Clinical Characterization and Outcome of Anti-IgLON5 Disease (ICP-IGLON5)

Identification, Clinical Characterization, and Prognosis of Anti-IgLON5 Disease

Anti-IgLON5 disease is a neurological disorder associated with antibodies to IgLON5, a neuronal cell adhesion protein of unknown function. Most patients develop a combination of significant sleep disturbances (non-rapid eye movement (NREM) and rapid eye movement parasomnias with obstructive sleep apnoea), bulbar dysfunction (dysarthria, dysphagia, vocal cord paralysis or episodes of respiratory failure) and gait instability. Early autopsy studies showed deposits of phosphorylated tau protein mainly in neurons of the brainstem tegmentum, suggesting a primary neurodegenerative disease. However, the results of subsequent studies have provided increasing support for an immune-mediated pathogenesis. First, there is a strong association with the human leukocyte antigen (HLA) haplotype DRB1*10:01-DQB1*05 : 01, which is present in ~60% of patients (compared to 2% in the normal population); secondly, recent autopsy studies have shown the absence of abnormal tau deposits; and thirdly, in live neurons in culture, IgLON5 antibodies cause irreversible loss of surface IgLON5 clusters and cytoskeletal changes such as dystrophic neurites and axonal bulges. Together, these studies suggest that antibody-mediated disruption of IgLON5 function leads to neurofilament and cytoskeletal alterations that can potentially result in tau accumulation.

Over the last two years, an increase in diagnoses of anti-IgLON5 disease has been observed in the French Reference centre of Autoimmune Encephalitis. This could be related to a better knowledge of the disease, or to other yet unknown factors. Clinical characterisation of these patients is essential to understand the underlying reasons for the increase in diagnoses and to improve knowledge of this disease. Furthermore, the response of these patients to immunosuppressive drugs and the long-term prognosis remain unknown.

Study Overview

• Status: Recruiting
• Conditions: Anti-IgLON5 Disease
• Intervention / Treatment: Other: Evaluation of clinical and paraclinical data.

• Study Type: Observational
• Enrollment (Estimated): 50

Contacts and Locations

• Study Contact: Name: Jerome Honnorat, professor; Phone Number: 33472357806; Email: jerome.honnorat@chu-lyon.fr
• Study Contact Backup: Name: Marine Villard; Phone Number: 0427855460; Email: marine.villard@chu-lyon.fr

Study Locations

• France
  • Bron, France, 69677
    • Recruiting
    • Hospices Civils de Lyon
    • Contact: Jérome Honnorat, professor; Phone Number: +334 72 35 78 06; Email: jerome.honnorat@chu-lyon.fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

All patients tested positive for anti-IgLON5 antibodies.

Description

Inclusion Criteria:

• Patients > 18 ans
• Anti-IgLON5 antibody positivity

Exclusion Criteria:

- Lack of clinical data

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Patients with anti-IgLON5 antibodies; Adults patients who tested positive for anti-IgLON5 antibodies in the French Reference centre of Autoimmune Encephalitis	Other: Evaluation of clinical and paraclinical data.; Retrospective data collection from available medical files of patient.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Prevalence of IGLON5 disorder	Prevalence of : Sleeping disorders; Respiratory dosorders; Cognitive disorders; Abnormal movements	At baseline

Collaborators and Investigators

• Sponsor: Hospices Civils de Lyon

Study record dates

Study Major Dates

• Study Start (Actual): February 23, 2023
• Primary Completion (Actual): May 31, 2023
• Study Completion (Estimated): December 31, 2023

Study Registration Dates

• First Submitted: November 9, 2023
• First Submitted That Met QC Criteria: November 9, 2023
• First Posted (Actual): November 14, 2023

Study Record Updates

• Last Update Posted (Actual): November 14, 2023
• Last Update Submitted That Met QC Criteria: November 9, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Keywords: Anti-IgLON5 disease, autoimmune encephalitis, neural antibodies
• Other Study ID Numbers: 69HCL23_1173

Drug and device information, study documents

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