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)

Screening, diagnosis and management of hypothyroidism in pregnancy: Number 10 - October 2022

Key points Pregnancy places a metabolic overload on the maternal thyroid, especially in the first trimester, mainly because of the demand imposed by the conceptus. The fetal thyroid becomes functionally mature only around pregnancy week 20. Until then, the fetus depends on the transfer of maternal thyroid hormones (THs). Thyroid hormones are essential for the adequate fetal neurofunctional and cognitive development. Hypothyroidism brings higher risks of obstetric and fetal complications, namely, first-trimester miscarriage, preeclampsia and gestational hypertension, placental abruption, prematurity, low birth weight, and higher perinatal morbidity and mortality. Primary hypothyroidism (involvement of the gland with difficulty in producing and/or releasing TH) is the most common form of disease presentation, with the main etiology of Hashimoto's thyroiditis of autoimmune origin. In about 85%-90% of cases of Hashimoto's thyroiditis, antithyroid antibodies are present; the antithyroperoxidase (ATPO) is the most frequent. Positivity for ATPO is determined when circulating values exceed the upper limit of the laboratory reference. It implies greater risks of adverse maternal-fetal outcomes. Such a correlation occurs even in ranges of maternal euthyroidism. The critical point for the diagnosis of hypothyroidism during pregnancy is an elevation of thyroid-stimulating hormone (TSH). The measurement of free thyroxine (FT4) differentiates between subclinical and overt hypothyroidism. In subclinical hypothyroidism, FT4 is within the normal range, whereas in overt hypothyroidism, FT4 values are below the lower limit of the laboratory reference. Treatment of hypothyroidism is performed with levothyroxine (LT4) replacement with the aim of achieving adequate TSH levels for pregnancy. Some women have a previous diagnosis of hypothyroidism, and may or may not be compensated at the beginning of pregnancy. Even in compensated cases, the increase in LT4 dose is necessary as soon as possible. In the postpartum period, adjustment of the LT4 dose depends on the condition of previous disease, on the positivity for ATPO, and also on the value of LT4 in use at the end of pregnancy. Recommendations In places with full technical and financial conditions, TSH testing should be performed for all pregnant women (universal screening) as early as possible, ideally at the beginning of the first trimester or even in preconception planning. In places with less access to laboratory tests, screening is reserved for cases with greater risk factors for decompensation, namely: previous thyroidectomy or radioiodine therapy, type 1 diabetes mellitus or other autoimmune diseases, presence of goiter, previous history of hypo or hyperthyroidism or previous ATPO positivity. The TSH dosage should be repeated throughout pregnancy only in these cases. The diagnosis of hypothyroidism is made from the TSH value > 4.0 mIU/L. Pregnant women with previous hypothyroidism, overt hypothyroidism diagnosed during pregnancy or those with the above-mentioned higher risk factors for decompensation should be referred for risk antenatal care, preferably in conjunction with the endocrinologist. Overt hypothyroidism in pregnancy is identified when TSH > 10 mIU/L, and treatment with LT4 is readily recommended at an initial dose of 2 mcg/kg/day. TSH values > 4.0 mUI/L and ≤ 10.0 mUI/L require FT4 measurement with two diagnostic possibilities: overt hypothyroidism when FT4 levels are below the lower limit of the laboratory reference, or subclinical hypothyroidism when FT4 levels are normal. The treatment for subclinical hypothyroidism is LT4 at an initial dose of 1 mcg/kg/day, and the dose should be doubled upon diagnosis of overt hypothyroidism. In cases of TSH > 2.5 and ≤ 4.0 mIU/L, if there are complete conditions, ATPO should be measured. If positive (above the upper limit of normal), treatment with LT4 at a dose of 50 mcg/day is indicated. If conditions are not complete, the repetition of the TSH dosage should be done only for cases at higher risk. In these cases, treatment with LT4 will be established when TSH > 4.0 mIU/L at a dose of 1 mcg/kg/day; if needed, the dose can be adjusted after FT4 evaluation. Women with previous hypothyroidism should have their LT4 dose adjusted to achieve TSH < 2.5 mIU/L at preconception. As soon as they become pregnant, they need a 30% increase in LT4 as early as possible. In practice, they should double the usual dose on two days a week. Levothyroxine should be given 30-60 minutes before breakfast or three hours or more after the last meal. Concomitant intake with ferrous sulfate, calcium carbonate, aluminum hydroxide and sucralfate should be avoided. The target of LT4 therapy during pregnancy is to achieve a TSH value < 2.5 mIU/L. Once the therapy is started, monthly control must be performed until the mentioned goal is reached. In the postpartum period, women with previous disease should resume the preconception dose. Cases diagnosed during pregnancy in use of LT4 ≤ 50 mcg/day may have the medication suspended. The others should reduce the current dose by 25% to 50% and repeat the TSH measurement in six weeks. Cases of ATPO positivity are at higher risk of developing postpartum thyroiditis and de-escalation of LT4 should be performed as explained.

