Multiplex family with GAD65-Abs neurologic syndromes.

Objective: Neurologic autoimmune syndromes associated with anti-glutamate acid decarboxylase 65 antibodies (GAD65-Abs) are rare and mostly sporadic.

Methods: We describe a niece and her aunt with GAD65-Abs neurologic syndromes. High-resolution HLA typing of Class I and Class II alleles was performed using next-generation sequencing.

Complex HLA association in paraneoplastic cerebellar ataxia with anti-Yo antibodies.

Anti-Yo paraneoplastic cerebellar degeneration (PCD) is a devastating autoimmune complication of gynecological cancers. We hypothesized that as for other autoimmune diseases, specific HLA haplotypes are associated. We conducted high resolution HLA typing of Class I/Class II in 40 cases versus ethnically matched controls.

Genetic alterations and tumor immune attack in Yo paraneoplastic cerebellar degeneration.

Paraneoplastic cerebellar degenerations with anti-Yo antibodies (Yo-PCD) are rare syndromes caused by an auto-immune response against neuronal antigens (Ags) expressed by tumor cells. However, the mechanisms responsible for such immune tolerance breakdown are unknown. We characterized 26 ovarian carcinomas associated with Yo-PCD for their tumor immune contexture and genetic status of the 2 onconeural Yo-Ags, CDR2 and CDR2L.

Netrin-1 receptor antibodies in thymoma-associated neuromyotonia with myasthenia gravis.

Objective: To identify cell-surface antibodies in patients with neuromyotonia and to describe the main clinical implications.

Methods: Sera of 3 patients with thymoma-associated neuromyotonia and myasthenia gravis were used to immunoprecipitate and characterize neuronal cell-surface antigens using reported techniques. The clinical significance of antibodies against precipitated proteins was assessed with sera of 98 patients (neuromyotonia 46, myasthenia gravis 52, thymoma 42; 33 of them with overlapping syndromes) and 219 controls (other neurologic diseases, cancer, and healthy volunteers).

Characteristics in limbic encephalitis with anti-adenylate kinase 5 autoantibodies.

Objective: To report 10 patients with limbic encephalitis (LE) and adenylate kinase 5 autoantibodies (AK5-Abs).

Methods: We conducted a retrospective study in a cohort of 50 patients with LE with uncharacterized autoantibodies and identified a specific target using immunohistochemistry, Western blotting, immunoprecipitation, mass spectrometry, and cell-based assay.

Results: AK5 (a known autoantigen of LE) was identified as the target of antibodies in the CSFs and sera of 10 patients with LE (median age 64 years; range 57-80), which was characterized by subacute anterograde amnesia without seizure and sometimes preceded by a prodromal phase of asthenia or mood disturbances.

Neuroleptic intolerance in patients with anti-NMDAR encephalitis.

Objective: To precisely describe the initial psychiatric presentation of patients with anti-NMDA receptor (NMDAR) antibodies encephalitis (anti-NMDAR encephalitis) to identify potential clues enhancing its early diagnosis.

Methods: We retrospectively studied the French Reference Centre medical records of every adult patient with anti-NMDAR encephalitis to specify the patients' initial psychiatric symptoms leading to hospitalization in a psychiatric department and the reasons underlying the diagnosis of anti-NMDAR encephalitis.

Results: The medical records of 111 adult patients were reviewed.

Prostate cancer, Hu antibodies and paraneoplastic neurological syndromes.

Prostate cancer is the most common cancer among American and European men. Nervous system affection caused by local tumor growth or osseous metastases are the main causes of neurological symptoms in prostate cancer patients. Prostate cancer is rarely reported in association with paraneoplastic neurological syndromes (PNS).

Neuronal central nervous system syndromes probably mediated by autoantibodies.

In the last few years, a rapidly growing number of autoantibodies targeting neuronal cell-surface antigens have been identified in patients presenting with neurological symptoms. Targeted antigens include ionotropic receptors such as N-methyl-d-aspartate receptor or the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor, metabotropic receptors such as mGluR1 and mGluR5, and other synaptic proteins, some of them belonging to the voltage-gated potassium channel complex. Importantly, the cell-surface location of these antigens makes them vulnerable to direct antibody-mediated modulation.

A clinical approach to diagnosis of autoimmune encephalitis.

Encephalitis is a severe inflammatory disorder of the brain with many possible causes and a complex differential diagnosis. Advances in autoimmune encephalitis research in the past 10 years have led to the identification of new syndromes and biomarkers that have transformed the diagnostic approach to these disorders. However, existing criteria for autoimmune encephalitis are too reliant on antibody testing and response to immunotherapy, which might delay the diagnosis.

CSF IgA NMDAR antibodies are potential biomarkers for teratomas in anti-NMDAR encephalitis.

