Lithium and endocrine dysfunction / Litio y disfunción endocrina

Abstract Lithium carbonate is a commonly prescribed drug for bipolar disorders. In addition to its action on the central nervous system, lithium has systemic effects on multiple organs such as kidney, heart, motor end plate, thyroid and parathyroid glands. It can cause hypothyroidism, hyperthyroidism, goiter and oph thalmopathy by different mechanisms. It increases intrathyroid iodine content or compete for iodine transport, resulting in low iodine uptake by the thyroid. It also inhibits the coupling of iodotyrosine residues to form iodothy ronines and inhibits the release of T4 and T3. Lithium has direct actions on parathyroid glands by antagonizing the calcium sensing receptor, which may induce hypercalcemia or even hyperparathyroidism, requiring surgery in some cases. Furthermore, it inhibits the expression of aquaporins, mainly aquaporin 2, in the renal collecting tubule by unknown mechanisms leading to nephrogenic diabetes insipidus. This adverse effect is usually reversible after drug withdrawal. However, some patients may present irreversible kidney damage due to chronic interstitial nephropathy.

Resumen El carbonato de litio es un fármaco que se prescribe comúnmente para el tratamiento de trastornos bipolares. Además de su acción sobre el sistema nervioso central, el litio tiene repercusiones sistémicas, afectando a múltiples órganos como el riñón, el corazón, la placa motora terminal y glándulas tiroides y paratiroides. Puede causar hipotiroidismo, hipertiroidismo, bocio y oftalmopatía por diferentes mecanismos; también aumentar el contenido de yodo intratiroideo o competir por el transporte de yodo, lo que resulta en una baja captación tiroidea de yodo. Inhibe el acoplamiento de residuos de yodotirosina para formar yodotironinas e inhibe la liberación de T4 y T3. Tiene acciones directas sobre las glándulas paratiroides antagonizando el receptor sensor de calcio, lo que puede inducir hipercalcemia e incluso hiperparatiroidismo, y puede requerir cirugía en algunos casos. Inhibe la expresión de acuaporinas en el túbulo colector renal, prin cipalmente acuaporina 2, por mecanismos que aún no se conocen, produciendo diabetes insípida nefrogénica; este efecto adverso suele ser reversible tras la suspensión del fármaco. Sin embargo, algunos pacientes pueden presentar daño renal irreversible por nefropatía intersticial crónica.

Depleción corporal de magnesio durante el embarazo por nefropatía hipercalcemica. Reporte de caso y revisión de la literatura / Magnesium depletion secondary to hypercalcémie nephropathy during pregnancy: Case report and literatura review

Resumen El magnesio sérico es el "ion olvidado" en la práctica médica: la mayoría de veces no se tiene en cuenta en los estudios clínicos, sus alteraciones tienden a ser ignoradas y su aproximación terapéutica no está definida de forma adecuada. La sintomatologia producto de la hipomagnesemia es inespecífica y su aproximación diagnostica es compleja. Se presenta el caso de una paciente con hipomagnesemia sintomática severa asociada a daño renal por hipercalcemia durante la gestación.

Abstract Serum magnesium is the «forgotten ion¼ in medical practice. Most of the time it is not taken into account in clinical studies, its alterations tend to be ignored and its therapeutic approach is not well defined. The symptomatology produced by hypomagnesemia is nonspecific and its diagnostic approach is complex. We present the case of a pregnant patient with symptomatic hypomagnesemia secondary to renal damage due to hypercalcemia.