Prevalencia de hipotiroidismo subclínico y biomarcadores de riesgo cardiovascular en pacientes del Hospital General de Riobamba / Prevalence of subclinical hypothyroidism and biomarkers of cardiovascular risk in patients of the General Hospital of Riobamba

El Hipotiroidismo subclínico (HSC) es definido bioquímicamente por una elevación en la concentración sérica de la hormona TSH con niveles normales de T4 libre. El objetivo de este estudio fue determinar la prevalencia de HSC en los pacientes que asistieron a la consulta de medicina interna del Hospital General IESS de Riobamba. Así como, analizar la correlación entre los parámetros hormonales y ciertos marcadores bioquímicos asociados con el incremento de riesgo cardiovascular. Se realizó una investigación de tipo descriptiva, observacional, con un diseño no experimental de corte transversal, que abarcó el periodo comprendido desde enero de 2019 hasta septiembre de 2021. 245 pacientes fueron diagnosticados con HSC, lo cual representó el 10.58 % del universo poblacional estudiado, 61.2% eran del sexo femenino, mientras que el 38.8% del sexo masculino. El mayor número de casos (59.61 %) se observó en el grupo etario mayor de 65 años, distribuidos de la siguiente manera: (22.86% hombres y 36.75% mujeres), también se encontró que el HSC está asociado con un perfil lipídico aterogénico, caracterizado por un incremento en la concentración de colesterol total y LDL los cuales se correlacionaron positivamente con las concentraciones de TSH.

Subclinical hypothyroidism (SH) is biochemically defined by an elevation in the serum concentration of TSH hormone with normal levels of free T4. The aim of this study was to determine the prevalence of SH in patients attending the internal medicine clinic of the General Hospital IESS of Riobamba. Also, to analyze the correlation between hormonal parameters and certain biochemical markers associated with increased cardiovascular risk. A descriptive, observational, non-experimental cross-sectional design was performed, covering the period from January 2019 to September 2021. 245 patients were diagnosed with SH, which represented 10.58 % of the population universe studied, 61.2% were female, while 38.8% were male. The highest number of cases (59.61 %) was observed in the age group over 65 years, distributed as follows: (22.86% men and 36.75% women), it was also found that SH is associated with an atherogenic lipid profile, characterized by an increase in the concentration of total cholesterol and LDL which correlated positively with TSH concentrations.

Approach to Subclinical Hypothyroidism in Adults / Abordaje del Hipotiroidismo subclínico en el Adulto

Thyroid pathology is the morphofunctional evolution of the thyroid glands that leads to different types of clinical pictures. Within it is subclinical hypothyroidism, which is a biochemical alteration due to the elevation of thyroid-stimulating hormone (TSH) between 4.5 to 10 mUI that can occur with or without symptoms of multifactorial origin. The worldwide prevalence is 4-10% and Latin America 15-25%. 90% of patients with this pathology do not require treatment, but in turn there is an overmedicalization and underdiagnosis of it. This bibliographic review analyzes from its morphofunctional changes towards clinical criteria for a comprehensive approach to subclinical hypothyroidism, where we have an individualization by its comorbidities, age group, diagnostic algorithm, follow-up and differentiated treatment according to recent studies within this pathology. Therefore, an adequate diagnosis, follow-up and treatment provides a better lifestyle for patients.

