Renal Pathology Flashcards
What are the four main components of the kidney?
- Glomeruli
- Tubules
- Interstitium
- Vasculature
The ______ is a network of capillaries between the afferent and efferent arterioles.
Glomeruli
The _____ arteriole brings blood to the capillary bed; whereas, the _______ arteriole drains blood away from the capillary bed.
afferent
efferent
a = arrives at capillary bed e = exits from the capillary bed
What are the three layers of the capillary wall in the glomeruli?
endothelium
basement membrane
epithelium (lining the urinary space)
Epithelial cells have many _______ from the cell body that connect to the basement membrane.
finger-like projections (podocytes)
A membrane, called the _______, connects the adjacent processes and is important in preventing proteinuria.
slit diaphragm
The capillary wall is permeable to water and small molecules. What is is impermeable to?
albumin and larger proteins
What are the supporting cells within the capillary bed?
mesangial cells (connective tissue)
What is the purpose of the tubules of the kidneys?
the filtrate from the glomeruli travels through the system of tubules and the tubular epithelium which reabsorbs or secretes particular substance = formation of urine
The interstitium is formed by ____ and _____ between the tubules and glomeruli.
collagen and blood vessels
What is “azotemia?”
elevated blood urea nitrogen (BUN) and creatine (breakdown of skeletal muscle) due to a decreased Glomerular Filtration Rate (GFR)
Azotemia PLUS other clinical symptoms (gastroenteritis, peripheral neuropathy, dermatitis, acidosis, pericarditis, hyperkalemia) = _______
uremia
What are the three major clinical renal syndromes?
- Acute Nephritic Syndrome
- Nephrotic Syndrome
- Acute Renal Failure
Which renal syndrome is characterized by mild/moderate proteinuria, hematuria, and hypertension?
Acute Nephritic Syndrome
Which renal syndrome is characterized by severe proteinuria? What is “severe?”
Nephrotic Syndrome
>3.5 grams per day
**Nephrotic...NAPHROTIC** N a+ decrease (hyponatremia) A lbumin decrease (hypoalbuminemia) P roteinuria >3.5g per day H yperlipidemia R enal vein thrombosis O rbital edema T hromboembolism I nfection (loss of immunoglobulins in urine) C oagulability (loss of ATIII in urine)
Severe proteinuria that is characteristic of Nephrotic Syndrome will result in severe ______.
Edema
True or False: Nephrotic syndrome is characterized by severe proteinuria and hyperalbuminemia.
False…HYPO-albuminemia (low serum albumin)
What are the clinical signs of “acute renal failure?”
- acute onset of azotemia (high levels of nitrogen containing compounds)
- Oliguria (reduced urine) or Anuria (no urine)
Which is more common: Autosomal Dominant Polycystic Kidney Disease or Autosomal Recessive Polycystic Kidney Disease?
Dominant (adult) is more common= 1 in every 500- 1000 people)
Recessive (childhood) is seen in 1 out of every 20,000 live births
What is the clinical presentation of Autosomal Dominant Polycystic Kidney Disease?
MULTIPLE EXPANDING CYSTS in both kidneys
- gradual onset of renal failure (account for 10% of failures)
- Urinary tract hemorrhage (hematuria)
- Pain
- Hypertension
- Urinary Tract Infection
Autosomal Dominant Polycystic Kidney Disease effects the ______ gene on chromosome ______.
PKD1
chromosome 16
What is the defective protein in Adult Polycystic? What is the defective protein in Childhood Polycystic?
Adult : Polycystin-1
Child: Fibrocystin
_____ of patients of Adult Polycystic Disease will have cysts in the _____. Where might they develop saccular aneurysms (30% of the time)?
1/3 = in the liver
may develop “berry” aneurysms in the Circle of Willis (30%)
With polycystic kidney disease (adult), what is the gross pathology of the kidneys?
VERY LARGE… up to 4 kg (normal is ~0.2kg)
-filled with cysts arising from every part of the tubular system
When do Adult Polycystic patients begin to notice symptoms?
they begin to get “flank pain” around the 4th decade with hypertension, UTI, and hematuria
When does renal failure occur in those patients with Autosomal Recessive Polycystic Kidney Disease?
infancy - several years of age (rare)
True or False: In both the dominant and recessive forms of Polycystic Kidney Disease, the cysts can arise from any part of the tubular system.
False:
dominant = all levels of the nephron
recessive = collecting tubules in cortex/medulla
Which gene is effected in Dominant Polycystic Kidney Disease? Which gene is effected in Recessive Polycystic Kidney Disease?
Dominant: PKD1
Recessive: PKHD1
True or False: Cysts associated with Recessive Polycystic Kidney Disease are all uniform-sized large cysts.
False,
uniform size, SMALL
What are the mechanisms of glomerular injury?
- Immune Complex deposits in glomerular basement membrane (GBM) or mesangium– complexes active complements which will cause damage
- anti-GBM antibody
- epithelial and endothelial cell injury
What are three mechanisms for pathologic evaluation of kidney biopsies?
- Light Microscope
- Immunofluorescence
- Electron Microscopy
Which stains are used to detect basement membranes?
PAS
Methenamine Silver
Which stain is used to detect collagen?
Trichrome Stain
Which method of evaluation is used to identify immune complexes, epithelial cell changes, basement membrane morphology and other changes?
“changes” is the key word = use electron microscopy
What are the patterns of deposition of immune complexes as seen through immunofluorescence microscopy?
- Circulating Immune Complex Deposition = granular and spotty
- anti-GBM = linear
could have a mix of granular and linear = antibody against glomerular antigen
What is the most obvious clinical sign of Nephrotic Syndrome?
Severe Edema (from heavy proteinuria) aka: "anasarca"
What are the four causes of Nephrotic Syndrome?
- *Know this**
1. Minimal Change Disease (children)
2. Focal Segmental Glomerulosclerosis (adults)
3. Membranous Nephropathy
4. Nodular Glomerulosclerosis (diabetes)
What is the most common cause of nephrotic syndrome in children?
Minimal Change Disease (accounts for 2/3 of cases)
What is the pathology of nephrotic syndrome?
Foot Process Effacement - “busted down” processes diminish the ability to hold epithelium together
- glomerulus appears normal
- no immune complex deposition
True or False: Children with Minimal Change Disease show a poor response to treatment with corticosteroids.
False, GOOD response to corticosteroids (especially children)
What are the most common cause of adult nephrotic syndrome?
Focal Segmental Glomerulosclerosis
Membranous Nephropathy*** (THE most common)
Do adults with Focal Segmental Glomerulsclerosis show a positive response to corticosteroids?
NO! poor response
-renal failure after 10 years in 50% of patients
Focal Segmental Glomerulosclerosis may be ____, _____, or _____.
Primary (idiopathic)
Secondary (to another disease)
Familial (genetic)