Nephrotic Syndrome Pathology Flashcards
Check out this sweet flow chart
What vein in the body is most likely to have thrombosis in nephrotic syndrome?
Renal vein.
Because at no place in the body would the ATIII level be lowest than that leaving the kidney.
Nephrotic syndromes cause protein deficiencies
- Antithrombin III
- HD lipoprotein
- Immunoglobulin and complement
- Albumin
- General
What is the consequence for having low levels of each of these?
- Antithrombin III
- Clotting tendency (especially in renal vein)
- HD lipoprotein
- accelerated atherogenesis
- Immunoglobulin and complement
- Susceptibility to infections
- Albumin
- edema, hypotension, and drug toxicity (many drugs need to complex to albumin to maneuver through the body)
- General
- protein malnutrition and growth retardation in kids
Does nephrotic syndrome progress to chronic renal failure?
Yes, and vice versa
Is nephrotic pathology typically inflammatory or non-inflammatory?
Non-inflammatory
What are the two general mechanisms for nephrotic syndromes? Give examples of each.
- Circulating factors/Ig’s bind to glomerular epithelial cell membranes (podocytes) and/or glomerular basement membrane without fixing complement (e.g. minimal change disease and FSGS)
- Loss of polyanion (charge selective) - albumin can freely go through if negative charge is lost
- GEC detachment from GBM (size selective)
- Complement-fixing anti-glomerular epithelial cell antibodies (e.g. membranous nephropathy)
- Alternative pathway
- C5b-9 which increases permeability of GBM (size selective)
- May involve oxidants/proteases from GEC
What are the 3 major diseases that comprise of the majority of all nephrotic disease? Which of these is more common in children vs adults?
Membranous glomerulonephropathy (more common in adults)
Minimal change disease (more common in children)
Focal segmental glomerulosclerosis (more common in adults)
What’s this?
Minimal change disease (entirely normal by LM, foot process effacement on EM, negative on IF)
Not hypercellular
Open capillary loops
No inflammatory cells
No basement membrane thickening
No scarring
Pedicels look connected
How do you treat minimal change disease? What’s the prognosis?
Treat with steroids.
Prognosis is good.
What’s this?
Focal segmental glomerulosclerosis
Focal - only some glomeruli involved
Segmental - only a portion of the glomeruli involved
Sclerosis - scarring
See how some glomeruli have too much pink. On the right picture, you can see that the sclerosis attaches to the bowman’s capsule.
What are the 4 major categories of causes for FSGS?
- Idiopathic/hereditary (primary) FSGS
- HIV-associated nephropathy
- Heroin nephropathy
- Secondary FSGS (hyperfiltration injury)
What is this?
Membranous nephropathy
Thicker and fuzzier. Rigid openings. Membranes have thickened.
What’s this?
Membranous nephropathy.
Silver stain shows “strings of pearls”.
What’s this?
Membranous nephropathy.
IF shows finely granular deposits (IgG and C3) circling around capillary loops.
EM shows deposits (dark spots) along the BM. These are subepithelial deposits.
If there are complement deposits, how come there isn’t an inflammatory process with membranous nephropathy? Because of where the deposits are. They are in bowman’s capsule, not the vasculature.
Injured podocytes are filled in with basement membrane material.
How do you treat membranous nephropathy? What’s the prognosis?
Treat with steroids.
Some progress to ESRD.
What are the stages of membranous nephropathy (including treatment) to lead to this?
Subepithelial deposits, more basement membrane material is formed eventually encasing the deposits, deposits dissolve if treated successfully.
Membranous glomerulonephropathy/nephropathy occurs most often in adults and can be often associated with other diseases (in 15% of cases). Diagnosis requires further workup. What should you rule out?
“Bugs, drugs, tumors, and rheum”
Infections
Drugs (rheumatoid meds)
Malignant tumors (lung, colon, melanoma)
Systemic lupus erythematosus
What is this? Is it nephritic, nephrotic, or mixed?
45 y/o female
Fine until 2-3 weeks ago
Flu like symptoms
Edema
Dark urine
Lethargic
Creatinine 2.3
UA shows RBCs, RBC casts, 4+ protein
Albumin 1.8
Membranoproliferative glomerulonephritis
Mixed (nephritic bc hematuria, RBC casts, and functional loss; nephrotic bc proteinuria, edema, hypoalbuminemia)
Diffuse
Double contour membranous change seen in silver stain
What’s this?
Membranoproliferative glomerulonephritis
Bright prominent immune complex deposits by IF.
Subendothelial deposits cause damage to the endothelial cell. The endothelial cells retract and a new layer of basement membrane between the deposit and itself as a form of protection. This is why you get a double contour membranous change known as “tram tracking”
How does membranoproliferative glomerulonephritis look morphologically?
Cell proliferation and thickening of glomerular basement membrane with double contours.
In membranoproliferative glomerulonephritis, are deposits subepithelial or subendothelial?
Subendothelial
How do you treat membranoproliferative glomerulonephritis? What’s the prognosis?
Treat with steroids and maybe interferons.
Some progress to ESRD
What is this?
Renal amyloidosis.
Amorphous fluffy pink material in glomeruli and vessels.
Positive on congo red stain with apple green birefrigencence
How does renal amyloidosis present?
Initially with proteinuria, develops to nephrotic syndrome, and eventually ESRD
What’s this?
Renal emyloidosis.
Classic “spilled spaghetti” look.
What are the top 3 causes of ESRD?
- Diabetes
- HTN/vascular disease
- Glomerulonephritis
Diabetes mellitus causes kidney lesions. Explain
- Hyaline arteriolar disease
- microvascular is effected. Hyaline deposition causes narrowing of arterioles
- If a patient has retinopathy, there is likely damage to the kidneys as well.
- Diabetic glomerulosclerosis
- Glomerulus scars from within
- Mesangium hyperproduce mesangial matrix and strangles itself out causing mesangial “lysis”.
- Consequence of altered glucose and insulin metabolism.
What is this?
Diabetes mellitus kidney lesions
Histology: hypocellular mesangium with big nodules of fibrosis.
EM: thickening of basement membrane
True or False: Diabetes increases risk of pyelonephritis
True (acute and chronic)
This can cause renal scarring and renal papillary necrosis.
What causes this?
Diabetes and HTN
What causes this?
Malignant (accelerated) hypertensive renal disease.
Very little blood can get through vessels so prognosis is poor.
