Nephritic Syndromes

Question 1

What is Nephritic Syndrome

Answer 1

Red Blood cells (Hematuria)
RBC casts
WBCs and inflammation

Question 2

IgA Nephropathy (Berger’s Disease) + Henoch Schonlein

Answer 2

• Accumulation of abnormal IgA1
• IgG targets and binds = immune complex
• IgA1-IgG immune complex deposits in mesangium
• ICs activate complement –> hypercellularity
• Glomerular Injury
• Mesangial proliferation
• Usually follows respiratory or GI infection (due to increase IgA)
• Hematuria due to glomerular injury
• Henoch Schonlein Purpura = more systemic form (vasculitis, renal, etc)

Question 3

Alport Syndrome

Answer 3

Mutation in Type 4 collagen

• Type 4 collagen important in glomerulus of kidney, eye, and cochlea
• Mutation causes defect in basement membrane –> thinning and porous
• Splitting of lamina densa
• RBCs get into filtrate –> microscopic hematuria and eventually gross hematuria
• Proteinuria over time
• Fewer healthy glomeruli –> Renal insufficiency and HTN
• Hearing loss also possible
• Eye problems

Question 4

Post-streptococcal Glomerulonephritis

Answer 4

Happens after Group A Beta-Hemolytic Strep infection
- Most common in children 1-6 wks after impetigo or pharyngitis

• Immune complexes get trapped in GBM - subendothelial
• Enlarged hypercellular glomerulus
• Subendothelial humps on EM
• Hematuria
• Oliguria (less urine than normal)
• Decrease complement levels (on blood testing)
• Increase anti-streptolysin O or anti-DNase B titers

Question 5

Membranoproliferative Glomerulonephritis

Answer 5

Triggered by immune deposits in walls of glomerulus
Usually young adults (<30y)

1. Immune Complex Mediated
2. Complement Mediated
3. Could form after chronic infection due to antigens
   - Immune complexes activate classical complement pathway
   - ICs + complement deposit
4. Inappropriate activation of alternate complement pathway
   - C3 convertase stabilized
   - C3 converted to C3a and C3b continuously
   - Complement deposits in BM

• Mesangial hypercellularity
• Mesangial interposition - grows into basement membrane –> split BM = TRAM TRACK APPEARANCE
• Hematuria + Proteinuria
• May also cause nephrotic syndrome

Question 6

Rapidly Progressive Glomerulonephritis

Answer 6

Proliferation of cells in Bowman’s space forms a CRESCENT SHAPE
- Leads to severe glomerular injury and quick renal failure

3 types: IC, anti-GBM deposition (associated with Goodpasture’s Disease) , Pauci-Immune

Pauci-Immune - no anti-GMN or ICs

• ANCAs are found
• cANCA (cytoplasmic) or pANCA (perinuclear)
• Glomerulus breaks and lets a lot of stuff into Bowman’s space –> v damaged
• Hematuria
• Low GFR
• Renal Failure

Question 7

SLE Nephritis (Also nephrotic syndrome)

Answer 7

Inflammation of kidney as a result of SLE

• SLE = autoimmune + IC formation –> tissue destruction
• Many organs affected

Early presentation

• Joint swelling
• Butterfly rash
• IC deposition in kidneys cause inflammatory reaction
• Crescent shaped in Bowmans Space
• WIRE LOOP PATTERN in BM

Class II = just mesangial
Class III or IV = diffuse proliferative

• Proteinuria
• Hematuria
  Nephrotic v nephritis might depend on location of deposition

Question 8

Thrombotic Microangiopathy (TTP)

Answer 8

Damage to vascular endothelium
Platelet aggregation
Hemolytic anemia (RBC shearing)

• ADAMSTS-13 defect
• Platelets can aggregate on vasculature and occlude
• endothelial cell swelling

Question 9

HUS

Answer 9

Typical = HUSD+ = shiga toxin
Atypical = HUSD- = no diarrhea

Atypical = Complement regulatory deficiency –> activation causes platelet, endothelial, and leukocyte activation

• small vessel occlusion
• Hemolytic anemia

No C3 staining