Nephrotic Syndrome Pathology Flashcards
5 clinical manifestations of nephrotic syndrome
- edema
- proteinuria (over 3g per 24hrs)
- hypoproteinemia
- hyperlipidemia
- lipiduria (oval fat bodies)
can have some overlap w/ nephritis- hematuria, azotemia, HTN (quantitative difference)
why renal biopsy?
clinical and lab data not enough to narrow treatment regimen, tx can be personalized w/ enough info
6 main diseases on DDx for nephrotic syndrome
- amyloidosis
- diabetic glomerulosclerosis
- MCD
- membranous nephropathy
- FSGS (focal segmental glomerulosclerosis)
- MPGN (membranoproliferative)
age range for amyloid nephrotic syndrome
50s-70s
renal mainfestation of amyloid
proteinuria and nephrotic syndrome (NS)
most common peptides causing amyloid NS
AL amyloid (Ig light chians) and AA amyloid (A protein)
LM appearance of amyloid
pink depositions in glomerulus, destroys normal structure
IF and other stains for amyloid
congo red- pinkish stain in glomerulus
congo red polarized- apple green deposits
IF: anti lambda light chains
EM: fibrils
why is prevalence likely underestimated for older pts w/ diabetic GS (glomerulosclerosis)
this is the presumed Dx w/ older pts w/ NS, often not biopsied w/o other findings
most common cause of end stage renal disease
diabetic nephropathy- underlied by diabetic GS (proteinuria, progressive loss of GFR, HTN)
histo LM appearance of diabetic GS
progressive thickening of GBM, increas in mesangial matrix eventually into Kimmelstiel-wilson nodules
most common cause of childhood NS
MCD- over 90% but it is rarely biopsied, often treated w/ steroids
LM and IF of MCD
often normal (minimal change)
pathologic change in MCD
foot processes of podocytes are effaced, become one continuous sheet of cytoplasm (visible by EM)
not specific! can happen w/ other diseases, for Dx needs to be w/o other changes
population risk for FSGS
african americans
define “focal segmental” for FSGS
focal= some not all glomeruli (contrast to diffuse)
segmental= some but not all of a glomerulus (contrast to global)
list some causes of FSGS
- idopathic (unkown, primary)
- secondary: viruses (HIV, parvovirus B19), podocyte mutations, drugs (heroin, interferon alpha, pamidronate), adaptive structural changes (Sickle cell, obesity)
population for membranous nephropathy (MN)
caucaisians
describe LM for MN (or MG, membranous glomerulapathy)
thick cap walls but no hypercellularity
IF and EM for MN
granular capillary wall via IgG staining w/ IF
subepithelial dense deposits via EM (think about thickening the capillary wall)
pathogenesis for MN
- IgG capable of crossing BM into interstitium
- bind to protein antigens from podocytes, form lattices and can fix complement
- accumulate under podocyte (subepithelial), podocytes lay down collagen around deposits
primary/secondary MN causes
primary: anti phospholipase A2 receptor, other podocyte antigen autoAb
secondary:
- SLE
- infections (hep B, syphilis)
- exposure (metals, penicillamine)
- malignancy (carcinoma, sarcoma, lymphoma, leukemia)
