Management of liver and gastrointestinal toxicity induced by immune checkpoint inhibitors: Position statement of the AEEH–AEG–SEPD–SEOM–GETECCU / Manejo de las toxicidades digestivas secundarias al tratamiento con inhibidores de checkpoint: documento de posicionamiento de la AEEH-AEG-SEPD-SEOM-GETECCU

The development of the immune checkpoint inhibitors (ICI) is one of the most remarkable achievements in cancer therapy in recent years. However, their exponential use has led to an increase in immune-related adverse events (irAEs). Gastrointestinal and liver events encompass hepatitis, colitis and upper digestive tract symptoms accounting for the most common irAEs, with incidence rates varying from 2% to 40%, the latter in patients undergoing combined ICIs therapy. Based on the current scientific evidence derived from both randomized clinical trials and real-world studies, this statement document provides recommendations on the diagnosis, treatment and prognosis of the gastrointestinal and hepatic ICI-induced adverse events.(AU)

El descubrimiento de los inhibidores de checkpoint inmunológicos (ICI) es uno de los logros más importantes en los últimos años en Oncología. Sin embargo, su uso en aumento ha conlllevado a un incremento de los efectos adversos inmunomediados (irAEs). Los eventos hepáticos y gastrointestinales incluyen la hepatitis, colitis y síntomas de tracto digestivo superior, que son de los irAEs más frecuentes, con incidencias entre el 2 y 40%, ésta última en paciente tratados con combo de ICI. Basados en la evidencia científica tanto de ensayo clínicos randomizados como de estudio de vida real, este documento de consenso aporta recomendaciones sobre el diagnóstico, tratamiento y pronóstico de los efectos adversos hepáticos y gastrointestinales asociados con la inmunoterapia.(AU)

Enterocolitis and other immunotherapy and targeted therapy-related gastrointestinal manifestations: A review for gastroenterologist.

New oncologic treatments, particularly immunotherapy (IT), have revolutionized the treatment of advanced-stage malignant tumors. Immune checkpoint inhibitors are the main form of IT and act by increasing T cell activity and the organism's immune response against neoplastic cells. Targeted therapy is another form of IT that acts by inhibiting oncogenes or inflammation signaling and tumor angiogenesis pathways. However, these mechanisms of tumor destruction can interfere with the host's immune self-tolerance or with the mechanisms of epithelial tissue repair and predispose to immune system-mediated adverse events that can affect multiple organs, including the digestive tract. The gastrointestinal manifestations of damage caused by IT can range from low-grade mucositis to ulceration, and in some cases, necrosis and perforation. Any part of the gastrointestinal tract can be affected, but there is greater involvement of the small bowel and colon, with a pattern similar to that seen in inflammatory bowel disease. The most common clinical manifestation is chronic diarrhea. The differential diagnosis includes enteropathogenic infections, especially those caused by opportunistic microorganisms; adverse drug reactions; and other inflammatory and malabsorption disorders. Treatment is guided by damage severity. Mild cases can be treated with antidiarrheals and rehydration in the outpatient setting; moderate cases with hospitalization, systemic steroids, and temporary suspension of IT; and severe cases with immunosuppressants or biologic agents and definitive suspension of IT.

Immune-mediated hepatitis: Basic concepts and treatment.

Immunotherapy with immune checkpoint inhibitors (ICIs) has revolutionized advanced cancer management. Nevertheless, the generalized use of these medications has led to an increase in the incidence of adverse immune-mediated events and the liver is one of the most frequently affected organs. Liver involvement associated with the administration of immunotherapy is known as immune-mediated hepatitis (IMH), whose incidence and clinical characteristics have been described by different authors. It often presents as mild elevations of amino transferase levels, seen in routine blood tests, that spontaneously return to normal, but it can also manifest as severe transaminitis, possibly leading to the permanent discontinuation of treatment. The aim of the following review was to describe the most up-to-date concepts regarding the epidemiology, diagnosis, risk factors, and progression of IMH, as well as its incidence in different types of common cancers, including hepatocellular carcinoma. Treatment recommendations according to the most current guidelines are also provided.

