Pathogenesis (development of disease)
In Hashimoto’s thyroiditis, an autoimmune reaction (pathological reaction of the immune system toward the body’s own tissue) – primarily T-cell-mediated – results in infiltration (invasion) with lymphocytes (subgroup of white blood cells) and atrophy (regression) of the follicles (= vesicles inside which the hormones are stored in an inactive form as a so-called colloid), which can lead to fibrosis (transformation of specialized organ parenchyma into connective tissue) of the thyroid gland. Antibodies to thyroperoxidase (TPO antibodies; TPO-Ak) and to thyroglobulin (TG antibodies; AG-Ak) may be detected.
Etiology (Causes)
Biographic causes
- Genetic burden from parents, grandparents.
Behavioral causes
- Nutrition
- Excessive iodine intake and selenium deficiency appear to have an important role as triggers of autoimmune thyroiditis in genetically predisposed individuals.
Disease-related causes
- Diabetes mellitus type 1 (risk about 40%).
- Hepatitis C