Medios de contraste intravascular en tomografía computada y resonancia magnética: lo que el clínico necesita saber / Intravascular contrast media in computed tomography and magnetic resonance imaging: what the clinician needs to know

Introducción: los medios de contraste en radiología se utilizan para mejorar la visibilidad de los tejidos normales y patológicos, lo que permite distinguirlos entre sí mediante la modificación de las características de imagen de los tejidos. Permite no solo una mejor evaluación morfológica de las lesiones, sino también una evaluación cinética funcional y de contraste. Objetivos: presentar una revisión actualizada sobre los medios de contraste intravascular en radiología, con énfasis en los conceptos que el médico clínico no radiólogo debe tener presente al momento de su indicación. Métodos: se realizó una revisión bibliográfica de literatura radiológica relevante sobre medios de contraste intravascular: clasificación, indicaciones, contraindicaciones y precauciones que debe adoptar el médico clínico. Resultados: aunque los medios de contraste en radiología tienen un excelente perfil de seguridad, su uso no está exento de riesgos y debe basarse en criterios apropiados después de una evaluación clínica exhaustiva, ponderando riesgos y beneficios para cada paciente individual. Conclusión: la comunicación entre médicos tratantes, nefrólogos y radiólogos es funda-mental para evaluar casos clínicos complejos o que requieran consideraciones especiales al momento de indicar la administración de un medio de contraste intravascular.

Introduction: Imaging contrast media are used to enhance the visibility of normal and pathologic tissues, allowing distinction of one another by modifying tissue imaging characteristics. This allows both enhanced morphologic assessment of lesions and also contrast kinetics evaluation. Objectives: To present an updated review on intravascular imaging contrast media. Emphasis will be put on useful concepts that general physicians must take into account when indicating contrast-enhanced imaging studies.Methodology: A bibliographic review of relevant imaging literature on intravascular contrast media was performed: classification, appropriate indications, contraindications, and tips for proper use by the general physician. Results: Although imaging contrast media have an excellent safety profile, its use is not risk-free and must be based on appropriateness criteria applied after a thorough clinical evaluation, balancing the risks and benefits for each patient. In particular, intravascular contrast media, such as those based on iodine for computed tomography and gadolinium chelates for magnetic resonance imaging, must be used with caution. Conclusion: Effective communication between radiologists and referring physicians is key in the evaluation of complex cases that require protocol adjustments when considering the use of intravascular contrast media for imaging studies.

Diabetes insípida nefrogénica inducida por litio: reporte de 2 casos en niños con trastorno del ánimo / Lithium-induced Nephrogenic Diabetes Insipidus: Report of 2 Cases in Children with Mood Disorder

La diabetes insípida (DI) es un síndrome caracterizado por poliuria y polidipsia asociado a la producción crónica de grandes volúmenes de orina diluida, secundario a una disminución de la secreción o acción de la hormona antidiurética (ADH) [1]. El litio es el principal fármaco implicado en la inducción de esta patología cuando se presenta de forma secundaria. [2]. Se presentan 2 reportes de casos de niños de 10 y 12 años con uso de litio por diagnóstico de trastorno del ánimo. Palabras Clave: Diabetes Melitus, trastornos del ánimo, nefrogénica, litio, hormona antidiurética

Diabetes insipidus (DI) is a syndrome characterized by polyuria and polydipsia associated with the production of large volumes of diluted urine, secondary to a decrease in the secretion or action of antidiuretic hormone (ADH) [1]. Lithium is the main drug involved in the induction of this pathology when it appears with a preventable cause [2]. Two case reports of children 10 and 12 years old with mood disorder and lithium use are presented with the intention of being alert to clinical manifestations and observation by caregivers.Key words: Diabetes insipidus, mood disorders, nephogenic, lithium, antidiuretic hormone.

Imágenes del depósito de gadolinio en el sistema nervioso central / Images of gadolinio deposit in the central nervous system Abstract

Magnetic resonance imaging has been shown to be very useful in the diagnosis and monitoring of multiple diseases affecting the central nervous system. Gadolinium has been used extensively worldwide. It has been estimated that since its introduction more than two hundred million doses of GBCA have been administered globally. Gadolinium-based contrast agents (GBCAs) were long considered medicines with a high safety profile, the literature reports incidences of immediate adverse effects such as headache, dizziness, and altered sense of taste. Studies performed a few years after the introduction of GBCA showed that there were gadolinium deposits in the tissues but their clinical significance was not known. It wasn’t until 2006 when the first reports were published that associated the gadolinium ion tissue deposits from GBCA with a systemic inflammatory entity of the connective tissue similar to scleroderma known as Nephrogenic Systemic Fibrosis (NSF), in patients with chronic renal failure. In 2013, the association between the use of GBCAs and the progressive increase in the signal intensity of the dentate nucleus and the globus pallidus in T1-weighted MRI images without contrast medium, was described for the first time. This review describes the most relevant aspects of the pathophysiology of these findings taking into account their differential diagnosis.

