Objective. To define the most effective treatment for polyarteritis nodosa (PAN) and Churg-Strauss syndrome (CSS).
Methods. We conducted a prospective, randomized, multicenter trial in which 78 patients were randomly assigned to receive either prednisone and plasma exchange (group A; n = 36) or prednisone alone (group B; n = 42) as first-line treatment of PAN and CSS. Patients with hepatitis B virus—related PAN were not included in this study. The end point of the study was control of the disease (recovery and remission) or death.
Results. Clinical symptoms and laboratory findings did not differ statistically in the 2 groups at study entry. Initial control of the disease was similar in both groups. The assigned treatment was stopped in 16 patients because of lack of efficacy. Oral cyclophosphamide or dapsone therapy reversed the disease evolution in 7 of these 10 group A patients and in 4 of these 6 group B patients. At 7 years of followup, 56 patients had completely recovered (27 in group A, 29 in group B), 7 patients were in clinical remission, and 15 patients had died (19.2%; 6 group A patients and 9 group B patients). The prednisone—plasma exchange combination was no more beneficial than corticosteroids alone in preventing relapses over the long term. There was no significant difference in the 7-year cumulative survival rates of the two groups (83% and 79%, respectively).
Conclusion. Based on our data, we conclude that combined treatment with prednisone and plasma exchange is not superior to treatment with prednisone alone and must not be systematically employed for initial treatment of PAN and CSS. In most cases, cyclophosphamide as second-line treatment is effective and well tolerated.