Endocrine Abstracts

Aim: Antineutrophil cytoplasmic antibody (ANCA) positivity is usually determined in medium and large vessel vasculitis. This antibody has two different forms. Cytoplasmic ANCA (PR3-ANCA) occurs against proteinase-3, while perinuclear ANCA (MPO-ANCA) occurs against myeloperoxidase and bactericidal- permeability increasing proteins. The presence of ANCA is mostly seen in systemic vasculitis and also in drug induced vasculitis. There is no sufficient data about prevalence of positivity ANCA and development of antithyroid antibodies after treatment. In this study our aim was to investigate MPO-ANCA and PR3-ANCA levels in Graves’s patients using propylthiourasil (PTU).

Material and method: Graves patients (9 men, 41 women) using PTU and 37 healthy control group were included in the study. ANCA levels of patients and control groups were evaluated.

Results: Mean level of PR3-ANCA in Graves group was significantly higher than control group (P=0.025). No significant difference was found between levels of MPO-ANCA (P>0.05). Positive correlation was observed between Anti-TPO, Anti-Tg with PR3-ANCA in patient group (respectively, P=0.001, r=0.47; P=0.03, r=0.310). Longer duration of treatment in the patient group showed increased levels of PR3-ANCA (P=0.024, r=0.314). PR3-ANCA levels in Anti-Tg positive patients were higher than those with negative (P=0.018). MPO-ANCA and PR3-ANCA were positive in two Graves patients while only MPO-ANCA positive in two patients.

Conclusion: PTU may cause ANCA positivity but vasculitis not develop in all cases. In our study; higher ANCA levels were found in Graves’s patients receiving long term PTU treatment.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.