Glomerular Disease Flashcards
trichrome stain
used to demonstrate fibrosis (blue)
focal vs. diffuse
refers to distribution of glomerular lesions throughout the kidney
(less than 50% of glomeruli affected = focal)
segmental vs. global
refers to distribution of lesions w/in individual glomeruli
endocapillary vs. extracapillary proliferation
endocapillary: proliferation of mesangial, endothelial, and inflammatory cells filling up capillary lumens and involve glomerular tuft
extracapillary: profile of epithelial cells in Bowman’s capsule to fill Bowman’s space = crescentic
nephrotic syndrome
heavy proteinuria
edema
hypoalbuminemia
hyperlipidemia
cause of nephrotic syndrome (pathology)
messed up epithelial foot processes – look at GBMs!
big 5 causes of nephrotic syndrome
minimal change disease focal segmental glomerulosclerosis (FSGS) membranous glomerulopathy diabetes amyloid
minimal change disease pathology
Light and EM: normal
EM: diffuse effacement of epithelial cell foot processes
proximal tubular epithelial cells may have protein resorption droplets
who gets MCD? what causes it?
mostly children
many cases are primary, but also can be caused by NSAIDs, lithium, lymphoid malignancies, food rxns, bee stings
course and tx of MCD
benign course
responsive to steroids
focal segmental glomerulosclerosis pathology
Light microscope: focal segmental capillary collapse and sclerosis - usually solidification of part of the glomerular tuft
IF: negative - but might have non-specific IGM staining
EM: moderately extensive effacement of foot processes
causes of FSGS
mostly primary secondary causes: - virus-assoc (HIV etc) - drug induced (heroin etc) - familial/genetic - adaptations to hemodynamic alterations (reduction in functioning # of nephrons; hemodynamic stress on initially normal nephrons (HTN, DM, CHF, sickle cell))
course and tx of FSGS
progressive
poor response to tx
membranous glomerulopathy pathology
Light: thickened capillary walls w/ “spikes” on silver stain
IF: diffuse, granular IgG and C3 along capillary walls
EM: numerous subepithelial deposits, with eventual incorporation into GBM
causes of membranous glomerulopathy
primary
secondary: drugs, tumors, lupus, infections
diabetic glomerulopathy - pathology
light: diffuse and nodular (Kimmelstiel-Wilson) glomerulosclerosis [+ hyaline deposition in the arterioles]
IF: linear IgG and albumin in GBMs - non-specific trapping
EM: diffuse thickening of GBMs and increase in mesangial matrix [+ effacement of epithelial foot process (secondary to proteinuria)]
amyloidosis - pathology
Light: diffuse and sometimes nodular glomerulosclerosis, with + congol red
IF: pos kappa or lambda light chains
EM: aggregates of 8-12nm fibrils
glomerular diseases presenting with nephritis
- post-infectious glomerulonephritis
- Membranoproliferative glomerulonephritis
- SLE nephropathy
post-infectious glomerulonephritis - pathology
gross: “flea-bitten” kidney
Light: diffuse proliferative GN (diffuse hypercellularity w/ PMNs)
IF: prominent granular or globular C3 (and sometimes IgG), mainly sub endothelial (+/- mesangial) deposits
EM: scattered large sub epithelial humps
sx of nephritic syndrome
hematuria
azotemia
variable degrees of proteinuria, edema, HTN
cause, course of post-infectious glomerulonephritis
classic acute diffuse proliferative GN
cause: usually streptococcal
course: prognosis good. usually self-limited, occasionally pts develop presences –> worse outcome
membranoproliferative glomerulonephritis - pathology
Light: proliferative GN, often hyperlobulated w/ duplicated “tram-track” GBMs
IF: prominent granular or globular C3 (and sometimes IgG), mainly sub endothelial +/- mesangial
EM: duplicated GBMs w/ mesangial interposition and large sub endothelial (+/- mesangial) deposits
course and causes of membranoproliferative GN
course: vast majority progresses to ESRD regardless of rx
causes:
- primary
- secondary: assoc w/ hepatitis B and C
clinical presentation of membranoproliferative GN
combo of nephritic and nephrotic syndrome
