Predictive factors for mortality in elderly Japanese patients with severe microscopic polyangiitis: A retrospective single-center study

Purpose: To determine mortality and its predictive factors in elderly Japanese patients with severe microscopic polyangiitis (MPA).Method: This retrospective single-center study determined the mortality of 52 patients with MPA who were admitted to our geriatric medical center from 2002 to 2014. The variables at baseline, including patient demographics, clinical characteristics, and treatment, were analyzed for their association with mortality.Result: Mean age at onset of MPA was 73.2 years, and the one-year survival rate was 65.9%. Relapse was observed in 32.7%. Among variables at diagnosis, age, cardiomyopathy, central nervous system (CNS) involvement, alveolar hemorrhage, disease severity, the 1996 Five-Factor Score (FFS), and the 2009 FFS were associated with mortality in univariate analysis. Cardiomyopathy, CNS involvement, age>65 years, disease severity, Birmingham Vasculitis Activity Score, the 1996 FFS, and the 2009 FFS were associated with relapse-free survival in univariate analysis.Conclusion: We investigated mortality and relapse-free survival and their predictive factors in elderly Japanese patients with severe MPA. Age, disease severity, the 1996 FFS, and the 2009 FFS at diagnosis were prognostic factors for both mortality and relapse-free survival.