La patología tiroidea es la alteración morfofuncional de la glándula tiroides que lleva a diferentes tipos de cuadros clínicos. Dentro de ella se encuentra el Hipotiroidismo subclínico que es una alteración bioquímica por la elevación de la Hormona Estimulante de la tiroides (TSH) entre 4,5 a 10 mUI que puede presentarse con o sin sintomatología y tiene etiología multifactorial. La prevalencia mundial es del 4-10 % y latinoamericana del 15-25%. El 90% de pacientes con esta patología no requieren tratamiento, pero a su vez existe una sobremedicalización y una subdiagnóstico del mismo. La presente revisión bibliografía analiza a partir de su alteración morfofuncional hacia criterios clínicos para un abordaje integral del Hipotiroidismo subclínico, donde tenemos una individualización por sus comorbilidades, grupo etario, algoritmo diagnóstico, seguimiento y tratamiento diferenciado según últimos estudios dentro de esta patología. Por lo que un adecuado diagnóstico, seguimiento y tratamiento brinda un mejor estilo de vida a los pacientes.

Elementos básicos para el diagnóstico y manejo terapéutico del coma mixedematoso en el paciente adulto / Basic elements for the diagnosis and therapeutic management of myxedematous coma in adult patients

Introducción: A pesar de su baja incidencia, la gravedad del cuadro clínico y la alta mortalidad hacen del coma mixedematoso una complicación a tener en cuenta. Objetivo: Describir los elementos básicos para el diagnóstico y manejo terapéutico del coma mixedematoso en el paciente adulto. Métodos: Se realizó una búsqueda de literatura relevante sobre el tema. Se utilizaron buscadores de información científica como Pubmed y Google Académico. La estrategia de búsqueda incluyó los siguientes términos como palabras clave: hipotiroidismo primario, hipotiroidismo subclínico, diagnóstico y tratamiento. Fueron evaluados artículos de revisión, de investigación y páginas web que tuvieran menos de 10 años de publicados. Se consideraron los textos en idioma español e inglés y que hicieran referencia específicamente al tema de estudio a través del título. Fueron excluidos los artículos que no cumplieron con estas condiciones. Esto permitió el estudio de 64 artículos, de los cuales 40 fueron referenciados. Conclusiones: Para el diagnóstico del coma mixedematoso en el paciente adulto lo más importante es sospecharlo en aquellas personas que presenten factores precipitantes, acompañados de síntomas y signos de hipotiroidismo severo con diferentes grados de insuficiencia del sistema nervioso central, hipotermia, hipoventilación, insuficiencia circulatoria e hiponatremia. A esto se sumaría el escenario humoral característico y los posibles hallazgos dependientes de la enfermedad causante del hipotiroidismo. Se debe tratar con un reemplazo agresivo de levotiroxina sódica (vía endovenosa u oral, según posibilidades), unido a otras medidas de apoyo en el entorno hospitalario(AU)

Introduction: Despite its low incidence, the severity of the clinical picture and the high mortality make myxedematous coma a complication to be taken into account. Objective: Describe the basic elements for the diagnosis and therapeutic management of myxedematous coma in adult patients. Methods: A search of relevant literature on the subject was carried out. Pubmed and Google Scholar were used as search engines for scientific information. The search strategy included the following keyword terms: primary hypothyroidism, subclinical hypothyroidism, diagnosis and treatment. Review articles, research articles and Web pages that, in general, had less than 10 years of publication, in Spanish and English that specifically referred to the subject of study through the title were evaluated. Articles that did not meet these conditions were excluded. This allowed the study of 64 articles, of which 40 were referenced. Conclusions: For the diagnosis of myxedematous coma in the adult patient, the most important thing is to suspect it in those people who present precipitating factors, accompanied by symptoms and signs of severe hypothyroidism with different degrees of central nervous system insufficiency, hypothermia, hypoventilation, circulatory insufficiency and hyponatremia. To this would be added the characteristic humoral scenario and the possible findings dependent on the disease causing hypothyroidism. It should be treated with an aggressive replacement of levothyroxine sodium (intravenous or oral way, accodring to the possibilities), together with other supportive measures in the hospital setting(AU)

Hipertiroidismo transitorio posterior a trauma cuello en accidente de tránsito Reporte de caso con enfoque Médico Legal / Transient hyperthyroidism after neck trauma in a traffic accident. Case report with a Legal Medical approach

Resumen El hipertiroidismo transitorio posterior a un trauma de cuello es un hecho infrecuente. Se presenta el caso de una femenina de 23 años, quien sufrió un accidente de tránsito presentando trauma en cuello al golpearse con la manivela de una motocicleta, posteriormente presentó supresión de TSH y elevación de T4 circulante, con ultrasonido y TAC que descartaron hematomas o rupturas de la glándula, que luego de manejo conservador presentó normalización de las hormonas tiroideas y evolucionó sin secuelas. Se hizo una revisión de la literatura sobre tiroiditis e hipertiroidismo transitorio post trauma de cuello.

