Predictors of all-cause Mortality and Infection During inducing Treatment in ANCA-Associated Vasculitis: a Population-Based Cohort Study

Objective. To determine the predictors of all-cause mortality and infection during inducing treatment in a population-based cohort of ANCA-associated vasculitis (AAV). Methods. The study included 198 cases of AAV diagnosed in Renji Hospital from May 2011 through May 2020. Outcome data were collected during follow-up of AAV patients. Severe infection events (requiring hospitalization and treatment with intravenous antibiotics) during induction therapy were also identified. Demographic, clinical and laboratory results were tested as potential predictors in multivariable models. Results. A total of 198 patients were followed from time of disease diagnosis to August 2020 or death. 168 patients are alive with a median follow up of 36 (20-60) months. Leading causes of death within 6 months were infection (42%), respiratory failure (25%) and renal failure (17%). After 6 months, the major causes of death were infection (39%), respiratory failure (22%), cancer (17%) and cardiovascular / cerebrovascular events (11%). Multivariable analysis showed that older age (>65 years), higher Birmingham Vasculitis Activity Score (BVAS, ≥15), infection at diagnosis or during induction therapy and disease relapse (≥2 times) were independent predictors of all-cause mortality. Besides, higher S-creatinine, BVAS ≥15, myeloperoxidase (MPO) positivity and lack of prophylaxis with sulfamethoxazole (SMZ) were predictors of severe infection events during induction therapy. Conclusion. Patients with older age and higher disease activity are at increased risk of death. The events of infection at diagnosis or during induction therapy and disease relapse also threaten patients’ lives. Besides, poorer renal function, high disease activity and MPO positivity are associated with severe infection. SMZ prophylaxis during induction therapy may be an effective measure to reduce the risk of infection.