Las imágenes por resonancia magnética han mostrado ser de gran utilidad en el diagnóstico y seguimiento de múltiples enfermedades que afectan el sistema nervioso central. El gadolinio se ha utilizado ampliamente a nivel mundial. Se estima que desde su introducción se han administrado más de doscientos millones de dosis de MCBG en el mundo. Los medios de contraste basados en Gadolinio (MCBG) fueron considerados por mucho tiempo medicamentos con un alto perfil de seguridad, la literatura reporta incidencia de efectos adversos inmediatos como cefalea, mareo y alteración del sentido del gusto. Estudios realizados pocos años después de la introducción de los MCBG mostraron que había depósitos de gadolinio en los tejidos, pero no se conocía su significancia clínica Fue hasta 2006 cuando se publicaron los primeros reportes que asociaban el depósito tisular del ion gadolinio proveniente de los MCBG con una entidad inflamatoria sistémica del tejido conectivo similar a la escleroderma conocida como Fibrosis Sistémica Nefrogénica (FSN) en pacientes con falla renal crónica. En 2013 se describió por primera vez la asociación entre el uso de los MCBG y el aumento progresivo de la intensidad de señal del núcleo dentado y los globos pálidos en las imágenes de RM ponderadas en T1 sin medio de contraste. En esta revisión se describen los aspectos más relevantes de la fisiopatología de estos hallazgos considerando su diagnóstico diferencial.

Análisis de costo efectividad del ácido gadotérico frente a otros medios de contraste basados en gadolinio / Analysis of Cost Effectiveness of Gadoteric Acid versus Other Contrast Agents Gadolinium-Based

Objetivo: Hacer una análisis de costo-efectividad en el uso del ácido gadotérico en resonancia magnética para pacientes con insuficiencia renal crónica tipo 4 y 5, en comparación con otros medios de contraste gadolínicos. Métodos: Mediante un modelo de árbol de decisión, desde la perspectiva del tercero pagador, se compararon diferentes medios de contraste gadolínicos. El desenlace de análisis fue sobrevida medida en años de vida ganados, para una esperanza de vida de 64,5 años y una edad promedio de 60 años. Se manejaron los precios del mercado obtenidos del Sistema de Información de Precios de Medicamentos, en pesos colombianos de 2013. Se evaluó el costo de las tecnologías para una presentación de 15 ml. Resultado: La efectividad de medios de contraste se evaluó en términos de seguridad. La principal complicación se encontró en la fibrosis sistémica nefrogénica luego del uso de estos medios de contraste en pacientes con enfermedad renal avanzada, siendo letal en más del 56 % de los casos. Se encontró que no se informan casos de fibrosis sistémica nefrogénica con el uso de ácido gadotérico y de gadobutrol. El primero mostró un promedio de años de vida de 1,706 y fue el menos costoso de todos. En el análisis tipo Montecarlo con variaciones de ±50 %, mantiene su dominancia en el 100 % de las iteraciones. Conclusiones: El ácido gadotérico es la opción más favorable por su dominancia y mejor o igual en efectividad frente a los demás medios de contraste gadolínicos.

