All the glomeruli are diffuse, too many nuclei
Post strep GN
Example: scarlet fever 2 weeks ago, presents with hematuria, RBC casts, mild to moderate
proteinuria, HP, periorbital puffiness. EM: lumen of capillary, bump on lumen is endothelial cell,
underneath is BM (grayish), and epithelial cells under. Has boulders that are denser than the
normal glomerular BM – these are immune complexes. In this case, it the bacteria is the Ag-Ab
immune complexes. Which side are they closer to? Closer to epithelial side, therefore they are
subepithelial deposits – hence post strep GMN.
Example: 35 y/o female with “+” serum ANA with a rim pattern (meaning you have anti DNA
Ab’s present). Lupus almost always involves the kidney. There are 6 types, and the important
one to know is type IV, which is a diffuse proliferative glomerulonephritis, which is the MC
overall one seen in Lupus. Has many nuclei, therefore proliferative; has wire loops. (orient to
EM) deposits in BM are anti DNA deposits. Would you agree that they are in the endothelial
cell? Yes. So what is this location? Subendothelial deposits. Podocytes with slit pores in btwn
are not fused b/c if they were, it would be nephrotic syndrome. Also see lumen, endothelial
cells and deposits. Immune complexes are so big they can’t get through the BM.
Glomerulus surrounded by proliferating cells that are parietal cells b/c not in the glomerulus,
and has crescent shape, hence the name crescentic glomerular nephritis. This is the WORST
glomerular nephritis to have b/c in 3 months; pts will go into acute renal failure and die unless
pt is on dialysis. Many dz’s have a crescentic glomerulonephritis, but the only one I need to
know is Goodpastures; this is a NEPHRITIC dz; this dz has crescentic glomerulonephritis on bx
(therefore a BAD dx).
Pt with casts (fatty casts), polarized specimen with maltese cross – this is cholesterol in the urine.
When cholesterol is polarized, it looks like a maltese cross. These fatty casts are pathonognomic
for nephrotic syndrome. Greater than 3. 5 grams protein for 24 hrs, fatty casts in the urine, ascites,
pitting edema, risk of spontaneous peritonitis if you are a child. Organism? Strep pneumonia in kids,
E coli in adults.
Lipoid nephrosis aka Minimal Change Dz:
Example: EM of 8 y/o boy that had an URI one week ago, and now is all swollen, has pitting
edema throughout body (anasarca) and ascites, normo-tensive, no HTN; saw nothing on renal
bx; but then did a EM – see RBC in glomerular capillary lumen. So, see endothelial cells, see BM
(without electron dense deposits), podocytes (fused) – fusion of podocytes is ALWAYS seen in
any cause of nephrotic syndrome. Maltese crosses in urine. Dx? Lipoid nephrosis. All pt with
nephrotic syndrome have hypercholesteremia. Since they have glomerular dz and some of the cholesterol can get into the urine, some can form casts in the urine. Aka minimal change dz.
Why is this happening? Has lost neg charge in GBM, therefore albumin can get through. These
pts have a select proteinuria – the only protein in these pt’s urine is albumin, and it is greater
than 3.5 grams per 24 hrs. Rx – corticosteroids (usually goes away in 1 year never to come back
again). The MCC nephrotic syndrome in kids.
Focal Segmental Glomerulosclerosis
Example: pt that is HIV “+”, pitting edema – therefore look at urine and note that is greater than
3.5 grams over 24 hrs. Has fatty casts in urine and has HTN. Do bx, and already know what you
are gonna see b/c it the MCC nephrotic syndrome in AIDs pt. On bx, some of the glomeruli are
abnormal and others are normal, but only a part of the glomerulus is messed up. Therefore, it is
focal segmental. B/c the renal bx with EM and immunofluorence did NOT show deposits,
therefore it’s glomerulosclerosis. So, this is called focal segmental glomerulosclerosis. This is the
MC lesion in AIDs pts and IVDA’s. Next to rapidly progressive crecentric glomerulonephritis,
this is the next worse glomerular dz.
Diffuse membranous glomerulonephritis
Example: adult with pitting edema, over 3.5 gram per 24 yrs, fatty casts. Do a bx and see not
many ‘dots’ therefore not a proliferative dz. However the BM is thicker. Dx? Diffuse
membranous glomerulonephritis = MCC nephrotic syndrome in adults. This is subepithelial
deposit. Epimembranous spikes – spike like lesion on the outside of GBM seen with silver
stain = diffuse