Encefalitis aguda mediada por anticuerpos contra el receptor ionotrópico de glutamato activado por N-metil-D-aspartato (NMDAR): análisis de once casos pediátricos en Argentina (Premio Benito Yelín) / [Acute encephalitis anti-ionotropic glutamate receptor activated N-methyl-D-aspartate (NMDAR): analysis of eleven pediatric cases in Argentina (Benito Yelín Award)].

Encephalitis are an inflammatory processes of various origin, among which include autoimmune origin. The identification of antibodies against the N-methyl-D- aspartate, allowed clinical immunological characterization of an entity susceptible to immunomodulatory therapy. Originally described in young women associated with ovarian teratoma, is now a recognized entity in children even in the absence of detectable tumors. The aim of the study was conducted through review of medical records, was to describe the clinical, developmental and findings in further studies of eleven children with confirmed diagnosis of this entity through identification of specific antibodies. All debuted with psychiatric symptoms in nine associating seizures, and two extrapyramidal movements. In the evolution of language all had commitment nine severe autonomic symptoms, one with hypoventilation and requirements of ARM. Brain MRI was abnormal in three. Eight had voltage EEG asymmetry and / or amplitude, three of them had spikes. Six had CSF pleocytosis and three of seven positive oligoclonal bands. Five IgM serology for mycoplasma were positive. CPK increase occurred in conjunction with antisychotics in five. With immunomodulatory treatment, five had complete recovery three behavioral disorders / cognitive deficits and one severe. A patient’s clinical picture resolved without treatment. In any associated tumor was detected. We conclude that in front of a child with acute encephalopathy and clinical support this entity after infectious cause were ruled out, immunomodulatory therapy should be started early, avoid the use of antipsychotic drugs and search for possible hidden tumors.

The expanding spectrum of clinically-distinctive, immunotherapy-responsive autoimmune encephalopathies / O espectro em expansão das encefalopatias autoimunes clinicamente distintas e que respondem à imunoterapia

The autoimmune encephalopathies are a group of conditions that are associated with autoantibodies against surface neuronal proteins, which are likely to mediate the disease. They are established as a frequent cause of encephalitis. Characteristic clinical features in individual patients often allow the specificity of the underlying antibody to be confidently predicted. Antibodies against the VGKC-complex, mainly LGI1(leucine-rich glioma-inactivated 1), CASPR2 (contactin-associated protein 2), and contactin-2, and NMDA (N-methyl, D-aspartate) -receptor are the most frequently established serological associations. In the minority of cases, an underlying tumour can be responsible. Early administration of immunotherapies, and tumour removal, where it is relevant, offer the greatest chance of improvement. Prolonged courses of immunotherapies may be required, and clinical improvements often correlate well with the antibody levels. In the present article, we have summarised recent developments in the clinical and laboratory findings within this rapidly expanding field.

As encefalopatias autoimunes constituem um grupo de condições associadas à presença, no soro, de anticorpos contra proteínas de superfície neuronais. Acredita-se que esses anticorpos sejam mediadores da ocorrência da doença, sendo reconhecidos atualmente como causas frequentes de encefalite. Apresentações clínicas características permitem, muitas vezes, predizer o grupo específico de anticorpos subjacentes. Anticorpos contra o complexo VGKF, especialmente LGI1 (leucine-rich glioma-inactivated1), CASPR2 (contactin-associated protein 2) e contactina-2, e contra o receptor NMDA(N-methyl, D-aspartate) são as associações sorológicas mais frequentemente estabelecidas. Na minoria dos casos, pode ser detectado um tumor subjacente. As maiores chances de melhora estão relacionadas à administração precoce de imunoterapia e à remoção do tumor, quando presente. A duração da imunoterapia pode se prolongada e a melhora se correlaciona, muitas vezes, com os níveis séricos de anticorpos. Neste artigo, estão resumidos os avanços recentes nos achados clínicos e laboratoriais neste campo que está em tão rápida expansão.

Autoimmune disorders of the neuromuscular junction.

The neuromuscular junction (NMJ) is a specialized synapse with a complex structural and functional organization. It is a target for a variety of immunological disorders and these diseases usually respond well to immunotherapies. The understanding of the immunological basis of myasthenia gravis, the most common neuromuscular junction disorder, has improved in the recent years. Most patients have antibodies to the acetylcholine receptor (AChR), but around 10% have AChR antibodies that are only identified by novel methods, and up to 5% have muscle-specific kinase antibodies which define a different subgroup of myasthenia. The spectrum of antibodies and their pathophysiological aspects are being elucidated. Even though less common, Lambert Eaton myasthenic syndrome (LEMS) is important to recognize. The abnormality in LEMS is a presynaptic failure to release enough packets of ACh, caused by antibodies to the presynaptic voltage-gated calcium channels. More than half these patients have a small cell carcinoma of lung. Acquired neuromyotonia (NMT) is a condition associated with muscle hyperactivity. Clinical features include muscle stiffness, cramps, myokymia, pseudomyotonia and weakness. The immune mechanisms of acquired NMT relate to loss of voltage-gated potassium channel function. This review will focus on the important recent developments in the immune-mediated disorders of the NMJ.

A case of Miller Fisher syndrome with anti GQ1b in Thailand.

Miller-Fisher syndrome (MFS) is a rare variant of Guillain-Barré syndrome (GBS) and is characterized by the clinical triad of ataxia, ophthalmoplegia, and areflexia. The incidence rate in Thailand has not been established but it occurred approximately 1-5% that of GBS. Here, the authors report a Thai patient diagnosed as MFS that had a positive test of antibodies against the ganglioside GQ1b. These antibodies have diagnostic and pathogenic importance to MFS because of high sensitivity and specificity. All other investigations, such as cerebrospinal fluid analysis, electrophysiological studies, and imaging studies had no significant abnormalities. The patient was successfully treated with intravenous immunoglobulin and fully recovered within one month. After eighteen months follow-up, he is still healthy and has had no recurrent symptoms.

Acetylcholine receptor antibody in Thai generalized myasthenia gravis patients.

The authors studied acetylcholine receptor antibody (AChR Ab) in twenty-six Thai patients diagnosed as having generalized myasthenia gravis and fifteen control cases. AChR Ab assay was done by radio-immunoassay technique and reported by titer in nmole/L. The positive result was defined by titer more than 0.5 nmole/L. In the myasthenia gravis group, age ranged from 18 to 64 years old with mean of 34 years old. The female: male ratio was 4.2:1. Duration of disease before taking blood sample ranged from 1 month to 14 years with a mean of 3.9 year The AChR Ab could be detected in 21 out of 26 patients (80.7%). In the control group, tests were all negative. The results of the test made the sensitivity of 80.7% and specificity of 100%. The positive predictive value was 100%, the negative predictive value was 75%, and the prevalence was 60.3%. There was no correlation between AChR Ab titer and clinical features. This test is a very valuable test in case of uncertainly in the diagnosis of myasthenia gravis.