[Antibodies against thyroid gland peroxidase and thyroglobulin in various thyroid diseases]

Autoantibodies to thyroperoxidase (anti-TPOAb) and thyroglobulin (anti-TgAb) were measured in 564 patients with various thyroid disorders and in 59 healthy subjects using chemiluminometric immunoassay. The frequency of elevated titers was 8.6% in healthy subjects, 76.2% in patients with untreated hyperthyroidism and diffuse goiter, 80.7% in patients with relapse of hyperthyroidism. 83.4% of patient with hyperfunction changed spontaneously to hypothyroidism and 71.5% of patients with hypothyroidism and goiter had antibodies above the normal range. Unexpectedly low prevalence of autoantibodies were detected in patients with primary myxoedema without goiter (48.2%) and in patients with endocrine ophthalmopathy and euthyroidism (33.2%). In the subgroup of patients with hyperthyroidism under methimazole treatment we found an incidence of positivity of 56% and the mean of positive values was lower compared with the untreated ones. In 42.8% of patients with hyperthyroidism and diffuse goiter treated successfully by methimazole, surgery or radioiodine elevated concentrations of antibodies could be detected, however they were in remission for more than five years. 197 (82.4%) of the patients with positive antibody titers showed higher concentrations to peroxidase compared with thyroglobulin. 57.9% of serum samples positive for anti-TPOAb were negative for anti-TgAb, whereas 9.4% of samples positive for anti-TgAb were anti-TPOAb negative. The diagnosis of thyroid autoimmunity could generally be based on measurement of anti-TPOAb with additional measurement of anti-TgAb in special cases.