title: Clinical Relationship Between IgG4-Positive Hashimoto's Thyroiditis and Papillary Thyroid Carcinoma.
abstract: Hashimoto's thyroiditis (HT) can be divided into IgG4-positive and IgG4-negative HT. The potential association between IgG4-positive HT and papillary thyroid carcinoma (PTC) remains poorly understood.
  
  
  
  The aim was to investigate the relationship between IgG4-positive HT and PTC and to compare the prognostic parameters of PTC patients with and without IgG4-positive HT.
  
  
  
  This was a retrospective study.
  
  
  
  A total of 66 HT patients (18 HT-alone, 48 HT with PTC) with serum samples stored before the operation were collected. Another 18 PTC-alone patients were collected as controls.
  
  
  
  Expression of IgG4, IgG, and TGF-β1 in thyroid tissues and serum levels of IgG4, TgAb IgG, TgAb IgG4, TPOAb IgG, and TPOAb IgG4 were measured.
  
  
  
  Seventeen HT patients with PTC (35.4%) were IgG4-positive HT, whereas only one patient (5.6%) was found to be IgG4-positive in the HT-alone group. In contrast, there were only a few IgG4-positive plasma cells in the PTC-alone group. The association of IgG4-positive HT and PTC was statistically significant (P < .05). Moreover, serum levels of TgAb IgG4 and the ratios of TgAb IgG4 to TgAb IgG were significantly higher in the HT with PTC and the PTC-alone groups than in the HT-alone group (P < .05). Furthermore, in the HT with PTC group, the average tumor diameter of 17 IgG4-positive HT with PTC patients was 1.7 ± 0.8 cm, whereas of 31 IgG4-negative HT patients with PTC, the diameter was 1.2 ± 0.6 cm (P = .01). A considerably higher percentage of lymph node metastasis (41.2% vs 12.9%; P = .026) was found in PTC patients with IgG4-positive HT as compared with those with IgG4-negative HT.
  
  
  
  PTC may be facilitated by preexisting autoimmune inflammation of IgG4-positive HT. IgG4-positive HT with PTC cases may have worse clinical outcomes. The high levels of TgAb IgG4 might present a risk factor for PTC.
authors: Departments of Endocrinology (Y.Y., G.L., Y.Z., N.Y., Yin.G., Yan.G., X.G.), Geriatrics (J.Z.), and Pathology (T.L.), Peking University First Hospital, Beijing 100034, China.
authors: Yang
authors: Y
authors: Yu
authors: Departments of Endocrinology (Y.Y., G.L., Y.Z., N.Y., Yin.G., Yan.G., X.G.), Geriatrics (J.Z.), and Pathology (T.L.), Peking University First Hospital, Beijing 100034, China.
authors: Jing
authors: J
authors: Zhang
authors: Departments of Endocrinology (Y.Y., G.L., Y.Z., N.Y., Yin.G., Yan.G., X.G.), Geriatrics (J.Z.), and Pathology (T.L.), Peking University First Hospital, Beijing 100034, China.
authors: Guizhi
authors: G
authors: Lu
authors: Departments of Endocrinology (Y.Y., G.L., Y.Z., N.Y., Yin.G., Yan.G., X.G.), Geriatrics (J.Z.), and Pathology (T.L.), Peking University First Hospital, Beijing 100034, China.
authors: Ting
authors: T
authors: Li
authors: Departments of Endocrinology (Y.Y., G.L., Y.Z., N.Y., Yin.G., Yan.G., X.G.), Geriatrics (J.Z.), and Pathology (T.L.), Peking University First Hospital, Beijing 100034, China.
authors: Yang
authors: Y
authors: Zhang
authors: Departments of Endocrinology (Y.Y., G.L., Y.Z., N.Y., Yin.G., Yan.G., X.G.), Geriatrics (J.Z.), and Pathology (T.L.), Peking University First Hospital, Beijing 100034, China.
authors: Nan
authors: N
authors: Yu
authors: Departments of Endocrinology (Y.Y., G.L., Y.Z., N.Y., Yin.G., Yan.G., X.G.), Geriatrics (J.Z.), and Pathology (T.L.), Peking University First Hospital, Beijing 100034, China.
authors: Ying
authors: Y
authors: Gao
authors: Departments of Endocrinology (Y.Y., G.L., Y.Z., N.Y., Yin.G., Yan.G., X.G.), Geriatrics (J.Z.), and Pathology (T.L.), Peking University First Hospital, Beijing 100034, China.
authors: Yanming
authors: Y
authors: Gao
authors: Departments of Endocrinology (Y.Y., G.L., Y.Z., N.Y., Yin.G., Yan.G., X.G.), Geriatrics (J.Z.), and Pathology (T.L.), Peking University First Hospital, Beijing 100034, China.
authors: Xiaohui
authors: X
authors: Guo
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000097:blood; D002291:Carcinoma, Papillary / Q000097:blood / Q000209:etiology* / Q000473:pathology; D005260:Female; D050031:Hashimoto Disease / Q000097:blood / Q000150:complications* / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000097:blood / Q000209:etiology* / Q000473:pathology
chemical_list: D001323:Autoantibodies; D007074:Immunoglobulin G