Lecture 19 - Renal Disease 1 Flashcards
what are glomeruli?
network of capillaries between afferent arteriole (bringing blood to the capillary bed) and efferent arteriole (drains blood away from capillary bed)
what does the capillary wall consist of?
endothelium, basement membrane, and epithelium (lining the urinary space)
what part of the glomeruli connects adjacent processes (called the slit diaphragm) and is important in preventing proteinuria?
membrane
the capillary wall is permeable to water and small molecules and impermeable to _____ and _____ proteins
impermeable to ALBUMIN and LARGER proteins
the capillaries are supported by connective tissue called what?
mesangium
what part of the kidney resorbs some substances and secretes other substances, eventually forming urine
tubular epithelium
what part of the kidney is formed by collagen and blood vessels between the tubules and glomeruli
interstitium
the ______ arterioles supply the capillary bed around some of the tubules (vasa recta)
efferent arterioles
*Absence of blood flow through the glomeruli reduces oxygen delivery to the tubules
what is azotemia?
elevation of the blood urea nitrogen (BUN) and creatine levels, due to decreased filtration of blood through the glomeruli (decreased glomerular filtration rate)
what is uremia?
association of azotemia with clinical signs and symptoms, including gastroenteritis, peripheral neuropathy, pericarditis, dermatitis, hyperkalemia, and metabolic acidosis
what is acute nephritic syndrome?
results from glomerular injury and is characterized by acute onset hematuria, mild to moderate proteinuria, azotemia, and hypertension
what is nephrotic syndrome?
glomerular syndrome characterized by heavy proteinuria (>3.5 grams per day), hypoalbuminemia, severe edema, hyperlipidemia, and lipiduria
what is acute renal failure?
acute onset of azotemia with oliguria (or anuria)
what is the prevalence of autosomal dominant (adult) polycystic kidney disease?
1 out of every 500-1000 people
what are the two examples given of congenital cystic renal disease?
- autosomal dominant (adult) polycystic kidney disease
2. Autosomal recessive (childhood) polycystic kidney disease
what is the clinical presentation of autosomal dominant (adult) polycystic kidney disease?
characterized by multiple expanding cysts in both kidneys
-Gradual onset of renal failure in adult, urinary tract hemorrhage (hematuria), pain, hypertension, UTI
what is the etiology of autosomal dominant (adult) polycystic kidney disease?
defective gene is PKD1 (in 90% of families) located on chromosome 16
*The gene encodes of polycystin-1
in autosomal dominant (adult) polycystic kidney disease, what ratio of patient have cysts in the liver and aneurysms may develop where?
1/3 of patients have cysts in liver
aneurysms may develop in the CIRCLE OF WILLIS (intracranial)
in regard to the pathology of autosomal dominant (adult) polycystic kidney disease, up to how large can the kidneys get and what arises in every part of the tubular system?
-very large (up to 4 kg) kidneys with numerous cysts that arise in every part of the tubular system
what is the prevalence of autosomal recessive (childhood) polycystic kidney disease?
1 in 20,000 live births
what is the clinical presentation in autosomal recessive (childhood) polycystic kidney disease?
renal failure develops from infancy to several years of age - it is rare
autosomal recessive (childhood) polycystic kidney disease is due to mutations in what gene?
PKHD1 gene
what is the extrarenal pathology of autosomal recessive (childhood) polycystic kidney disease?
almost all have liver cysts and progressive liver fibrosis
what is the pathology in autosomal dominant (adult) polycystic kidney disease?
numerous small uniform-size cysts from collecting tubules in cortex and medulla
what are the mechansisms of glomerular injruy in glomerular diseases?
- Immune complex deposits in glomerular basement membrane (GBM) of mesangium. These may result from circulating immune complexes that deposit in the glomerulus or circulating antibodies directed against glomerular components or non-glomerular antigens “planted” in the glomerulus
- Epithelial and endothelial cell injury
what are the 3 pathologic evaluations of kidney biopsies?
- light microscopy
- immunogluorescence
- electron microscopy
what is the most common cause of nephrotic syndrome in children?
minimal change disease
*Good response to treatment (esp. in children)
what is the pathology in minimal change disease
normal-appearing glomeruli by light microscopy
- no immune complexes
- electron microscopy demonstrates effacement of epithelial cell foot processes
what is the pathology of focal and segmental glomerulosclerosis?