Objective: To evaluate the cost - effectiveness of the use of gadoteric acid in magnetic resonance in patients with type 4 and 5 chronic renal failure, versus other gadolinic contrast media methods. Methods: From the perspective of a third party payer, different gadolinic contrast media were compared using a decision tree model. The analysis outcome was survival measured in years of life gained, for a life expectancy of 64.5 years an average age of 60 years. Market prices obtained from the Information System on Drug Prices for Colombia were handled in Colombian pesos (2013). The technology costs for a 15 ml presentation were evaluated. Result: The effectiveness of contrast media was assessed in terms of security. The main complication was nephrogenic systemic fibrosis in the use of these contrast media in patients with advanced renal disease. It was lethal in over 56% of cases. We found no cases of nephrogenic systemic fibrosis reported using gadoteric acid and gadobutrol. The first showed an average life of 1,706 years; and was the least expensive compared to all the analyzed ones. In the Monte Carlo analysis with variations of + / -50 %, it maintains its dominance in 100% of iterations. Conclusions: Gadoteric acid is the most favorable option due to its dominance. Its effectiveness is greater than or equal to the effectiveness of other contrast media.

Diabetes insípida nefrogénica / Nephrogenic diabetes insipidus

La hormona antidiurética arginina vasopresina (AVP) es liberada de la hipófisis, y regula la reabsorción de agua en las células principales del túbulo colector renal. La unión de la AVP al receptor tipo 2 de la AVP en la membrana basolateral induce la translocación de los canales acuosos de la acuaporina-2 hacia la membrana apical de las células principales de los túbulos colectores, induciendo la permeabilidad al agua de la membrana. Lo anterior da como resultado la reabsorción de agua en el túbulo colector de la nefrona, bajo la influencia de un gradiente osmótico. La diabetes insípida nefrogénica es causada por la resistencia parcial o total al efecto de la AVP. La diabetes insípida nefrogénica congénita es una alteración asociada con mutaciones en los genes AVPR2 o AQP2, ocasionando la incapacidad del paciente para concentrar la orina. La diabetes insípida nefrogénica adquirida o secundaria puede ser causada por desbalances electrolíticos (hipercalcemia, hipokalemia), enfermedades renales o extrarrenales y fármacos (toxicidad por litio). En este artículo se revisan las causas, manifestaciones clínicas, diagnóstico y tratamiento de los pacientes con diabetes insípida nefrogénica. También, con base en la comprensión de los mecanismos íntimos de la alteración, se exploran nuevas estrategias terapéuticas.

The anti-diuretic hormone arginine-vasopressin (AVP) is released from the pituitary and regulates water reabsorption in the principal cells of the kidney collecting duct. Binding of AVP to the arginine-vasopressin receptor type-2 in the basolateral membrane leads to translocation of aquaporin-2 water channels to the apical membrane of the principal cells of the collecting duct, inducing water permeability of the membrane. This results in water reabsorption in the collecting duct of the nephron following an osmotic gradient. Nephrogenic diabetes insipidus is caused by partial or complete renal resistance to the effects of AVP. Congenital nephrogenic diabetes insipidus is a disorder associated with mutations in either the AVPR2 or AQP2 gene, causing the inability of patients to concentrate their urine. Acquired nephrogenic diabetes insipidus can be caused by electrolyte imbalances (e.g., hypercalcemia, hypokalemia), renal/extra-renal diseases and drugs (e.g., lithium toxicity). This article reviews the causes, clinical manifestations, diagnosis and treatment of patients with nephrogenic diabetes insipidus. Based on more in-depth mechanistic understanding, new therapeutic strategies are current being explored.

Fibrosis sistémica nefrogénica: Presentación de un caso y revisión de la literatura / Nephrogenic systemic fibrosis: A case report and review of the literature

La fibrosis sistémica nefrogénica (FSN) es una enfermedad fibrosante de reciente identificación, que afecta exclusivamente a pacientes con insuficiencia renal. Se caracteriza por una fibrosis extensa de los tejidos, especialmente de la piel. Aunque su etiología no es del todo conocida, se ha asociado fuertemente al uso de contrastes de gadolinio en pacientes con insuficiencia renal avanzada. Se describe a continuación un caso de FSN diagnosticado en España.

