SM 209: Nephritis

Question 1

What are the common features of Nephritic Syndrome?

Answer 1

Key: Hematuria (gross or micro)
Other: Oliguria, Azotemia, HTN (renal VC due to poor filtrate flow)
Biopsy: Cell proliferation within glom and damage to GBM, RBCs escape to urine but may be damaged/dysmorphic

Question 2

Acute Post-Streptococcal GN

Population, Timing, Key Features, Tx, Biopsy

Answer 2

Pop: Kids
Timing: 1-6 weeks after Group A Strep Pharyngitis/Impetigo
Key: Cola-colored urine + low serum complement levels
Tx: may self-resolve (if not use steroids)
LM - neutrophils/lymphocytes in glom, fibrin thrombi in capillary loops
FM - granular IgG + C’ in “starry sky” pattern
EM - dense SUBENDOTHELIAL humps

Question 3

Crescentic GN

Population, Key Features, Biopsy, Types

Answer 3

Pop = adults
Rapid loss of renal fx, progress to need for dialysis; CLINICAL SYNDROME not disease
LM - crescents in most gloms (proliferation of parietal epithelial cells of Bowman’s Capsule - impedes filtration and causes damage)
Type 1: Anti-GBM
Type 2: advanced IC disease (SLE, PSGN, Henoch Schonlein Purpura)
Type 3: Pauci Immune (ANCA assoc)

Question 4

RPGN Type 1

Name, Biopsy, Key Features

Answer 4

Anti-GBM disease - antibody recognizes type IV collagen
FM - LINEAR IgG deposits +/- C3
EM - no distinct deposits
Goodpasture’s syndrome - anti-GBM also recognizes alveolar basement membrane - causes hemoptysis

Question 5

RPGN Type 2

Name, Biopsy, Key Features

Answer 5

IC disease = SLE, PSGN, Henoch-Schonlein Purpura
FM - granular IC deposits, C3 + IgG/IgA
EM - LUMPY BUMPY granular appearance

Question 6

RPGN Type 3

Name, Biopsy, Key Features

Answer 6

“Pauci”-Immune
FM Negative, EM no deposits
ANCA associated - seen in vasculitides (purpura, ulcers, pulm hemorrhage, peripheral neuropathies, fever/flu sx)
p-ANCA = MPO
c-ANCA = PR3
MPA - microscopic polyangiitis (vasculitis + neutrophils)
GPA - granulomatosis with polyangiitis (vasculitis with neutrophils + granulomas)
EGPA - eosinophilic GPA (GPA with asthma/eosinophils)
LM: Necrotizing Vasculitis - blood vessel inflammation, fibirn coat/collapse

Question 7

IgA Nephropathy

Population, Feature, Pathogenesis, Biopsy

Answer 7

Pop: Kids/Young Adults
Feature: recurrent hematuria (usually immediately after URI), abnormal IgA deposits in GBM - ICs lodge in kidney, activate C’ - damage to GBM
LM - MESANGIAL proliferation, deposits, crescents
FM - IgA + C3 deposit in MESANGIUM (stalks illuminated)
EM - MESANGIAL deposits

Question 8

Lupus Nephritis

Key Features, Class, Biopsy

Answer 8

Autoimmune disease - inflammation of multiple organs
6 classes - tx dependent on class
minimal change - active change - chronic change with increasing severity
FM - FULL HOUSE (IgG, IgM, IgA, C3, C1q deposits)
Active Lesions - hypercellularity, fibrin, apoptotic bodies
Chronic Lesions - sclerosis, cresents
EM: from mesangial deposits/proliferation to “SPIKE AND DOME” membranous lupus nephritis

Question 9

Amyloidosis

Key Features, Classes, Biopsy

Answer 9

Amyloid protein deposits, form beta sheet polymers, resistant to degradation in multiple organs
AA: Amyloid of Serum Amyloid A - occurs in chronic inflammation (autoimmune or Hep B/C)
AL: Amyloid of Light Chains
AH: Amyloid of Heavy Chains
AL/AH occur in lymphoid neoplasms
A-beta-2M: amyloid of beta-2-microglobin - seen in chronic hemodialysis patients
ATTR: amyloid of tranthyretin - seen in elderly or familial
LM: uneven/diffuse pink amorphous material in glom, can replace entire glom
APPLE-GREEN BIREFRINGENCE on CONGO-RED STAIN