Acenocoumarol induced anticoagulant-related nephropathy with newly diagnosed IgA nephropathy: A repeat biopsy case report

Abstract Anticoagulant-related nephropathy (ARN) is an underestimated cause of acute kidney injury (AKI) with poor renal and overall prognosis. Pathogenesis is not fully elucidated yet, although AKI is probably resulting from glomerular hemorrhage and most commonly has been described in patients with glomerular lesions, that alter the glomerular permeability, and conditions with glomerular hyperfiltration. Herein, we describe a case with a 58-year-old man who presented with macroscopic hematuria and AKI, and recently taking acenocoumarol for aortic valve replacement. The first renal biopsy showed red cell casts in the renal tubules, one glomerular crescent formation in the glomeruli with mild immunoglobulin A deposition, and severe interstitial inflammation. Based on these findings, the patient was diagnosed with acenocoumarol induced ARN with newly diagnosed IgA nephropathy and switched to tinzaparin with a short course of corticosteroids. Renal improvement in ARN is usually partial and is delayed, as confirmed by a second biopsy in our patient after six months.