1770 Clinical characteristics and outcomes in patients with ANCA-associated vasculitis (AAV) and kidney involvement—a Swedish single-center cohort

Abstract Background and Aims Poor patient outcomes in ANCA-associated vasculitis (AAV) with kidney involvement is attributed to multiple factors such as delay in diagnosis, inadequate efficacy of treatments and long-term complications due to the disease as well as the toxic effects of immunosuppressive therapy. The aim of the present study was to evaluate the clinical characteristics of a Swedish cohort of patients with AAV (granulomatosis with polyangiitis; GPA and microscopic polyangiitis; MPA) and kidney involvement to study causes of death and predictors of all-cause mortality. Method This retrospective single-centre cohort study included 93 patients from the Uppsala region in mid-Sweden, diagnosed with AAV and kidney involvement between 1993 and 2023. Clinical and laboratory variables were obtained from review of electronic medical records as well as patient follow-up visits. Differences between groups were assessed using independent t-test and Chi-square test. Multivariable logistic regression analyses were performed to evaluate the influence of risk factors of interest on all-cause mortality. Results 93 patients, 71 (76%) were clinically diagnosed with MPA, and 22 (24%) with GPA. The median age at diagnosis was 66.5 ± 13 years. eGFR at diagnosis was 29 ± 23.5 ml/min/1.73 m2 and 15% of patients were dialysis-dependent AAV at diagnosis. Patients with MPA and GPA received comparable induction therapy except for PLEX which was significantly more frequent in patients with GPA (52% vs 26% respectively, p = 0.041). 56 (60%) of patients died during follow up and survival time was 7.1 ± 6.9 years. Baseline clinical and biochemical characteristics are shown in Table 1. A multivariate logistic regression showed that older age at diagnosis (OR 95% CI 1.012-1.110; p = 0.013) and being dialysis-dependent at diagnosis (OR 95% CI 1.343-16.079; p = 0.015) significantly predicted all-cause mortality (Table 2). Causes of death are presented in Fig. 1. Infections was the most common cause of death (30%). Conclusion Long-term prognosis and patient survival were significantly associated with age and dialysis-dependency at diagnosis in this cohort of patients diagnosed with AAV and kidney involvement. Infections was the most common cause of death. Figure 1: Causes of mortality in patients with AAV and kidney involvement (n = 56). Table 1: Baseline clinical and biochemical characteristics of patients with AAV and kidney involvement (n = 93). Variables All patients with AAV