Objective: To evaluate the presence of immunoglobulin A (IgA) subtype of anti-NMDA receptor (NMDAR) antibodies (IgA-NMDAR-Abs) in the CSF of patients with immunoglobulin G (IgG)-NMDAR-Ab encephalitis and to describe the potential association with a specific clinical pattern.

Methods: The retrospective analysis for the presence of IgA-NMDAR-Abs in 94 CSF samples from patients with anti-NMDAR encephalitis diagnosed between October 2007 and February 2014 was conducted at the French Reference Centre on Paraneoplastic Neurological Syndrome. This observational study compared 39 patients with both IgA- and IgG-NMDAR-Abs to 55 patients with only IgG-NMDAR-Abs.

Paraneoplastic subacute lower motor neuron syndrome associated with solid cancer.

We retrospectively analyzed three patients with pure motor neuronopathy followed for more than four years in our center. The patients presented a rapidly progressive lower motor neuron syndrome (LMNS) over the course of a few weeks leading to a severe functional impairment. The neurological symptoms preceded the diagnosis of a breast adenocarcinoma and a thymoma in the first two patients, one of them with anti-CV2/CRMP5 antibodies.

Inhibitory axons are targeted in hippocampal cell culture by anti-Caspr2 autoantibodies associated with limbic encephalitis.

Contactin-associated protein-like 2 (Caspr2), also known as CNTNAP2, is a cell adhesion molecule that clusters voltage-gated potassium channels (Kv1.1/1.2) at the juxtaparanodes of myelinated axons and may regulate axonal excitability.

CRMPs: critical molecules for neurite morphogenesis and neuropsychiatric diseases.

Neuronal polarity and spatial rearrangement of neuronal processes are central to the development of all mature nervous systems. Recent studies have highlighted the dynamic expression of Collapsin-Response-Mediator Proteins (CRMPs) in neuronal dendritic/axonal compartments, described their interaction with cytoskeleton proteins, identified their ability to activate L- and N-type voltage-gated calcium channels (VGCCs) and delineated their crucial role as signaling molecules essential for neuron differentiation and neural network development and maintenance. In addition, evidence obtained from genome-wide/genetic linkage/proteomic/translational approaches revealed that CRMP expression is altered in human pathologies including mental (schizophrenia and mood disorders) and neurological (Alzheimer's, prion encephalopathy, epilepsy and others) disorders.

Therapeutic approaches in antibody-associated central nervous system pathologies.

Initially, antibodies targeting intracellular compounds were described in patients with paraneoplastic neurological syndromes (PNS) such as anti-Hu, anti-Yo, anti-Ri or anti-CV2/CRMP5 antibodies. As more than 90% of patients with these antibodies suffer from an associated cancer, these antibodies were used as biomarkers of an underlying tumour. Recently, autoantibodies targeting cell-surface synaptic antigens have been described in patients with neurological symptoms suggesting PNS.

Seronegative paraneoplastic cerebellar degeneration: the PNS Euronetwork experience.

Background And Purpose: To describe the characteristics of patients presenting a paraneoplastic cerebellar degeneration without classical onconeural antibodies (seronegative PCD).

Methods: Thirty-nine seronegative PCD patients from the Paraneoplastic Neurological Syndrome Euronetwork were retrospectively analyzed and compared with 180 patients with PCD associated with classical onconeural antibodies (seropositive PCD).

Results: No patient had anti-CASPR2 or anti-mGluR1 antibodies.

Clinical specificities of adult male patients with NMDA receptor antibodies encephalitis.

Objective: The aim of this study was to describe the clinical features and specificities of adult male patients with NMDA receptor antibodies (NMDAr-Abs) encephalitis.

Methods: Observational study of 13 adult male patients who were diagnosed with NMDAr-Abs encephalitis at the French Paraneoplastic Neurological Syndrome Reference Center.

Results: Adult male patients frequently presented initially with a seizure (8/13, 61.

Autoimmune N-methyl-D-aspartate receptor encephalitis is a differential diagnosis of infectious encephalitis.

Background: For 60% of acute febrile encephalitis cases, the cause is unknown. Autoantibodies directed against different synaptic proteins or receptors in patients with autoimmune encephalitis have recently been described and could indicate a differential diagnosis of infectious encephalitis.

Objective: The aim of this study was to retrospectively investigate the presence of autoantibodies directed against synaptic proteins or receptors in patients with acute febrile encephalitis.

Autoimmune limbic encephalopathy and anti-Hu antibodies in children without cancer.

Objective: The aim of this study was to describe the clinical presentation of children and adolescents with anti-Hu antibodies (Hu-Abs).

Methods: This was a retrospective study of children and adolescents with Hu-Abs collected by the French Paraneoplastic Neurological Syndrome (PNS) Reference Center between January 1, 2000 and December 31, 2011.

Results: The center identified 251 patients with Hu-Abs.