Collection of Biological Samples From Patients With Rare Neurological Diseases

Neuroimmunology is a rapidly expanding field since major advances have been made in basic immunology and numerous new clinical entities have been identified in the last 10 years. Even if these discoveries have led to major advances in patient's management and treatment, a lot of work needs to be done to improve the diagnosis and prognostic biomarkers. It is widely known that the immune system is implicated in a variety of neurological disorders such as infections, encephalitis or multiple sclerosis. Numerous neurological disorders affecting the central and peripheral nervous system can be attributed to the immune system and need to be recognized as some of them can be cured by appropriate immunotherapy. These neurological disorders include autoimmune encephalitis and paraneoplastic neurological syndromes but also myasthenia, chronic demyelinating inflammatory polyneuropathy and other neuromuscular pathologies.

These neurological disorders are characterized by the presence of autoantibodies in the patient's sera or cerebral spinal fluid (CSF). These autoantibodies are generally highly specific and necessary to make the diagnosis. However, in some cases, despite strong clinical arguments for a neuroimmunological disorder, we do not identify autoantibodies, leading to inappropriate treatment and a blind follow-up considering the risk of recurrence or of associated tumor. Furthermore, even if the specific role of some autoantibodies or of immune T cells in some of these pathologies are suspected or already documented, for most of them the exact mechanism is still unknown. We need to explore the sera and CSF of these patients to identify new diagnosis and prognosis biomarker. Moreover, the availability of immune cells isolated from these patients will help us to decipher the pathophysiological mechanisms to create new therapeutic strategies. For this, animal models are already available in Centre Physiopathology Toulouse and in the French reference center in Lyon. As genetic susceptibilities may underlie, at least in part, the variability of the clinical manifestations and of the response to treatment, DNA from patients will be collected and immune genes sequencing will be compared to other control groups, included international database.

• Identification of new autoantibodies. [Time frame: Day 0 and through study completion, an average of 1 year]
• Identification of biomarkers regarding the severity (such as cytokines, axonal damages...) in order to help the therapeutic decisions. [Time frame: Day 0 and through study completion, an average of 1 year]
• Exploration of the pathophysiological mechanisms of rare autoimmune neurological pathologies. [Time frame: Day 0 and through study completion, an average of 1 year]