Electron microscopy in Minimal Change Disease typically demonstrates which finding?

Electron microscopy in Minimal Change Disease typically demonstrates which finding?

• A. Diffuse effacement of podocyte foot processes and loss of negative charge of the GBM
• B. Subepithelial immune complex deposits
• C. Mesangial proliferation
• D. Fibrin deposition

Answer: (A)

Minimal Change Disease causes nephrotic-range proteinuria through podocyte injury. The defining electron microscopy finding is diffuse effacement (fusion) of the podocyte foot processes with disruption of the slit diaphragms, which also diminishes the negative charge of the glomerular filtration barrier. This loss of charge selectivity explains why albumin leaks into the urine while larger proteins are less affected. Light microscopy is usually normal and immunofluorescence is negative, reflecting the absence of immune complex deposits. Subepithelial immune deposits, mesangial proliferation, and fibrin deposition point to other glomerular diseases such as membranous nephropathy, mesangial proliferative GN, and rapidly progressive GN, respectively, and are not characteristic of minimal change disease.

Minimal Change Disease causes nephrotic-range proteinuria through podocyte injury. The defining electron microscopy finding is diffuse effacement (fusion) of the podocyte foot processes with disruption of the slit diaphragms, which also diminishes the negative charge of the glomerular filtration barrier. This loss of charge selectivity explains why albumin leaks into the urine while larger proteins are less affected. Light microscopy is usually normal and immunofluorescence is negative, reflecting the absence of immune complex deposits.

Subepithelial immune deposits, mesangial proliferation, and fibrin deposition point to other glomerular diseases such as membranous nephropathy, mesangial proliferative GN, and rapidly progressive GN, respectively, and are not characteristic of minimal change disease.