Prevalence of positive anti-neutrophil cytoplasmic antibody (ANCA) in patients receiving anti-thyroid medication

Abstract

Objective: Vasculitis is a rare complication of anti-thyroid medications. There are 32 cases of antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis in association with anti-thyroid medication reported in the English literature. The objectives of this study were to assess the frequency of positive ANCA in patients on long-term anti-thyroid medication, and to follow patients prospectively from commencement of medication to determine whether they became ANCA-positive after therapy. Design: Prospectively collected cross-sectional study of two groups of patients: (i) who had received long-term (>18 months) anti-thyroid medication, and (ii) newly diagnosed thyrotoxicosis before commencement of anti-thyroid medication attending clinic between 28 April 1998 and 30 September 1998. Data were collected for age, sex, ethnicity, underlying thyroid disease, medication and duration, and symptomatology. Results: Eight of 30 patients on long-term anti-thyroid medication (26.7%) were ANCA-positive. All ANCA-positive patients were female, seven were taking propylthiouracil (PTU) at the time of testing. ANCA-positive patients had taken PTU for a mean Ϯ S.D. of 7.9 Ϯ 10.2 years, compared with 0.8 Ϯ 2.2 years in ANCA-negative patients (Mann-Whitney, P < 0.0001). The ten patients with newly diagnosed thyrotoxicosis were ANCA-negative before commencement of carbimazole. One (10%) became ANCApositive within 8 months of therapy. Conclusions: In our population, ANCA-positivity in association with long-term anti-thyroid medication is common (26.7%). One patient who was ANCA-negative prior to anti-thyroid therapy has become ANCA-positive. ANCA should be tested in patients receiving long-term anti-thyroid medications, and in patients with adverse reactions. As PTU is more commonly associated with vasculitis and positive ANCA, carbimazole may be the preferred medication for long-term use. Patients with positive ANCA should be followed, and considered for definitive anti-thyroid therapy, to allow cessation of medication. ANCA-positivity may resolve after cessation of anti-thyroid medication.

Occurrence of antineutrophil cytoplasmic antibodies and associated vasculitis in patients with hyperthyroidism treated with antithyroid drugs: A long‐term followup study

“…Although ANCA are present relatively often in patients treated with antithyroid drugs, the prevalence of AAV is much lower (22,(27)(28)(29). In our study, 7 of 11 patients treated with antithyroid drugs who were positive for MPO, PR3, or HLE ANCA did not have, or develop, vasculitis (64%).…”

“…Clinical signs were present in 2 of 6 ANCA-positive 110 Slot et al patients who had used PTU, in 2 patients using other antithyroid drugs, and in none of the patients who were not treated with antithyroid drugs. The presence of ANCA, and of ANCA-associated vasculitis, in patients using antithyroid drugs for treatment of hyperthyroidism have been recurrently reported (15)(16)(17)(18)(19)(20)(21)(22)(23)27). Reported prevalence of ANCA in patients treated with antithyroid drugs varies from 4% to 46%; prevalence of AAV is lower (0 -1.4%) (22,(27)(28)(29).…”

“…ANCA in drug-induced AAV are most frequently directed against MPO (11-16,18 -22); however, cases in which patients were PR3-ANCA positive are also observed (12,15,18,20,22). ANCA in these patients may also be directed against human leukocyte elastase (HLE) or lactoferrin, and the presence of ANCA directed to 2 or more antigens may even be an indication of drug-induced dis-ease (15,23).…”

Limited versus severe Wegener's granulomatosis: Baseline data on patients in the Wegener's granulomatosis etanercept trial

“…First, WG, Graves' disease, and Hashimoto thyroiditis all have major autoimmune features and may therefore share etiologic factors (e.g., susceptibility alleles). Second, it is known that Ͼ25% of patients with Graves' disease who are treated with propylthiouracil develop ANCA (usually directed against myeloperoxidase) (34), and that some of these patients develop ANCA-associated vasculitis, including WG (35).…”

Auto-imunidade ANCA (Anticorpo Anti-Citoplasma de Neutrófilos) positiva induzida por propiltiouracil: relato de caso e revisão da literatura

“…Desta forma, o uso prolongado das tionamidas aumenta o risco deste grave efeito colateral. Deve-se notar que a remissão clínica pode preceder a negativação do ANCA (5,6,27).…”