Clinical characteristics and prognostic factors in an Argentinian cohort with ANCA-associated vasculitis

ANCA-associated vasculitis is a heterogeneous group of rare autoimmune conditions of unknown cause. Clinical characteristics and prognostic factors were analyzed in 47 patients: 20 (42.5%) with granulomatosis with polyangiitis, 17 (36.2%) with microscopic polyangiitis, 6 (12.8%) with renal-limited vasculitis, and 4 (8.5%) with eosinophilic granulomatosis with polyangiitis. Mean age at diagnosis was 53.5 ± 16.5 years and the median of BVAS (Birmingham Vasculitis Activity Score) was 14 (4-42). The most frequent clinical manifestations were: general in 44 (93.6%), renal in 30 (63.8%) and respiratory in 28 (59.6%). All received corticosteroids at the beginning of treatment. Intravenous cyclophosphamide was associated in 20 (42.5%) and oral route in 14 (29.8%); azathioprine in 3 (6.4%) and rituximab in 2 (4.2%). At a median follow-up of 35.5 months (range 0.14-234), 21 relapses were recorded in 14 patients. Overall mortality was 3.5 deaths per 100 patient-year in the whole group. Those over 55 years old, the presence of alveolar hemorrhage, those with FFS (Five Factor Score) of 2, and patients with MPA had poor prognosis. Renal involvement, ANCA pattern and BVAS were not associated to a poorer prognosis.