title: A meta-analysis of patients with chronic hepatitis C treated with interferon-alpha to determine the risk of autoimmune thyroiditis.
abstract: OBJECTIVE
  In order to analyze the effect on autoimmune thyroiditis (AT) of current anti-hepatitis C virus (HCV) treatment in HCV-infected patients, we performed a systematic review with meta-analysis of the available literature. The present meta-analysis was conducted to evaluate the strength and the consistency of the association between treatments with interferon-alpha (IFN-alpha) for HCV infection and AT.
  
  
  METHODS
  A search in Medline, PubMed, and EMBASE was conducted with a systematic review of clinical studies in English and other languages. Only studies in HCV subjects compared to a control group with hepatitis B (positive HBsAg) were considered. The relative risk (RR) of AT was regarded as the most reliable outcome end-point. The pooled odds ratio (OR) and 95% confidence intervals (95% CI) were calculated from the raw study data using the Mantel-Haenszel methods. We used a statistical evaluation of heterogeneity by the chi2-test to assess whether the variation in treatment effect within trials of the same group was greater than it might be expected.
  
  
  RESULTS
  We identified 35 clinical trials with a total of 6.403 patients. Five trials were selected for analysis involving a total of 625 patients with hepatitis C treatment with IFN-alpha and 456 HBsAg-positive controls. These studies yielded a combined adjusted OR of 4.98 (95% IC 1.56-15.91). The test for heterogeneity was significant (P = 0.0008), and the test for overall effect was Z statistic 2.71 (P = 0.007).
  
  
  CONCLUSIONS
  Our meta-analysis indicates that treatment with IFN-alpha for HCV infection has an increased risk of AT.
authors: Faculdade de Medicina da Universidade Estadual de Santa Cruz, Bahia, Brazil. luis_jesuino@yahoo.com.br
authors: Luis Jesuino de Oliveira
authors: LJ
authors: Andrade
authors: Argemiro
authors: A
authors: D'Oliveira
authors: Carolina Alves Costa
authors: CA
authors: Silva
authors: Paulo
authors: P
authors: Nunes
authors: Larissa Santos
authors: LS
authors: França
authors: Ana Micheline Andrade
authors: AM
authors: Malta
authors: Raymundo
authors: R
authors: Paraná
mesh_terms: D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000009:adverse effects* / Q000627:therapeutic use; D016022:Case-Control Studies; D005260:Female; D019698:Hepatitis C, Chronic / Q000188:drug therapy*; D006801:Humans; D016898:Interferon-alpha / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D013967:Thyroiditis, Autoimmune / Q000139:chemically induced*
chemical_list: D000998:Antiviral Agents; D016898:Interferon-alpha