Uso adecuado de las pruebas de laboratorio para la evaluación de la función tiroidea en pediatría / Appropriate use of laboratory tests for evaluation of thyroid function in pediatrics

Las pruebas de función tiroidea (PFT) son esenciales para el diagnóstico preciso y el seguimiento eficaz de la disfunción tiroidea. Existe un incremento progresivo y estable de los pedidos de PFT, incluso se han incorporado las mismas a los exámenes de salud anuales en niños sanos. Representan más del 60% de las pruebas realizadas en el laboratorio de endocrinología, tanto en adultos como en los laboratorios especializados en pediatría. Para hacer un uso eficiente de las PFT, antes de solicitarlas debemos preguntarnos… ¿Para quién? ¿Cuándo solicitarlas? ¿Qué pruebas solicitar? ¿Cómo solicitarlas? y ¿Cómo interpretar correctamente los resultados? Un resultado anormal en las PFT no siempre implica patología tiroidea asociada. Las PFT tienen importante variabilidad intra e interindividual lo que hace más compleja su correcta interpretación. La pesquisa de enfermedad tiroidea neonatal es un importante aporte a la prevención de la deficiencia mental en la infancia, su aplicación obligatoria posibilita un diagnóstico temprano, para asegurar su éxito debe considerarse en el marco de un programa integral de detección con estrategias de confirmación, tratamiento temprano y seguimiento a corto, mediano y largo plazo. No debe hacerse un uso indiscriminado de la prueba de estímulo con TRH en el diagnóstico de la patología tiroidea. En pediatría la estrategia de tamiz de enfermedad tiroidea es conveniente realizarla mediante la medición de por lo menos TSH y T4 libre e incluir la determinación de ATPO en grupos de riesgo, a diferencia de la determinación aislada de TSH como es recomendado en adultos. (AU)

Thyroid function tests (TFTs) are essential for accurate diagnosis and effective monitoring of thyroid dysfunction. There is a progressive and steady increase in requests for TFTs, and they have even been incorporated into annual health examinations in healthy children. They represent more than 60% of the tests performed in the endocrinology laboratory, both in adults and in specialized pediatric laboratories. To efficiently use TFTs, before requesting them we should ask ourselves... For whom? When to request them? Which tests to request? How to request them? and How to correctly interpret the results? An abnormal TFT result does not always imply thyroid disease. TFTs have significant intra- and inter-individual variability, which makes their correct interpretation more complex. Screening for newborn thyroid disease is an important contribution to the prevention of intellectual disability in childhood and its mandatory use enables early diagnosis; however, to ensure the test to be successful, it should be considered within the framework of a comprehensive screening program with strategies for confirmation, early treatment, and short-, medium-, and long-term follow-up. The TRH stimulation test in the diagnosis of thyroid disease should not be used indiscriminately. In children, the screening strategy for thyroid disease should be performed by measuring at least TSH and free T4 and include the measurement of TPO-ab in risk groups, as opposed to the isolated measurement of TSH as recommended in adults. (AU)

Uso de PCR digital para definir terapéuticas específicas y seguimiento en enfermedades autoinflamatorias / Use of digital PCR to define specific therapeutics and follow-up in autoinflammatory diseases