Electroporación irreversible: ampliando las fronteras de la ablación / Irreversible electroporation: Beyond the limits of tumor ablation

La electroporación irreversible o IRE (irreversible electroporation) es una técnica de ablación tumoral no térmica basada en la aplicación de pulsos eléctricos de alto voltaje entre pares de agujas insertadas alrededor de un tumor. La corriente generada favorece la creación de nanoporos en la membrana plasmática, desencadenando la apoptosis. Por ello, la IRE puede utilizarse de manera segura en localizaciones cercanas a estructuras vasculares delicadas, contraindicadas para el resto de técnicas termoablativas. Actualmente la IRE se emplea con éxito para la ablación de tumores en páncreas, riñón e hígado y, de manera muy extendida, como opción terapéutica focal para el cáncer de próstata. La necesidad de un manejo anestésico específico y la colocación precisa y en paralelo de múltiples agujas implican un alto nivel de complejidad, siendo necesaria una gran experiencia del equipo intervencionista. No obstante, se trata de una técnica muy prometedora con una gran capacidad inmunológica sistémica que puede provocar un efecto a distancia del tumor tratado (efecto abscopal).(AU)

Irreversible electroporation (IRE) is a non-thermal tumor ablation technique. High-voltage electrical pulses are applied between pairs of electrodes inserted around and/or inside a tumor. The generated electric current induces the creation of nanopores in the cell membrane, triggering apoptosis. As a result, IRE can be safely used in areas near delicate vascular structures where other thermal ablation methods are contraindicated. Currently, IRE has demonstrated to be a successful ablation technique for pancreatic, renal, and liver tumors and is widely used as a focal therapeutic option for prostate cancer. The need for specific anesthetic management and accurate parallel placement of multiple electrodes entails a high level of complexity and great expertise from the interventional team is required. Nevertheless, IRE is a very promising technique with a remarkable systemic immunological capability and may impact on distant metastases (abscopal effect).(AU)

Avelumab to treat Merkel cell carcinoma: real-life experience in a dedicated oncology center. / Avelumab en el tratamiento del carcinoma de células de Merkel: experiencia en vida real en un centro monográfico oncológico.

The arrival of immunotherapy has revolutioned the management of patients with metastatic Merkel cell carcinoma (MCC). We conducted an observational, retrospective study of 14 cases treated with avelumab. The response rate was 57%: complete response was reached in 29% of patients, and partial responses in 29%. The drug proved effective in 83% (5/6) of the patients with a single metastatic site. However, the disease progressed in 75% (3/4) of the patients with bone metastases. PD1-L expression, MCC polyomavirus (MCPyV) positivity, and an impaired neutrophil-to-lypmhocyte ratio (NLR) could not be associated with responses to the therapy. Avelumab is an effective and safe drug for the management of advanced MCC, and its effectiveness appears to be impacted by the number and location of metastases.

Irreversible electroporation: Beyond the limits of tumor ablation.

Irreversible Electroporation (IRE) is a non-thermal tumor ablation technique. High-voltage electrical pulses are applied between pairs of electrodes inserted around and/or inside a tumor. The generated electric current induces the creation of nanopores in the cell membrane, triggering apoptosis. As a result, IRE can be safely used in areas near delicate vascular structures where other thermal ablation methods are contraindicated. Currently, IRE has demonstrated to be a successful ablation technique for pancreatic, renal, and liver tumors and is widely used as a focal therapeutic option for prostate cancer. The need for specific anesthetic management and accurate parallel placement of multiple electrodes entails a high level of complexity and great expertise from the interventional team is required. Nevertheless, IRE is a very promising technique with a remarkable systemic immunological capability and may impact on distant metastases (abscopal effect).

Management of liver and gastrointestinal toxicity induced by immune checkpoint inhibitors: Position statement of the AEEH-AEG-SEPD-SEOM-GETECCU.

