title: Antineutrophil Cytoplasmic Antibody-Positive Small-Vessel Vasculitis Associated with Antithyroid Drug Therapy: How Significant Is the Clinical Problem?
abstract: BACKGROUND
  The aim of this review was to delineate the characteristics of antineutrophil cytoplasmic antibody (ANCA)-associated small-vessel vasculitis associated with antithyroid drugs (ATD). A PubMed search was made for English language articles using the search terms antithyroid drugs AND ANCA OR ANCA-associated vasculitis.
  
  
  CONCLUSIONS
  The literature includes approximately 260 case reports of ANCA-associated small-vessel vasculitis related to ATD, with 75% of these associated with thiouracil derivatives (propylthiouracil [PTU]) and 25% with methyl-mercapto-imidazole derivatives (MMI/TMZ). The prevalence of ANCA-positive cases caused by ATD varied between 4% and 64% with PTU (median 30%), and 0% and 16% with MMI/TMZ (median 6%). Young age and the duration of ATD therapy were the main factors contributing to the emergence of ANCA positivity. Before ATD therapy initiation, the prevalence of ANCA-positive patients was 0-13%. During ATD administration, 20% of patients were found to be positive for ANCA. Only 15% of ANCA-positive patients treated with ATD exhibited clinical evidence of vasculitis, corresponding to 3% of all patients who received ATD. Clinical manifestations of ANCA-associated vasculitis related to ATD were extremely heterogeneous. When vasculitis occurred, ATD withdrawal was usually followed by rapid clinical improvement and a favorable prognosis.
  
  
  CONCLUSIONS
  ANCA screening is not systematically recommended for individuals on ATD therapy, particularly given the decreasing use of PTU in favor of TMZ/MMI. Particular attention should be given to the pediatric population with Graves' disease who receive ATD, as well as patients treated with thiouracil derivatives and those on long-term ATD therapy.
authors.affiliation: 1 Service of Endocrinology and Metabolic Diseases, CHRU de Lille , Lille, France .
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Balavoine
authors.affiliation: 2 Department of Internal Medicine, Division of Endocrinology, University Hospital Saint Pierre , Brussels, Belgium .
authors.forename: Daniel
authors.initials: D
authors.lastname: Glinoer
authors.affiliation: 3 Institut d'Immunologie, CHRU de Lille , Lille, France .
authors.forename: Sylvain
authors.initials: S
authors.lastname: Dubucquoi
authors.affiliation: 1 Service of Endocrinology and Metabolic Diseases, CHRU de Lille , Lille, France .|3 Institut d'Immunologie, CHRU de Lille , Lille, France .
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Wémeau
mesh_terms: D000367:Age Factors; D056648:Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis / Q000453:epidemiology*; D013956:Antithyroid Agents / Q000627:therapeutic use*; D006801:Humans; D006980:Hyperthyroidism / Q000188:drug therapy*; D008713:Methimazole / Q000627:therapeutic use*; D015995:Prevalence; D011441:Propylthiouracil / Q000627:therapeutic use*; D013997:Time Factors
chemical_list: D013956:Antithyroid Agents; D008713:Methimazole; D011441:Propylthiouracil