Las enfermedades autoinflamatorias (AIDs) son un grupo heterogéneo de desórdenes monogénicos o poligénicos, con características de disregulación inmune innata y/o adaptativa, cuyo mecanismo central es la autoinflamación pero también pueden presentarse con autoinmunidad e inmunodeficiencia. En estos últimos años el desarrollo de las tecnologías de secuenciación masiva han provocado una explosión en el descubrimiento de nuevos genes responsables de AIDs monogénicas. Esto remarca la importancia de implementar este tipo de estudios para llegar a un diagnóstico definitivo sobre todo en este grupo de patologías genéticamente muy diversas donde los fenotipos clínicos se solapan. Sin embargo, dada la presencia de variantes de significación incierta (VUS), los resultados pueden no ser concluyentes planteándose la necesidad de desarrollar pruebas funcionales para determinar la patogenicidad de dichas variantes genéticas. En nuestro grupo de trabajo estamos aplicando la PCR digital en gotas (ddPCR), una técnica cuantitativa de 3era generación altamente sensible, especifica y reproducible que no necesita de curvas de calibración, para desarrollar pruebas funcionales que permitan no sólo reclasificar variantes VUS para lograr diagnósticos definitivos sino también estudiar los mecanismos responsables de las principales AIDs que permitan una estratificación de las terapéuticas especificas a aplicar y de esta manera poder contribuir al diagnóstico, tratamiento y seguimiento de nuestros pacientes en forma personalizada. (AU)

Autoinflammatory diseases (AIDs) are a heterogeneous group of monogenic or polygenic disorders, with characteristics of inborn and/or adaptive immune dysregulation, whose central mechanism is autoinflammation but may also present with autoimmunity and immunodeficiency. In recent years the development of massive sequencing technologies has led to an exponential increase in the discovery of new genes responsible for monogenic AIDs. This emphasizes the importance of the implementation of this type of studies to make a definitive diagnosis, especially in this group of genetically very diverse diseases with overlapping clinical phenotypes. However, given the presence of variants of uncertain significance (VUS), the results may not be conclusive, raising the need to develop functional tests to determine the pathogenicity of these genetic variants. In our working group we are applying droplet digital PCR (ddPCR), a highly sensitive, specific and reproducible third generation quantitative technique that does not require calibration curves, to develop functional tests that allow not only to reclassify VUS variants to achieve definitive diagnoses but also to study the mechanisms responsible for the main AIDs that allow for the stratification of specific treatments to be used and thereby contribute to the individualized diagnosis, treatment, and follow-up of our patients (AU)

Evaluación del panel de enfermedades hepáticas autoinmunes (INMUNOBLOT) en el diagnóstico de enfermedades hepáticas / Utility of the detection of autoantibodies in autoinmune liver diseases using immunoblot

INTRODUCTION: For the diagnosis of liver diseases, clinical criteria, biochemical, immunological and histological parameters are included. The autoimmune panel is an immunoblot that contemplates the detection of antibodies against 9 different hepatic antigens, which could guide the diagnosis of these pathologies. OBJECTIVE: To describe the usefulness of the autoimmune panel in the diagnosis of liver diseases. Methods: Observational, descriptive study. All autoimmune panels performed between January 2020 and August 2021 (n = 279) were reviewed, and the ones with positive result selected (n = 101). Clinical records were reviewed, including: clinical, biochemical, immunological and histological characteristics. Diagnosis was determined by clinical suspicion (clinical, biochemical and immunological parameters), only through autoimmune panel, and according to liver biopsy in available cases. RESULTS: 45 patients with complete clinical history were included in the analysis; 82% women, median age 58 years (16-79). Clinical suspicions included autoimmune hepatitis (AIH) in 12 patients (27%), primary biliary cholangitis (PBC) in 10 patients (22%), overlap syndrome (AIH/PBC) in 17 (38%), and others in 6 (13%). The diagnosis of PBC was confirmed by autoimmune panel in 9/10 and 11/17 patients with clinical suspicion of PBC and HAI/PBC, respectively. Of the 27 patients with initial clinical suspicion of PBC, 14 had negative AMA and AMA-M2 (6 had Sp100 and 5 gp210 as the only markers and 3 had positive Sp100 and PML). In 10/14 patients, the diagnosis was confirmed by panel and/or compatible liver biopsy. CONCLUSION: The autoimmune panel turns out to be a useful diagnostic tool for liver diseases, especially PBC in isolation or in overlap syndrome.