- Partial (segmental) sclerosis of some (focal) glomeruli characterized by increased mesangial matrix collagen with obliteration of capillary loops
- The idiopathic form ha no immune complexes
- It is one of the most common causes of nephrotic syndrome in adults
- may be primary (idiopathic) or secondary to other glomerular diseases, loss or scarring of other glomeruli, or genetic
focal and segmental glomerulosclerosis has poor response to ______ treatment - renal failure in 50% of people after 10 years
corticosteroid
membranous nephropathy (glomerulonephritis) is most common in what age group?
most common in adults age 30-50
membranous nephropathy (glomerulonephritis) may be primary (disease limited to the kidney) or secondary due to what
- infection
- malignancy
- SLE
- drugs
what is the pathology of membranous nephropathy (glomerulonephritis)?
immune complexes in the epithelial side (subepithelial) of the GBM demonstratable by immunofluorrescence and electron microscopy
membranous nephropathy (glomerulonephritis) has a poor response to corticosteroid treatment with what percent developing renal failure in 2-20 years?
40%
what are some characteristics of glomerular disease in diabetes mellitus?
- minimal proteinuria progresses, over 10-15 years, to severe proteinuria
- thick glomerular basement membranes, diffuse increase in mesangial matrix and formation of mesangial nodules (the latter is nodular glomerulosclerosis or Kimmelstiel-Wilson lesion)
what nephrotic syndrome is described:
- most commonly occurs in children 1-4 weeks after streptococcal pharyngitis (other indications as well)
- Pathology: proliferation of endothelial and mesangial cells; infiltration of neutrophils and monocytes; immune complexes in GBM and sometimes in the mesangium
acute postinfectious (poststreptococcal) glomerulonephritis
*progression to chronic renal disease is more likely in adults
what nephrotic syndrome is described:
- usually occurs in children and young adults
- hematuria is noted 1-2 days after non-specific upper respiratory tract viral infection
IgA nephropathy
in IgA nephropathy, what is increased in production?
IgA
Duhhhhhhh
when IgA nephropathy is associated with systemic manifestations (purpuric skin rash and arthritis) it is called what?
Henoch-Schonlein purpura
what is the pathology of IgA nephropathy?
mesangial deposition of immune complexes containing IgA and variable proliferation of mesangial and endothelial cells
-occasionally there is epithelial cell proliferation with crescents
crescentic or rapidly progressive glomerulonephritis may be associated with what?
-antibodies directed against a glomerular basement antigen, deposition of immune complexes, or lack of immune complex deposition (called pauci-immune glomerulonephritis)
what renal disease is described:
- loss of glomeruli and tubules leads to fibrosis
- damaged glomeruli become completely sclerotic (global sclerosis)
- Advanced loss of tubules and glomeruli, the remaining glomeruli develop adaptive changes
- changes eventually lead to further injury and progressive renal failure
chronic (end-stage) renal disease
what renal disease is described: affects the tubules, interstitium, and pelvis
- often secondary to bacterial infection
- infection may spread from urinary bladder, up the ureters and into the renal pelvis and kidney (ascending)
- second but less common route in infection is through hematogenous spread of bacteria
acute pyelonephritis
what is the clinical manifestation in acute pyelonephritis?
sudden onset with pain at the costovertebral angle and systemic evidence of infection
-often there is accomapnying dysuria, frequency and urgency
what is the pathology of acute pyelonephritis?
patchy interstitial and tubular neutrophilic inflammation
what are predisposing conditions that may contribute to the etiolgoy in acute pyelonephritis?
- urinary tract obstruction
- instrumentation
- vesicoureteral reflux
- pregnancy
- gender and age
- DM
- immunosuppression
what is chronic pyelonphrititis characterized by?
mononuclear inflammatory infiltration and irregular scarring
-repeated bouts of acute/ continuous inflammation may lead to this
what is the etiology (types of drugs) of drug induced interstitial nephritis?
- some antibiotics
- NSAIDS
- The pathogenesis involves hypersensitivity reaction to the drugs
what is the pathology of drug induced interstitial nephritis?