Abstract Transient hyperthyroidism after neck trauma is not common. The case of a 23-year-old female is presented, who suffered a traffic accident presenting trauma to the neck when hitting with the crank of a motorcycle, subsequently presented suppression of TSH and elevation of circulating T4, with ultrasound and CT that ruled out bruises or ruptures of the gland, which after conservative management presented normalization of thyroid hormones and evolved without sequelae. A review of the literature on thyroiditis and transient hyperthyroidism after neck trauma was conducted.

Hiperplasia de hipófise secundária a hipotireoidismo primário - relato de caso / Pituitary hyperplasia secondary to primary hypothyroidism - case report

A hiperplasia hipofisária é definida como um aumento não neoplásico no número de um dos tipos de células presentes na hipófise. Ela pode ocorrer por um processo fisiológico ou patológico. O hipotireoidismo primário prolongado é uma das causas patológicas desta condição, e ocorre devido a perda do feedback negativo. O objetivo desse relato foi demonstrar a presença de hiperplasia hipofisária em um paciente masculino com características corporais sugestivas de acromegalia. A investigação laboratorial confirmou a presença de hipotireoidismo primário e descartou a acromegalia. Foi instituído tratamento com levotiroxina, levando a regressão da hiperplasia hipofisária. Esse caso ilustra a importância de uma investigação apropriada em pacientes com hiperplasia hipofisária, bem como discute a fisiopatologia e o tratamento dessa doença.

Pituitary hyperplasia is defined as a non-neoplastic increase in the number of one of the cell types present in the pituitary gland. It can occur by a physiological or pathological process. Prolonged primary hypothyroidism is one of the pathological causes of this condition and occurs due to the lack of negative feedback. The objective of this report was to demonstrate the presence of pituitary hyperplasia in a male patient with body characteristics suggestive of acromegaly. Laboratory investigation confirmed the presence of primary hypothyroidism and ruled out acromegaly. Treatment with levothyroxine was instituted, leading to regression of pituitary hyperplasia. This case illustrates the importance of an appropriate investigation in patients with pituitary hyperplasia, as well as discussing the pathophysiology and treatment of this disease.

Hipotiroidismo subclínico en el embarazo / Subclinical hypothyroidism in pregnancy

Las alteraciones de la función tiroidea incluida el hipotiroidismo subclínico son unas de las patologías más frecuentes durante el embarazo, y se asocian a importantes complicaciones maternas, fetales y neonatales. Se han desarrollado múltiples guías de práctica clínica por sociedades internacionales en busca de unificar el enfoque diagnóstico y terapéutico de las patologías tiroideas durante la gestación, sin embargo hay evidencia insuficiente sobre la realización de tamizaje y aún más sobre las intervenciones terapéuticas en caso del hipotiroidismo subclínico, se presenta la siguiente revisión de la literatura para vislumbrar a la luz de información actualizada como realizar el abordaje integral de las pacientes gestantes con hipotiroidismo subclínico (AU)

Alterations in thyroid function, including subclinical hypothyroidism, are one of the most frequent pathologies during pregnancy, and are associated with important maternal, fetal, and neonatal complications. Multiple clinical practice guidelines have been developed by international societies in search of unifying the diagnostic and therapeutic approach of thyroid pathologies during pregnancy, however there is insufficient evidence on screening and even more on therapeutic interventions in case of subclinical hypothyroidism , the following review of the literature is presented to envision in the light of updated information how to carry out a comprehensive approach to pregnant patients with subclinical hypothyroidism (AU)

Alteraciones tiroideas en la infancia y en la adolescencia. Parte 2: hipotiroidismo / Thyroid disorders in childhood and adolescence. Part 2: Hypothyroidism