Nephrogenic systemic fibrosis (NSF) is a rare condition appearing only in patients with severe renal impairment and characterized by widespread tissue fibrosis. Although the pathogenesis of this disorder remains unclear, there is evidence of a strong association between gadolinium-based contrast agents (Ga-CA) exposure and the triggering of this disease. Cellular elements involved in pathogenesis of NSF include bone-marrow-derived collagen producing fibrocytes, myofibroblasts and activated macrophages. We present the case of a caucasian female with advanced renal failure who underwent several times magnetic resonance imaging (MRI) procedures using Ga-CA. The patient developed a progressive fibrosing disorder with bilateral indurated papules on the lower legs, joint contractures and hairlessness, and was diagnosed of NSF based on the histologic findings of skin biopsies. Later in the disease she presented with systemic involvement and fatal evolution.

Diabetes insípida: generalidades y diagnóstico en pacientes pediátricos / Diabetes insipidus: overview and diagnosis in pediatric patients

La diabetes insípida es una enfermedad caracterizada por la incapacidad parcial o total para concentrar la orina, debido a una deficiencia en la secreción de vasopresina (diabetes insípida central), resistencia en la acción de la misma (diabetes insípida nefrogénica) o a ingesta excesiva de agua (polidipsiaprimaria). Las principales manifestaciones son polidipsia, poliuria y nicturia; la diabetes insípida central tiene un inicio repentino, mientras que la nefrogénica tiene un inicio más gradual. Gracias a los avances en laboratorio clínico, imaginología y biología molecular, ha mejorado el diagnóstico etiológico de la diabetes insípida, pasando de 50% de casos idiopáticos a solo entre 10% y 20%, de forma que se ha logrado un tratamiento más oportuno, con la consecuente reducción del riesgo de secuelas. En este sentido, es de especial importancia descartar causas secundarias, tales como medicamentos o desórdenes metabólicos en la diabetes insípida nefrogénica y tumores cerebrales, traumatismos craneoencefálicos, enfermedades infiltrativas, enfermedades autoinmunes o infecciones de sistema nervioso central en el caso de la diabetes insípida central. En cuanto al tratamiento, para la diabetes insípida central se recomienda el uso de desmopresina, análogo sintético de la vasopresina, y para la nefrogénica aporte de agua, limitación a la ingesta de sal y el consumo de diuréticos y antinflamatorios no esteroideos. En este artículo de revisión se describirá la fisiopatología, manifestaciones clínicas, diagnóstico y tratamiento de la diabetes insípida en la edad pediátrica.

Diabetes insipidus is a disease characterized by partial or total inability to concentrate urine; the disease can be caused by vasopressin secretion deficiency (central diabetes insipidus), resistance to its action (nephrogenic diabetes insipidus) or an excessive consumption of water (primary polydipsia). The main signs and symptoms of the disease are polydipsia, polyuria, and nocturia; in addition, central diabetes insipidus has an insidious onset, whereas nephrogenic diabetes insipidus has a gradual onset. Because of the advances in clinical laboratory, imaging techniques and molecular biology, the etiologic diagnosis of diabetes insipidus has improved, and the rate of idiopathic diabetes insipidus, which initiallycorresponded to 50% of patients, has dramatically decreased to 10%-20% of patients; therefore, it has been achieved more timely treatments, resulting in reduction of the risk of sequelae. Accordingly, it is pivotal to rule out secondary causes of diabetes insipidus, such as drug consumption or metabolic disorders in patients with nephrogenic diabetes insipidus, and brain tumors, encephalic trauma, infiltrative diseases, autoimmune disorders or central nervous system infections in case of patients suffering of central diabetes insipidus. Regarding treatment, it is recommended to use desmopressin, an analogue of vasopressin, for the treatment of central diabetes insipidus, whereas water consumption, decrease of salt consumption and treatment with diuretic and non-steroidal anti-inflammatory drugs are recommended for treatment of patients with nephrogenic diabetes insipidus. This review article describes physiopathology, signs and symptoms, diagnosis, and treatment of children with diabetes insipidus.

