What are the main clinical features of Microscopic polyangiitis?

• renal impairment: raised creatinine, haematuria, proteinuria
• fever
• other systemic symptoms: lethargy, myalgia, weight loss
• rash: palpable purpura
• cough, dyspnoea, haemoptysis
• mononeuritis multiplex

What is Microscopic polyangiitis?

a small-vessel ANCA vasculitis

Which antibodies are seen in Microscopic polyangiitis?

• pANCA (against MPO) - positive in 50-75%
• cANCA (against PR3) - positive in 40%