Expert consensus on quality control for detecting autoantibodies / 中华内科杂志

Autoantibodies are important biomarkers of autoimmune diseases and crucial for disease diagnosis, differential diagnosis, and the evaluation of disease activity and prognosis. Specifying the requirement of quality control for detecting autoantibodies is essential for accurately reporting relevant results. In 2023, National Clinical Research Center for Dermatologic and Immunologic Diseases (Peking Union Medical College Hospital), Experimental Diagnosis Research Committee, Rheumatology and Immunology Physicians Committee of Chinese Medical Doctor Association, Autoantibodies Detection Committee, Chinese Rheumatism Data Center invited relevant clinical and laboratory experts to develop the current consensus based on the national standards, the industry guidelines, the national situation, and the experience of quality control regarding autoantibody detection. This consensus aims to standardize the quality control of autoantibody detection in relevant laboratories in China.

Síndrome de Guillain-Barré como forma de presentación de lupus eritematoso sistémico en paciente masculino / Guillain Barré Syndrome as a form of presentation of systemic lupus erythematosus in a male patient

El lupus eritematoso sistémico es una enfermedad reumática, autoinmune, inflamatoria, sistémica y crónica que se caracteriza por afectar principalmente pacientes femeninas en edad fértil. Su mecanismo patogénico se centra en la presencia de un proceso inflamatorio crónico que es el responsable de las manifestaciones clínicas y complicaciones de la enfermedad. Las manifestaciones clínicas se subdividen en articulares y extraarticulares. Entre estas últimas la afectación neurológica cobra especial atención tanto por su frecuencia de presentación elevada como por la gravedad de estas. El síndrome de Guillain-Barré es una enfermedad autoinmune, que puede aparecer como complicación del lupus eritematoso sistémico y se caracteriza por parálisis motora y otros síntomas y signos neurológicos. El objetivo del presente trabajo es reportar el caso de un paciente masculino, de 27 años de edad, que comienza con manifestaciones neuropáticas y se llega a diagnosticar un síndrome de Guillain-Barré que constituyó la forma de presentación del lupus eritematoso sistémico. Por ser una forma de presentación poco común, se considera importante su reporte para conocimiento de la comunidad médica(AU)

Systemic lupus erythematosus is a rheumatic, autoimmune, inflammatory, systemic and chronic disease that is characterized by mainly affecting female patients of childbearing age. Its etiopathogenic mechanism focuses on the presence of a chronic inflammatory process that is responsible for the clinical manifestations and complications of the disease. Clinical manifestations are subdivided into articular and extra-articular. Within the latter, neurological involvement receives special attention both due to its high frequency of presentation and its severity. Guillain-Barré syndrome is an autoimmune disease that can appear as a complication of lupus erythematosus and is characterized by motor paralysis and other neurological signs and symptoms. The objective of this paper is to report the case of a 27-year-old male patient who began with neuropathic manifestations and was diagnosed with Guillain-Barré syndrome, which was the presentation of systemic lupus erythematosus. Because it is an uncommon form of presentation, its report is considered important for the knowledge of the medical community(AU)

Refractory iron deficiency anemia as an early manifestation of autoimmune gastritis in a teenager / Anemia ferropénica refractaria como presentación temprana de gastritis autoinmune en un adolescente

Abstract Autoimmune gastritis is an underdiagnosed disease in the pediatric population due to the absence of specific signs and symptoms and late clinical manifestations. Iron deficiency anemia has recently been identified as an early hematological manifestation, allowing an early diagnostic approach. We present the case of a Colombian teenager, with no history of autoimmunity, with refractory iron deficiency. He underwent extension studies; biopsies and serology compatible with autoimmune gastritis were documented, requiring parenteral iron in its evolution. This pathology is underdiagnosed in our context since early diagnosis requires a high index of suspicion to prevent associated complications.

