Longterm Prognosis of 121 Patients with Eosinophilic Granulomatosis with Polyangiitis in Japan

OBJECTIVE: We investigated the risk factors for relapse or prognosis of eosinophilic granulomatosis with polyangiitis (EGPA) in Japanese patients presenting to our hospital. METHODS: From June 1999 through March 2015, we retrospectively recruited 121 patients with EGPA according to the American College of Rheumatology criteria. Frequent relapse was defined as disease occurrence at least once every 2 years after a period of initial remission. The study endpoint was the last examination performed. We used multiple logistic regression to analyze risk factors for relapse or survival in EGPA. RESULTS: Gastrointestinal (GI) involvement with both abnormalities on endoscopy and biopsy (p < 0.01) and symptoms; myocardial involvement with both abnormalities on 1 or more cardiac investigations and symptoms (p < 0.01); and treatment at initial or maintenance with immunosuppressants (p < 0.01) or administration of intravenous immunoglobulin (IVIG; p < 0.01) were associated significantly more often with frequent relapse than with infrequent. Overall 5-, 10-, and 20-year survival rates were 91.1%, 83.7%, and 68.6%, respectively. Survival in EGPA was associated with age of onset < 65 years. Age at onset of EGPA was the only significant predictor of survival (p < 0.01). Myocardial or GI tract involvement did not affect mortality risk. CONCLUSION: Patients with myocardial or GI tract involvement had frequent relapses, but these conditions were not reflected in increased mortality. Treatment with immunosuppressants or IVIG in addition to corticosteroids might have improved the prognosis in Japanese patients with EGPA.