P0429OUTCOMES OF LUPUS NEPHRITIS OVER AN ERA OF EVOLVING IMMUNOSUPPRESSION

Abstract Background and Aims The reported incidence of lupus nephritis (LN) is approximately 6.1 cases per million population per year in Scotland based on Scottish Renal Registry biopsy data. Despite immunosuppressive treatment, approximately 10-30% of patients will progress to established renal failure (ERF) within 15 years. In December 2007, our unit moved from a protocol of Cyclophosphamide/ steroid induction with Azathioprine/ Prednisolone maintenance to Mycophenolate/ steroid induction and maintenance. We undertook this study to compare remission rates before and after this change. Method A retrospective electronic patient record analysis was performed for all patients in our centre with a documented native renal biopsy showing a histopathological diagnosis of LN, between 1 July 1993 and 31 December 2017. Repeat biopsies were excluded. Baseline demographics, histopathological class and first and second line induction and maintenance therapies were recorded. Endpoints analysed were; partial and complete response (as defined in KDIGO Clinical Practice Guideline for Glomerulonephritis 2012), time to achieve this response, relapse, progression to ERF and death. Results 120 patients who underwent a biopsy during the 24.5-year period received a diagnosis of lupus nephritis. 82.5% of patients were Caucasian. Median duration of follow-up was 72 months. 15% of patients died and 5% developed ERF within the follow-up period, representing one death per 56 patient years and one incident case of ERF per 168 patient years. There were 40 patients in the pre-December 2007 group and 80 in the post-December 2007 group. Those in the earlier group were younger, with a mean age of 35.4 years versus 44.8 years in the later group (p=0.002). 23% had class V in the earlier group compared to 15% in the later group (p=0.31). Proportions of female patients were 80% and 75% in the early and late groups respectively (p=0.54). Median creatinine was 106µmol/L in the pre-December 2007 group and 89.5 µmol/L in the post-December 2007 group (p=0.96). Patients in the pre- and post- December 2007 groups had comparable rates of complete response, at 72% and 71% respectively. However, those diagnosed before December 2007 were slower to respond, with a median time to achieve complete response of 10.5 months, compared to 6 months in those diagnosed after 1 December 2007 (p=0.007). Conclusion Following a change in our immunosuppressive induction regimen from Cyclophosphamide/ steroids to Mycop