Frequency of appearance of myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) in Graves' disease patients treated with propylthiouracil and the relationship between MPO-ANCA and clinical manifestations

Clin Endocrinol (Oxf). 2001 May;54(5):651-4. doi: 10.1046/j.1365-2265.2001.01282.x.


Objective: Myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA)-positive vasculitis has been reported in patients with Graves' disease who were treated with propylthiouracil (PTU). The appearance of MPO-ANCA in these cases was suspected of being related to PTU because the titres of MPO-ANCA decreased when PTU was stopped. Nevertheless, there have been no studies on the temporal relationship between the appearance of MPO-ANCA and vasculitis during PTU therapy, or on the incidence of MPO-ANCA in untreated Graves' disease patients. Therefore, we sought to address these parameters in patients with Graves' disease.

Patients: We investigated 102 untreated patients with hyperthyroidism due to Graves' disease for the presence of MPO-ANCA, and for the development vasculitis after starting PTU therapy. Twenty-nine of them were later excluded because of adverse effects of PTU or because the observation period was less than 3 months. The remaining 73 patients (55 women and 18 men), all of whom were examined for more than 3 months, were adopted as the subjects of the investigation. The median observation period was 23.6 months (range: 3-37 months).

Measurements: MPO-ANCA was measured at intervals of 2-6 months.

Results: Before treatment, the MPO-ANCA titres of all 102 untreated Graves' disease patients were within the reference range (below 10 U/ml). Three (4.1%) of the 73 patients were positive for MPO-ANCA at 13, 16 and 17 months, respectively, after the start of PTU therapy. In two of them, the MPO-ANCA titres transiently increased to 12.8 and 15.0 U/ml, respectively, despite continued PTU therapy, but no vasculitic disorders developed. In the third patient, the MPO-ANCA titre increased to 204 U/ml and she developed a higher fever, oral ulcers and polyarthralgia, but the symptoms resolved 2 weeks after stopping PTU therapy, and the MPO-ANCA titre decreased to 20.7 U/ml by 4 months after discontinuing PTU.

Conclusions: PTU therapy may be related to the appearance of MPO-ANCA, but MPO-ANCA does not appear to be closely related to vasculitis.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Antibodies, Antineutrophil Cytoplasmic / blood*
  • Antithyroid Agents / adverse effects
  • Antithyroid Agents / therapeutic use*
  • Biomarkers / blood
  • Child
  • Female
  • Graves Disease / drug therapy
  • Graves Disease / immunology*
  • Humans
  • Male
  • Middle Aged
  • Peroxidase / immunology*
  • Propylthiouracil / adverse effects
  • Propylthiouracil / therapeutic use*
  • Time Factors
  • Vasculitis / chemically induced*
  • Vasculitis / immunology


  • Antibodies, Antineutrophil Cytoplasmic
  • Antithyroid Agents
  • Biomarkers
  • Propylthiouracil
  • Peroxidase