The development of the immune checkpoint inhibitors (ICI) is one of the most remarkable achievements in cancer therapy in recent years. However, their exponential use has led to an increase in immune-related adverse events (irAEs). Gastrointestinal and liver events encompass hepatitis, colitis and upper digestive tract symptoms accounting for the most common irAEs, with incidence rates varying from 2% to 40%, the latter in patients undergoing combined ICIs therapy. Based on the current scientific evidence derived from both randomized clinical trials and real-world studies, this statement document provides recommendations on the diagnosis, treatment and prognosis of the gastrointestinal and hepatic ICI-induced adverse events.

Inmunoterapia vs. terapia diana en el paciente con melanoma avanzado y mutación BRAF V600, ¿por cuál comenzar? / Immunotherapy and Targeted Therapy in Patients With Advanced Melanoma and the V600 BRAF Mutation: Which One First?

El paciente con melanoma avanzado, metastásico o de alto riesgo, cuenta con opciones de tratamiento sistémico, inmunoterapia y terapias dirigidas, que han mejorado significativamente su supervivencia. El 50% de los pacientes con melanoma presentan mutación del gen BRAF. La toma de decisiones en cuanto a la secuencia óptima de tratamiento sistémico debe tener en cuenta factores relacionados con el medicamento, factores clínicos del paciente, así como los propios del tumor. Aunque la combinación ipilimumab-nivolumab es la que proporciona mejores resultados de supervivencia en todos los pacientes, la toxicidad asociada y el perfil de las terapias diana las puede hacer recomendables como primera línea en pacientes en determinadas situaciones clínicas. El objetivo de esta revisión es proporcionar un algoritmo de toma de decisiones en cuanto a la primera línea de tratamiento sistémico, inmunoterapia vs. terapias dirigidas, en el paciente con melanoma avanzado con mutación BRAF (AU)

Systemic treatment with immunotherapy or targeted therapy can significantly improve survival in patients with advanced (metastatic or high-risk) melanoma. Fifty percent of patients with melanoma have a BRAF mutation. Decisions on optimal sequencing of systemic treatments should take into account drug- and tumor-related factors and patient characteristics. Although the combination of ipilimumab and nivolumab is associated with the best survival outcomes, it is associated with significant toxicity. Targeted therapy may be a more favorable option in certain clinical situations. We review the literature on immunotherapy and targeted therapy in melanoma and present an algorithm for guiding decision-making on their use as first-line systemic treatments for advanced BRAF-mutated melanoma (AU)

[Translated article] Immunotherapy and Targeted Therapy in Patients With Advanced Melanoma and the V600 BRAF Mutation: Which One First? / Inmunoterapia vs. terapia diana en el paciente con melanoma avanzado y mutación BRAF V600, ¿por cuál comenzar?

Systemic treatment with immunotherapy or targeted therapy can significantly improve survival in patients with advanced (metastatic or high-risk) melanoma. Fifty percent of patients with melanoma have a BRAF mutation. Decisions on optimal sequencing of systemic treatments should take into account drug- and tumor-related factors and patient characteristics. Although the combination of ipilimumab and nivolumab is associated with the best survival outcomes, it is associated with significant toxicity. Targeted therapy may be a more favorable option in certain clinical situations. We review the literature on immunotherapy and targeted therapy in melanoma and present an algorithm for guiding decision-making on their use as first-line systemic treatments for advanced BRAF-mutated melanoma (AU)

El paciente con melanoma avanzado, metastásico o de alto riesgo, cuenta con opciones de tratamiento sistémico, inmunoterapia y terapias dirigidas, que han mejorado significativamente su supervivencia. El 50% de los pacientes con melanoma presentan mutación del gen BRAF. La toma de decisiones en cuanto a la secuencia óptima de tratamiento sistémico debe tener en cuenta factores relacionados con el medicamento, factores clínicos del paciente, así como los propios del tumor. Aunque la combinación ipilimumab-nivolumab es la que proporciona mejores resultados de supervivencia en todos los pacientes, la toxicidad asociada y el perfil de las terapias diana las puede hacer recomendables como primera línea en pacientes en determinadas situaciones clínicas. El objetivo de esta revisión es proporcionar un algoritmo de toma de decisiones en cuanto a la primera línea de tratamiento sistémico, inmunoterapia vs. terapias dirigidas, en el paciente con melanoma avanzado con mutación BRAF (AU)

