title: [Distribution and significance of IgG subclasses of serum antithyroglobulin antibody in Hashimoto thyroiditis].
abstract: OBJECTIVE
  To evaluate the distribution and significance of IgG subclasses of antithyroglobulin antibody in sera from patients with Hashimoto thyroiditis.
  
  
  METHODS
  Sera from 112 patients with Hashimoto thyroiditis were collected and patients were divided into 3 groups, i. e. hypothyroidism, subclinical hypothyroidism and euthyroidism. Antigen specific ELISA was used to detect the distribution of IgG subclasses of antithyroglobulin antibody.
  
  
  RESULTS
  The positive rates of IgG subclasses of TgAb were IgG1 90.2%, IgG2 58.0%, IgG3 19.6% and IgG4 87.5% respectively. The mean geometric titers of IgG1 in sera from patients with hypothyroidism and subclinical hypothyroidism were 1: 450.8 and 1: 245.5 respectively, both being significantly higher than that with euthyroidism (1:8.7, P < 0.01). The mean geometric titers of IgG2 in sera from patients with hypothyroidism and subclinical hypothyroidism were 1: 37.3 and 1: 3.2 respectively, both being also significantly higher than that with euthyroidism (1: 0.2, P < 0.01 and P < 0.05 respectively) and that with hypothyroidism was significantly higher than that with subclinical hypothyroidism (P < 0.05).
  
  
  CONCLUSIONS
  The distribution of IgG subclasses of antithyroglobulin antibody in sera from patients with Hashimoto thyroiditis was predominantly IgG1, IgG2 and IgG4. High titers of IgG1 and IgG2 implicated the possibility of development from subclinical hypothyroidism to overt hypothyroidism.
authors.affiliation: Department of Endocrinology, Peking University First Hospital, Beijing 100034, China.
authors.forename: Mao-rong
authors.initials: MR
authors.lastname: Li
authors.forename: Xiao-hui
authors.initials: XH
authors.lastname: Guo
authors.forename: Ying
authors.initials: Y
authors.lastname: Gao
authors.forename: Yan-ming
authors.initials: YM
authors.lastname: Gao
authors.forename: Gui-zhi
authors.initials: GZ
authors.lastname: Lu
authors.forename: Yan
authors.initials: Y
authors.lastname: Hui
authors.forename: Shu-feng
authors.initials: SF
authors.lastname: Wang
authors.forename: Bing-yin
authors.initials: BY
authors.lastname: Shi
authors.forename: Wei-ping
authors.initials: WP
authors.lastname: Teng
mesh_terms: D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D050031:Hashimoto Disease / Q000097:blood / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood* / Q000145:classification; D008297:Male; D008875:Middle Aged
chemical_list: D001323:Autoantibodies; D007074:Immunoglobulin G; C006606:anti-thyroglobulin