renal pathology Flashcards
what is the leading cause of kidney failure
2nd leading cause
diabetes and HTN
renal cortex is responsible for
all filtration
most disease in kidney is focused in
glomeruli
what portion of the kidney is most sensitive to ischemia?
cortex
what portion of the medulla is thick ascending limbs, thick and thin descending limbs and collecting ducts?
outer
what portion of the medulla is thin limbs of loop of Henle and distal collecting ducts?
inner
what effect on permeability of glomerular capillary wall does increasing negative charge have?
decrease
are diaphragms present in fenestrated endothelium pores?
no
what is the podocyte membran protein found in podocyte slit diaphragms?
nephrin
what makes up the glomerulus filtration barrier
endothelium,
basement membrane, and layer
of podocyte foot processes.
inflammation of kidney blood vessels seen in which conditions
systemic vasculitis,
transplant rejection
what glomerular histologic alteration is more than 3 nuclei/mesangial area
“Endocapillary” proliferation: endothelial, mesangial, leukocyte
Visceral epithelial proliferation
Parietal epithelial proliferation (“crescent”)
Leukocytic infiltration
hypercellularity
T/F: patients w diabetes have a lot of endocapillary hypercellularity of mesangium
false- they have a lot of extracellular matrix material that expands that area
T/F: patients w proliferative glomerulonephritis have hypercellularity w lots of neutrophils and lymphocytes
true … kids w post-strep infection also can get this, where they have a cross reactive antigen that deposits w/in the GBM starting an immune process
what glomerular histologic alteration can result from Protein deposits: immune complex, organized deposits (polymers)?
mesangium
what indicates severe glomerular injury?
is proliferative lesion, composed of epithelial and/or inflammatory cells, collagen and fibrin, and results in partial filling of Bowman’s space?
crescents
what changes can you have in GBM
thickening
mesangial cell inerpositioning
heterlogous protein deposition
thinning/splitting
what is term for nuclear fragmentation resulting in necrosis?
karyorrhexis
what is glomerular hyalinosis
deposition of serum proteins
homogenous eosinophilic appearance
global glomerular lesions affect
entirety of individual glomeruli
segmental glomerular lesions affects
portion of individual glomeruli
diffuse glomerular lesions affects
all glomeruli
focal glomerular lesions affects
some but not all
3 phases of immune complex disease
complex formation
deposition of tissues
activation of inflammatory response
anti GBM disease antibodies directed against
type 4 collagen
IF of anti GBM disease
linear deposition of Ig along GBM
goodpastures syndrome has
anti GBM antibody
renal disease
pulmonary disease
subepithelial deposits fo GBM are associated with
“humps” near the outer GBM… these can make it hard to see foot processes
how do immune complexes activate neutrophils and macrophages
by by cross-linking Fc receptors: induces mediator release Proinflammatory cytokines Prostaglandins Chemotactic molecules Lysosomal proteases
what complex involved in complement cascade via C1 complex consists of C5-9 (cell lysis)?
MAC (membrane attack complex)
what components of the complement cascade are Anaphylatoxins that cause vascular permeability?
C3a
C5a
what component of the complement cascasde is a Chemotactic products leukocyte migration?
C5a
in diabetes, what hormone can cause Glomerular hyperfiltration, which can lead to Glomerular Hypertension, and Hypertrophy of GBM?
ANP (atrial natriuretic peptide)
when do you get non-immunologic compensatory hyperfiltration injury?
