title: Possible reasons for different pattern disappearance of thyroglobulin and thyroid peroxidase autoantibodies in patients with differentiated thyroid carcinoma following total thyroidectomy and iodine-131 ablation.
abstract: The purpose of this study was to reveal some possible factors for the differences between the pattern of disappearance of thyroglobulin autoantibodies (anti-Tg) and thyroid peroxidase autoantibodies (anti-TPO) in patients with differentiated thyroid carcinoma following thyroidectomy and iodine-131 ablation. Patients with a history of follicular cell derived cancer (papillary, follicular, both papillary and follicular, Hürthle cell) and high pre-operative titers of anti-TPO and/or anti-Tg autoantibodies were retrospectively studied. Thyroglobulin (Tg) levels were measured using radio-immunometric assay (RIA). Anti-Tg and anti-TPO levels during the first 6 yr' follow-up were measured by passive agglutination, during the following 10 yr by ELISA method and during the last 2 yr by chemiluminescence assay. A statistically significant difference was observed between median time (72 months) of disappearance of anti-TPO and median time (39 months) of disappearance of anti-Tg in patients with complete ablation of thyroid tissue, following iodine-131 administration (p=0.0395, Logrank statistic=4.24, Kaplan-Meier method). A statistically significant difference was observed between median time (106 months) of disappearance of anti-TPO and median time (33 months) of disappearance of anti-Tg in patients >45 yr of age (p=0.034) and between median time (111 months) of disappearance of anti-TPO and median time (41 months) of disappearance of anti-Tg in patients with tumor size <2 cm (p=0.0175). We concluded that patients with differentiated thyroid carcinoma and pre-surgical elevated titers of both Tg and anti-TPO tend to become earlier anti-Tg seronegative. Although tumor size and age may influence the pattern of thyroid autoantibody reduction, the exact reasons for the different rhythm of autoantibodies decrease must further be evaluated.
authors.affiliation: Department of Endocrinology, Diabetes and Metabolism, Metaxa Memorial Anticancer Research Hospital, Piraeus, Greece. thomasproge@endo.gr
authors.forename: D
authors.initials: D
authors.lastname: Thomas
authors.forename: V
authors.initials: V
authors.lastname: Liakos
authors.forename: E
authors.initials: E
authors.lastname: Vassiliou
authors.forename: F
authors.initials: F
authors.lastname: Hatzimarkou
authors.forename: A
authors.initials: A
authors.lastname: Tsatsoulis
authors.forename: P
authors.initials: P
authors.lastname: Kaldrimides
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000096:biosynthesis / Q000097:blood*; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007453:Iodide Peroxidase / Q000276:immunology*; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D015996:Survival Rate; D013954:Thyroglobulin / Q000276:immunology*; D013964:Thyroid Neoplasms / Q000276:immunology / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D013965:Thyroidectomy
chemical_list: D001323:Autoantibodies; D007457:Iodine Radioisotopes; D013954:Thyroglobulin; D007453:Iodide Peroxidase