Clinical-Laboratory Evaluation of a Group of Patients with Hashimoto Thyroiditis

Abstract

Chronic lymphocytic thyroiditis (or chronic thyroiditis, or Hashimoto thyroiditis -HT) was first described in 1992 in Germany by the Japanese pathologist Hakuru Hashimoto as a new disease called lymphomatous struma. Today it represents the most frequent cause of hypothyroidism and goiter in the US and in areas of iodine sufficiency. It is the main cause of goiter in children and young adults and of idiopathic mixedema. The most important auto antibodies are antithyroglobulin (Anti-TG), antithyroperoxidase (Anti-TPO) and TSH receptor antibody blocker (TRAB). In the initial phase Anti-TG is markedly elevated while Anti-TPO is only mildly elevated. Anti-TG may disappear, but Anti-TPO continues to be positive for many years. Its pathogenesis has not been fully clarified. The estimate is that the pathogenesis of this immune disease is due genetic factors in 70 to 80% of cases and to environmental factors in 20 to 30% of cases. The study was conducted on 399 patients, 336 women (87.2%) and 63 men (12.8 %), ranging in age from 11 to 95 years. The predominant age ranges were 20 to 70 years for women and 30 to 60 years for men. Blood samples were obtained for the determination of TSH, T4L, T3L, thyroglobulin, and anti-TPO, anti-thyroglobulin and TSH receptor (TRAB) antibodies by chemiluminescence. Anti-TPO and anti-TG autoantibody values were higher in Anti-TPO-positive and AntiTG -negative: Type 1 thyroiditis; and in Anti-TPO-negative and AntiTG -positive: Type 2 thyroiditis; and in Anti-TPO-positive and antiTG -positive: Type 3 thyroiditis; and in Anti-TPO-negative and AntiTG -negative: Type 4 thyroiditis. Autoantibody expression was similar in men and women, with predominance of type 4 > type 3 > type 2> type 1 when considering the oldest age of each sex (95 years for women and 85 years for men). When considering the youngest age studied, the following results were obtained: type 2 > type 4 > type 1> type 3 for women and type 3 > type 1 > type 4 > type 2 for men.