Nephrogenic systemic fibrosis: concepts and perspectives / Fibrose nefrogênica sistêmica: conceitos e perspectivas

Nephrogenic systemic fibrosis is a chronic, progressive condition that develops in some patients with renal impairment after exposure to gadolinium-based contrast agents used in magnetic resonance imaging. Thickening of the skin is typical, usually affecting the extremities. Visceral organs can also be affected. The diagnosis of the disease requires careful clinicopathological correlation. Treatment aims at restoring renal function, which is associated with delayed progression and, eventually, remission of skin changes. Reduction and prevention of nephrogenic systemic fibrosis cases are based on limiting the use of gadolinium-based contrast agents in patients with kidney disorders (especially in patients with advanced renal failure at stages 4 and 5), and restricting their use to situations in which they are essential to diagnosis/follow-up. Other than limiting exposure to gadolinium based contrast agents, no effective preventive methods have been reported. Due to increased awareness about the disease among radiologists and nephrologists, the incidence of nephrogenic systemic fibrosis is declining.

Fibrose nefrogênica sistêmica é condição crônica, progressiva, desenvolvida caracteristicamente em pacientes nefropatas após exposição a contrastes radiológicos que contenham gadolínio. O espessamento cutâneo é aspecto típico, envolvendo predominantemente as extremidades. Envolvimento visceral pode ocorrer. O diagnóstico da doença requer cuidadosa correlação clínico-patológica. O tratamento visa à restauração da função renal, que se associa ao retardo da progressão e, eventualmente, remissão das alterações cutâneas. A prevenção da ocorrência e redução da incidência baseiam-se na limitação do uso de contrastes à base de gadolínio em nefropatas (especialmente na insuficiência renal avançada em estágios 4 e 5), restringindo-os às condições nas quais seja imprescindível ao diagnóstico/acompanhamento. À exceção da restrição de exposição aos agentes de contraste a base de gadolínio, não há métodos preventivos efetivos relatados. Devido à ampla divulgação da doença entre radiologistas e nefrologistas, a incidência da fibrose nefrogênica sistêmica está em declínio.

El litio y su relación con la acuaporina-2 y el canal de sodio ENaC / Lithium and its relation with the epithelial sodium channel and aquaporin-2

Desde hace más de cuarenta años que el litio es usado para el tratamiento de la enfermedad bipolar; recientes estudios sugieren también su utilidad en el trastorno cognitivo mínimo tipo amnésico. El litio es filtrado en el glomérulo y un 65-75% del mismo es reabsorbido en el túbulo contorneado proximal y en el asa ascendente de Henle por el transportador Na+, K+, 2Cl- y vía paracelular. Una pequeña fracción del litio entra en las células principales del túbulo colector por medio del canal epitelial de sodio sensible al amiloride (ENaC) localizado en la membrana apical de la célula. Luego de 10- 20 años de tratamiento con litio los enfermos pueden desarrollar poliuria, acidosis tubular e insuficiencia renal crónica que puede terminar en una forma de diabetes que no responde a la arginina vasopresina llamada diabetes insípida nefrogénica. Se cree que estas fallas renales son consecuencias de una reducción en el número de moléculas de acuaporina 2 en la membrana apical. Las causas para esto son complejas. El litio es un poderoso inhibidor de la isoforma beta de la enzima glicógeno sintetasa quinasa y esto está asociado a una menor actividad de la adenilato ciclasa que lleva a una disminución en la concentración intracelular de cAMP. Esto finalmente interferiría con la síntesis de nuevas moléculas de acuaporina 2 y con el tráfico de ellas desde la zona subapical de la célula hacia la membrana celular, causando la disminución en la reabsorción de agua en la parte distal del nefrón.

