Immunofluorescence (IF): Essential for subclassification.
- Immune-complex MPGN: Granular capillary wall and mesangial positivity for IgG, IgM, C3, and sometimes C1q/C4.
- Complement-mediated MPGN (C3 Glomerulopathy): Dominant or exclusive C3 positivity with negative/trace immunoglobulins.
Electron Microscopy (EM):
- Type I: Subendothelial and mesangial electron-dense deposits.
- Type II (Dense Deposit Disease): Continuous, highly electron-dense "sausage-like" deposits within the lamina densa of the GBM.
- Type III: Complex subendothelial, mesangial, and subepithelial deposits with GBM disruption.
H&E Diagnostic Status: H&E and silver stains can identify the pattern of injury, but IF and EM are absolutely required to determine the underlying etiology and make a definitive diagnosis.

Kidney, Medical

Pathologies