El hipotiroidismo es la disfunción tiroidea más frecuente, resultante de una disminución de la actividad biológica de las hormonas tiroideas en los tejidos. El objetivo es realizar una revisión y actualización del hipotiroidismo adquirido en la infancia y adolescencia con énfasis en el hipotiroidismo primario. La causa más común es la tiroiditis de Hashimoto o tiroiditis linfocitaria crónica. La característica distintiva es el impacto profundo en el crecimiento esquelético, maduración y desarrollo puberal, con potencial repercusión en la talla adulta. Los signos y síntomas del hipotiroidismo adquirido son similares a los adultos y, en general, no se asocia con compromiso del desarrollo neuromadurativo.La presunción clínica se confirma con niveles elevados de tirotrofina y disminuidos de tiroxina libre. Las metas del tratamiento incluyen lograr adecuado crecimiento, maduración sexual, desarrollo neuromadurativo y cognitivo óptimo. En la mayoría de los pacientes, el tratamiento de reemplazo revierte los signos y síntomas.

Hypothyroidism is the most frequent thyroid dysfunction. It is the consequence of a decrease in the biological activity of thyroid hormones in target tissues. The aim of this paper is to review and update acquired hypothyroidism in childhood and adolescence with emphasis on primary hypothyroidism due to its greater frequency. Hashimoto's thyroiditis, also known as chronic lymphocytic thyroiditis, is the most common cause of primary acquired hypothyroidism. The distinctive feature is the profound impact on skeletal growth, maturation, and pubertal development, with potential implications on adult height. Signs and symptoms of acquired hypothyroidism are similar to those reported in adults and are generally not associated with neurodevelopmental impairment. Biochemi confirmation of primary hypothyroidism requires the finding of elevated thyrophine and decreased free thyroxine levels. Treatment goals are to achieve normal growth and maturation as well as cognitive development. In most of the patients, replacement treatment reverses symptoms and signs of hypothyroidism and may decrease goiter size.

A practical contemporary approach to decision-making on subclinical hypothyroidism

ABSTRACT Subclinical hypothyroidism (Shypo) is an increasingly frequent condition in common medical practice. Its diagnosis continues to pose a challenge since a series of non-thyroidal and temporary conditions can elevate serum TSH levels. In addition, the consequences of Shypo are still up for debate. Although detrimental cardiovascular effects have been consistently demonstrated in the young, they are less evident in older adults (65-79 years), and even more so in the oldest old (≥80 years). In the absence of evidence of any benefits of treating Shypo in patients' clinical manifestations and unfavorable outcomes, the most effective decision-making approach should include a thorough investigation of the patient's condition integrating all relevant clinical data, such as TSH levels, age, quality of life, comorbidities, cardiovascular risk, safety, and personal preferences. The decision-making process needs to take into account the risk of levothyroxine overtreatment and the resulting adverse consequences, such as reduction of bone mineral density, heart failure, and atrial fibrillation. Hence, current evidence suggests that individuals with TSH > 10 mU/L, who test positive for TPO Ab or are symptomatic may benefit from levothyroxine treatment. However, a more cautious and conservative approach is required in older (≥65 years of age), and oldest-old (≥80 years) patients, particularly those with frailty, in which the risk of treatment can outweigh potential benefits. The latter may benefit from a wait-and-see approach.

Disfunción tiroidea por I131-Metayodo Benzilguanidina en pacientes con neuroblastoma / Thyroid dysfunction due to 131I-metaiodobenzylguanidine in patients with neuroblastoma

Resumen: Introducción: El tratamiento del neuroblastoma en estadios avanzados incluye quimioterapia, cirugía y terapia con I131-Metayodo benzilguanidina (I131-MIBG). La disfunción tiroidea se reporta entre 12 y 85% a pesar de la protección tiroidea. Objetivo: Identificar la frecuencia de disfunción tiroidea en casos de neu roblastoma tratados con I131-MIBG. Pacientes y Método: Estudio transversal. Se incluyeron todos los casos con diagnóstico de neuroblastoma que recibieron I131-MIBG en el periodo de 2002-2015, a los cuales se les realizó antropometría completa, perfil de tiroides: hormona estimulante de tiroides (TSH), Triyodotironina total y libre (T3t y T3l), tiroxina total y libre (T4t, T4l), y anticuerpos antitiroglobulina y antiperoxidasa. Resultados: Se identificaron un total de 27 pacientes; once fallecieron (40%). De los 16 casos sobrevivientes, 9 (56%) presentaron disfunción tiroidea: 2 (13%) casos con hipotiroidismo subclínico y 7 (44%) casos con hipotiroidismo clínico (3 casos por retraso en el desa rrollo psicomotor y 4 por desaceleración del crecimiento). Los pacientes presentaron manifestaciones clínicas a los 16,1 meses (1,2-66,3 meses) de recibir el radiofármaco a una dosis acumulada de 142 mCi (96-391.5 mCi). No se logró evidenciar diferencias en la edad al diagnóstico, la edad al inicio del tratamiento con el I131-MIBG, la dosis acumulada del I131-MIBG y el tiempo trascurrido entre la dosis y el perfil tiroideo entre los casos con o sin disfunción tiroidea. Conclusiones: El 56% de los pacientes con neuroblastoma presentaron disfunción tiroidea. La mayoría de los casos con hipotiroidismo fue ron referidos cuando los datos de disfunción tiroidea eran clínicamente evidentes. Se propone en esta poblacion realizar perfil tiroideo semestral y valoración anual por un endocrinólogo pediatra durante los primeros 5 años posteriores al diagnóstico oncológico.