Reacciones sarcoideas relacionadas con inhibidores de puntos de control inmunitario / Sarcoid-like Reactions to Immune Checkpoint Inhibitors

Los inhibidores de puntos de control inmunitario (ICI) pueden producir toxicidades cutáneas inmunomediadas entre las que se encuentran las reacciones sarcoideas. Nuestro objetivo fue analizar retrospectivamente los datos clínicos e histológicos de los pacientes en tratamiento con ICI que desarrollaron reacciones sarcoideas cutáneas entre 2019 y 2022. Se incluyeron siete pacientes (seis mujeres y un varón, con una edad mediana de 65años). La mediana de tiempo de instauración de la clínica fue de 4meses y la forma de presentación más frecuente fue la sarcoidosis papulosa de las rodillas, seguida de la sarcoidosis subcutánea. En todos se confirmó el diagnóstico histológicamente y no se observaron diferencias respecto a la sarcoidosis idiopática. Solo en dos casos fue preciso retirar la inmunoterapia. Las reacciones sarcoideas por ICI suelen ser leves y no suelen requerir la interrupción del tratamiento. Es fundamental obtener una confirmación histológica para distinguirlas de la progresión tumoral (AU)

Immune checkpoint inhibitors (ICIs) can cause immune-mediated cutaneous adverse events, including sarcoid-like reactions. The aim of this study was to retrospectively analyze clinical and histologic data from patients who developed cutaneous sarcoid-like reactions between 2019 and 2022 while under treatment with ICIs. We studied 7 patients (6 women and 1 man) with a median age of 65years. Median time to onset of symptoms was 4months. The most common presentation was papular sarcoidosis of the knees followed by subcutaneous sarcoidosis. Diagnosis was confirmed histologically in all cases, and no differences were observed relative to idiopathic sarcoidosis. Discontinuation of ICI therapy was required in just two patients. ICI-induced sarcoid-like reactions tend to be mild and generally do not require treatment discontinuation. Histologic confirmation is essential for distinguishing these reactions from tumor progression (AU)

[Translated article] Sarcoid-like Reactions to Immune Checkpoint Inhibitors / Reacciones sarcoideas relacionadas con inhibidores de puntos de control inmunitario

Immune checkpoint inhibitors (ICIs) can cause immune-mediated cutaneous adverse events, including sarcoid-like reactions. The aim of this study was to retrospectively analyze clinical and histologic data from patients who developed cutaneous sarcoid-like reactions between 2019 and 2022 while under treatment with ICIs. We studied 7 patients (6 women and 1 man) with a median age of 65years. Median time to onset of symptoms was 4months. The most common presentation was papular sarcoidosis of the knees followed by subcutaneous sarcoidosis. Diagnosis was confirmed histologically in all cases, and no differences were observed relative to idiopathic sarcoidosis. Discontinuation of ICI therapy was required in just two patients. ICI-induced sarcoid-like reactions tend to be mild and generally do not require treatment discontinuation. Histologic confirmation is essential for distinguishing these reactions from tumor progression (AU)

Los inhibidores de puntos de control inmunitario (ICI) pueden producir toxicidades cutáneas inmunomediadas entre las que se encuentran las reacciones sarcoideas. Nuestro objetivo fue analizar retrospectivamente los datos clínicos e histológicos de los pacientes en tratamiento con ICI que desarrollaron reacciones sarcoideas cutáneas entre 2019 y 2022. Se incluyeron siete pacientes (seis mujeres y un varón, con una edad mediana de 65años). La mediana de tiempo de instauración de la clínica fue de 4meses y la forma de presentación más frecuente fue la sarcoidosis papulosa de las rodillas, seguida de la sarcoidosis subcutánea. En todos se confirmó el diagnóstico histológicamente y no se observaron diferencias respecto a la sarcoidosis idiopática. Solo en dos casos fue preciso retirar la inmunoterapia. Las reacciones sarcoideas por ICI suelen ser leves y no suelen requerir la interrupción del tratamiento. Es fundamental obtener una confirmación histológica para distinguirlas de la progresión tumoral (AU)

Immunotherapy in multiple myeloma. / Inmunoterapia en el mieloma múltiple.