Resumen La gastritis autoinmune es una enfermedad subdiagnosticada en la población pediátrica. Lo anterior se debe a la ausencia de signos y síntomas específicos y manifestaciones clínicas tardías. Recientemente se ha identificado la anemia ferropénica como una manifestación hematológica precoz, lo que permite un enfoque diagnóstico temprano. Se presenta el caso de un adolescente colombiano, sin antecedentes de autoinmunidad, con ferropenia refractaria, en el que se realizaron estudios de extensión y se documentaron biopsias y serología compatible con gastritis autoinmune, con requerimiento de hierro parenteral en su evolución. Esta patología es subdiagnosticada en nuestro medio, ya que el diagnóstico temprano requiere un alto índice de sospecha, lo que permite la prevención de las complicaciones asociadas.

Recurrent hypoglycemic coma and diabetic ketoacidosis caused by insulin antibody: a rare case of type 1 diabetes mellitus / Hipoglicemia hiperinsulinémica causada por anticuerpos antiinsulina: informe de un caso

ABSTRACT Insulin antibodies (IAs) induced by exogenous insulin rarely cause hypoglycemia. However, insulin autoantibodies (IAAs) in insulin autoimmune syndrome (IAS) can cause hypoglycemia. The typical manifestations of IAS are fasting or postprandial hypoglycemia, elevated insulin level, decreased C-peptide levels, and positive IAA. We report a 45-year-old male with type 1 diabetes mellitus (T1DM) treated with insulin analogues suffering from recurrent hypoglycemic coma and diabetic ketoacidosis (DKA). His symptoms were caused by exogenous insulin and were similar to IAS. A possible reason was that exogenous insulin induced IA. IA titers were 61.95% (normal: 300 mU/L and < 0.02 nmol/L when hypoglycemia occurred. Based on his clinical symptoms and other examinations, he was diagnosed with hyperinsulinemic hypoglycemia caused by IA. His symptoms improved after changing insulin regimens from insulin lispro plus insulin detemir to recombinant human insulin (Gensulin R) and starting prednisone.

Los anticuerpos contra la insulina (AI) inducidos por la insulina exógena raramente causan hipoglucemia. No obstante, los autoanticuerpos contra la insulina (AIA) en el síndrome autoinmune de insulina (SAI) pueden causar hipoglucemia. Las manifestaciones típicas del SAI son la hipoglucemia en ayunas o posprandial, niveles elevados de insulina, la disminución del nivel de péptido C y AIA positivos. Presentamos un paciente hombre de 45 años con diabetes mellitus de tipo 1 (DMT1) tratado con análogos de insulina, que sufría comas hipoglucémicos recurrentes y cetoacidosis diabética (CAD). Sus síntomas fueron causados por la insulina exógena y fueron similares al SAI. La posible razón fue que la insulina exógena indujo AI. El título de AI era del 61,95% (Normal: 300 mU/L y < 0,02 nmol/L cuando se producía la hipoglucemia. Basados en sus síntomas clínicos y otros exámenes, se le diagnosticó hipoglucemia hiperinsulinémica causada por la AI. Sus síntomas mejoraron después de cambiar el régimen de insulina de lispro más insulina detemir a insulina humana recombinante (Gensulin R) y de empezar a tomar prednisona.

Connective tissue diseases and the liver injury / 中华肝脏病杂志

Connective tissue disease (CTD) are closely related to liver abnormality. CTD can affect the liver causing various degrees of liver injury, coexist with other liver diseases, especially autoimmune liver disease (ALD). Medications for CTD can also lead to liver injury or reactivate the hepatitis B virus. CTD patients can also be positive for ALD-related autoantibodies without corresponding manifestation; and vis versa. The diagnosis and differential diagnosis should be made on integrating clinical presentation, laboratory, imaging, and histological studies, not solely relying on autoantibody positivity.