Abstract: Introduction: The treatment of advanced neuroblastoma includes chemotherapy, surgery, and radiotherapy with 131-I-Metaiodobenzylguanidine (131-I-MIBG). Despite strategies to protect thyroid function, its dysfunction is reported between 12 and 85%. Objective: To identify the frequency of thyroid dys function in cases of neuroblastoma treated with 131-I-MIBG. Patients and Method: Cross-sectional study. We included all the cases with neuroblastoma treated with 131-I-MIBG between 2002 and 2015, with complete somatometry, and complete thyroid profile (TSH, free and total T3 and T4, and anti-thyroglobulin and antiperoxidase antibodies). Results: 27 patients were identified out of which eleven died (40%). Out of the 16 surviving cases, 9 (56%) presented thyroid dysfunction: 2 (13%) cases with subclinical hypothyroidism and 7 (44%) cases with clinical hypothyroidism (3 cases due to psychomotor developmental delay and 4 due to growth deceleration). The patients presented cli nical manifestations at 16.1 months (1.2-66.3 months) after receiving the radiopharmaceutical at acumulative dose of 142 mCi (96-391.5 mCi). No differences were found in the age at diagnosis, age at the start of treatment with 131-I-MIBG, the cumulative dose of 131-I-MIBG, and the time elapsed between the dose and the thyroid profile among the cases with or without thyroid dysfunction. Con clusions: 56% of patients with neuroblastoma had thyroid dysfunction. Most of the cases with hypothyroidism were referred when thyroid dysfunction was clinically evident. A thyroid profile should be performed every 6 months, along with an annual endocrinological evaluation during the next 5 years in these patients.

Selective case finding versus universal screening for detecting hypothyroidism in the first trimester of pregnancy: a comparative evaluation of a group of pregnant women from Rio de Janeiro

ABSTRACT Objective Maternal hypothyroidism during pregnancy may lead to adverse outcomes. Recently published guidelines by the American Thyroid Association (ATA) do not advocate for universal screening but recommend a case-finding approach in high-risk pregnant women. The present study aims to evaluate the accuracy of this approach in identifying women with thyroid dysfunction during early pregnancy. Subjects and methods This is a multiple-center, cross-sectional study. Three hundred and one pregnant women were enrolled. Anamnesis and a physical examination were performed to detect which women fulfilled the criteria to undergo laboratory screening of thyroid dysfunction, according to the ATA's 2017 guidelines. The Zulewski's validated clinical score was applied to assess signs and symptoms of hypothyroidism. Serum levels of thyrotropin (TSH), free thyroxine (FT4), anti-thyroperoxidase (TPO-Ab), and anti-thyroglobulin (Tg-Ab) antibodies were determined. Results Two hundred and thirty one women (78%) were classified as high risk, and 65 (22%) were classified as low risk for thyroid dysfunction. Regarding the clinical score, 75 patients (31.2%) presented mild symptoms that were compatible with SCH, of which 22 (7.4%) had symptoms as the only risk factor for thyroid disease. 17 patients (5.7%) had SCH, of which 10 (58.8%) belonged to the high-risk group, and 7 (41.2%) belonged to the low-risk group. OH was found in 4 patients (1.4%): 3 (75%) in the high-risk group and 1 (25%) in the low-risk group. Conclusions The ATA's proposed screening criteria were not accurate in the diagnosis of thyroid dysfunction in pregnancy. Testing only the high-risk pregnant women would miss approximately 40% of all hypothyroid patients.

