title: Acute kidney injury during warfarin therapy associated with obstructive tubular red blood cell casts: a report of 9 cases.
abstract: Acute kidney injury (AKI) during warfarin therapy usually is hemodynamic secondary to massive blood loss. Here, we report pathological findings in kidney biopsy specimens from 9 patients with warfarin overdose, hematuria, and AKI. Kidney biopsy specimens from patients on warfarin therapy with AKI were identified in our database within a 5-year period. Each kidney biopsy specimen was evaluated by using semiquantitative morphometric techniques, and medical history was reviewed for conditions explaining AKI. Biopsy specimens with morphological findings of active glomerulonephritis and active inflammatory lesions were excluded from the study. Biopsy specimens from 9 patients were selected. At presentation with AKI, each patient had an abnormal international normalized ratio (mean 4.4 +/- 0.7 IU) and increased serum creatinine level (mean, 4.3 +/- 0.8 mg/dL). Morphologically, each biopsy specimen showed evidence of acute tubular injury and glomerular hemorrhage: red blood cells (RBCs) in Bowman space and numerous occlusive RBC casts in tubules. Each biopsy specimen showed chronic kidney injury. Six of 9 patients did not recover from AKI. These data suggest that warfarin therapy can result in AKI by causing glomerular hemorrhage and renal tubular obstruction by RBC casts. Our experience suggests that this may be a potentially serious complication of warfarin therapy, especially in older patients with underlying chronic kidney injury.
authors: Department of Pathology, The Ohio State University, Columbus, OH 43210, USA.
authors: Sergey V
authors: SV
authors: Brodsky
authors: Anjali
authors: A
authors: Satoskar
authors: Jun
authors: J
authors: Chen
authors: Gyongyi
authors: G
authors: Nadasdy
authors: Jeremiah W
authors: JW
authors: Eagen
authors: Mirza
authors: M
authors: Hamirani
authors: Lee
authors: L
authors: Hebert
authors: Edward
authors: E
authors: Calomeni
authors: Tibor
authors: T
authors: Nadasdy
mesh_terms: D058186:Acute Kidney Injury / Q000139:chemically induced* / Q000175:diagnosis / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000009:adverse effects* / Q000627:therapeutic use; D001706:Biopsy; D004912:Erythrocytes / Q000473:pathology*; D005260:Female; D006417:Hematuria / Q000139:chemically induced / Q000175:diagnosis / Q000473:pathology; D006470:Hemorrhage / Q000139:chemically induced / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D007668:Kidney / Q000473:pathology; D007687:Kidney Tubules, Proximal / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D013927:Thrombosis / Q000517:prevention & control; D014859:Warfarin / Q000009:adverse effects* / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D014859:Warfarin