- occurs when 50-70% nephron mass lost
- endothelial and epithelial injury of glomeruli
- glomeruli capillary hypertension
all these problems lead to focal segmental GS and proteinuria
what is alports syndrome
Thinning, splitting, and basket weaving of glomerular BM b/c cant form type 4 collagen\
Also go deaf
if you damage glomeruli you also damage
tubules
clinical signs of acute glomerulonephritis
- Hematuria (blood in urine),
- hypertension
- Azotemia (increased BUN & nitrate products in body)
- oliguria (not peeing as much)
- edema, proteinuria - variable
etiologies of acute glomerulonephritis
- post infectious GN (post-strep)
- primary glomerular disease -> IgA nephropathy, MPGN
- multi system diseases -> lupus, vasculitides
rapidly progressing glomerulonephritis will appear clinically as
acute nephritis,
rapid progression to ARF
think crescents
pathology of rapidly progressing glomerulonephritis
Crescentic Glomerulonephritis-> proliferation of parietal epithelial cells forming a layer >2 cells thick… also will see endocapillary proliferation
pathogenesis of rapidly progressing glomerulonephritis
- there will be severe glomerular, antibody-mediated injury
- can be lupus (most common), also can be IgA, anti-GBM, etc
what defines nephrotic syndrome
- proteinuria > 3.5 g/24 hours (usually they have damage to podocytes which causes this)
- edema
- hyperlipidemia, lipiduria
- hypoalbuminemia (the moment GBM is damaged, albumin gets thru- this tells u kidney is damaged)
pathogenesis of nephrotic syndrome
glomerular injury resulting in altered capillary permeability and loss of barrier function w passage of proteins
The moment the GBM is damaged, _______ starts getting thru… this tells u kidney is damaged and can be a sign before the damage gets really bad. Check this in diabetics
albumin
what defines nephritic syndrom
hematuria decreased urine output oliguria elevated BUN & creatine HTN proteinuria, edema
causes of nephritic syndrom
Acute post infections glonerulonephritis
IgA nephropathy
Systemic lupus erythematous
proteinuria greater than ____ mg/day is abnormal
150mg/day… this could be from a glomerular defect in filtration function of capillary wall, or tubular failure of reabsorption (small proteins usually reabsorbed here)
how do u test for proteinuria
- “dip stick” – detects urine albumin, but not IgL
- Sulfosalicylic acid preparation – detects all proteins
what causes the complication of accelerated atherosclerosis in nephrotic syndrome
hyperlipidemia
what is the nephrotic syndrome complication is due to hyperfibrinogenemia & loss of AT III, can lead to Renal vein thrombosis
Pulmonary embolism?
hypercoagulation
what type of anemia, due to loss of transferrin, can result as a complication of nephrotic syndrome?
hypochronic microcytic
what pathology resulting from a complication of nephrotic syndrome results from loss of Ig?
infection
what pathology resulting from a complication of nephrotic syndrome results from loss of cholecalciferol binding protein?
hypercalcemia
what pathology resulting from a complication of nephrotic syndrome results from loss of thyroxine binding globulin?
hypothyroidism
etiologies of nephrotic syndrome from primary glomerular lesions
- minimal change disease
- focal segmental glomerulosclerosis
- membranous glomerulopathy
- membranoproliferative glomerulopathy (often nephritic)
- IgA nephropathy (often nephritic)
etiologies of nephrotic syndrome from systemic diseases
- diabetes
- SLE
- amyloidosis
what disease accounts for over half of the nephrotic syndrome cases in kids?
minimal change disease… peak age is 2-6 yrs old
clinical features of minimal change disease
proteinuria highly selective for albumin
how do u detect MCD
nothing shows up on light microscopy or IF!
you will see extreme podocyte damage on electron microscopy!!
most kidney problems start with ____________ that pisses off immune system leading to kidney dis
upper respiratory infection
clinical features of FSGS (focal segmented glomerulosclerosis)
- proteinuria (may or may not be in nephrotic range)
- hematuria v common
- *normal renal function early, but later progressive loss of function (e.g. creatinine begins to rise)
- hypertension
- affects both children & adults, M>F
FSGS much higher incidence in
african americans
histo of FSGS
- focal, segmental, global glomerulosclerosis
- segmental sclerosis of any glomeruli is abnormal and indicates glomerular injury
- global sclerosis of small numbers of glomeruli is normal (when this becomes >10% u have a problem)
FSGS pathogenesis
- decreased renal mass can lead to this
- morbid obesity- causes kidneys to work harder
- chronic pyelonephritis - more common in women except in older men when prostate clamps bladder
what is collapsing glomerulopathy
Worse variant of FSGS related to HIV or idiopathic. Fastest developing and leading to kidney failure.
clinical signs of collapsing glomerulopathy
- massive proteinuria
- rapid progression to renal failure
- poor response to therapy
pathogenesis of membranous glomerulopathy (MGN)
immune complex deposition
etiologies of membranous glomerulopathy (MGN)
- autoantibody against glomerular epithelial cell antigens (idiopathic)
- happens secondary to: malignancy, SLE (called membranous lupus nephritis), and infection
you see spikes and holes in jones silver stain w which dis
membranous glomerulopathy (MGN)
clinical presentation of MGN
- nonselective proteinuria, usually nephrotic
- hematuria common
- hypertension rare
what do u see on IF of MGN
granular IgG and C3 along capillary wall