title: Time to disappearance of thyroglobulin antibodies and influencing factors in patients with papillary thyroid carcinoma.
abstract: OBJECTIVE
  To investigate the time to disappearance of thyroglobulin antibodies (TgAb) and its influencing factors in papillary thyroid carcinoma (PTC) patients with positive TgAb after radioiodine ((131)I) ablation.
  
  
  METHODS
  We retrospectively analyzed the clinical data of 64 PTC patients who had undergone a total thyroidectomy and subsequent (131)I therapy. Patients were divided into two groups according to the presence of concurrent Hashimoto thyroiditis (HD). TgAb1 (TgAb levels determined before (131)I therapy) were above the normal thresholds in all patients. The method of survival analysis (including Life tables and Cox Regression analysis) was used to assess the time to disappearance of TgAb and its influencing factors.
  
  
  RESULTS
  The median time to disappearance of positive TgAb (9.0 months vs. 10.4 months, P=0.923) showed no significant difference between these two groups. Cox Regression analysis showed that, among the potential influencing factors including TgAb [partial regression coefficient (B)=-0.004, P=0.001], age(B=-0.018, P=0.362), sex (B=0.644, P=0.320) and HD (B=0.341, P=0.372), only TgAb1 was correlated with the TgAb negative conversion time.
  
  
  CONCLUSIONS
  TgAb1 has remarked influence on the time to disappearance of positive TgAb in PTC patients. Patients with a higher TgAb need longer time to achieve negative conversion.
authors: Department of Oncology, the Affiliated Hospital of Qingdao University Medical College, Qingdao 266003, China.
authors: Tian-jun
authors: TJ
authors: Li
authors: Yan-song
authors: YS
authors: Lin
authors: Jun
authors: J
authors: Liang
authors: Fang
authors: F
authors: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood*; D002277:Carcinoma / Q000276:immunology / Q000532:radiotherapy*; D002291:Carcinoma, Papillary; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000276:immunology / Q000532:radiotherapy*; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D007457:Iodine Radioisotopes; C006606:anti-thyroglobulin