277. ANCA-associated renal vasculitis: the Northern Irish experience

Background: We examined the demographic characteristics, treatment and outcomes of ANCA-associated vasculitis (AAV) in Northern Ireland. Methods: Adult cases of newly diagnosed biopsy-proven pauci-immune glomerulonephritis between 1st January 2011 and 31st August 2019 were identified from central pathology records. Cases were excluded if they were unknown to adult renal services, had less than 1 year follow-up, had relapsed disease (initial diagnosis before 2011) or had AAV in a renal transplant. Data were collected retrospectively using the Northern Ireland Electronic Care Record and the eMed regional renal database. Results: We identified 123 patients of whom 69 (56%) were male. The median age at diagnosis was 67 years (IQR 59-73). Median follow-up time was 46 months (IQR 23 - 81). Seventy-six (62%) were MPO positive, 45 (36%) were PR3 positive, 2 were ANCA negative and 3 were dual positive with anti-glomerular basement membrane antibodies. The median serum creatinine at diagnosis was 196 umol/l (IQR 149 - 272). The majority of patients (n=90, 73%) had multi-system disease while 33 (27%) patients had renal-limited disease. Most patients (n=88, 73%) received oral cyclophosphamide (CyP) induction with 11 (9%) receiving intravenous CyP, 7 (6%) receiving Rituximab (RTX) and 3 (2%) receiving RTX and CyP. All patients received corticosteroids at induction and 20 patients required plasmapheresis. Complete remission occurred in 117 patients (95%). Median time to remission was 105 days. Relapse requiring admission to hospital or organ/life-threatening disease occurred in 26 patients (21%). The median time to first major relapse was 666 days (IQR 348 – 1123). Fifteen (12%) patients reached end-stage renal disease (ESRD), 5 were dialysis dependent from presentation and the median time to ESRD for the other 10 patients was 309 days (IQR 24 - 914). An additional 8 patients required renal replacement in the study time period but recovered renal function. Complications of treatment were common. The most common was infection requiring intravenous antibiotics or admission with 57 patients (46%) having 1 or more episodes. Of the 114 patients screened for diabetes mellitus (DM), 23 (20%) developed a new diagnosis of Type 2 DM or steroid induced diabetes. Cancer was also common with 11 patients (9%) having 1 or more episodes, the majority being non-melanomatous skin cancer. The median time to first cancer episode was 38 months (IQR 28 – 72). Twenty per cent of patients died during the follow up period. The median time to death was 26 months (IQR 5 – 59) from diagnosis. The cause of death was either unknown/undocumented or infection in the majority of patients (8 and 10 patients respectively). Conclusions: This retrospective study of AAV in Northern Ireland over the last decade shows that renal and patient survival is comparable to other studies but complication rates were high, particularly the rate of significant infection. However, most patients received oral CyP induction and conventional prednisolone dosing. More data is required to see whether the use of newer agents (RTX) and lower-dose prednisolone may reduce complication rates. Disclosures: Non