Macro TSH como causa de hipotiroidismo refractario: a propósito de dos casos clínicos / Macro TSH as a cause of refractory hypothyroidism: based on two clinical cases

Se presenta el caso de dos mujeres con hipotiroidismo, con TSH persistentemente elevada, lo que hacía aumentar la dosis de levotiroxina y llegar a un hipertiroidismo clínico con TSH anormalmente alto. Se realizó un seguimiento de los niveles de TSH y T4 libre, durante un período de 20 y 10 meses respectivamente. En ambas situaciones no hubo una respuesta esperable a las dosis de levotiroxina ascendentes. Después de descartar causas posibles que explicaran esta situación, se sospechó y confirmó la presencia de Macro TSH, que es un complejo biológicamente inactivo de TSH e Inmunoglobulina G. Se obtiene como resultado la estabilidad de ambas pacientes siendo su seguimiento prioritariamente clínico y con mediciones de T4L, comprendiendo por qué la TSH persiste elevada. Nos pareció interesante la comunicación de estos casos, que permite recordar causas atípicas de refractariedad al tratamiento con levotiroxina, como es la macro TSH, indispensable pesquisar para el manejo adecuado de estos pacientes.

An inadequate response to levothyroxine treatment in a patient with hypothyroidism suggests lack of intake, lack of absorption, nephrotic syndrome, thyroid hormone resistance among other reasons. We present the case of two women with hypothyroidism and a persistently elevated level of TSH, which required increasing the dose of levothyroxine, resulting in a clinical hyperthyroidism with an abnormally high TSH. A TSH and free T4 follow up was performed during a period of 20 and 10 months respectively, in both situations there was not an adequate response to rising levothyroxine treatment. After ruling out other possible causes that could explain this situation, it was suspected and then confirmed the presence of Macro TSH, which is a biologically inactive complex of TSH and Immunoglobulin G. Therefore, both patients achieved disease stability once controlled by clinical state and free T4 measurements, understanding why THS persited high. We present these interesting cases, because this allows us to remember atypical causes of refractory treatment with levothyroxine, such as the Macro TSH, indispensable to search for the proper management of these patients.

Variables predictivas de talla baja adulta en pacientes con hipotiroidismo adquirido grave de origen autoinmune / Predictive outcome measures of adult short stature in patients with severe acquired autoimmune hypothyroidism

El hipotiroidismo por tiroiditis de Hashimoto es la causa más frecuente de disfunción tiroidea en niños.Nuestro objetivo fue analizar el impacto en la talla final según la talla y el estadio puberal al momento del diagnóstico en menores de 18 años con hipotiroidismo grave de origen autoinmune. De los 79 pacientes, el 78,5 % fueron mujeres. Los que presentaron bocio (el 56 %) mostraron mejor talla en el diagnóstico que los que no lo tenían (puntaje de desvío estándar de media de talla: 0,2 vs. -2,42; p < 0,0001). Cinco niñas (el 6,3 %) presentaron pubertad precoz. De los pacientes con talla final (n: 33), dentro de los que presentaron talla baja al momento del diagnóstico, los púberes tuvieron una talla final significativamente menor que los prepúberes (puntaje de desvío estándar media: -2,82 vs. -1,52; p = 0,0311).El diagnóstico tardío de hipotiroidismo grave en pediatría tiene un impacto negativo en la talla final, especialmente, en los pacientes puberales al momento del diagnóstico.

Hypothyroidism caused by Hashimoto's thyroiditis is the most common reason for thyroid dysfunction in children. Our objective was to analyze its impact on final stature in relation to height and pubertal stage at the time of diagnosis in children younger than 18 years with severe autoimmune hypothyroidism. Out of 79 patients, 78.5 % were girls. Those with goiter (56 %) had a better height at diagnosis than those without goiter (mean standard deviation score for height: 0.2 versus −2.42; p < 0.0001). Five girls (6.3 %) had precocious puberty. When considering the final stature of patients (n: 33), among those with short stature at the time of diagnosis, pubertal children had a significantly shorter final stature than prepubertal children (mean standard deviation score for height: −2.82 versus −1.52; p = 0.0311). The late diagnosis of severe hypothyroidism in pediatrics has a negative impact on final stature, especially in those who were pubertal patients at the time of diagnosis

