Robbins Reading Ch. 20 Flashcards
What is Azotemia?
biochemical abnormality that referes to elevation of BUN and Creatinine, usually related to GFR
What can cause prerenal azotemia?
- hypoperfusion of kidneys
- hypotension or fluid loss or shock
- heart failure
- cirrhosis
- absence of parenchymal damage
What causes Postrenal azotemia?
- urine flow is obstructed idstal to kidney
What is the term for when azotemia begins showing clinical signs and symptoms with the abnormal labs?
Uremia
What is Nephritic syndrome?
- glomerular disease dominated by acute onset of gross or microscopic hematuria with dysmorpihic RBC’s and rec cell casts on UA, diminished FGR, proteinuria, and htn
- inflammation in the glomeruli
What characterizes Nephrotic syndrome?
- due to glomerular disease characterized by heavy proteinuria more than 3.5 gm/day
- also hypoalbuminemia, severe edema, hyperlipidemia, and lipiduria
What characterizes Acute Kidney Injury?
- rapid decline in GFR, within hours to days, also presents with dysregulation of fluid and electrolyte balance & retention of metabolic waste products
- severe forms can present as oligouria or anuria
What defines CKD?
- diminished GFR persistently less than 60 for 3 months from any cause &/or albuminuria
Renal tubular defects are doinated by ___, ___, and ____.
Renal tubular defects are doinated by polyuria, nocturia, and electrolyte disorders.
What causes renal tubular defects?
- result of disease that directly affect tubular structures or those that cause defects in function
What characterizes UTI’s? (whats found in urine)
bacteriuria and pyruia
What are the manifestations of nephrolithiasis?
- spasms of severe pain known as renal colic
- hematuria
Most commonly CKD is the end result and major cause of death from renal disease in what two diseases?
Diabetes and hypertension
What collagen makes up the GBM?
Type IV
What causes hypercellularity in inflammatory diseases of the glomerulus?
- proliferation of mesangial or endothelial cells
- Infiltration of leukocytes
- this in combination with proliferation of mesangial or endothelial cells in known as endocapillary proliferation
-
Formation of crescents
- accumulation of leukocytes and mesangial/endothelial cells
- plasma proteins leak into urinary space and are exposed to procoagulatnts leading to fibrin deposition- this is trigger for crescent formation but true mechanism is unknown
What are the four basic tissue reactions to glomerulopathies?
- hypercellularity
- basement membrane thickening
- hyalinosis
- sclerosis
What are the three ways thickening of glomerular basememnt membrane is seen on EM?
- deposition of amprphous electone dense material such as immune complexes on BM, could also be fibrin, amyloid, cryoglobulins, and fibrillary proteins
- Increased synthesis of protein components of basememtn membrane
- FOrmation of additional layers of basement membrane
What is hyalinosis and how does it look under light microscopy?
- accumulation of material that is homogenous and eospinohilic
- If extensive the depositis can obliteralte lumens of the glomerular tuft
What is sclerosis? What parts does it involve in the kidney?
- deposition of extracecllular collagenous matrix confined to mesangial areas
- can be confined to mesangial areas (diabetic glomerulosclerosis) or inolve capillary loops
What cell types are critical for the glomerular filtration barrier and if injured lead to leakage of proteins into urinary space?
Podocytes
What are the two types of antibody associated injuries in the kidney? Which one is predominate?
- Abs reacting within the the glomoerulus
- major form of injury- not circulating like previously thought
- depositon of circulating Ag-Ab complexes in glomerulus
What is the “classic example” of glomerular injury resultilng from the locatl formation of immune complexes? This disorder is an AI disease caused by antibodies to tissue components with an unclear trigger
Membranous nephropathy
What antigen underlies most cases of primary human membranous nephropathy?
PLA2R aka M type phospholipase A2 receptor
What kind of immune deposition will be seen on immunoflourescence with membranous nephropathy?
Granular
Secondary forms of membranous nephropathy can be experimentally induced by ___&___.
drugs and graft vs host disease
What kind of immunoflourescent pattern will be seen in anti-glomerular basement membrane induced glomerulonephritis?
Diffuse linear pattern
What other basement membranes do anti GBM antibodies corss react with?
lung alveoli (good pastures)
What complement pathway is activated in dense-deposit disease aka membranoproliferative glomerulonephritis?
alternative complement pathway
How do neutrophils cause damage to kidneys and what brings neutrophils in?
- they enter glomerulus as result of complement activation and Fc mediated activation
- they release oxygen free radicals and arachidonic acid metabolistes which reduce GFR
How do platelets contribute to glomerular injury?
release eicosanoids and other mediators that contribute to cascular injury and proliferation of glomerular cells
How do resident glomerular cells contribute to injury of kidney?
- mesangial cells produce inflammatory mediators, ROS, chemokines etc.. that initiates inflammatory responses
____ stimulates mesangial cells to produce oxidants, proteases, and other mediators. In the absence of neutrophils ___ can cause proteinuria.
C5b-C9 stimulates mesangial cells to produce oxidants, proteases, and other mediators. In the absence of neutrophils C5b-C9 can cause proteinuria.
What growth factor is involved with mesangial cell proliferation?
- PDGF
Loss of what cells with a limited capacity to replicate are features of glomerular injury including focal and segmental glomerulosclerosis and diabetic nepropathy.
Podocytes
Losing what structure in the glomerular basement membrane is key to proteinuria occuring?
normal slit diaphragms
What mutations cause rare hereditary forms of nephrotic syndrome?
- nephrin
- podocin
- both components of slit diaphragm
What happens when GFR is reducced to around 30-50% of its normal function and nephrons are destroyed?
Progression to ESRD will occur over time at a steady rate
What is focal segmental glomerulosclerosis?
- progressive fibrosis involving portions of glomeruli that develops after many types of renal injury and leads to proteinuria and functional impairment
What initiates the glomerulosclerosis?
adaptive change by the unaffected glomeruli of the diseased kidney
What is the most successful intervention to FSGS?
Renin angiotensin system inhibitors which will reduce intraglomerular htn
What is tubulointerstitial fibrosis?
- Tubular damage and interstitial inflammation and is a component of many of many acute and chronic glomerulonephropathies
What is Acute proliferative glomerulonephritis? (aka poststreptococcal, postinfectious glomerulonephritis)
- diffuse proliferation of glomerular cells associated with influx of leukocytes, lesions are usually caused by immune complexes
What is poststreptococcal glomerulonephritis?
- immune complexes containing streptococcal antigens and specific antibodies formed din situ
- appears 1-4 weeks after streptococcal infection most frequently in kids aged 6-10
What will strep antibodies and serum complement levels be in poststreptococcal GN patients?
- elevated titers of Abs against strep antigens
- serum complement levels are low showing that activation and consumption of complement is occuring
What is the streptococcal angigenic componenet responsible for the immune reaction in post streptococcal GN?
Streptococcal pyogenic exotoxin B (SpeB)
Describe the histology seen with Poststrep GN.
- enlarged hypercellular glomeruli
- Electron microscopy shows amorphous electron dense deopsits on epithelial side of membrane and appearance of humps
What are the signs of a kid developing PSGN?
- malaise
- fever
- nausea
- oligouria
- hematuria (cola colored)
- 1-2 weeks after recovery from sore throat