Disappearance of humoral thyroid autoimmunity after complete removal of thyroid antigens.
BACKGROUND
The development of antibodies to thyroid peroxidase, thyroglobulin, and thyroid-stimulating hormone (TSH) receptor is a main feature of autoimmune thyroid diseases.


OBJECTIVE
To investigate whether complete removal of thyroid antigens results in the abatement of humoral thyroid autoimmunity.


METHODS
Retrospective chart review study of patients treated and monitored with a standard prospective protocol.


METHODS
University hospital in Pisa, Italy, between 1976 and 1994.


METHODS
182 patients with differentiated thyroid carcinoma and serum antibodies to thyroid peroxidase, thyroglobulin, or TSH receptor due to coexistent clinical Hashimoto thyroiditis, Graves disease, or focal autoimmune thyroiditis.


METHODS
Total thyroidectomy and radioiodine treatment to ablate residual or metastatic thyroid tissue. Regular follow-up with iodine-131 whole-body scanning and serum thyroglobulin measurement. Mean follow-up (+/-SD) was 10.1 +/- 4.1 years (range, 4 to 20 years).


METHODS
Serum antibodies to thyroid peroxidase, thyroglobulin, and TSH receptor.


RESULTS
Thyroid peroxidase, thyroglobulin, and TSH-receptor antibodies progressively disappeared after the initial treatment. The median disappearance time was 6.3 years for thyroid peroxidase antibodies and 3.0 years for thyroglobulin antibodies. There was a statistically significant correlation between the disappearance of thyroid tissue and that of thyroid antibodies. The coexistence of Hashimoto thyroiditis or Graves disease with thyroid cancer did not modify the pattern of disappearance of thyroid antibody compared with patients with focal autoimmune thyroiditis.


CONCLUSIONS
Complete ablation of thyroid tissue with its antigenic components results in the disappearance of antibodies to all major thyroid antigens, thus supporting the concept that continued antibody production depends on the persistence of autoantigen in the body.
Chiovato
Luca
L
Università di Pisa, Pisa, Italy.
Latrofa
Francesco
F
Braverman
Lewis E
LE
Pacini
Furio
F
Capezzone
Marco
M
Masserini
Lucio
L
Grasso
Lucia
L
Pinchera
Aldo
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood*; D015551:Autoimmunity; D002648:Child; D005260:Female; D006801:Humans; D007453:Iodide Peroxidase / Q000276:immunology; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011989:Receptors, Thyrotropin / Q000276:immunology; D012189:Retrospective Studies; D013954:Thyroglobulin / Q000276:immunology; D013959:Thyroid Diseases / Q000150:complications / Q000276:immunology*; D013961:Thyroid Gland / Q000276:immunology*; D013964:Thyroid Neoplasms / Q000150:complications / Q000276:immunology / Q000628:therapy; D013965:Thyroidectomy
D001323:Autoantibodies; D007457:Iodine Radioisotopes; D011989:Receptors, Thyrotropin; D013954:Thyroglobulin; D007453:Iodide Peroxidase