Conversion to Graves disease from Hashimoto thyroiditis: a study of 24 patients

ABSTRACT Objective: The conversion of Hashimoto's thyroiditis (HT) to hyperthyroidism due to thyrotropin receptor antibodies is intriguing and considered rare. The contribution of TSH receptor blocking antibodies (TRAb), which may be stimulators (TSAb) or blockers (TBAb), is suspected. We describe clinical and biological variables in a series of patients switching from Hashimoto's thyroiditis to Grave's disease. Subjects and methods: Retrospective case study of 24 patients with Hashimoto's thyroiditis followed during 48 ± 36 months that developed later Graves' disease (GD). These variables were analysed in the hypo and hyperthyroid phase: age, sex, initial TSH, free triiodothyronine (fT3), free thyroxine (fT4), anti-TPO, TBII antibodies, parietal cell autoantibodies, time between hypo and hyperthyroidism, thyroid volume and levothyroxine doses (LT). Results: In HT, mean TSH was 9.4 ± 26.1 UI/L and levothyroxine treatment was 66.2 ± 30.8 µg/day. The switch to GD was observed 38 ± 45 months after HT diagnosis. As expected, we found significant differences on TSH, FT3, FT4 and TBAb levels. Three out of 14 patients had parietal cell autoantibodies. In two of these three cases there was an Helicobacter pylori infection. There were no significant differences between HT and GD groups with respect to thyroid volume. Conclusions: To our knowledge, large series documenting the conversion of HT to GD are scarce. Although rare, this phenomenon should not be misdiagnosed. Suspicion should be raised whenever thyroxine posology must be tapered down during the follow-up of HT patients. Further immunological and genetic studies are needed to explain this unusual autoimmune change.

Abordaje de la muerte súbita en niños y jóvenes desde la patología forense en Bizkaia y Sevilla (España) / A forensic pathology approach to sudden death in children and young adults in Biscay and Seville (Spain)

La muerte súbita (MS) en niños y jóvenes constituye un complejo problema multifactorial con implicaciones médico-legales y socio-familiares. En su investigación, la patología forense tiene una función importante ya que al tratarse de muertes inesperadas es necesaria una autopsia médico-legal para determinar la causa y el mecanismo de la muerte. La mayor parte de estas muertes tienen un origen cardiovascular y muchas de ellas tienen un componente hereditario. La autopsia puede ser la única posibilidad de que se efectúe un diagnóstico correcto de la enfermedad y que la familia reciba una orientación médica adecuada que permita la identificación de familiares asintomáticos y la prevención de futuras muertes. Para realizar un abordaje adecuado se requiere la colaboración de las distintas especialidades médicas implicadas (médicos forenses, patólogos, pediatras, cardiólogos, microbiólogos, genetistas), quienes deben trabajar de forma coordinada de acuerdo a protocolos internacionales. En este artículo se revisan las características epidemiológicas y clínico-patológicas de las principales enfermedades que se pueden manifestar como MS en niños y jóvenes y se presenta la casuística de las provincias de Sevilla y Bizkaia en los últimos años. Finalmente, se destaca la trascendencia de la patología forense en el abordaje y prevención de estos fallecimientos.

Sudden death (SD) in children and young adults is a complex multifactorial problem that entails medical forensic and socio-familial implications. Forensic pathology plays an important role in these cases due to the fact that they tend to occur unexpectedly, and therefore a postmortem examination is needed to determine cause and mechanism of death. Most of these deaths are of cardiovascular origin and many of them have a hereditary component. The autopsy may be the only way to establish the correct diagnosis of the underlying condition enabling the family to receive proper medical counseling, to identify asymptomatic relatives at risk, and to prevent subsequent deaths. A proper approach requires the collaboration of various medical specialties (coroners, pathologists, pediatricians, cardiologists, microbiologists, geneticians), who must work in coordination in accordance to international protocols. In this article, the epidemiologic and clinical-pathological features of the main conditions that may lead to SD in children and young adults are reviewed and a case series from Seville and Biscay provinces is presented. Finally, the importance of forensic pathology in the management and prevention of these cases is underlined.