Endocrinopatías por inmunoterapia oncológica / Endocrinopathies by oncological immunotherapy

La relación entre inmunidad y cáncer es compleja. Las células tumorales desarrollan mecanismos de evasión a las respuestas del sistema inmunitario. Esta capacidad permite su supervivencia y crecimiento. La inmunoterapia ha transformado el tratamiento oncológico mejorando la respuesta inmunitaria contra la célula tumoral. Esta se basa en el bloqueo de los puntos de control inmunitario mediante anticuerpos monoclonales contra la molécula inhibidora CTLA-4 (antígeno 4 del linfocito T citotóxico [CTLA-4]) y la proteína 1 de muerte celular programada y su ligando (PD-1/PD-L1). Aunque los inhibidores de los puntos de control inmunitario (ICIs) son fármacos bien tolerados, tienen un perfil de efectos adversos conocido como eventos adversos inmunorrelacionados (EAI). Estos afectan varios sistemas, incluyendo las glándulas endocrinas. Los eventos adversos endocrinos más frecuentes son la disfunción tiroidea, la insuficiencia hipofisaria, la diabetes mellitus autoinmune y la insuficiencia suprarrenal primaria. El creciente conocimiento de estos efectos adversos endocrinos ha llevado a estrategias de tratamiento efectivo con el reemplazo hormonal correspondiente. El objetivo de esta revisión es reconocer la incidencia de estas nuevas endocrinopatías, la fisiopatología, su valoración clínica y el manejo terapéutico. (AU)

The relationship between immunity and cancer is complex. Tumor cells develop evasion mechanisms to the immune system responses. This ability allows their survival and progression. Immunotherapy has transformed cancer treatment by improving the immune response against tumor cells. This is achieved by blocking immune checkpoints with monoclonal antibodies against cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) and programmed cell death protein 1 and its ligand (PD-1 / PD-L1). Although the immune checkpoint inhibitors (ICIs) are well tolerated drugs, they have a profile of adverse effects known as immune-related adverse events (irAES). These involve diverse systems, including the endocrine glands. The most frequent endocrine immune-related adverse events are thyroid and pituitary dysfunction, autoimmune diabetes mellitus and primary adrenal insufficiency. The increasing knowledge of these irAES has led to effective treatment strategies with the corresponding hormonal replacement. The objective of this review is to recognize the incidence of these new endocrinopathies, the physiopathology, their clinical evaluation, and therapeutic management. (AU)

Clinical and hormonal characteristics of patients with different types of hypophysitis: a single-center experience

ABSTRACT Objective: The inflammation of the pituitary gland is known as hypophysitis. It is a rare disease accounting for approximately 0.24%-0.88% of all pituitary diseases. The natural course of hypophysitis is variable. Main forms are histologically classified as lymphocytic, granulomatous, IgG4 related and xanthomatous. We aim to present our patients with hypophysitis and compare clinical, laboratory and radiological features. Subjects and methods: We retrospectively reviewed our database of 1.293 patients diagnosed with pituitary diseases between 2010 and 2017. Twelve patients with hypophysitis were identified. Demographical data, clinical features, endocrinological dysfunction, imaging findings, treatment courses and follow-up periods were evaluated. Results: The frequency of hypophysitis was found 0.93% in all cases of the pituitary disease. Twelve patients (nine females and three males), ages between 17-61 years, were evaluated. The characteristic features of our patients tended to be predominantly female and young. Diagnosis of hypophysitis was made after pituitary biopsy in four patients, and in eight patients after pituitary operation due to adenoma. Headache (67%) and visual problems (33%) were the most frequent nonendocrine symptoms. Anterior pituitary hormone deficiencies (63.7%) and/or diabetes insipidus (17%) were seen among patients. According to histopathological forms, four had lymphocytic, seven had granulomatous and one had xanthogranulomatous types. Contrast enhancement heterogeneous and thickened pituitary stalk were the most common radiological alterations. Conclusion: Hypophysitis should be considered in the differential diagnosis of sellar masses. It can mimic pituitary adenomas in radiological and endocrinological aspects. The different patterns of pituitary hormone deficiencies may be seen in the course of the disease.

Hipofisitis linfoplasmocitaria con expresión de IgG4 / IgG4- related lymphoplasmacytic hypophysitis

La hipofisitis linfoplasmocitaria con expresión de inmunoglobulina G4 (IgG4) es una entidad de reciente conocimiento. Pertenece al grupo de enfermedades relacionadas a IgG4 (IgG4-RD, del inglés: IgG4-related disease), donde uno o varios órganos pueden estar comprometidos, con síntomas compresivos u obstructivos, o disfuncionalidad por infiltración celular. La hipófisis puede estar afectada en forma aislada. Clínicamente, se presentan con diabetes insípida, hipopituitarismo y/o síntomas de masa ocupante selar, siendo los principales diagnósticos diferenciales los adenomas selares no secretantes, y otros tipos de hipofisitis. Para arribar al diagnóstico de este tipo patología es necesaria la presencia de una imagen de agrandamiento selar o engrosamiento del tallo pituitario en la resonancia magnética nuclear, una histopatología característica con inmunomarcación positiva para IgG4 en más de 10 células plasmáticas por campo de gran aumento y la presencia de IgG4 sérica elevada. Tienen una excelente respuesta a glucocorticoides, por lo que una sospecha diagnóstica oportuna evitaría una cirugía innecesaria en la mayoría de los pacientes con esta entidad.

Immunoglobulin G4 (IgG4)-related lymphoplasmacytic hypophysitis is a recently known entity. It belongs to the IgG4-related diseases (IgG4-RD), in which one or more organs may be involved, with compressive or obstructive symptoms, or dysfunctionality due to cellular infiltration. The pituitary gland can be isolatedly affected. Clinically, lymphoplasmacytic hypophysitis presents with diabetes insipidus, hypopituitarism and/or symptoms of an occupying sellar mass, being the non-secreting sellar adenomas and other types of hypophysitis the main differential diagnosis. In order to reach the diagnosis, the presence of pituitary enlargement or pituitary stalk thickening on an MRI scan, a distinctive histopathology with positive for IgG4 immunostaining in more than 10 plasma cells per high-powerfield, and elevated serum IgG4 levels, confirms this type of hypophysitis. As this entity has an excellent response to glucocorticoids, the diagnosis suspicion may avoid an unnecessary surgery in most patients.