Patients with multiple myeloma who present with refractory disease or relapse after receiving the main classes of available drugs -immunomodulators, proteasome inhibitors and antibodies against CD38- do not have satisfactory therapeutic alternatives. New treatments based on the redirection of T lymphocytes to act directly against tumor cells, such as bispecific antibodies and T cells with chimeric antigen receptors, are changing this scenario. The published information confirms unprecedented antitumor activity of these agents in patients with refractory myeloma and they will certainly represent the backbone of the treatment of these patients in the immediate future. However, these therapies also present specific characteristics and medium or long-term toxicities that pose new healthcare challenges. In this review, we address the current results and future challenges of the administration of these treatments in patients with relapsed or refractory multiple myeloma.

Immunotherapy and Targeted Therapy in Patients With Advanced Melanoma and the V600 BRAF Mutation: Which One First? / Inmunoterapia vs. terapia diana en el paciente con melanoma avanzado y mutación BRAF V600, ¿por cuál comenzar?

Systemic treatment with immunotherapy or targeted therapy can significantly improve survival in patients with advanced (metastatic or high-risk) melanoma. Fifty percent of patients with melanoma have a BRAF mutation. Decisions on optimal sequencing of systemic treatments should take into account drug- and tumor-related factors and patient characteristics. Although the combination of ipilimumab and nivolumab is associated with the best survival outcomes, it is associated with significant toxicity. Targeted therapy may be a more favorable option in certain clinical situations. We review the literature on immunotherapy and targeted therapy in melanoma and present an algorithm for guiding decision-making on their use as first-line systemic treatments for advanced BRAF-mutated melanoma.

[Translated article] Immunotherapy and Targeted Therapy in Patients With Advanced Melanoma and the V600 BRAF Mutation: Which One First?

Systemic treatment with immunotherapy or targeted therapy can significantly improve survival in patients with advanced (metastatic or high-risk) melanoma. Fifty percent of patients with melanoma have a BRAF mutation. Decisions on optimal sequencing of systemic treatments should take into account drug- and tumor-related factors and patient characteristics. Although the combination of ipilimumab and nivolumab is associated with the best survival outcomes, it is associated with significant toxicity. Targeted therapy may be a more favorable option in certain clinical situations. We review the literature on immunotherapy and targeted therapy in melanoma and present an algorithm for guiding decision-making on their use as first-line systemic treatments for advanced BRAF-mutated melanoma.

[Translated article] Sarcoid-like Reactions to Immune Checkpoint Inhibitors.

Immune checkpoint inhibitors (ICIs) can cause immune-mediated cutaneous adverse events, including sarcoid-like reactions. The aim of this study was to retrospectively analyze clinical and histologic data from patients who developed cutaneous sarcoid-like reactions between 2019 and 2022 while under treatment with ICIs. We studied 7 patients (6 women and 1 man) with a median age of 65years. Median time to onset of symptoms was 4months. The most common presentation was papular sarcoidosis of the knees followed by subcutaneous sarcoidosis. Diagnosis was confirmed histologically in all cases, and no differences were observed relative to idiopathic sarcoidosis. Discontinuation of ICI therapy was required in just two patients. ICI-induced sarcoid-like reactions tend to be mild and generally do not require treatment discontinuation. Histologic confirmation is essential for distinguishing these reactions from tumor progression.

Sarcoid-like Reactions to Immune Checkpoint Inhibitors. / Reacciones sarcoideas relacionadas con inhibidores de puntos de control inmunitario.

