An Overlap of Anticoagulant-Related and IgA Nephropathy: A Case Report.

Introduction: Anticoagulant-related nephropathy (ARN) is an increasingly recognized cause of acute kidney injury (AKI), initially associated with warfarin use. Supratherapeutic warfarin levels were implicated in kidney toxicity. With the widespread adoption of direct oral anticoagulants (DOACs), it becomes imperative to understand their potential risk for ARN and its clinical presentation. Case Presentation: We report a case of a 64-year-old male prescribed DOAC for paroxysmal atrial fibrillation management, presenting with heart failure and worsening AKI. Hematuria and mild proteinuria were also observed. Despite management attempts, AKI persisted, prompting a kidney biopsy. Histopathological examination revealed acute tubular injury with numerous intratubular red blood cell casts consistent with ARN. Additionally, findings indicative of IgA nephropathy (IgAN), including mesangial hypercellularity and IgA dominant deposition, were noted. Conclusion: This case underscores the emerging risk of ARN associated with DOACs and emphasizes the potential exacerbation of ARN in the presence of underlying glomerular diseases such as IgAN. Clinicians should maintain a high index of suspicion for ARN in patients on anticoagulation therapy, particularly DOACs, who present with AKI and urinary abnormalities, as early recognition and intervention are crucial in preventing further renal damage.