The wide employment of oral anticoagulants and the introduction of new anticoagulant agents highlight disparate kind of toxicities that can affect many different organ systems. Renal toxicity by oral anticoagulants is a well-known entity characterized by hematuria and the worsening of renal function associated with uncontrolled INR values. Although it is mainly a clinical diagnosis, renal biopsy may help especially in challenging cases when multiple comorbidities and underlying renal conditions exist. The mechanism of the anticoagulant-induced damage is still debated and special tissue stains (such as Perls') could help in detecting the direct tubular toxicity induced by chronic glomerular bleeding. The employment of a diagnostic clinic-pathological flow-chart can help in the prompt detection and full characterization of these cases, improving the management of the patient.
Keywords: Anticoagulant nephropathy; Perls staining; Warfarin-related nephropathy.