Question

Which of the following is the true statement regarding minimal change disease?

• A. Loss of foot processes
• B. Antigen-antibody complexes
• C. Loss of foot processes along with loss of charge across the membrane, hence leading to proteinuria
• D. Destruction of the glomerulus, with minimal tissue only remaining intact

Hint:

MCD proteinuria comes from foot process effacement plus loss of the glomerular basement membrane's negative charge barrier.

Answer 1

The Correct Option is C

Step 1: Recall what minimal change disease looks like.
Minimal change disease (MCD) is the commonest cause of nephrotic syndrome in children. On light microscopy the glomeruli look normal, and immunofluorescence is negative, which is why the name says "minimal change."

Step 2: Identify the real lesion on electron microscopy.
Electron microscopy shows diffuse effacement (loss) of the podocyte foot processes. The podocytes also lose the negatively charged glycoprotein coat on their surface, so the glomerular basement membrane loses its normal negative charge barrier.

Step 3: Connect the lesion to proteinuria.
Because the membrane's charge barrier is lost along with the foot processes, small negatively charged proteins like albumin can cross the filter and pass into urine. This is why MCD produces a selective, albumin-heavy proteinuria.

Step 4: Rule out the wrong options.
Loss of foot processes alone, without stating the charge barrier defect, is only part of the picture, so plain "loss of foot processes" understates the mechanism. Antigen-antibody immune complexes are the mechanism in membranous and other immune complex glomerulonephritides, not in MCD, where immunofluorescence stays negative. Destruction of the glomerulus with only minimal tissue left describes a severe scarring process, which is the opposite of MCD, where the glomerular architecture stays intact.

Final Answer:
MCD causes proteinuria through combined loss of foot processes and loss of the membrane's negative charge barrier. \[ \boxed{\text{Loss of foot processes with loss of charge, causing proteinuria}} \]