Apixiban-Associated Anticoagulant-Related Nephropathy in a Patient with Undiagnosed Sickle Cell Trait

Introduction: Anticoagulant-related nephropathy (ARN) is an under-recognized complication of anticoagulant use. To our knowledge, we present the fourth reported case of ARN in a patient on apixaban. Case Description: A 66-year-old male with a history of paroxysmal atrial fibrillation presented with a 3-day history of headache and painless hematuria and was found to have acute kidney injury (AKI) with Cr at 3.9 mg/dl from 0.8 mg/dl two months earlier. His medications included metoprolol succinate 200mg daily, apixaban 5 mg twice daily, and aspirin 81 mg daily. Renal function continued to decline without a clear etiology prompting kidney biopsy. Histology revealed marked glomerular hematuria with extensive red blood cell (RBC) cast formation and tubular obstruction . Also demonstrated were sickled RBCs and hemoglobin electrophoresis later confirmed sickle cell trait. Discussion: Decision Making: In the absence of other apparent causes, glomerular hemorrhage leading to AKI was attributed to use of apixaban with an additive component of sickle cell hemoglobinopathy. The initial plan was to hold apixaban, resume at half-dose once renal function improved, and refer the patient for percutaneous left atrial appendage closure. However, the patient ultimately progressed to end-stage renal disease and the previous dose of apixaban was resumed. Conclusion: ARN is a rare but serious complication of apixaban that can lead to irreversible kidney injury in certain patients. AKI in the absence of other obvious causes in anticoagulated patients should prompt consideration of ARN.