Inflammatory Glomerular Disease Flashcards
5 histologic-ish stages of the response to glomerular capillary injury?
- Injury.
- Proliferation.
- Acellular crescent formation.
- Cellular crescent formation.
- Scarring (glomerular and interstitial).
4 aspects of nephritic clinical syndrome?
Microscopic hematuria.
Proteinuria.
Hypertension.
Edema.
3 mechanisms for glomerular capillary injury?
Auto-antibodies.
Immune complexes.
…Mechanism X…
When glomerular capillaries are affecting by autoantibodies, what specific structure do they target? (what antigen?)
The glomerular basement membrane (GBM).
Type IV collagen.
How do both auto-antibodies and immune complexes in the glomerulus cause inflammation?
Via complement fixation.
Is Rapidly Progressing Glomerular Nephritis (RPGN) a specific disease process?
No. It’s a syndrome of a combined subacute rise in serum Cr and a nephritic syndrome.
(i.e. there are multiple potential underlying causes)
What other organ can be affected when there are auto-Abs against the GBM?
Lungs.
If both happen, this is called Goodpasture’s Syndrome.
How do anti-GBM vs. immune complexes appear differently on immunofluorescence?
Anti-GBM: linear (I think a better word would be “continuous”)
Immune complexes: granular
What’s the mechanism, usually, behind a glomerulonephritis that doesn’t stain for immune elements (antibodies or complement)?
Vasculitis.
Clinical presentation of Goodpasture’s syndrome? (2 main features)
Hemoptysis.
RPGN (rapidly progressive GN)
(These 2 features define a “pulmonary-renal syndrome”)
3 diseases in the DDx of renal-pulmonary syndrome?
Goodpasture’s (Abs against GBM).
SLE.
ANCA-positive small vessel vasculitis.
Light microscopy features of Goodpasture’s?
Hypercellular glomeruli with crescents and fibrin in Bowman’s space.
EM findings in Goodpasture’s?
Mainly useful for the negatives: no electron-dense deposits.
Treatment for Goodpasture’s?
Immune suppression.
Plasmapheresis.
Rituximab - anti-CD20 (probably).
3 types of GN caused immune complex deposition?
Post-infectious (esp. post-Strep) GN.
Lupus Nephritis.
IgA nephropathy / Henoch-Schoenlein Purpura
What does post-infectious GN look like by light microscopy?
Proliferation with PMN infiltration
On what side of the GBM are the immune deposits in post-infectious GN?
On the epithelial, Bowman’s space side.
So these are “subepithelial” deposits.
(one can imagine that this is because the immune complexes form after their constituent parts have filtered through the GBM)
What should you do to confirm the diagnosis of post-Strep GN?
Get confirmation from the patient’s PCP that they genuinely had Strep pharyngitis a few weeks ago.
Can also test for anti-Streptolysin O Abs.
Treatment / prognosis of post-Strep GN?
It’ll go away on its own.
Renal presentation of SLE?
RPGN
3 serological findings in lupus nephritis?
Positive ANA
Positive anti-DNA Abs.
Hypocomplementemia.
How does lupus nephritis look by H&E?
Proliferation limited to mesangium… or like post-infectious GN but with fewer PMNs.
(but the exam wouldn’t ever ask you distinguish lupus nephritis from post-infectious GN this way)
On what side of the GBM are immune complexes deposited in lupus nephritis?
On the endothelial side - “subendothelial deposits”.
(one can imagine that lupus-associated immune complexes are pre-formed in the blood, and thus get stuck on the blood side of the GBM –whether or not that’s accurate)
Thickening of glomerular capillary loops was an H&E finding associated with what disease process?
Lupus nephritis (not sure how specific this is, though)
Which immune elements are seen in lupus nephritis immune complexes? (eg. IgG vs. IgA vs. complement)
All of them - a “full house” pattern.
IgG, IgA, IgM, C1q, C3, C4
In IgA nephropathy, what are typical H&E findings? (2 things)
Mesangial hypercellularity.
Focal crescents.
Where are the immune complexes deposited in IgA nephropathy?
In the mesangium.
What’s a variant of IgA nephropathy that affects the skin?
Henoch-Schoelein Purpura
4 aspects of Henoch-Schoenlein Purpura?
RPGN.
Purpura.
Arthritis.
Colitis.
In “small vessel vasculitis” what vessels are affected?
Small arteries -> veins.
What’s a common cause of pauci-immune GN?
Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis
Light microscopy findings in ANCA-associated small vessel vasculitis -> GN?
Vasculitis with fibrinoid necrosis (but this is hard to find).
Crescents with segmental necrosis.
