Flashcards in Pathology 1 Deck (22):
Total loss of glomerular architecture due to scarring
Hyper segmentation of normal lobular architecture of tuft due to intracapillary hypercellularity or significant mesangial expansions
Dissolution or attenuation of mesangial matrix and degeneration of mesangial cells, often associated with glomerular cap aneurysms
Extension of mesangial cells in peripheral cap walls in space between endothelial cells and GBM (sub endothelial zone)
due to large and confluent subendothelial immune deposits
Three or more mesangial and/or inflammatory cells per mesangial area in section 2-3 micrometers in thickness
In both meaangium and endocapillaries
Subepithelial electron dense immune type deposits with cigar or dome like appearance
Hydropic degeneration/osmotic nephrosis
Fine regular cytoplasmic vacuolization of proximal tubules
Large irregular sized coarse vacuoles in cytoplasm of tubular epithelial cells, especially distal tubular cells
What is the definition of nephrotic syndrome?
Insidious onset of:
Heavy proteinuria (>3.5 g/24 hrs)
Hypoalbuminemia (plasma albumin <3 g/dl)
What is the pathophysiology of nephrotic syndrome?
Increased glomerular permeability to plasma proteins
Urinary loss and increased tubular catabolism of albumin
Na and water retention by kidney, decreased plasma oncotic pressure in systemic capillaries due to hypoalbuminemia
Increased hepatic synthesis of lipoproteins (also abnormal transport of lipids and decreased catabolism)
How is the vascular component of the kidney arranged?
Renal artery --> segmental artery --> inter lobar artery --> arcuate artery --> inter lobular artery --> afferent arterioles
These are end arteries and arterioles
What are the different components of the glomerulus?
Endothelial cells - separates blood from GBM, fenestrated
Visceral epithelial cells = podocytes
Parietal epithelial cells line bowman's capsule
What do podocytes do in the glomerulus?
Foot processes attach to GBM and separated by filtration slits bridged by slit diaphragms
Slit diaphragms have nephrin and podocin that control permeability
Why effacement causes proteinuria
What do mesangial cells do in the glomerulus?
Between capillary loops and support tuft
Synthesize mesangial matrix and share features with smooth muscle (contractile) and macrophages (phagocytic)
What does the GBM do in the glomerulus?
Acellular membrane of type IV collagen and heparan sulfate
Fixed negative charge - repels negatively charged proteins
What are the different ways of classifying renal disease?
Clinical - major syndromes
Etiologic - but frequently unknown
Immunopathologic - based on IF findings
Morphological - mainstay, based on LM and EM patterns
What are most primary glomerular diseases?
Immunologic in nature
Exogenous or endogenous antigens can form immune complexes in circulation and deposit or in situ - activates complement and leukocytes to cause injury
What is the pathogenesis of FSGS?
Overall most common nephrotic syndrome in adults
Soluble circulating permeability inducing factor cases after renal transplant
Glomerular hypertension causes podocyte injury in secondary
What is the clinical course of FSGS?
At least half get end stage renal disease within 10 years