SHM Converge Scientific Abstract ePoster Gallery-Warfarin Related Kidney Damage, a Case of Anticoagulant-Related Nephropathy

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This document describes anticoagulant-related nephropathy (ARN), a rare but important and often underdiagnosed cause of acute kidney injury (AKI) in patients receiving anticoagulation, especially warfarin. ARN is typically suspected when a patient develops AKI, often with hematuria, in the setting of a supratherapeutic INR, commonly >3.0. Earlier diagnoses relied on renal biopsy showing glomerular hemorrhage with red blood cell casts, but biopsy is now often avoided because of bleeding risk. The exact mechanism is not fully understood; warfarin-induced thrombin depletion is the leading theory, though newer work suggests a role for reduced activated protein C and endothelial protein C receptor signaling.<br /><br />The paper emphasizes that ARN is clinically significant because it can accelerate chronic kidney disease progression and is associated with increased short- and long-term mortality. There is also uncertainty about whether novel oral anticoagulants (DOACs/NOACs) carry similar renal risks, though available trial data have not shown major differences in AKI rates.<br /><br />A case is presented of a 78-year-old man on chronic warfarin for prior DVT who developed right leg erythema and swelling after recent hernia surgery. He was given antibiotics including trimethoprim-sulfamethoxazole, after which his INR became markedly elevated. He was later hospitalized with severe AKI (creatinine rising from 0.96 to 12.88 mg/dL), gross hematuria, proteinuria, dysmorphic RBCs, anemia, and INR 6.9. Extensive serologic and hematologic workup was negative, supporting ARN, likely worsened by drug interactions from outpatient antibiotics. After switching to less nephrotoxic antibiotics, providing IV fluids, and holding warfarin, kidney function and INR improved, and he was discharged with nephrology follow-up.<br /><br />The main message is that ARN should be considered in any anticoagulated patient with AKI and hematuria, and prevention through careful INR and renal monitoring is essential.

Asset Subtitle

Brittanee J. Samuelson

Meta Tag

Author List Brittanee J. Samuelson, Gregory M. Garrison, Hannah Scott, Matthew D. Decker

Category Clinical Vignettes

Concept Anticoagulant-Related Nephropathy

Concept Acute Kidney Injury

Concept Hematuria

Concept Warfarin

Concept Oral Anticoagulant

Distinguished Non-Finalist

Presenter Organization Mayo Clinic Rochester Family Medicine Residency

Presenting Author Brittanee J. Samuelson

Track Adult

Keywords

anticoagulant-related nephropathy

acute kidney injury

warfarin

hematuria

supratherapeutic INR

red blood cell casts

chronic kidney disease

novel oral anticoagulants

drug interaction

renal monitoring

Anticoagulant-Related Nephropathy

Acute Kidney Injury

Hematuria

Warfarin

Oral Anticoagulant