260. LONG TERM OUTCOMES OF PATIENTS WITH ANCA-ASSOCIATED VASCULITIS PRESENTING WITH SEVERE RENAL DYSFUNCTION

Background: Rapidly progressive glomerulonephritis (RPGN) is an important cause of morbidity and mortality in ANCA-associated vasculitis (AAV). Studies have specifically addressed the outcome of patients presenting with severe renal injury, traditionally defined as dialysis dependence or a serum creatinine (SCr) of over 500 μmol/l, and in particular the benefit of plasma exchange. Recent research has challenged the role of plasma exchange in this patient set. Here we describe the long term patient and renal outcomes in a large cohort of patients treated consistently with a regime including plasma exchange, at a single centre over 40 years. Methods: This is a retrospective analysis of patients treated between 1977 and 2017 with newly presenting AAV and severe renal dysfunction. Patients were classified as being dialysis-independent with a SCr >500 µmol/L or as dialysis-dependent. Dialysis- dependent renal failure was defined as the need for dialysis within 72 hours of admission. Patients with a concomitant anti-glomerular basement membrane (GBM) antibody were excluded. Clinical, laboratory and histopathological data were collated. Patients were treated consistently with steroids, cyclophosphamide, and plasma exchange (+/- rituximab post 2011), with azathioprine as first line maintenance therapy. Results: Data were obtained for 181 patients. The 149 patients who presented with dialysis-dependence had a 1 yr survival of 71% and a 5 yr survival of 50%. At 1 yr., 58% of these patients had regained independent renal function. There was no significant difference in terms of demographics or ANCA type when comparing the patients who came off dialysis with those who remained on. There was also no obvious correlation with histological class as determined by the international classification for AAV. At 5 years, 48% had independent renal function. Patient survival was 71% and 50 % at 1 and 5 years respectively. For the dialysis-independent patients, renal survival was 92% and 87% and patient survival was 87% and 53% at 1 and 5 years respectively (Table). There was a non-significant trend to improved renal and patient outcomes in patients presenting after 2000. Conclusion: This a large cohort of patients with severe renal dysfunction given treatment including plasma exchange at a single center. Both renal and patient outcomes were comparable with other studies. There was a striking difference in outcomes for dialysis dependent patients when compared to those who had a SCr of > 500 but retained independent renal function. Abstract 260 Table 1: Renal and patient survival at one and 5 years according to initial renal function Disclosures: None