17 - Minimal Change Nephrotic Syndrome

Abstract

Minimal change disease (MCD) is a predominant cause of idiopathic nephrotic syndrome (NS) in children. Because most children with idiopathic NS are steroid sensitive, they are not typically biopsied, and the diagnosis of MCD is inferred in these patients. In adults, MCD accounts for a minority of cases of idiopathic NS. The renal biopsy in MCD is notable for the absence of abnormalities by light microscopy, none to minimal deposits by immunofluorescence microscopy, and extensive effacement of foot processes by electron microscopy. Although the cause of MCD is unknown, an interaction between intrinsic structural defects and immunologic disturbances is thought to play a role in pathogenesis. The mainstay of therapy is prednisone, and the majority of patients do respond to steroids. In those patients who frequently relapse or who are steroid dependent, steroid sparing regimens, including cyclophosphamide, calcineurin inhibitors, mycophenolate, and most recently rituximab, have been used with varying outcomes. In those patients who are steroid resistant, progressive chronic kidney disease is common, unlike in steroid-sensitive patients, in whom kidney function is usually preserved.