Immune checkpoint inhibitors (ICIs) can cause immune-mediated cutaneous adverse events, including sarcoid-like reactions. The aim of this study was to retrospectively analyze clinical and histologic data from patients who developed cutaneous sarcoid-like reactions between 2019 and 2022 while under treatment with ICIs. We studied 7 patients (6 women and 1 man) with a median age of 65years. Median time to onset of symptoms was 4months. The most common presentation was papular sarcoidosis of the knees followed by subcutaneous sarcoidosis. Diagnosis was confirmed histologically in all cases, and no differences were observed relative to idiopathic sarcoidosis. Discontinuation of ICI therapy was required in just two patients. ICI-induced sarcoid-like reactions tend to be mild and generally do not require treatment discontinuation. Histologic confirmation is essential for distinguishing these reactions from tumor progression.

Management of liver and gastrointestinal toxicity induced by immune checkpoint inhibitors: Position statement of the AEEH-AEG-SEPD-SEOM-GETECCU

The development of the immune checkpoint inhibitors (ICI) is one of the most remarkable achievements in cancer therapy in recent years. However, their exponential use has led to an increase in immune-related adverse events (irAEs). Gastrointestinal and liver events encompass hepatitis, colitis and upper digestive tract symptoms accounting for the most common irAEs, with incidence rates varying from 2 % to 40 %, the latter in patients undergoing combined ICIs therapy. Based on the current scientific evidence derived from both randomized clinical trials and real-world studies, this statement document provides recommendations on the diagnosis, treatment and prognosis of the gastrointestinal and hepatic ICI-induced adverse events (AU)

El descubrimiento de los inhibidores de checkpoint inmu nológicos (ICI) es uno de los logros más importantes en los últimos años en Oncología. Sin embargo, su uso en aumen to ha conlllevado a un incremento de los efectos adversos inmunomediados (irAEs). Los eventos hepáticos y gastroin testinales incluyen la hepatitis, colitis y síntomas de tracto digestivo superior, que son de los irAEs más frecuentes, con incidencias entre el 2 % y 40 %, esta última en paciente tratados con combo de ICI. Basados en la evidencia científica tanto de ensayo clínicos randomizados como de estudio de vida real, este documento de consenso aporta recomenda ciones sobre el diagnóstico, tratamiento y pronóstico de los efectos adversos hepáticos y gastrointestinales asociados con la inmunoterapia. (AU)

Aspectos prácticos sobre la determinación de PD-L1 en el tratamiento de carcinoma urotelial. Consenso del grupo de uropatología de la SEAP / Practical aspects of PD-L1 assessment in the treatment of urothelial carcinoma: Consensus of the uropathology group of the SEAP

La reciente llegada de nuevos fármacos de inmunoterapia para el tratamiento del carcinoma urotelial hace necesario establecer criterios para armonizar la determinación de PD-L1 mediante inmunohistoquímica como factor pronóstico y para la selección de pacientes a tratar. En este escenario, un grupo de uropatólogos de la Sociedad Española de Anatomía Patológica, junto con un oncólogo médico como colaborador externo subespecializado en urooncología, ha elaborado este documento de recomendaciones basadas en la evidencia disponible. En la determinación de PD-L1 son especialmente relevantes la selección de la muestra analizada, su procesamiento, la plataforma de inmunohistoquímica y anticuerpo empleados, así como el algoritmo que se aplique para la lectura. Todos estos aspectos deben indicarse en el informe de resultados, que debería poder ser fácilmente interpretable en un contexto de rápida evolución de terapias inmunológicas.(AU)

The recent addition of novel immunotherapy drugs for the treatment of urothelial carcinoma makes it necessary the establishment of criteria to harmonize the immunohistochemical assessment of PD-L1, both as a prognostic factor and for the selection of patients to be treated. In this scenario, a group of uropathologists from the Spanish Society of Pathological Anatomy, together with a medical oncologist as an external collaborator subspecialized in uro-oncology, have prepared this document of recommendations based on the available evidence. During PD-L1 assessment it is especially relevant the selection of the sample, its processing, the immunohistochemical platform and antibody used, and the algorithm applied in the interpretation of results. All these aspects must be indicated in the results report, which should be easily interpretable in a context of rapid evolution of immunological therapies.(AU)

Adverse renal effects of check-point inhibitors (ICI) in cancer patients: Recommendations of the Onco-nephrology Working Group of the Spanish Society of Nephrology.

