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

Abstract

A terapêutica com drogas antitireoidianas pode ser acompanhada de efeitos colaterais. Propiltiouracil (PTU) pode induzir vasculites anticorpo anti-citoplasma de neutrófilos (ANCA) positivas, na maioria das vezes relacionadas ao subtipo mieloperoxidase (ANCA-MPO). O nosso objetivo é relatar o caso de uma paciente com doença de Graves que desenvolveu auto-imunidade induzida por PTU, com manifestações cutâneas, pulmonares e renais, associadas à positividade do ANCA. O exame anátomo-patológico pulmonar revelou hemorragia difusa e a biópsia renal demonstrou glomeruloesclerose segmentar e focal. Foi tratada com pulsoterapia com corticóides e ciclofosfamida, com boa evolução clínica. Este caso enfatiza a necessidade de detecção e tratamento precoce deste efeito adverso relativamente raro do PTU.

Diffuse alveolar haemorrhage secondary to propylthiouracil-induced vasculitis

“…Positive cases of ANCA-PR3, human leucocyte elastase and lactoferrin have also been described. In the present case we find a situation of overlap with positivity for MPO and PR3, rarely described in the literature 3 13 14 20…”

“…Adverse side effects include elevated liver enzymes, leukopenia, rash and arthralgia. Rarely, it can be associated with vasculitis, accounting for about 93% of thionamide-induced cases 3 12…”

“…Prevalence of ANCA-positive patients treated with PTU ranges from 4% to 46% 2 3. Although ANCA are present with relative frequency in these patients, the prevalence of vasculitis is much lower (0–1.4%) 4 5.…”

“…Resolution of signs and symptoms and decline in ANCA usually occur with medication withdrawal. However, clinical remission may precede ANCA negativation, with rare cases presenting high or rising ANCA-MPO titres in the remission phase irrespective of clinical recurrence 3 5 15 24 30 31…”

“…The development of cytoplasmic antibodies (antineutrophil cytoplasmic antibodies, ANCAs) is common in patients treated with PTU 2 3. However, ANCA-associated vasculitis is rare with pulmonary involvement being possible in this context 4 5…”