In properly selected patients with differentiated thyroid cancer, antithyroglobulin antibodies decline after thyroidectomy and their sole presence should not be an indication for radioiodine ablation

ABSTRACT Objective Our objective was to evaluate the trend of antithyroglobulin antibodies (TgAb) during follow-up of patients with differentiated thyroid cancer (DTC) treated without RAI, as well as their role in the risk of recurrence. Subjects and methods This was a prospective, descriptive study. A total of 152 consecutive patients with DTC treated in a single institution undergoing total thyroidectomy without RAI and followed for a median of 2.3 years (0.5-10.3) were divided in two groups: TgAb(-) (n = 111) and TgAb(+) (n = 41). Patients were classified according to AJCC 7th and 8th editions, as well as to their risk of recurrence and response to treatment categories. Results Both groups, TgAb(-) and TgAb(+), were similar regarding patient and tumor characteristics. At the end of follow-up, 90 (59.2%), 57 (37.5%), 3 (2%) and 2 (1.3%) patients achieved excellent, indeterminate, biochemically incomplete and structurally incomplete response, respectively. The risk of structural recurrence was similar in both groups (TgAb[-] 0.9% vs. TgAb[+] 2.4%, p = 0.46). In the TgAb(+) group, TgAb became negative in 10 (24.4%), decreased ≥ 50% without negativization in 25 (60.9%), decreased < 50% in 4 (9.8%) and remained stable or increased in 2 (4.9%) cases. The only incomplete structural response had increasing TgAb during follow-up. Conclusions In properly selected patients with DTC, TgAb concentration immediately after total thyroidectomy should not mandate RAI ablation, and their trend during follow-up may impact the risk of recurrence.

Prevalencia de anticuerpos antiperoxidasa y antitiroglobulina en jóvenes con hipotiroidismo subclínico y clínico / Prevalence of antiperoxidase and antithyroglobulin antibodies in young people with clinical and subclinical hypothyroidism

Introducción: El diagnóstico temprano de hipotiroidismosubclínico y el hallazgo de anticuerpos antitiroideos son de granvalor para el estudio de las enfermedades tiroideas. Objetivos: determinarla prevalencia de anticuerpos antitiroideos en hombres ymujeres jóvenes con hipotiroidismo subclínico y clínico, y compararsu frecuencia entre ambos sexos. Materiales y métodos: se estudiaron280 estudiantes de la Universidad Antonio Nariño, en laciudad de Bogotá, entre los 18 y 30 años. A los participantes en elestudio se les realizó TSH y T4 libre por quimioluminiscencia parala identificación de casos de hipotiroidismo subclínico y clínico. Atodos los individuos con alteraciones en las pruebas de función tiroidease les realizaron anticuerpos antitiroideos antiperoxidasa yantitiroglobulina por microelisa. Resultados: se encontró una altaprevalencia de anticuerpos antitiroideos antiperoxidasa y antitiroglobulinaen los jóvenes que presentaron hipotiroidismo, y unaprevalencia de hipotiroidismo en jóvenes de 4,64%, sin encontrarsediferencias estadísticamente significativas entre hombres y mujeres.Conclusión: existe en la población de jóvenes estudiados conhipotiroidismo subclínico una alta prevalencia de anticuerpos quesugerirían causa autoinmune en nuestra población universitaria. Sedeben realizar ensayos clínicos adicionales que permitan investigarotras posibles causas de hipotiroidismo como postinfecciosas, tóxicasy medioambientales, así mismo una posible asociación de estapatología con otras condiciones autoinmunes.

Abstract: Introduction: An early diagnosis of subclinical hypothy-roidism and the discovery of antithyroid antibodies are really valu-able in preventing severe thyroid diseases. Objectives: To determine the prevalence of antithyroid antibodies in young men and women with subclinical and clinical hypothyroidism, and to compare their frequency among both genders. Materials and methods: The case study enrolled 280 students between 18 and 30 years of age from the Antonio Nariño University in Bogotá. TSH and free T4 was deter-mined by chemoluminescence in all participants of the study for the identification of possible clinical and subclinical hypothyroidism. All individuals with alterations in their thyroid function tests had also their antiperoxidase and antithyroglobulin antibodies as-sessed by microelisa. Results: A high prevalence of antiperoxi-dase and antithyroglobulin antithyroid antibodies was detected in young people who had hypothyroidism, and the prevalence of hypothyroidism in young people was 4,64%. No statistically sig-nificant difference was found between the prevalence in men and women. Conclusion: There was a high prevalence of antibodies in the study population of young people with subclinical hypo-thyroidism, which could suggest an autoimmune cause in our university population. It is also necessary to carry out other clini-cal trials which could allow the investigation of possible causes of hypothyroidism like post-infectious, toxic and environmental and also a possible association between this disease and other autoimmune conditions.