Neuropathy and Anti-GFAP Antibodies

Study Overview
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Brief Summary
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Anti-Glial Fibrillary Acidic Protein (GFAP) are antibodies associated to inflammatory diseases of the central nervous system. The GFAP protein is highly expressed by astrocytes explaining these syndromes, but GFAP is also expressed by immature and non-myelinating Schwann cells. Thus, these antibodies could also lead to damages of the peripheral nervous system (PNS). Moreover, such damages have already been reported on small studies, and there is a need for larger cohorts. The investigators will use the cohort of patients with neurological syndromes and anti-GFAP antibodies identified in the cerebrospinal fluid (CSF) of the Reference center for paraneoplastic neurological syndromes and autoimmune encephalitis to determine the frequency of the PNS involvement in these patients.

Official Title
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Study of the Consequences of Anti-GFAP Antibodies on the Peripheral Nervous System

Conditions
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Neurological Diseases or Conditions, Neurological Diseases Associated to Anti GFAP Antibodies

Intervention / Treatment
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* Other: Clinical examination
* Other: electroneuromyography (ENMG)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - Age > 18 years old Neurological symptoms Anti-GFAP antibodies identified in the CSF Exclusion Criteria: - Uncomplete data in the medical records of patients

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients presenting with neurological symptoms and anti-GFAP antibodies in the CSF.<br>This is a non-interventional study involving biological samples. Samples are already stored in biobank repositories and collected as part of good clinical practice in the diagnostic process of patients with suspected autoimmune encephalitis, meaning that the standard diagnostic and therapeutic approaches will not be altered in the selected study population. Patients have already gave explicit written consent for biological specimens sampling and storage at the iological Resource Center of the Hospices Civils de Lyon (CRB-HCL) (including tissue, cells or biological fluids). The group will be composed of patients included in the French cohort of patients with neurological syndromes and anti-GFAP antibodies in the CSF. | Other: Clinical examination<br>* The examination performed by the clinician of the patient will be analyzed from the cohort as previously explained.<br>Other: electroneuromyography (ENMG)<br>* Data from the ENMGs will be extracted from the cohort and analyzed.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cranial nerves abnormality at clinical examination of abnormal ENMG | Data concerning the clinical examination and the ENMG will be extracted from the cohort of patients with neurological syndroms and anti-GFAP antibodies identified in the cerebrospinal fluid (CSF) of the Centre de reference des syndromes neurologiques paranéoplasiques et encéphalites auto-immunes. | Immediately after diagnosis | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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GFAP, neuropathy