Síndrome de Van Wyk-Grumbach / Van Wyk-Grumbach syndrome

RESUMEN El síndrome de Van Wyk-Grumbach se caracteriza por hipotiroidismo primario de larga duración asociado a pubertad precoz. Se presenta una paciente de 7 años, mestiza, que acude por sangrado vaginal, acompañado de hiperpigmentación de las areolas sin galactorrea, abdomen globuloso, mixedema, hirsutismo, baja talla, astenia y retraso escolar. La química sanguínea mostró anemia, hipercolesterolemia y hipertransaminasemia; los estudios de imágenes constataron derrame pericárdico, retraso marcado de la edad ósea, incremento de las dimensiones de la silla turca y gran quiste del ovario con aparente criterio quirúrgico. Los estudios hormonales confirmaron la sospecha de hipotiroidismo primario asociado a hiperprolactinemia. El tratamiento sustitutivo con levotiroxina sódica revirtió los signos y síntomas de pubertad precoz, lo que evitó la cirugía del quiste de ovario; la recuperación en el ambiente escolar y social fue indiscutible. Reconocer esta entidad evita tratamientos absolutamente contraindicados, como la extirpación de los quistes o el tratamiento quirúrgico de la hiperplasia hipofisaria(AU)

ABSTRACT Van Wyk-Grumbach syndrome is characterized by long-lasting primary hypothyroidism associated with precocious puberty. A case of a 7-year-old female mestizo patient is reported. She came to consultation for vaginal bleeding, accompanied by hyperpigmentation of the areolas without galactorrhea, globular abdomen, myxedema, hirsutism, short stature, asthenia and school delay. Blood chemistry showed anemia, hypercholesterolemia and hypertransaminasemia. Imaging studies showed pericardial effusion, marked delay in bone age, increased dimensions of Turkish chair and large ovarian cyst with apparent surgical criteria. Hormonal studies confirmed the suspicion of primary hypothyroidism associated with hyperprolactinemia. Substitute treatment with levothyroxine sodium reversed the signs and symptoms of precocious puberty, which prevented ovarian cyst surgery; the recovery in the school and social environment was certain. Recognizing this entity avoids absolutely contraindicated treatments, such as the removal of cysts or the surgical treatment of pituitary hyperplasia(AU)

Miocardiopatía dilatada secundaria a hipotiroidismo primario. Reporte de un caso / Dilated cardiomyopathy secondary to primary hypothyroidism. A case report

Resumen El vínculo entre el hipotiroidismo y varias enfermedades cardiovasculares va más allá de la asociación con los factores de riesgo vascular clásicos. Sin embargo, la miocardiopatía dilatada es una forma rara de presentación del hipotiroidismo. Se reporta el caso de una paciente femenina de 52 años que acude a urgencias por presentar tos húmeda, edema en miembros inferiores y disnea de esfuerzo, así como otros síntomas y signos típicos de hipotiroidismo. La radiografía de tórax revela cardiomegalia y el ecocardiograma informa ventrículo izquierdo dilatado, fracción de eyección disminuida y derrame pericárdico. La TSH estaba aumentada y T4 libre disminuida. Luego de comenzar tratamiento hormonal con levotiroxina se alcanzó la resolución de los síntomas y de las alteraciones radiológicas y ecocardiográficas. El presente caso resalta la importancia de realizar un interrogatorio exhaustivo y examen físico completo que aporten las pistas diagnósticas para sospechar el hipotiroidismo en pacientes con miocardiopatía dilatada.

ABSTRACT The link between hypothyroidism and several cardiovascular diseases goes beyond the association with classical vascular risk factors. However, dilated cardiomyopathy is a rare form of presentation of hypothyroidism. We report the case of a 52-year-old female patient who comes to the emergency room for having wet cough, lower limb edema and dyspnea on exertion, as well as other typical symptoms and signs of hypothyroidism. Chest x-ray reveals cardiomegaly and the echocardiogram reports dilated left ventricle, decreased ejection fraction and pericardial effusion. TSH was increased and free T4 was decreased. After starting hormonal treatment with levothyroxine, resolution of symptoms and radiological and echocardiographic alterations was achieved. The present case highlights the importance of a thorough interrogatory and complete physical examination that provide the diagnostic clues to suspect hypothyroidism in patients with dilated cardiomyopathy.