IgA Nephropathy Is the Most Common Underlying Disease in Patients With Anticoagulant-Related Nephropathy.

Introduction: Anticoagulant-related nephropathy (ARN) is a relatively novel recognized entity characterized by hematuria-associated acute kidney injury (AKI) in the context of overanticoagulation. Preexisting or underlying kidney disease seems to be a predisposing factor; however, few studies have described histologic findings in patients with ARN. We aimed to evaluate underlying kidney pathology in patients on oral anticoagulation who presented an episode of AKI with hematuria in whom a kidney biopsy was performed. Methods: Retrospective observational multicenter case study in patients treated with oral anticoagulants who developed macroscopic or intense hematuria followed by AKI. Only patients with available kidney biopsy specimens were included. Histologic findings and clinical data throughout follow-up were analyzed. Results: A total of 26 patients were included with a median age of 75 years (62-80) and a follow-up period of 10.1 months. Of the patients, 80% were male, and most cases (92%) were on anticoagulation with vitamin K antagonists (VKAs). At admission, median serum creatinine (SCr) level was 4.2 mg/dl (2.8-8.2), median international normalized ratio (INR) 2.4 (1.5-3.4), and 11 patients (42%) required acute dialysis during hospitalization. Kidney biopsy results revealed that all patients except 1 had an underlying nephropathy: IgA nephropathy (IgAN) in 19, probable IgAN in 1, diabetic nephropathy in 3, nephrosclerosis in 1, and idiopathic nodular glomerulosclerosis in 1. At 12 weeks after discharge, only 6 subjects (24%) attained complete kidney recovery whereas 7 (28%) remained on chronic dialysis. Conclusion: IgAN was the most common underlying kidney disease in our biopsy-proven series of ARN, in which a significant percentage of patients did not achieve kidney function recovery.

The need for genetic study to diagnose some cases of distal renal tubular acidosis. / Necesidad de estudio genético para el diagnóstico de algunos casos de acidosis tubular renal distal.

We describe the case of a young woman who was diagnosed with advanced kidney disease, with an incidental finding of nephrocalcinosis of unknown aetiology, having been found asymptomatic throughout her life. The genetic study by panels of known genes associated with tubulointerstitial disease allowed us to discover autosomal dominant distal renal tubular acidosis associated with a de novo mutation in exon 14 of the SLC4A1 gene, which would have been impossible to diagnose clinically due to the advanced nature of the kidney disease when it was discovered.