Advances in gut microbiomes and immunology of IgG4-related hepatobiliary and pancreatic diseases / 中华肝脏病杂志

IgG4-related disease (IgG4-RD) is an immune-mediated condition associated with chronic fibroinflammatory lesions that can affect nearly any organ. IgG4-related hepatobiliary and pancreatic diseases are IgG4-RD involving the hepatobiliary and pancreatic system, which is characterized with elevated serum IgG4 concentrations, large numbers of IgG4 positive lymphoplasma cells infiltration in affected organs, storiform fibrosis, and imaging changes of organ morphology. Due to the lack of reliable biomarkers, histopathology is still an important basis for diagnosis. The pathogenesis of IgG4-related hepatobiliary and pancreatic diseases has not been clarified. This review focuses on the recent advances in intestinal microecology-immunology, host genetics-immunity and recurrence monitoring of IgG4-related hepatobiliary and pancreatic diseases.

Guidelines on the diagnosis and management of primary sclerosing cholangitis (2021) / 中华肝脏病杂志

In 2015, the first Chinese consensus on the diagnosis and management of primary sclerosing cholangitis was issued. In the past years, more data have emerged from the literature. Herein, the Autoimmune Liver Disease Group of the Chinese Society of Hepatology organized an expert group to review the evidence and updated the recommendations to formulate the guidelines. There are 21 recommendations on PSC clinical practice. To facilitate the differentiation between PSC and IgG4-related sclerosing cholangitis, 10 recommendations on IgG4-SC are also attached. These guidelines aim to provide a working reference for the management of PSC and IgG4-SC.

Guidelines on the management of cholestasis liver diseases (2021) / 中华肝脏病杂志

In 2015, the Chinese Society of Hepatology and Chinese Society of Gastroenterology issued the consensus on the diagnosis and management of cholestatic liver diseases. In the past years, more data have emerged from clinical practice. Herein, the Autoimmune Liver Disease Group of the Chinese Society of Hepatology organized an expert group to review the evidence and updated the recommendations to formulate the guidelines. There are 22 recommendations on clinical practice of cholestatic liver diseases. The guidelines aim to provide a working reference for the management of cholestatic liver diseases.

Clinical utility of anti-DFS70 for identifying antinuclear antibody-positive patients without systemic autoimmune rheumatic disease

INTRODUCTION@#The antinuclear antibody (ANA) test is a screening test for systemic autoimmune rheumatic disease (SARD). We hypothesised that the presence of anti-DFS70 in ANA-positive samples was associated with a false-positive ANA test and negatively associated with SARD.@*METHODS@#A retrospective analysis of patient samples received for ANA testing from 1 January 2016 to 30 June 2016 was performed. Patient samples underwent ANA testing via indirect immunofluorescence method and anti-DFS70 testing using enzyme-linked immunosorbent assay.@*RESULTS@#Among a total of 645 ANA-positive samples, the majority (41.7%) were positive at a titre of 1:80. The commonest nuclear staining pattern (65.5%) was speckled. Only 9.5% of ANA-positive patients were diagnosed with SARD. Anti-DFS70 was found to be present in 10.0% of ANA-positive patients. The majority (51/59, 86.4%) of patients did not have SARD. Seven patients had positive ANA titre > 1:640, the presence of anti-double stranded DNA and/or anti-Ro60. The presence of anti-DFS70 in ANA-positive patients was not associated with the absence of SARD (Fisher's exact test, p = 0.245).@*CONCLUSION@#The presence of anti-DFS70 was associated with a false-positive ANA test in 8.6% of our patients. Anti-DFS70 was not associated with the absence of SARD.