The most widely used approach in the immunotherapy treatment of cancer is the administration of monoclonal antibodies directed against regulatory molecules of immune control that inhibit the activation of T cells, the so-called check point inhibitors (ICI). ICI nephrotoxicity epidemiology and pathology; its diagnosis with or without kidney biopsy; the type and duration of treatment; the possibility of rechallenging after kidney damage; and its indication in patients with cancer and renal transplantation are certainly controversial. In the absence of definitive studies, this document is intended to specify some recommendations agreed by the group of Onconephrology experts of the Spanish Society of Nephrology in those areas related to ICI nephrotoxicity, in order to help decision-making in daily clinical practice in Onconephrology consultations.

[Report of two cases of anti-LGI1 autoimmune encephalitis in Mexico]. / Reporte de dos casos de encefalitis autoinmune anti-LGI1 en México.

Background: Anti-LGI1 encephalitis is characterized by a pattern of inflammation that predominantly affects the limbic system It is part of the autoimmune encephalitis that attack neuronal surface antigens. It is characterized by the triad of subacute dementia, faciobrachial dystonic crises, and hyponatremia, presenting an excellent response to immunotherapy. The aim of this article is to describe the clinical evolution and functional outcome at 6 months of two patients with anti-LGI1 encephalitis using clinical cases. Clinical cases: Case 1: 62-year-old man with 8-week symptoms manifested by changes in mood, disorientation, and focal motor seizures. Case 2 A 72-year-old woman with a 5-month evolution of rapidly progressive dementia, hyponatremia and bitemporal hyperintensities on MRI. In both, due to clinical suspicion, acute dual immunotherapy with steroid and immunoglobulin was given with substantial improvement. Subsequently, the existence of anti-LGI1 antibodies in cerebrospinal fluid was confirmed. Although both patients received a dose of rituximab during their hospitalization, only the patient in the first case continued biannual doses of rituximab. The second patient was not initially considered to continue long-term immunomodulatory treatment and experienced a relapse. Conclusions: These clinical vignettes present the reader with the classic characteristics of this disease. This can facilitate its recognition and timely initiation of treatment, improving the functional prognosis of patients.

Introducción: la encefalitis anti-LGI1 se caracteriza por un patrón de inflamación que afecta de forma predominante al sistema límbico. Forma parte de las encefalitis autoinmunes que atacan a antígenos de superficie neuronal. Se caracteriza por la tríada de demencia subaguda, crisis distónicas faciobraquiales e hiponatremia, presentando una respuesta excelente a la inmunoterapia. El objetivo de este trabajo es describir por casos clínicos la evolución clínica y resultado funcional a 6 meses de dos pacientes con encefalitis anti-LGI1. Casos clínicos: caso 1: hombre de 62 años con cuadro de 8 semanas, manifestado por cambios en el estado de ánimo, desorientación y crisis focales motoras. Caso 2: mujer de 72 años con una evolución de 5 meses de demencia rápidamente progresiva, hiponatremia e hiperintensidades bitemporales en RMN. En ambos, ante la sospecha clínica, se otorgó inmunoterapia dual aguda con esteroide e inmunoglobulina con mejoría sustancial, posteriormente se corroboró la existencia de anticuerpos anti-LGI1 en líquido cefalorraquídeo. Pese a que ambos pacientes recibieron una dosis de rituximab durante su hospitalización, solo el primer caso continuó dosis semestrales de rituximab. El segundo no fue considerado inicialmente para continuar con tratamiento inmunomodulador a largo plazo y presentó una recaída. Conclusiones: estos casos, presentan al lector las características clásicas de esta enfermedad. Esto puede facilitar su reconocimiento y la instauración oportuna del tratamiento, mejorando el pronóstico funcional de los pacientes.