Acute Kidney Injury due to Anticoagulant-Related Nephropathy : A Suggestion for Therapy

Abstract

The relationship between kidneys and anticoagulation is complex, especially after introduction of the direct oral anticoagulants (DOAC). It is recently growing evidence of an anticoagulant-related nephropathy (ARN), a form of acute kidney injury caused by excessive anticoagulation. The pathogenesis of kidney damage in this setting is multifactorial, and nowadays, there is no established treatment. We describe a case of ARN, admitted to our Nephrology Unit with a strong suspicion of ANCA-associated vasculitis due to gross haematuria and haemoptysis; the patient was being given dabigatran. Renal biopsy excluded ANCA-associated vasculitis and diagnosed a red blood cell cast nephropathy superimposed to an underlying IgA nephropathy. Several mechanisms are possibly responsible for kidney injury in ARN: tubular obstruction, cytotoxicity of heme-containing molecules and free iron, and activation of proinflammatory/profibrotic cytokines. Therefore, the patient was given a multilevel strategy of treatment. A combination of reversal of coagulopathy (i.e., withdrawal of dabigatran and infusion of its specific antidote) along with administration of fluids, sodium bicarbonate, steroids, and mannitol resulted in conservative management of AKI and fast recovery of renal function. This observation could suggest a prospective study aiming to find the best therapy of ARN.

Figure 1

Kidney function trends and therapeutic strategies' timeline during hospitalization.

Figure 2

(A) Extensive tubular injury, partially haemolyzed and/or fragmented red blood cells within tubular lumen (H&E 10x). (B) In light microscopy, 10 glomeruli were identified; two glomeruli with mild expansion of mesangial matrix, minimal segmental endocapillary proliferation, flocculo-capsular adhesion with irregularities of Bowman's capsule, and activation of parietal epithelium; tubular injury (PAS 20x). (C) Tubular injury (H&E 20x). (D) IF stain for IgA with mesangial, vessels walls, and endotubular material staining pattern (20x).