P0479USTEKINUMAB INDUCED PAUCI IMMUNE ANCA NEGATIVE VASCULITIS IN PATIENT WITH CHRON'S DISEASE

Abstract Background and Aims Crohns disease is a chronic transmural inflammation which can affect any segment of the gastrointestinal tract in a discontinuous fashion. Treatment for crohns include steroids, Immunosuppresants (thiopurines and methotrexate) and biological agents such as TNF antagonist (adalimumab, infliximab and certrolizumab pegol) and anti-integrin antibodies (natalizumab and vedolizumab). However in cases of refractory disease the management can become difficult. In such case, use of Ustekinumab is indicated. Tumour necrosis factor-alpha are first line biological agents for managing adult patients with moderate to severe disease . We present a rare case of Ustekinumab treatment and onset of renal disease secondary to crescentic glomerulonephritis in a 37-year-old female. We aim to discuss the presentation, diagnosis and management of the above condition. To the best of our knowledge, this type of presentation has not been described in existing literature. Method Patient’s hospital case records and GP correspondence were used to analyze this case. Results This is a case of a 37-year-old female with a four year history of refractory crohns disease affecting colon and terminal ileum. She was treated with numerous treatment modalities such as budesonide, mesalazine, azathioprine, mercaptopurine, adalimumab and vedolizumab over the years. However, these treatments were not successful as she had multiple hospital admissions every year with flare up of crohns requiring intravenous steroids. In January 2018, she was again admitted to hospital with a flare up of Crohns disease. Colonoscopy and imaging confirmed active disease with moderate severity. Further treatment strategies were discussed and Ustekinumab was decided as the best next treatment option. She had her first intravenous infusion in February 2018 and was planned for injections every 3 months. Her symptoms of Crohns disease improved with the Ustekinumab injections. After her second injection of Ustekinumab in May 2018, repeat blood tests showed acute kidney injury with creatinine of 127 umol/l from a baseline of 75 umol/l and a urea of 8.3 mmol/l from a baseline of 3 mmol/l. Urine dip in May was positive for protein and blood. She was referred to the renal team as an outpatient on the basis of these results for further management. Urea and creatinine had worsened to 10.4 mmol/l and 168 umol/l respectively. Urine protein creatinine ratio was 200. The initial impression was drug induced vasculitis versus Acute kidney injury (AKI) secondary to diarrhoea and poor intake. Considering the possibility of glomerulonephritis, serology testing for immunoglobulins, complements, blood and urine electrophoresis, ANA, ANCA, anti-GBM and viral serology tests were arranged, which all came back negative. ultrasound-guided percutaneous kidney biopsy was performed. Renal biopsy confirmed the diagnosis of pauci-immune glomerulonephritis with crescents (vasculitis). A diagnosis of Ustekinumab induced ANCA negative crescentic glomerulonephritis was established. Ustekinumab was discontinued and she was treated with prednisolone 60mg for four weeks, followed by tapering regime for 6-12 weeks in the community. Renal function improved with a creatinine of 120 umol/l, two months after stopping Ustekinumab. Repeated blood tests during these two months showed a steady and gradual decline in creatinine and eventually return back to normal level of 80 umol/l. Urinalysis showed proteinuria settling with no evidence of haematuria. Conclusion/learning points