Remission and Low Disease Activity in Granulomatosis With Polyangiitis and Microscopic Polyangiitis: Prevalence and Impact on Damage Accrual

Abstract

Objective: To assess the prevalence and impact on damage accrual of different levels of disease activity in patients with granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA). Methods: Patients with GPA and MPA followed for ≥5 years in 2 different centers were included. Disease activity and damage were assessed using the Birmingham Vasculitis Activity Score (BVAS) and Vasculitis Damage Index (VDI), respectively. Three levels of remission were defined: complete remission (BVAS = 0, negative for antineutrophil cytoplasmic antibody [ANCA], off treatment), clinical remission off therapy (CROffT; BVAS = 0, positive for ANCA), and clinical remission on therapy (CROnT; BVAS = 0, negative or positive for ANCA, glucocorticoids ≤5 mg/day and/or immunosuppressant). A low disease activity state (LDAS) was defined as 0 < 0.0001). By multivariate analysis, baseline ear, nose, and throat (P = 0.006), and lung involvement (P = 0.047) were negative predictors of prolonged remission. Conclusion: More than 60% of patients with GPA/MPA achieved prolonged remission, which was associated with better long-term outcomes. In contrast, prolonged LDAS correlated with increased damage accrual and was not a sufficient treatment target.