Long-term followup of polyarteritis nodosa, microscopic polyangiitis, and Churg-Strauss syndrome - Analysis of four prospective trials including 278 patients

Objective. To determine the long-term outcome of patients with polyarteriti s nodosa (PAN), microscopic polyangiitis (MPA), and Churg-Strauss syndrome (CSS), to compare the long-term outcome with the overall French population, to evaluate the impact on outcome of the type of vasculitis, prognostic fa ctors, and treatments administered at diagnosis, and to analyze treatment s ide effects and sequelae. Methods. Data from PAN, MPA, and CSS patients (n = 278) who were enrolled b etween 1980 and 1993 were collected in 1996 and 1997 and analyzed. Two prog nostic scoring systems, the Five-Factors Score (FFS) and the Birmingham Vas culitis Activity Score (BVAS), were used to evaluate all patients at the ti me of diagnosis. Results. The mean (+/- SD) followup of the entire population was 88.3 +/- 5 1.9 months (range 3 days to 192 months). Of the 85 deaths recorded, at leas t 41 were due to progressive vasculitis or its consequences. Death rates re flected disease severity, as assessed by the FFS (P = 0.004) and the BVAS ( P < 0.0002), and the 2 scores were correlated (r = 0.69). Relapses, rarer i n hepatitis B virus (HBV)-related PAN (7.9%) than in MPA (34.5%) (P = 0.004 ), occurred in 56 patients (20.1%) and did not reflect disease severity. Su rvival curves were similar for the subpopulation of 215 patients with CSS, MPA, and non-HBV-related PAN who were given first-line corticosteroids (CS) with or without cyclophosphamide (CYC). However, CS with CYC therapy signi ficantly prolonged survival for patients with FFS scores <greater than or e qual to>2 (P = 0.041). Relapse rates were similar regardless of the treatme nt regimen; only patients treated with CS alone had uncontrolled disease. C YC was associated with a greater frequency of side effects (P < 0.00001). Conclusion. Rates of mortality due to PAN (related or unrelated to HBV), MP A, and CSS reflected disease severity and were higher than the mortality ra te in the general population (P < 0.0004). Rates of relapse, more common in MPA than HBV-related PAN patients, did not reflect disease severity. Survi val rates were better among the more severely ill patients who had received first-line CYC. Based on these findings, we recommend that the intensity o f the initial treatment be consistent with the severity of the disease. The use of the FFS and BVAS scores improved the ability to evaluate the therap eutic response.