Determination of neuronal antibodies in suspected and definite Creutzfeldt-Jakob disease
IMPORTANCE: Creutzfeldt-Jakob disease (CJD) and autoimmune encephalitis with antibodies against neuronal surface antigens (NSA-abs) may present with similar clinical features. Establishing the correct diagnosis has practical implications in the management of care for these patients. OBJECTIVE: To determine the frequency of NSA-abs in the cerebrospinal fluid of patients with suspected CJD and in patients with pathologically confirmed (ie, definite) CJD. DESIGN, SETTING, AND PARTICIPANTS: A mixed prospective (suspected) and retrospective (definite) CJD cohort study was conducted in a reference center for detection of NSA-abs. The population included 346 patients with suspected CJD and 49 pati…
Immunoproteomic studies on paediatric opsoclonus-myoclonus associated with neuroblastoma
We aimed to identify new cell-membrane antigens implicated in opsoclonus-myoclonus with neuroblastoma. The sera of 3 out of 14 patients showed IgG electron-microscopy immunogold reactivity on SH-SY5Y neuroblastoma cells. Immunoprecipitation experiments using rat brain synaptosomes and SH-SY5Y cells led to the identification of: (1) thirty-one nuclear/cytoplasmic proteins (including antigens HuB, HuC); (2) seven neuronal membrane proteins, including the Shaw-potassium channel Kv3.3 (KCNC3), whose genetic disruption in mice causes ataxia and generalized muscle twitching. Although cell-based assays did not demonstrate direct antigenicity, our findings point to Shaw-related subfamily of the pot…
Clinical manifestations of the anti-IgLON5 disease
Objective:To report the presentation, main syndromes, human leukocyte antigen (HLA) association, and immunoglobulin G (IgG) subclass in the anti-IgLON5 disease: a disorder with parasomnias, sleep apnea, and IgLON5 antibodies.Methods:This was a retrospective clinical analysis of 22 patients. The IgG subclass was determined using reported techniques.Results:Patients' median age was 64 years (range 46–83). Symptoms that led to initial consultation included sleep problems (8 patients; 36%), gait abnormalities (8; 36%), bulbar dysfunction (3; 14%), chorea (2; 9%), and cognitive decline (1; 5%). By the time of diagnosis of the disorder, 4 syndromes were identified: (1) a sleep disorder with paras…
Frequency and Characterization of Movement Disorders in Anti-IgLON5 Disease
Background and ObjectivesAnti-IgLON5 disease is a recently described neurologic disease that shares features of autoimmunity and neurodegeneration. Abnormal movements appear to be frequent and important but have not been characterized and are underreported. We describe the frequency and types of movement disorders in a series of consecutive patients with this disease.MethodsIn this retrospective, observational study, the presence and phenomenology of movement disorders were assessed with a standardized clinical questionnaire. Available videos were centrally reviewed by 3 experts in movement disorders.ResultsSeventy-two patients were included. In 41 (57%), the main reason for initial consult…
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).Results:Immunoprecipitation studies identified 3 targets, including the Netrin-1 receptors DCC (deleted i…