title: The presence of thyroid peroxidase antibody of IgG2 subclass is a risk factor for thyroid dysfunction in chronic hepatitis C patients.
abstract: OBJECTIVE
  To investigate the prevalence of thyroid dysfunction (TD) and IgG subclasses of thyroid autoantibodies (TAs) and to determine the predictive factors of TD in chronic hepatitis C (CHC) patients.
  
  
  METHODS
  Three hundred and twelve untreated hepatitis C virus-infected patients without a history of TD or treatment with thyroid hormones were enrolled in a cross-sectional study. Clinical and biological factors were statistically analyzed to determine the correlation between TD and this patient population.
  
  
  RESULTS
  The incidence of TD WAS 12.5% in CHC patients. Clinical hypothyroidism (5.8%) and subclinical hypothyroidism (3.8%) were more frequent than clinical hyperthyroidism (1.6%) and subclinical hyperthyroidism (1.3%). The percentage of TA-positive patients was significantly higher in people 60 years than in those 60 years (31.9 VS 18.6%; P=0.042). Positive thyroid peroxidase antibody (TPOAb) was more frequent, and alanine aminotransferase (ALT) levels were lower in patients who displayed TD (TPOAb: 62.1 vs 10.8%, P=0.000; ALT: 43.5 vs 51 IU/l, P=0.046). The positive percentage of TPOAb IgG2 subclass in the TD group was significantly higher than that of patients without TD (66.7 vs 16.7%, P=0.005). Multiple logistic regression analysis indicated that only TPOAb IgG2 subclass positivity was an independent risk factor for TD in CHC patients (odds ratio=8; 95% CI: 1.225-52.246; P=0.030).
  
  
  CONCLUSIONS
  TPOAb IgG2 subclass positivity is a risk factor for TD in CHC patients before antiviral treatment. IgG2 subclass of TPOAb might play an important role in the presence of TD in CHC patients.
authors: Departments of Infectious Diseases, Peking University First Hospital, Xicheng District, Beijing, People's Republic of China.
authors: Cuiping
authors: C
authors: Shao
authors: Na
authors: N
authors: Huo
authors: Lanlan
authors: L
authors: Zhao
authors: Ying
authors: Y
authors: Gao
authors: Xiaohong
authors: X
authors: Fan
authors: Yingying
authors: Y
authors: Zheng
authors: Lifen
authors: L
authors: Wang
authors: Haiying
authors: H
authors: Lu
authors: Xiaoyuan
authors: X
authors: Xu
authors: Xiaohui
authors: X
authors: Guo
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001323:Autoantibodies / Q000276:immunology*; D003430:Cross-Sectional Studies; D005260:Female; D016174:Hepacivirus / Q000276:immunology; D019698:Hepatitis C, Chronic / Q000150:complications / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D007453:Iodide Peroxidase / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D013959:Thyroid Diseases / Q000150:complications / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D007074:Immunoglobulin G; D007453:Iodide Peroxidase