For more than 40 years lithium has been used to treat bipolar disorder and recent trials suggest a potential efficacy also in the treatment of the amnestic mild cognitive impairment. Lithium is filtered by the glomerulus and 65% - 75% of the filtered amount is reabsorbed along the proximal tubule and in the thick ascending limb of Henle's loop by the Na+, K+, 2Cl- transporter and via paracellular. A small fraction of lithium is reabsorbed in the collecting duct's principal cells through the epithelial Na channel (ENaC) located on the apical side of the cells. Polyuria, renal tubular acidosis and chronic renal failure are the most frequent adverse effects of lithium after 10-20 years of treatment and these alterations can reach to a vasopressin nonresponding form of diabetes insipidus entity called nephrogenic diabetes insipidus. It is believed that the molecular mechanisms of these renal changes are related to a reduction in the number of aquaporin-2 inserted in the apical membrane of the cells. The causes of this are complex. Lithium is a powerful inhibitor of the enzyme glycogen synthase kinase 3β and this is associated with a lower activity of adenylate cyclase with a reduction in the cAMP levels inside of the cells. The latter may interfere with the synthesis of aquaporin-2 and also with the traffic of these molecules from the subapical site to membrane promoting the impairment of water reabsorption in the distal part of the kidney.

Manifestações cutâneas na doença renal terminal / Cutaneous manifestations in end-stage renal disease

A prevalência da doença renal crônica aumentou nos últimos anos. Os efeitos dessa doença são complexos e podem levar à disfunção de múltiplos órgãos, entre eles, a pele. A maioria dos pacientes apresenta pelo menos uma alteração dermatológica. Algumas vezes, esses sintomas podem ser o primeiro sinal evidente de doença renal. Este artigo aborda as manifestações cutâneas relacionadas a disfunção renal grave ou doença renal terminal, divididas em não específicas e específicas, revisando quadro clínico, etiopatogenia e opções terapêuticas dessas dermatoses. Seu reconhecimento e trata mento precoces diminuem a morbidade, melhorando a qualidade de vida desses doentes.

The prevalence of chronic kidney disease has increased over the last years. The effects of this disease are complex and may lead to dysfunction of multiple organs, including the skin, with most patients presenting with at least one dermatologic alteration. Sometimes these symptoms can be the first clear sign of kidney disease. This article discusses the skin manifestations related to severe renal impairment or end-stage renal disease (ESRD), which are divided into nonspecific and specific, and reviews the clinical features, etiopathogenesis and therapeutic options for these dermatoses. Early recognition and treatment reduce morbidity and improve these patients' quality of life.

Diabetes insípida en pediatría: serie clínica y revisión de la literatura / Diabetes insipidus in pediatrics

Introduction: Diabetes insipidus (DI) is a syndrome characterized by polyuria and polydipsia secondary to a decreased secretion or action of the antidiuretic hormone (ADH). An early diagnosis is essential. Diagnosis is made by measuring plasma and urinary osmolarity and their changes under water deprivation and after DDAVP administration. Objective: Lo describe the clinical, radiological characteristics as well as the initial treatment of eight children with DI, 3 of them nephrogenic DI (DIN) and 5 with central DI. Methods: A Retrospective, descriptive study in DI patients under control at the Catholic University of Chile and Sotero del Rio Hospital between 1998-2008 is presented. Clinical files were evaluated collecting clinical, epidemiologic, biochemical and image data. Serum (Sosm) and urinary osmolarity (Uosm) were registered. DI was diagnosed with a Sosm > 300 and Usm < 600 mOsm/L. Central DI was defined as the inability to reach a Uosm > 600 or a 50 percent-increase after DDAVP treatment. Otherwise DI was classified as DIN. Results: Eight patients (5 males) were studied. Chief complaints were polydipsia/polyuria (5/8), hyperthermia (2/8), and failure to grow (1/8). MRI showed endocraneal lesion in all patients with Central DI. All of these utilized oral or inhalatory DDAVP treatment. Patients with Nephrogenic DI were trated with Hydrochlrothiazide. Conclusion: Polydipsia, polyuria, hyperthermia with hypernatremia are suggestive of DI in the first year of life. Water deprivation test is diagnostic in differentiating Central and Nephrogenic DI. MRI is an essential diagnostic tool in CDI. Manegement should be multidisciplinary, including a pediatician, nephrologist, endocrinologist and nutricionist.

