Community Minded

Sero-negative ANCA Vasculitis?  
A 31-year-old man presents with non-oliguric acute kidney injury (AKI) and an active urine sediment. Creatinine is 1.9 on admission and increases to 3.5 over 4 days. On day seven, a kidney biopsy with eight glomeruli demonstrates one with a crescent and segmental necrosis and another showing endocapillary proliferation, as well as some acute tubular necrosis (ATN). The immunofluorescence is negative. Antineutrophilic cytoplasmic antibody (ANCA), anti-glomerular basement membrane (GBM), complements and other serologies are all negative. There are no systemic symptoms of a vasculitis. Kidney function improves after pulse steroids, but with the AKI way out of proportion to the histology, is it mostly ATN? Would you still give him a full ANCA negative pauci-immune vasculitis induction protocol? Is there a role for rebiopsy? What do you think?

Summary provided by Roger Rodby, MD, FASN.
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