Acute Kidney Injury Associated with Minimal Change Nephrotic Syndrome in an Elderly Patient Successfully Treated with both Fluid Management and Specific Therapy Based on Kidney Biopsy Findings

Abstract

Oliguric acute kidney injury (AKI) with minimal change nephrotic syndrome (MCNS) has long been recognized. Several mechanisms such as hypovolemia due to hypoalbuminemia and the nephrosarca hypothesis have been proposed. However, the precise mechanism by which MCNS causes AKI has not been fully elucidated. Herein, we describe an elderly patient with AKI caused by MCNS who fully recovered after aggressive volume withdrawal by hemodialysis and administration of a glucocorticoid. A 75-year-old woman presented with diarrhea and oliguria, 43 and laboratory examination revealed nephrotic syndrome (NS) and severe azotemia. Fluid administration had no effect on renal dysfunction, and hemodialysis was initiated. Her renal function improved upon aggressive fluid removal through hemodialysis. Renal pathological findings revealed minimal change disease with faint mesangial deposits of IgA. After administration of methylprednisolone pulse therapy followed by oral prednisolone, she achieved complete remission from NS. The clinical course of this case supports the nephrosarca hypothesis regarding the mechanism of AKI caused by MCNS. Furthermore, appropriate fluid management and kidney biopsy are also important in elderly patients with AKI caused by NS.

Minimal Change Disease Following the Pfizer-BioNTech COVID-19 Vaccine

“…4 AKI has been described, however, as a complication of nephrotic syndrome, 2 including in the setting of MCD. 1 The explanation for the occurrence of AKI in our case may be found in the results of the kidney biopsy, demonstrating extensive acute tubular injury. This is indeed atypical for MCD, in which the pathologic hallmark is absence of visible alterations by light microscopy.…”

“…The clinical triad of MCD, NS and AKI has been previously described under a variety of circumstances (1) , (2) , including at least two cases following the influenza vaccine (3) , (4) . To the best of our knowledge, such occurrence has not been previously reported following the Pfizer-BioNTech or other COVID-19 vaccines.…”

“…Usually, the major presenting clinical features in MCD are related to NS, with overt peripheral edema, massive proteinuria with hypoalbuminemia and no major disturbance in glomerular filtration rate 4 . AKI has been described, however, as a complication of NS 2 , including in the setting of MCD 1 . The explanation for the occurrence of AKI in our case may be found in the results of the kidney biopsy, demonstrating extensive acute tubular injury.…”

Acute Kidney Injury in Monoclonal Gammopathies

“…Another pattern of functional renal impairment, which could eventually lead to AKI through renal ischemia, is one of renal edema, once again related to low oncotic force of plasma during the NS, induced by LC deposition disease (LCDD) or PGNMID (Figure 1). A large, swollen kidney at ultrasound or CT scanning may suggest renal intraparenchymal fluid accumulation, which could translate into elevated hydrostatic pressure within the organ due to a scarcely stretchable capsule [27,28]. The setting is similar to that induced by muscle ischemia following trauma, infection, or massive exercise with tissue swelling, the so-called "compartmental syndrome".…”

“…Poorly distensible peri-muscular fasciae are responsible of serious ischemia related to injuries to the forearms or legs, as an example [29]. The renal condition has been referred to as "nephrosarca" in some studies, echoing the "anasarca" setting of serosal edema in NS, cardiac failure, or decompensated cirrhosis of the liver [27][28][29]. AKI may, thus, well occur in NS due to kidney edema and resulting local ischemia (Figure 1).…”