Rapid decline in renal function:

1. Anti-GMB IV Col

  • Causes:
    • Anti-GBM disease (Goodpasture syndrome):Z Antibodies against type 4 collagen present in the basement membrane of the kidney and alveoli. Patients present with GN and hemoptysis.
      • Diagnosis: Renal biopsy showing linear deposits.
      • Treatment: Immunosuppressants and plasmapheresis. (Caution with renal transplantation in these patients.) - cyclosporin IL-2 Inhibitor; gum hyperplesia, HTN, corticosteroids; safer option LINEAR DEPOSITS OF GPS

2. Immune complex diseases: IgA

IgA nephropathy: Can be isolated GN or part of a systemic illness like Henoch-Schonlein purpura; systemic. Abnormal IgA antibodies have delayed clearance. IgA is attacked by antibodies/IgG, and the antibody/antibody complex deposits in the mesangial cells.

Problem: Damage to the kidney.

Note: C3 levels are normal.

History: Upper respiratory tract infection (URTI) or (GI) infection 1-3 days before GN onset or systemic illness. - due IgA mucous protective mechanism

Period: —/

Diagnosis: Renal biopsy showing mesangial deposits.

Treatment: Immunosuppressants and plasmapheresis in severe cases.

MESINGAL DEPOSITS IgA

3. Post-streptococcal GN: IgG - C3

Occurs after infection with Streptococcus pyogenes, either throat or skin infection. Symptoms appear 2-3 weeks after the initial infection. * Mechanism: Antigen and antibody (IgG) complex deposits in the subepithelial space. Complement system activation consumes C3, lowering its level. * Diagnosis: Typical history, blood tests showing high ASO titer, renal biopsy showing lumpy-bumpy subepithelial deposits. * Treatment: Antibiotics.

SUBEPITHELIAL DEPOSITS (EM)

4. Diffuse proliferative GN (Lupus nephritis): wire loop

50% of the glomeruli are affected (diffuse). Antigen/antibody complex deposits in the blood vessels (subendothelial).Z * Appearance: Blood vessels become thickened, showing a wire-loop appearance in renal biopsy. * Treatment: Immunosuppressants, e.g., IL2 inhibitors.

WIRE LOOPING(LM WITH STAIN); SLE

5. Pauci-immune disease:

Primarily caused by vasculitis. Examples: Granulomatosis with polyangiitis (Wegener granulomatosis), c-ANCA positive. Eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome), p-ANCA positive +- UC * Renal biopsy: Shows no immunocomplex deposition. * Treatment: Immunosuppresants