title: Clinical impact of thyroglobulin (Tg) and Tg autoantibody (TgAb) measurements in needle washouts of neck lymph node biopsies in the management of patients with papillary thyroid carcinoma.
abstract: OBJECTIVE
  The presence of thyroglobulin (Tg) in needle washouts of fine needle aspiration biopsy (Tg-FNAB) in neck lymph nodes (LNs) suspected of metastasis has become a cornerstone in the follow-up of patients with papillary thyroid carcinoma (PTC). However, there are limited data regarding the measurement of anti-Tg antibodies in these washouts (TgAb-FNAB), and it is not clear whether these antibodies interfere with the assessment of Tg-FNAB or whether there are other factors that would more consistently justify the finding of low Tg-FNAB in metastatic LNs.
  
  
  METHODS
  We investigated 232 FNAB samples obtained from suspicious neck LNs of 144 PTC patients. These samples were divided according to the patient's serum TgAb status: sTgAb- (n = 203 samples) and sTgAb+ (n = 29). The TgAb-FNAB levels were measured using two different assays. Tg-FNAB was also measured using two assays when low levels (< 10 ng/mL) were identified in the first assay of the metastatic LNs from the sTgAb+ samples.
  
  
  RESULTS
  The TgAb-FNAB results were negative in both assays in all samples. Low levels of Tg-FNAB were identified in 11/16 of the metastatic LNs of the sTgAb+ patients and 16/63 of the sTgAb- patients (p < 0.05) using assay 1. The measurement of the Tg-FNAB levels using assay 2 indicated additional metastases in 5 LNs of the sTgAb+ patients.
  
