the analysis of RACH antibodies.
Experimental: healthy volonteer	Other: Healhty controls; Frozen spinal fluid of 10 healthy controlled stored in a biobank in Munster, Germanywill be compared to the ones of Adults with Myasthenia and Adults with Alzheimer's disease

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
The ratio of the number of myasthenic patients with NS-NCD that may be related to myasthenia-related central nervous system damage to the total number of myasthenic patients with CND from all causes combined.	at day 0

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Measurement of RACH antibodies in serum	dosage by ELISA method of RACH antibodies	at day 0
Measurement of RACH antibodies in cerebrospinal liquid	dosage by ELISA method of RACH antibodies	at day 0

Collaborators and Investigators

• Sponsor: Centre Hospitalier Universitaire de Nice
• Investigators: Principal Investigator: SACCO GUILLAUME, MD, Centre Hospitalier Universitaire de Nice

Study record dates

Study Major Dates

• Study Start (Actual): April 17, 2024
• Primary Completion (Estimated): May 1, 2026
• Study Completion (Estimated): June 1, 2026

Study Registration Dates

• First Submitted: July 23, 2024
• First Submitted That Met QC Criteria: July 23, 2024
• First Posted (Actual): July 26, 2024

Study Record Updates

• Last Update Posted (Actual): April 2, 2025
• Last Update Submitted That Met QC Criteria: April 1, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: Alzheimer's Disease; Myasthenia; Anti-RACH antibodies; neurocognitve disorder
• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Mental Disorders; Dementia; Tauopathies; Neurodegenerative Diseases; Alzheimer Disease; Neurocognitive Disorders
• Other Study ID Numbers: 22-AOI-08

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No