Nephritic Syndromes

Question 1

Acute post-streptococcal glomerulonephritis

Answer 1

- 2 wks post strep (phar/imp) - IgG, IgM, C3 complexes to M-prot (Type 3 HS)
LM - glom enlarged + hypercellular
IF - starry sky/lumpy bumpy
EM - subepithelial IC
(age best prognostic indicator)

Question 2

Rapidly Progressive Glomerulonephritis (RPGN)

Answer 2

• crescent w/ fibrin, plasma prot (C3b), parietal cell, mono/macro (NO COLLAGEN)
• Goodpastures (hemoptysis) - Type 2 HS
• Granulomatosis w/ polyangiitis (pauci-immune)
• Microscopic polyangitis (pauci-immune)

Question 3

IgA Nephropathy (Berger disease)

Answer 3

• IgA-based IC deposits in mesangium
• presents in childhood w/ episodic hematuria
• Mesangial proliferation
• Henoch-Schonlein purpura (palpable purpura)

Question 4

Alport Syndrome

Answer 4

• Inherited mutation (X-linked) in type IV collagen causing thinning and splitting of GBM (basket weave appearance on EM)
• Can’t see, Cant pee, Cant hear a buzzing bee

Question 5

Membrano-proliferative glomerulonephritis (MPGN)

Answer 5

Type 1 - Subendothelial IC deposits (granular) w/ “tram-track” appearance on PAS and H&E (mesangial ingrowth splits GMB)
- Idiopathic, hep B/C
Type 2 - Intramembranous IC “dense deposits”
- C3 nephritic factor (auto-Ig to C3 convertase, stabilizing and decreased C3 (increased C3a/b)

(can progress to nephrotic syndrome)

Question 6

Diffuse Proliferative Glomerulonephritis (DPGN)

Answer 6

- D/t SLE or MPGN
LM - wire looping of capillaries
EM - subendothelial (and possible intramembranous) IgG-based ICs often w/C3
IF - granular
[most common cause of death in SLE]
(can progress to nephrotic syndrome)