PR3 vasculitis presenting with symptomatic splenic and renal infarction: a case report and literature review

BACKGROUND: ANCA-associated vasculitis is a life-threatening, systemic autoimmune disease. There is an increased risk of organ infarction but in many cases this is asymptomatic. We described here the first reported case of PR3 vasculitis presenting with symptomatic bilateral renal wedge infarction. CASE PRESENTATION: A 19-year old Caucasian woman with no past medical history presented on a number of occasions over a number of weeks with progressively more severe back pain, fevers and arthralgia. On the final presentation she was noted to have developed splinter haemorrhages and her blood tests revealed impaired renal function along with elevated inflammatory markers. She was subsequently found to have high titres of serum PR3 antibodies and focal necrotising glomerulonephritis on renal biopsy, consistent with a diagnosis of PR3 ANCA-associated vasculitis. Cross-sectional imaging revealed multiple wedge infarcts of her spleen and both kidneys, confirmed on contrast-enhanced ultrasound. Large vessel, cardiac and thrombophilic causes of thromboembolism were excluded. She was treated with high-dose corticosteroids and CD20 monoclonal antibodies (rituximab) and at time of writing, 4 months after initial presentation, has entered clinical remission. CONCLUSIONS: Here we describe the first reported case of PR3 vasculitis presenting with symptomatic renal wedge infarction. In patients with vasculitis who present with flank or back pain, infarction of abdominal organs should be considered in the differential. Both splenic and renal infarctions are likely underdiagnosed in the setting of ANCA-associated vasculitis but may have clinical impact in contributing to infection risk and the degree or renal recovery, respectively.