Pathogenesis of Hashimoto’s Thyroiditis (HT)

Rodrigo Arrangoiz MS, MD, FACS, FSSO
  • A genetic predisposition for HT:
    • Is evident in about 75% of cases
  • Certain HLA class II antigens:
    • Such as ARG74 in DR3:
      • Carry an increased risk for the development of several autoimmune disorders that
        include HT:
        • With cytotoxic T-lymphocytes antigen-4 (CTLA-4) also playing a role
  • A growing number of environmental factors:
    • Have been implicated in the etiology of HT as well
  • Interestingly, iodine supplementation programs in areas of iodine deficiency:
    • Have been associated with rising rates of HT and associated hypothyroidism
  • The element selenium (Se++):
    • Is an integral component of the selenoprotein deiodinase enzymes
    • Deiodinases are present in the thyroid as well as various peripheral tissues:
      • Regulating deiodination of thyroxine (T4) and
        triiodothyronine (T3)
    • Reduced serum Se++ levels:
      • Have been noted with cases of HT
    • Although some reports indicate benefits of selenium replacement therapy to reduce the occurrence of HT and the development of hypothyroidism:
      • This has not yet been fully proven
  • Remarkably, tobacco and moderate alcohol use:
    • Which have other negative effects:
    • Appear to be associated with a reduced risk of
      autoimmune related hypothyroidism
  • Although the development of some autoimmune conditions has been reportedly related to previous infectious exposures:
    • No such association has been noted with
      HT
  • Although radiation exposure:
    • Potentially increases the risk of developing thyroid malignancy:
      • It remains to be proven if this predisposes to the development of thyroid autoimmunity
  • Other studies have reported a connection between vitamin D deficiency and increased risk of autoimmunity:
    • As well as vitamin D supplementation reducing TPOAb titers in patients with HT on LT4 replacement therapy
  • In other autoimmune conditions such as Graves’ disease:
    • Stress has been identified as a potential promoting factor:
      • Albeit available data has not proven any effect on TPOAb production or development
        of hypothyroidism
  • Endogenous factors contributing to the risk for
    HT include:
    • Female gender:
      • 7:1 female:male ratio
    • Sex hormones such as:
      • Estrogen, postpartum thyroiditis (PPT), pregnancy, and the presence of fetal microchimerism
  • Patients with Down’s and Turner’s syndromes:
    • Also display an increased propensity toward development of autoimmune hypothyroidism
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Published by Rodrigo Arrangoiz MS, MD, FACS, FSSO

My name is Rodrigo Arrangoiz I am a breast surgeon/ thyroid surgeon / parathyroid surgeon / head and neck surgeon / surgical oncologist that works at Center for Advanced Surgical Oncology in Miami, Florida. I was trained as a surgeon at Michigan State University from (2005 to 2010) where I was a chief resident in 2010. My surgical oncology and head and neck training was performed at the Fox Chase Cancer Center in Philadelphia from 2010 to 2012. At the same time I underwent a masters in science (Clinical research for health professionals) at the University of Drexel. Through the International Federation of Head and Neck Societies / Memorial Sloan Kettering Cancer Center I performed a two year head and neck surgery and oncology / endocrine fellowship that ended in 2016. Mi nombre es Rodrigo Arrangoiz, soy cirujano oncólogo / cirujano de tumores de cabeza y cuello / cirujano endocrino que trabaja Center for Advanced Surgical Oncology en Miami, Florida. Fui entrenado como cirujano en Michigan State University (2005 a 2010 ) donde fui jefe de residentes en 2010. Mi formación en oncología quirúrgica y e n tumores de cabeza y cuello se realizó en el Fox Chase Cancer Center en Filadelfia de 2010 a 2012. Al mismo tiempo, me sometí a una maestría en ciencias (investigación clínica para profesionales de la salud) en la Universidad de Drexel. A través de la Federación Internacional de Sociedades de Cabeza y Cuello / Memorial Sloan Kettering Cancer Center realicé una sub especialidad en cirugía de cabeza y cuello / cirugia endocrina de dos años que terminó en 2016.

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