Miopatía necrotizante autoinmune: Presentación de un caso clínico / Autoimmune necrotizing myositis: Presentation of a clinical case

Las miopatías inflamatorias (MI) son un grupo heterogéneo de enfermedades musculares de rara ocurrencia, caracterizadas por inflamación de los distintos componentes del tejido muscular, ya sea de forma aislada o, más comúnmente, en el contexto de una afección sistémica. Las miopatías necrotizantes inmunomediadas (MNIM) constituyen un subtipo de miopatía inflamatoria caracterizada por debilidad muscular proximal, necrosis de miofibrillas con mínimo infiltrado celular inflamatorio en la biopsia muscular e infrecuente compromiso extramuscular asociado1. Si bien existen similitudes clínicas e histopatológicas, el espectro de las miopatías inflamatorias es considerablemente variable. Por este motivo, es fundamental realizar estudios complementarios para la identificación correcta del subtipo de MI a fin de determinar su pronóstico e implementar un adecuado tratamiento. Se presenta el caso de una paciente de 29 años, sin antecedentes personales y heredofamiliares de enfermedad autoinmune ni antecedentes patológicos relevantes, que consulta a la Guardia Médica de nuestra Institución por un cuadro de dolor e impotencia funcional en los cuatro miembros, con debilidad muscular a predominio de cintura escapular y en menor medida pelviana, acompañado de astenia, tendencia al sueño e hiporreactividad.

Inflammatory myopathies (IM) or myositis are a heterogeneous group of muscle diseases of rare occurrence. Such diseases are characterized by inflammation of the different components of muscle tissue, which can occur either in isolation or, more commonly, as part of a systemic disorder. Immune-mediated necrotizing myopathies (IMNM) are a type of autoimmune myopathy characterized by proximal muscle weakness, myofiber necrosis with minimal inflammatory cell infiltrate on muscle biopsy and infrequent extramuscular involvement1. Even though there are clinical and histopathological similarities. The spectrum of inflammatory myopathies is considerably variable. Therefore, the performance of complementary studies is essential for the proper identification of the IM subtype to contribute accurately on treatment so determine the better prognosis. The present article shows the case of a young 29 years old, with no personal and family history background of autoimmune disease and no relevant pathological background. The patient consulted the medical ward of the Institution with pain, functional impairment of upper and lower extremities, muscle weakness mainly located in the pectoral girdle area and, although to a lesser degree, in the pelvic girdle area. It was also associated with asthenia, tendency to drowsiness and hyporeactivity.

Subacute combined degeneration of the spinal cord with concomitant autoimmune disease: report of 2 cases

The etiology of subacute combined degeneration (SCD) of the spinal cord is closely associated with vitamin B12 (VitB12) deficiency. The clinical manifestations of SCD are complex and vary substantially. Due to some SCD patients with atypical manifestations and concomitant autoimmune disorders, the probability of misdiagnosis and missed diagnosis is still relatively high in the early stage. We report the cases of two patients who were missed or misdiagnosed at another hospital because of the normal initial VitB12 level and partial overlap of clinical manifestations, finally diagnosed as SCD with atypical manifestations and concomitant autoimmune disorders, pharyngeal-cervical-brachial Guillain-Barre syndrome in Case 1 and SCD with autoimmune thyroiditis in Case 2. After undergoing corresponding treatment, death was reported in Case 1 and improvement in Case 2. Analysis of the clinical manifestations and investigation of the underlying pathogenesis in such patients could help improve the rate of early diagnosis and allow timely treatment of SCD, thereby preventing disease progression and poor clinical outcomes.

Neumonía intersticial con características autoinmunes: reporte de caso / Interstitial Pneumonia with Autoimmune Features: case report

