Presence of anti-nuclear antibody associated with worse clinical outcomes of anti-NMDAR encephalitis.

Purpose: Systemic autoantibodies are important for the diagnosis of autoimmune diseases, but their roles in anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis are unknown. The purpose of our study is to investigate the characteristics and a prognosis of anti-NMDAR encephalitis with the prevalence of autoantibodies. Methods: Systemic autoantibodies were evaluated in 64 patients with anti-NMDAR encephalitis and 14 patients with autoimmune encephalitis with other forms. Then, according to systemic autoantibodies, patients with anti-NMDAR encephalitis were divided into an anti-nuclear antibody (ANA) positive group and an ANA negative group. The clinical outcome was assessed by a modified Rankin score at 12 months after the disease onset. Results: A total of 64 patients with anti-NMDAR encephalitis were enrolled, of which 28.13% (18/64) were positive for ANA. The titers of a positive anti-NMDAR antibody in CSF (p = 0.041) and serum (p = 0.031) in the ANA-positive group were significantly higher than the ANA-negative group. Patients with ANA positive than those with ANA negative showed lower rates of headache (p = 0.047) and speech disorder (p = 0.049). The presence of ANA was associated with a worse clinical outcome at 12 months (p = 0.043). Conclusion: ANA was prevalent in patients with anti-NMDAR encephalitis, and associated with a worse prognosis and impaired neurological recovery.

[Autoimmune encephalitis in pediatric population]

Autoimmune encephalitis can be defined as central nervous system inflammation, secondary to multiple causes, where we can possibly identify the formation of auto-antibody against neurotransmitter receptors or neuronal surface proteins. Approximately 50% of patients are seropositive;the auto-antibody against N-methyl-D-aspartate receptor (NMDAR) are the most common. In the pediatric population, the clinical presentation is characterized by movement disorders and seizures, psychiatric manifestations are more commonly found in young adults. An early intervention is associated with a better prognosis in these patients. In contrast to the seropositive group, seronegative autoimmune encephalitis is linked with less movement alterations and is related with a worse cognitive outcome. Much remains to be discovered about possible etiologies, molecular processes, detection, and interaction of yet undescribed antibodies,as well as increasing our knowledge about clinical manifestations in early disease and new diagnostic techniques that could improve the diagnosis of autoimmune encephalitis. The main goal of this document is to review the updates of the molecular field about the antibody against GluK2 and its clinical presentation in pediatric population;COVID-19 as a possible cause of autoimmune encephalitis;recognize the importance of psychiatric manifestation in early disease, especially catatonia as a marker of severity;additionally consider new imaging diagnostic method such as positron emission tomography (PET), which has shown to be more sensible than MRI (goal standard).

[Immune-mediated encephalitis in a child with a history of SARS-CoV-2 infection]. / Encefalitis inmunomediada en un niño con antecedente de infección por SARS-CoV-2.

Encephalitis are frequent clinical pictures in pediatric age. They can be divided into those caused by infection of the central nervous system and those of immune-mediated etiology (some of which may be para- or post-infectious). In March 2020, the WHO declared a SARS-CoV-2 pandemic. Pediatric reports of disease caused by this agent describe a wide range of clinical manifestations: respiratory and gastrointestinal compromise, neurological symptoms, among others; and a multisystemic inflammatory syndrome in children associated with COVID-19 (MIS-C). We describe the case of a 2-year-old boy with a diagnosis of anti-NMDAR antibody encephalitis, in whom a recent SARS-CoV-2 infection was serologically proven. The presence of positive serological markers for SARS-CoV-2 in a patient who presented encephalitis due to anti-NMDAR antibodies could be interpreted as a temporal association; establishing the possibility that the virus has acted as a trigger for an autoimmune disease.

Las encefalitis son cuadros clínicos frecuentes en la edad pediátrica. Pueden dividirse en aquellas causadas por la infección del sistema nervioso central y en las de etiología inmunomediada (algunas de las cuales pueden ser para- o posinfecciosas). En marzo de 2020 la Organización Mundial de la Salud declaró la pandemia por el coronavirus de tipo 2 del síndrome respiratorio agudo grave (SARS-CoV-2, por su sigla en inglés). Los reportes pediátricos de enfermedad por dicho agente describen una amplia gama de manifestaciones clínicas: compromiso respiratorio, gastrointestinal, síntomas neurológicos, entre otros; y el síndrome inflamatorio multisistémico asociado a COVID-19 (SIM-C). Describimos el caso de un niño de 2 años con diagnóstico de encefalitis por anticuerpos antirreceptor N-metil-d-aspartato (anti-NMDAR), en quien se comprobó, mediante serología, una infección reciente por SARS-CoV-2. La presencia de marcadores serológicos positivos para SARS-CoV-2 en un paciente que presentó encefalitis por anticuerpos anti-NMDAR podría interpretarse como una asociación temporal, estableciéndose la posibilidad de que el virus haya actuado como gatillo de una enfermedad autoinmunitaria.