- Interstitial infiltration of mononuclear inflammatory cells, often with neutrophils and many eosinophils
- Granulomas may be present
- the glomeruli are not involved in the inflammation
in drug induced interstitial nephritis, large doses of analgesics may lead to what?
interstitial nephritis with papillary necrosis (necrosis of the tips of the medullary pyramids)
what disease is described:
- Clinical - rapid onset of renal failure, reduced urine output, electrolyte imbalances, manifestations reversible over a period of weeks as the damaged tubular epithelium regenerates
- Etiology: injury to tubular epithelial cells from ischemia (ie. shock) or a toxin
- Pathology: dilation of tubules, interstitial edema, necrosis of epithelium (often very focal and subtle with ischemic injury, more diffuse with injury from a toxin)
acute tubular necrosis
what are the contributing factors of arterionephrosclerosis?
hypertension and diabetes
*May lead to gradual onset of chronic renal failure
what is the gross appearance of the kidney in arterionephrosclerosis?
- kidneys are symmetrically atrophic, with moderate reduction in size
- the kidney surface has an even fine granulairty and the cortex is thin
what are the histopathological features in arterionephrosclerosis?
- Narrowing of the lumens of arterioles and arteries caused by hyaline type of arteriolosclerosis and fibroelastic hyperplasia of muscular arteries
- tubular atrophy
- interstitial fibrosis
- global sclerosis of glomeruli
hypertension greater than 200/120 mm Hg - occurs in what percent of patients with essential hypertension?
5%
in the clinical manifestations of arterionephrosclerosis associated with malignant hypertension, there is relatively rapid onset of renal failure with increased intracranial pressure leading to what side effects?
- headache
- nausea
- vomiting
- visual impairment
in arterionephrosclerosis associated with malignant hypertension, arterioles show hyperplastic arteriolosclerosis, reducing blood flow and causing ____ of glomeruli
necrosis
in thrombotic thrombocytopenia purpura (TTP) there is acquired defect in _____, a plasma protein that degrades vWF multimers, the large von Willebrand factor components activate platelets under certain conditions
ADAMTS 13
*There is more widespread involvement of other organs in TTP
In hemolytic-uremic syndrome (HUS) endothelial cell injury which in most cases is due to a Siga-toxin from ____ or Shigella. the injury leads to platelet activation
E.coli
*In HUS renal involvement predominates and this disorder most often occurs in childen
what is another name for renal stones?
urolithiasis
stones in urolithiasis, result in what?
-urinary tract obstruction, ulceration of the urothelial lining and bleeding
small stonesmigrate to the ureters and produce what?
intense flant pain
large stones remain in the ____ and may be manifested by hematuria and superimposed infection; what are large stones also referred to as?
pelvis
Also referred to as “staghorn calculi”
*These large stones form a case of the pelvis and calyceal system
stones are unilateral in what percent of patients?
80%
what are the two frequent sites for formation of stones?
within the calyces and pelvis
*Stones may also develop in the bladder
what are the three types of stones?
- calcium
- magnesium ammonium phosphate
- uric acid
why do patients have calcium stones?
patients have increased concentration of calcium in the urine
why do patients have magnesium ammonium phosphate stones?
patients have persistantly alkaline urine, infection with proteus predisposes to these stones
why do patients have uric acid stones?
occur in patients with gout, leukemia (high cell turnover) or persistently acid urine
what are some other causes of hydronephrosis?
- congenital urinary tract obstructions
- enlarged prostate
- neoplasms
- neurogenic bladder
- pregnancy
in renal cell carcinoma how many times more likely are men than females to get this tumor?
2X
2:1 male: female ratio
what are some of the clinical manifestations associated with renal cell carcinoma?
- hematuria
- mass
- pain
- fever
- polycythemia
- paraneoplastic syndromes
what are the risk factors for renal cell carcinoma?
- smoking
- hypertension
- obesity
- cadmium exposure
- von Hippel-Lindau syndrome
where does renal cell carcinoma arise from?
tubular epithelium
*Often reach a large size prior to diagnosis, often invade the renal vein
in renal cell carcinoma, the most common histologic subtype has cells with what characteristics?
very pale or clear cytoplasm (clear cell carcinoma)
What tumor is described: abdominal mass, risk greatly increased in some inherited syndromes, occurs in children ages 2 to 5 years
Wilm’s tumor
what is the pattern in Wilm’s tumor?
triphasic pattern, with epithelial structures resembling primitive tubules or glomeruli, stroma (mesenchymal component) and blastema which recapituates early nephron formation
Wilm’s tumor illustrates ______ formation of renal structures in various stages of renal development
abortive
