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Abstract: PO0280

A Nutty Case of Oxalate Nephropathy

Session Information

Category: Acute Kidney Injury

  • 102 AKI: Clinical, Outcomes, and Trials

Authors

  • Kapa, Nandakishor, University of California Davis Medical Center, Sacramento, California, United States
  • Jen, Kuang-Yu, University of California Davis Medical Center, Sacramento, California, United States
  • Gafter, Lana, Summit Nephrology Medical Group, Inc., Roseville, California, United States
  • Wiegley, Nasim, University of California Davis Medical Center, Sacramento, California, United States
Introduction

Oxalate nephropathy occurs when considerable amounts of calcium oxalate crystals deposit in the renal parenchyma. Excessive dietary intake of oxalate-rich foods (including some associated with healthy eating) in otherwise healthy individuals can lead to secondary oxalate nephropathy. We report a case of severe AKI related to excessive nut consumption.

Case Description

A 41-year-old man with history of Hashimoto’s disease and pancytopenia presented to the hospital with 1 week of nausea and vomiting. Evaluation showed AKI with elevated serum creatinine (19.9 mg/dL), BUN (229 mg/dL), hematuria, and proteinuria (urine protein/creatinine ratio 1.6 gm/gm). Serologic workup showed mildly elevated kappa/lambda ratio (3.52) and low C3 (71mg/dL) but was otherwise unremarkable. Serum uric acid was high at 11.6 mg/dL. Renal ultrasound revealed normal kidney size with increased parenchymal echogenicity and punctate echogenic foci bilaterally. A renal biopsy was performed demonstrating widespread oxalate deposition with associated interstitial inflammation and tubular injury. Further history revealed no recent medications, infections, or ingestions, but did uncover a high intake of nuts (~1 pound) daily over the prior 1 year due to their perceived health benefits. He remained hemodialysis dependent on hospital discharge.

Discussion

Secondary oxalate nephropathy can result from increased enteric oxalate availability from dietary consumption. Diagnosis can be delayed when a review of diet and supplements is deferred. It is therefore essential to obtain a detailed dietary and pharmacologic history, particularly in all patients with unexplained kidney disease. Treatment is supportive including decreasing the high oxalate culprit foods in the diet.

H&E (left) and EM (right)