La neumonía intersticial con características autoinmunes por sus siglas en inglés, es una entidad en la que existe un compromiso pulmonar intersticial y hallazgos clínicos y paraclínicos que sugieren una enfermedad del tejido conectivo, aunque no cumplen criterios diagnósticos para ninguna de estas. Con fines de investigación, en el 2015 se describieron criterios para esta entidad, en los que se incluyeron características de los dominios clínicos, serológicos y morfológicos, con diversos patrones de compromiso pulmonar. En la actualidad, hay un aumento en el interés de esta entidad, pues algunos autores sugieren que se pueda tratar de una enfermedad autoinmune per se, cuyo órgano blanco principal sería el pulmón. Dado su reciente reconocimiento, son pocos los casos descritos en la literatura. Con el propósito de contribuir a la mejor identificación de esa entidad, presentamos el caso de una paciente de 68 años con afectación pulmonar en quien después de descartar otras causas se llegó al diagnóstico de neumonía intersticial con características autoinmunes al cumplir los criterios de cada dominio requerido. Se inició tratamiento con micofenolato mofetilo a dosis de 2,5 mg/día. En su evolución clínica, la paciente presentó mejoría y fue dada de alta con tratamiento ambulatorio(AU)

Interstitial pneumonia with autoimmune features is a condition in which patients can have clinical and serological findings suggesting of a connective tissue disease associated with an interstitial lung disease, nonetheless no criteria for an specific connective tissue disease are meeting. In 2015 classification criteria where proposed, the diagnosis is made in the presence of a combination of features from clinical, serological and morphological domain with various patterns of pulmonary involvement. Currently there is an increase in the interest of this condition, as some authors suggest that it can be an autoimmune pathology per se, whose main target organ would be the lung. Given its recent recognition, there are few cases described in the literature and therefore in order to contribute to the better identification of that entity, we present the case of a 65 year old patient with lung involvement in whom after ruling out other etiological causes reached the diagnosis of I Interstitial pneumonia with autoimmune by meeting criteria of each required domain(AU)

Encefalitis límbica: clínica, patogenia y problemas diagnósticos / Limbic encephalitis: clinic, pathogenesis and diagnostic problems

La encefalitis límbica es una enfermedad infrecuente y potencialmente grave, que puede o no ser paraneoplásica y se caracteriza por déficit de la memoria reciente, alteraciones psiquiátricas y convulsiones. De origen autoinmunitario, está asociada a anticuerpos séricos e intratecales contra antígenos neuronales intracelulares y de superficie, con especial afectación de zonas límbicas. En este artículo se revisan aspectos históricos y epidemiológicos, patogenia, síndromes más frecuentes y mejor delimitados, histopatología y estudios complementarios. Se repasan también las dificultades del diagnóstico diferencial y la necesidad de descartar siempre un tumor subyacente. La detección de autoanticuerpos neuronales es importante para el diagnóstico, la planificación terapéutica y el pronóstico. La inmunoterapia y, si corresponde, el tratamiento de la neoplasia son cruciales para lograr una recuperación neurológica sustancial. La encefalitis límbica es una entidad probablemente subdiagnosticada, con un pronóstico más favorable si se trata de forma temprana. El actual conocimiento de su patogenia puede además aportar claridad para la mejor comprensión de otros síndromes neurológicos y psiquiátricos que puedan compartir mecanismos autoinmunitarios, como algunos trastornos psicóticos y epilepsias farmacorresistentes. (AU)

Limbic encephalitis is a rare and potentially serious disease, which may or may not be paraneoplastic and is characterized by recent memory deficits, psychiatric disturbances and seizures. Of autoimmune origin, it is associated with serum and intrathecal antibodies against intracellular and surface neuronal antigens, with special involvement of limbic areas. This article reviews historical and epidemiological aspects, pathogenesis, more frequent and better defined syndromes, histopathology and complementary studies. The difficulties of differential diagnosis and the need to always rule out an underlying tumor are also reviewed. Detection of neuronal autoantibodies is important for diagnosis, therapeutic planning and prognosis. Immunotherapy and, if appropriate, neoplasm treatment, are crucial to achieve substantial neurological recovery. Limbic encephalitis is probably an underdiagnosed entity, with a more favorable prognosis if treated early. The current knowledge of its pathogenesis may also provide clarity for a better understanding of other neurological and psychiatric syndromes that may share autoimmune mechanisms, such as some psychotic disorders and drug-resistant epilepsies. (AU)