IgA nephropathy (Berger disease) is the most common primary glomerulonephritis worldwide. The key immunofluorescence finding is:

• A Granular C3 deposits in capillary walls
• B Dominant mesangial IgA deposits ✓
• C Linear IgG along the GBM
• D Subepithelial IgG and C3 'humps'

Explanation

IgA nephropathy is defined by dominant or co-dominant mesangial IgA deposits on immunofluorescence, often with IgG and C3. It classically presents with episodic macroscopic hematuria following mucosal infections (synpharyngitic hematuria). Linear IgG characterises anti-GBM disease; subepithelial humps are seen in post-streptococcal GN; granular C3 without immunoglobulin is seen in C3 glomerulopathy.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.