Anti-neutrophil cytoplasmic antibody (ANCA) in necrotising vasculitides with renal involvement.

Anti-neutrophil cytoplasmic antibody (ANCA) was detected in sera of 20 out of 32 patients with necrotising vasculitides involving the kidneys and other organs. It was of high titre and cytoplasmic type in Wegener's granulomatosis (8/9); and of low titre and cytoplasmic or perinuclear type in systemic polyarteritis (6/12), renal limited polyarteritis (5/9) and pulmonary renal syndrome (1/2). It fell to low or undetectable levels on clinical improvement or remission with cyclophosphamide therapy. Its detection was helpful in diagnosis and management of vasculitides with renal and extrarenal manifestations.