  
  CONCLUSIONS
  Factors other than the presence of TgAb-FNAB may contribute to the higher number of metastatic LNs with undetectable Tg-FNAB in the sTgAb+ group. In addition, the measurement of Tg-FNAB using different assays was useful to enhance the diagnosis of metastatic LNs, particularly when cytological and Tg-FNAB results are discordant.
authors.affiliation: Centro de Doenças da Tireoide e Laboratório de Endocrinologia Molecular e Translacional, Divisão de Endocrinologia, Departamento de Medicina, Escola Paulista de Medicina da Universidade Federal de São Paulo (EPM- -Unifesp), São Paulo, SP, Brasil.|Departamento de Medicina, Universidade de Fortaleza (Unifor), Fortaleza, CE, Brasil.
authors.forename: M Cecilia
authors.initials: MC
authors.lastname: Martins-Costa
authors.affiliation: Centro de Doenças da Tireoide e Laboratório de Endocrinologia Molecular e Translacional, Divisão de Endocrinologia, Departamento de Medicina, Escola Paulista de Medicina da Universidade Federal de São Paulo (EPM- -Unifesp), São Paulo, SP, Brasil.|Centro de Doenças da Tireoide, Instituto Israelita de Ensino e Pesquisa Albert Einstein (IIEPAE), São Paulo, SP, Brasil.|Fleury Medicina e Saúde, São Paulo, SP, Brasil.
authors.forename: Rui M B
authors.initials: RMB
authors.lastname: Maciel
authors.affiliation: Centro de Doenças da Tireoide e Laboratório de Endocrinologia Molecular e Translacional, Divisão de Endocrinologia, Departamento de Medicina, Escola Paulista de Medicina da Universidade Federal de São Paulo (EPM- -Unifesp), São Paulo, SP, Brasil.
authors.forename: Teresa S
authors.initials: TS
authors.lastname: Kasamatsu
authors.affiliation: Centro de Doenças da Tireoide e Laboratório de Endocrinologia Molecular e Translacional, Divisão de Endocrinologia, Departamento de Medicina, Escola Paulista de Medicina da Universidade Federal de São Paulo (EPM- -Unifesp), São Paulo, SP, Brasil.|Centro de Doenças da Tireoide, Instituto Israelita de Ensino e Pesquisa Albert Einstein (IIEPAE), São Paulo, SP, Brasil.|Fleury Medicina e Saúde, São Paulo, SP, Brasil.
authors.forename: Claudia C D
authors.initials: CCD
authors.lastname: Nakabashi
authors.affiliation: Centro de Doenças da Tireoide e Laboratório de Endocrinologia Molecular e Translacional, Divisão de Endocrinologia, Departamento de Medicina, Escola Paulista de Medicina da Universidade Federal de São Paulo (EPM- -Unifesp), São Paulo, SP, Brasil.|Centro de Doenças da Tireoide, Instituto Israelita de Ensino e Pesquisa Albert Einstein (IIEPAE), São Paulo, SP, Brasil.
authors.forename: Cleber P
authors.initials: CP
authors.lastname: Camacho
authors.affiliation: Centro de Doenças da Tireoide e Laboratório de Endocrinologia Molecular e Translacional, Divisão de Endocrinologia, Departamento de Medicina, Escola Paulista de Medicina da Universidade Federal de São Paulo (EPM- -Unifesp), São Paulo, SP, Brasil.
authors.forename: Felipe
authors.initials: F
authors.lastname: Crispim
authors.affiliation: Centro de Doenças da Tireoide e Laboratório de Endocrinologia Molecular e Translacional, Divisão de Endocrinologia, Departamento de Medicina, Escola Paulista de Medicina da Universidade Federal de São Paulo (EPM- -Unifesp), São Paulo, SP, Brasil.|Centro de Doenças da Tireoide, Instituto Israelita de Ensino e Pesquisa Albert Einstein (IIEPAE), São Paulo, SP, Brasil.
authors.forename: Elza S
authors.initials: ES
authors.lastname: Ikejiri
authors.affiliation: Centro de Doenças da Tireoide e Laboratório de Endocrinologia Molecular e Translacional, Divisão de Endocrinologia, Departamento de Medicina, Escola Paulista de Medicina da Universidade Federal de São Paulo (EPM- -Unifesp), São Paulo, SP, Brasil.|Centro de Doenças da Tireoide, Instituto Israelita de Ensino e Pesquisa Albert Einstein (IIEPAE), São Paulo, SP, Brasil.
authors.forename: M Conceição O
authors.initials: MCO
authors.lastname: Mamone
authors.affiliation: Centro de Doenças da Tireoide e Laboratório de Endocrinologia Molecular e Translacional, Divisão de Endocrinologia, Departamento de Medicina, Escola Paulista de Medicina da Universidade Federal de São Paulo (EPM- -Unifesp), São Paulo, SP, Brasil.|Centro de Doenças da Tireoide, Instituto Israelita de Ensino e Pesquisa Albert Einstein (IIEPAE), São Paulo, SP, Brasil.
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Andreoni
authors.affiliation: Centro de Doenças da Tireoide e Laboratório de Endocrinologia Molecular e Translacional, Divisão de Endocrinologia, Departamento de Medicina, Escola Paulista de Medicina da Universidade Federal de São Paulo (EPM- -Unifesp), São Paulo, SP, Brasil.|Centro de Doenças da Tireoide, Instituto Israelita de Ensino e Pesquisa Albert Einstein (IIEPAE), São Paulo, SP, Brasil.|Fleury Medicina e Saúde, São Paulo, SP, Brasil.
authors.forename: Rosa Paula M
authors.initials: RPM
authors.lastname: Biscolla
mesh_terms: D001323:Autoantibodies / Q000097:blood*; D044963:Biopsy, Fine-Needle / Q000295:instrumentation / Q000379:methods; D002277:Carcinoma / Q000097:blood* / Q000276:immunology / Q000473:pathology; D002291:Carcinoma, Papillary; D015200:Fluoroimmunoassay / Q000379:methods; D006801:Humans; D008198:Lymph Nodes / Q000276:immunology* / Q000473:pathology; D008207:Lymphatic Metastasis / Q000276:immunology / Q000473:pathology; D009333:Neck; D011237:Predictive Value of Tests; D012016:Reference Values; D015203:Reproducibility of Results; D013954:Thyroglobulin / Q000097:blood*; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000097:blood* / Q000276:immunology / Q000473:pathology; D014463:Ultrasonography
chemical_list: D001323:Autoantibodies; C006606:anti-thyroglobulin; D013954:Thyroglobulin