Acute Kidney Injury Caused by Renin-Angiotensin System Inhibitors During Minimal Change Disease Treatment

Abstract

A 76-year-old Japanese man with nephrotic syndrome was admitted to our department for treatment. After his admission, he was administered prednisolone (PSL) at 40 mg/day, and a percutaneous renal biopsy was performed. However, on the first day of admission, his urinary protein decreased from 5.05 g/gCr to 1.85 g/gCr. On the fourth day of admission, his urinary protein further decreased to 0.38 g/gCr and the patient developed acute kidney injury (AKI). Renin-angiotensin system (RAS) inhibitors were suspected to be the cause of AKI; therefore, they were discontinued. After the renal function improved, the urinary protein worsened again to 5.49 g/gCr. Renal pathology suggested minimal change disease (MCD); therefore, PSL was continued. The patient's urinary protein subsequently improved and he had no renal function impairment. Minimal change disease can be complicated by AKI through intravascular volume depletion caused by high urinary protein and hypoalbuminemia. However, when MCD is complicated by RAS inhibitor-associated AKI, the urinary protein may notably decrease, and the patient may present with an atypical course of MCDassociated AKI.

An Elderly Case of Minimal Change Nephrotic Syndrome: Correlation between Renal Tubular Dysfunction and the Onset of Oliguric Acute Kidney Injury Requiring Hemodialysis

“…A study by Arisz et al demonstrated that in patients with nephrotic syndrome, a decrease in GFR induced by indomethacin administration resulted in a greater decrease in urinary protein excretion than the reduction in GFR [ 8 ]. Renin-angiotensin system (RAS) inhibitors, known to reduce intra-glomerular pressure, may also lead to a notable decrease in urinary protein levels when MCNS is complicated by RAS inhibitor-associated AKI [ 19 ]. Reduced intra-glomerular pressure may explain severe AKI in MCNS, but it does not account for the abrupt increase in sCr levels observed in our patient, correlating with increased urinary total protein excretion.…”