Introducción: La diabetes insípida (DI) se caracteriza por poliuria y polidipsia, secundario a una disminución de la secreción o acción de la hormona antidiurética. Su diagnóstico precoz es fundamental. Objetivo: Describir las características clínicas, radiológicas y tratamiento inicial de una serie de ocho pacientes con DI. Diseño: Estudio descriptivo-restrospectivo. Universo: Pacientes con DI evaluados en la Universidad Católica de Chile y Hospital Dr. Sótero del Río entre 1998-2008. Pacientes y Métodos: Desde la ficha clínica se analizaron variables clínicas, epidemiológicas, bioquímicas e imágenes. Se determinó Osmolaridad sérica (OsmS) y urinaria (OsmU). Se consideró DI sí la OsmS > 300 mOsm con OsmU < 600 mOsm, Di-central (DIC) sí posterior a DDAVP la OsmU aumento > 50 por ciento ó > 600 mOsm, de los contrario se clasificó como nefrogénica (DIN). Resultados: Se reclutaron ocho pacientes con DI (5 varones), fueron DIN 3/8. El motivo de consulta fue: polidipsia-poliuria (5/8), hipertermia (2/8) y talla baja (1/8). La RNM mostró lesión intracraneana en todos los pacientes con DIC: nodulo hipofisiario, aracnoidocele selar, Histiocitosis X, germinoma y un paciente sin se±al de neurohipófisis. Los sujetos con DIC usaron DDAVP inhalatoria (4) y oral (1). Los sujetos con DIN usaron hidroclorotiazida. Conclusión: Polidipsia, poliuria, hipertermia con hipernatremia y falla de medro en lactantes son sugerentes de DI. La prueba de deprivación hídrica es fundamental en la diferenciación de DIC y DIN. La RNM cerebral es una herramienta diagnóstica imprescindible en la DIC. El tratamiento de estos pacientes debe ser multidiciplinario interactuando pediatra, nefrólogo, endocrinólogo y nutricionista.

Fibrose sistêmica nefrogênica: uma complicação grave do uso do gadolínio em pacientes com insuficiência renal / Nephrogenic systemic fibrosis: a severe complication of use to gadolinium in patients with kidney failure

Fibrose sistêmica nefrogênica (FSN), também conhecida como dermopatia fibrosante nefrogênica (DFN), é uma condição que ocorre apenas em pacientes com disfunção renal. Além das lesões cutâneas, esta síndrome inclui fibrose de músculo esquelético, articulações, fígado, pulmão e coração e pode ser fatal. Esta doença foi primeiramente descrita em 1997 e vários estudos descrevem a relação etiológica da FSN com a exposição a agentes de contraste contendo gadolínio, usado em exames de ressonância magnética. Esta revisão tem como objetivo alertar médicos clínicos e nefrologistas sobre essa nova patologia que acomete pacientes com alteração da função renal, demonstrando aspectos demográficos e epidemiológicos, apresentação clínica, diagnóstico e prognóstico além das opções de prevenção e terapêuticas atuais. Concluímos que todo paciente apresentando creatinina sérica elevada deve ter sua função renal (clearance de creatinina) estimada, visando a segurança na realização da ressonância magnética.

Nephrogenic systemic fibrosis (NSF), also known as nephrogenic fibrosing dermopathy (NFD), is a condition that has occurred only in patients with renal insufficiency. Besides lesions of the skin, this syndrome include fibrosis of skeletal muscle, joints, liver, lung, and heart, with possible fatal outcomes. This disease was first described in 1997 and several reports described the development of NSF after the exposure to gadolinium-based magnetic resonance imaging contrast agents. This review aims to alert physicians and nephrologists about this new pathology that affects patients with renal dysfunction, describing its demographic and epidemiologics aspects, clinic presentation, diagnosis and prognosis, beyond options to prevent and current treatment. We concluded that in all patient with elevated serum creatinine physicians should estimade his kidney function (creatinine clearence) in order to safety of magnetic resonance.