#1475 Anti-neutrophil cytoplasmic antibodies (ANCA) associated vasculitis (AAV) with glomerulonephritis (AAV-GN) in real world life

Abstract

Abstract Background and Aims Anti-neutrophil cytoplasmic antibodies (ANCA) associated vasculitis (AAV) with glomerulonephritis (AAV-GN) is a rare disease and the different treatment with plasma exchange are still controversial. We evaluate the AAV-GN outcomes of the last ten years in our centre. Method We retrospectively reviewed the clinical presentations and outcomes of AAV-GN patients in our centre between 2013-2022. We compared the presentation and prognosis according to the type of ANCA, serum creatinine (SCr) and the use of plasma exchange (PLEX). We included patients with AAV and kidney biopsy with at least 6 months of follow-up. Patients with positivity for both MPO and PR3, anti-GBM antibodies or did not meet inclusion criteria were excluded. Results Of 64 patients reviewed, 13 were excluded: 3 lack of follow-up, 3 absence of renal biopsy, 3 ANCA negative, and 4 concomitant anti-GBM antibodies. A total of 51 patients were included in the analysis (Table 1): 28 women (54.9%), age 66.75 ± 15.24 years, (64.7% over 65 years) and 44 (86.3%) with ANCA-MPO (+). Results comparing ANCA-MPO and PR3 in Table 1. The most frequent form of presentation was anaemia with haemoglobin 9.87 ± 2.04 mg/dL, acute kidney injury (AKI) AKIN III (39.2%), median SCr 2.78 (1.58-5.22) mg/dL, 41 (80.4%) with microhematuria, proteinuria 2.62 ± 2.7g/g, and 8 (15.7%) alveolar haemorrhage. 18 patients (25.3%) required hemodialysis, and 7 (13.5%) were transient (4 requiring <1 month). Rituximab was more used than cyclophosphamide (p < 0.001). Of the patients treated with plasma exchange (PLEX, n = 11), 6 (54.5%) had alveolar haemorrhage and/or 7 (63.6%) SCr>5.6 mg/dL, with no further infections or mortality at one year. Of the patients diagnosed with SCr>5.6 mg/dL, 9 (81.8%) were men (p = 0.008), 7 (63.6%) received PLEX (p < 0.001) and 6 (54.4%) died (p = 0.003). As expected, in the multivariate binary logistic regression SCr>5.6 at diagnosis was identified as independent risk factor for PLEX (p = 0.02, OR = 15.6 (95% CI 3.16-76.92). There were 13 deaths (25.5%), 6 in the first year after diagnosis. The most used maintenance treatment was MMF (52.9%), SCr and glomerular filtration rates at 2 years were 1.5 mg/dL and 45.36 mL/min/1.72 m² respectively. Conclusion The most common AAV-GN in our centre are ANCA-MPO+, and mainly affect people over 65 years of age, with rituximab being the most used treatment. ANCA-MPO+ patients have worse renal function at 18 months of follow-up. Mortality is higher in AAV-GN with serum creatinine greater than 5.6 mg/dL at diagnosis and in ANCA-MPO+. PLEX therapy is more used in cases of alveolar hemorrhage or severe renal involvement, without presenting an impact in our cohort in the incidence of infections or mortality at one year of follow-up.