Pathoma Nephrotic Syndrome Flashcards
Proteinuria means what?
More than 3.5 grams per day
When we are losing a lot of protein in the urine, what is one of the first things we think of and why? What does it lead to?
Hypoalbuminemia, low albumin, which is the main protein we are losing.
Low albumin means low oncotic pressure which means fluid retention = edema
Hypogammaglobuinemia and result?
We lose gammaglobulin, which will lead to an increase in infection
Why is a patient with high protein excretion hypercoagulable?
The body will preferentially lose Antithrombin III, leading to more coagulation
What other conditions are caused by low protein and why?
Hyperlipidemia and hypercholesterolemia. Blood becomes thin, so the body throws fat and cholesterol at it to beef it up
Most common cause of nephrotic syndrome in children
MCD - Minimal Change Disease
What other condition do we associate with MCD?
Hodgkin Lymphoma
Describe the layers of the glomerular filtration barrier
Endothelial cells with a basement membrane on top and the feet processes of the podocytes on top of that (also called the epithelial layer
What do we lose with MCD?
We lose the foot processes, or rather, they flatten out and take up a lot more space
What causes the damages seen in MCD?
Cytokines
H and E for MCD?
Normal Glomeruli!
Also no immune complex deposits and negative for Immunofluorescence
Wait how the hell do we see MCD…
Effacement of foot processes on EM
MCD direct protein effects
Selective proteinuria (loss of albumin but not immunoglobulin)
Treatment for MCD
Excellent response to steroids (damage is mediated by cytokines from T cells)
Focal segmental glomerulonephrosis (FSGS)?
Most common cause of nephrotic syndrome in Hispanics and African Americans
What do we associate with causes for FSGS?
HIV, heroin use and sickle cell disease
H and E, EM and IF/Immune complex results for FSGS
Focal and segmental sclerosis on H and E
Effacement of foot processes on EM
No immune complexes so negative IF
How can we distinguish FSGS from MCD if they look the same on all the histo tests?
FSGS is segmental, look at other areas of the glomerulus.
Also, focal only, so not all of the glomeruli will be affected
Also, you’ll see a pink sclerosis
Relate MCD to FSGS
If you are too late or the steroids dont work to stop MCD, your patient will develop FSGS. This will then progress to chronic renal failure
Membranous nephropathy is seen in who?
Most common cause of nephrotic syndrome in caucasian adults.
What is membranous nephropathy associated with?
Hepatitis B/C, solid tumors, SLE (important because this is how lupus patients can die) or drugs like NSAIDs and penicillamine
H and E, IF, and EM for membranous nephropathy
H and E = thick glomerular basement membrane (membranous)
Granular IF due to immune complex deposition
EM = subepithelial deposits with ‘spike and dome’ appearance on EM (dome over the immune complex deposits and spikes in between))
Discuss H and E and IF for Membranoproliferative glomerulonephritis
Thick capillary membranes on H and E, often with “tram-track” appearence
Due to immune complex deposition like Membranous nephritis so you’ll see that granular IF again)
Discuss the etiology behind the “tram track” appearence of Membranoproliferative glomerulonephritis
So remember those balls of complexes we had in between the podocytes? If they happen too close to the mesangial cells, which are holding these sections together, the mesangial cell will project part of its cytoplasm (proliferate) out to the complex to cut it in half. These two pieces look like two lines after the break
Discuss the subtypes of membranoproliferativeglomeruonephritis and what they are associated with
Type I = subendothelial - underneath the epithelial cells and basement membrane- Associated with HBV and HCV and also, more commonly associated with tram track!!
Type II = intramembranous in between the podocytes but still in the membrane - Associated with C3 nephritic factor
Discuss C3 nephritic factor and how it causes Type II membranoproliferative glomerulonephritis
C3 convertase is rapid and breaks apart quickly, turning C3 into C3a and b, which is your complement pathway. The factor holds the enzyme together continuously, so complement is overacting in Type II.
You’ll see decreased C3 and damage to the kidney
How does Diabetes Mellitus cause nephrotic problems?
High serum glucose leads to non enzymatic glycosylation of vascular basement membranes, making it leaky, resulting in hyaline arteriolosclerosis = thickening of the vascular wall
In regards to DM and its effect on the kidneys, ___ arteriole is more affected than the ____ arteriole, leading to a higher ___ ___ ___.
Efferent more than afferent, high Glomerular filtration pressure
What is special about the non enzymatic glycosylation seen in DM?
It is the first change in this disease!
Hyperfiltration pressure seen with DM on the kidney leads to what?
Microalbuminuria which eventually progresses to nephrotic syndrome
How do we characterize this glomerular damage caused from DM?
We’ll see sclerosis of mesangium and formation of Kimmelstiel-Wilson nodules
___ ___ slow progression of hyperfiltration-induced damage
ACE inhibitors
Most common organ affected by Systemic amyloidosis
Kidney
Etiology behind Systemic Amyloidosis
Amyloid deposits in mesangium resulting in nephrotic syndrome
What particular test can we use to see secondary amyloidosis
We will see apple-green birefringence under polarized light
