Hashimoto’s Thyroiditis in Adolescents

Abstract

The autoimmune thyroid diseases (AITD) comprise a series of interrelated conditions including Graves' disease (GD) and Hashimoto's thyroiditis (HT). AITD are the most prevalent diseases of the thyroid gland in the pediatric population, particularly in adolescence. 1HT is the leading cause of goiter and hypothyroidism in children and adolescents in countries with adequate iodine supplementation. [2][3] In an American population aged between 11 and 18 years, five new cases were detected out of 1,000 adolescents screened every year. 4 It is a much more common condition in females than in males: 4:1 to 8:1 depending on the geographic region. [4][5][6] In the last decade, discoveries in molecular biology field have allowed new insight into the genes involved in the development of AITD. At least six susceptibility genes whose variants have been associated with AITD were identified: HLA-DR, CD40, CTLA-4, PTPN22, thyroglobulin (Tg), and thyroid stimulating hormone (TSH) receptor. 7 Genetic susceptibility accounts for 70 % risk for disease that, once combined with environmental factors, play a crucial role in the initiation and progression of the disease. 8 Studies with immunoglobulin (Ig)-G4 autoantibody levels in juvenile thyroid disease patients showed evidence of heritability.9 EtiologyHT etiology is multifactorial. The susceptibility to the disease is determined by an interaction between genetic, environmental, and endogenous factors. 10,11 Genetic susceptibility is well evidenced by studies of monozygotic and dizygotic twins where the concordance rate for HT is around 38 % for monozygotic and 0 % for dizygotic twins. 12 Although genetic factors play a crucial role in the development of HT, nongenetic factors (environmental) are also involved. In immigrant populations from countries with a low incidence of diseases, this population adopts the new country's incidence rate. 13Strong evidence suggests iodine as the most significant environmental factor in the generation of thyroiditis. In fact, the prevalence of AITD increase in certain geographical regions, such as Japan and the US, and correlates with iodine intake. 14 The concentration of iodine in the thyroid AbstractHashimoto's thyroiditis (HT) is the most common cause of hypothyroidism in adolescence and mainly affects females. Being the archetype of an organ-specific T-cell-mediated disease, it is characterized by lymphocytic infiltration of the thyroid gland, damage to the thyroid follicular cells, and impaired ability to produce thyroid hormones. It may be associated with other autoimmune diseases and may arise in the context of congenital chromosomal aberrations. Symptoms of hypothyroidism develop insidiously. In adolescents the most common manifestation is the increase of the glandular volume. Hypothyroidism manifestations (asthenia, intolerance to cold, constipation, and/or skin and dry hair) are less common. The diagnosis is based on the presence of thyroid antibodies and characteristic imaging abnormalities on thyroid ultrasound. The treatment relies on t...

Robôs de conversação e o ethos

“…Em uma infinidade de casos, uma aplicação básica na área de Processamento de Linguagem Natural (doravante PLN) pode ser classificada como dotada de algum tipo de recurso vinculado à IA. Ao considerar, por exemplo, que um sistema, pra ser classificado como inteligente, deve ser flexível e capaz de se adaptar ao ambiente aprendendo e atualizando periodicamente o seu banco de dados de modo minimamente automático (vICCARI, 1989), é necessário dizer que muita das aplicações em PLN não tem um grau significativo de IA. Grosso modo, figuram nessa categoria quase todos os sistemas de "interação" automática por telefone, em sua maioria, pertencentes às próprias empresas de telefonia, conhecidos como Unidade de Resposta Audível (URA).…”

Reinterpreting patterns of variation in human thyroid function

“…affects women nine times more than males [ 19 ], and autoimmunity leading to underactive thyroid function ( hypothyroidism ) is the most common of all autoimmune and endocrine disorders [ 20 ]. Hashimoto’s thyroiditis , a condition characterized by chronic inflammation and the presence of thyroperoxidase ( TPO ) and thyroglobulin ( TG ) autoantibodies , causes the destruction of the thyroid gland and hypothyroidism [ 21 ]. In Graves’ disease , a mix of stimulating and blocking autoantibodies against the TSH-receptor overstimulates thyroid growth and hormone production, most often leading to hyperthyroidism , and in rare cases, hypothyroid or euthyroid Graves’ disease [ 4 , 22 , 23 ].…”

“…Given the influence of thyroid function on the reproductive axis, we hypothesize that in energetically challenging circumstances, lowered thyroid function plays a role in determining the pace of reproductive development and fertility. Lowered thyroid function may indeed contribute to delayed pubertal development [ 21 ], and although subclinical underactive thyroid function only mildly affects the menstrual cycle [ 176 ], for hypothyroid individuals menstruation is often less frequent [ 177 ]. Furthermore, women with severe hypothyroidism often fail to ovulate [ 177 ] and an underactive thyroid is a common cause of spontaneous abortion during the fertile years [ 178 ], although after conception, live birth rate is not always affected [ 179 ].…”