An Unusual Presentation of Pauci-Immune Necrotizing Glomerulonephritis.

Renal-limited pauci-immune necrotizing glomerulonephritis presenting as acute encephalopathy is a rare occurrence. A 67-year-old Hispanic male presented to the hospital after being found down. He was found to have acute renal failure and high anion gap metabolic acidosis. Hemodialysis did not improve his encephalopathy. A vasculitis workup resulted in a high antimyeloperoxidase (MPO) antibody level. Renal biopsy revealed globally sclerotic glomeruli with focal thickened capillary loops, suggestive of pauci-immune necrotizing and crescentic glomerulonephritis (GN). Treatment consisted of high dose methylprednisolone and rituximab for induction, and three cycles of plasmapheresis, in addition to hemodialysis for uremia. Upon discharge, he was continued on hemodialysis and continued treatment with prednisone. Patients who present acutely with persistent uremic encephalopathy despite hemodialysis may warrant pursuing an alternative diagnosis, such as glomerulonephritis. Prompt diagnosis and treatment are necessary to improve the prognosis since untreated pauci-immune glomerulonephritis carries a high mortality rate.