CHUSPAN PAN BP Treatment of Polyarteritis Nodosa and Microscopic Polyangiitis Without Poor-Prognosis Factors

To assess the efficacy of systemic corticosteroids alone as first-line treatment of polyarteritis nodosa and microscopic polyangiitis without poor-prognosis factors as defined by the five-factor score (FFS=0), and to compare the efficacy and safety of azathioprine vs pulse cyclophosphamide as adjunctive immunosuppressive therapy to treat failure or relapse.