Congenital cystic kidney Flashcards Preview

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Flashcards in Congenital cystic kidney Deck (45):
1

• Cortex – usually ~ 1 cm thick, contains

glomeruli, proximal tubules and distal tubule

2

• Medulla – divided into 8-18 medullary pyramids and contains

loops of Henle and collecting ducts

3

On an ultrasound, fat in the kidney will be:

black

4

Collecting duct – receives ~6 distal tubules and enters medulla. Join each other to form ________ which drain into calyx

ducts of Bellini

5

first segment of nephron after Bowman’s capsule. Epithelium with brush border

• Proximal tubule

6

Have a general idea of where different part of nephrons are located

see image

7

How many cells are there per capillary tuft in healthy nephron?

Urine goes from urniary space to: 

1-2 cells per tuft

from Bowmans space to tubules

8

Note difference between the proximal and distal tubule in nephron. 

What does the proximal tubule have on it?

Has brush border

9

What is special about the mesangium?

only place in the body where outside is lined with epithelium

10

• Fenestrated (70-100 nm)
• Negatively charged surface
• Form initial filtration barrier
• Synthesize and maintain GBM

Glomerular Endothelial Cells

11

These make up our secondary barrier:

Basement membrane has what type of charge?

Podocyte foot processes

negative

12

Glomerular Basement Membrane

• Composed of:
•  Main determinants of filtration:

What causes negative charge:
 

Type IV collagen

Size and charge

Heparin sulfate

13

GBM

What is permeable and impermeable of GBM:

 

– Water and cationic proteins of LMW (<70,000) are permeable
– Albumin permeability is limited by its negative charge

14

Podocytes are what type of cell?

*synthesize and maintain _____
• Cytoplasmic foot processes form :
 

Visceral epithelial

GBM 

filtration slit (slit pore)

15

Mesangial Cells

• Cell cytoplasm contains______ filaments
• Cells are surrounded by __________
• Funciton_______
 

myosin

GBM like matrix

Provides structural support

16

• Modulate glomerular filtration and provides structual support

Mesangial Cells

17

Note EM of podocytes, the foot process and endothelium

look at picture

18

What is wrong with this kidney?

Ectopic kidney

19

This is the most common congenital kidney disorder

Often fused at:

Increased incidence with:

Increases risk of:

Horseshoe Kidney
• Most common congenital kidney disorder
• 90% are fused at the lower pole
• Increased incidence with Turner’s syndrome
• Increased risk of infection and kidney stones

20

Autosomal Dominant Polycystic Kidney Disease (ADPKD)

how is it detected?

how often is it seen?

is it unilateral or bilateral?

prenatal ultrasound, palpable mass, untedtected

1 in 4,300 live births

can be uni or bi

21

Autosomal Recessive PKD
• Rare--1:20,000 live births
– More frequent in_______
• PKHD1 gene located on chromosome _____
 

caucasians

6p21

22

What do we see in utero on ultrasound of baby with autosomal recessive PKD?

– large hyperechoic kidneys, oligohydramnios, decreased urine in fetal bladder

23

What is the outcome of babies born with ARPKD?

outcomes/anatomy/features

Enlarged kidneys at birth
• Serious cases incompatible with life– Perinatal mortality 30-50%
• Associated with maternal oligohydramnios
– Potter’s facies
– Pulmonary hypoplasia

24

Main extrarenal manifestations of ARPKD are:

ARPKD
• Main extrarenal manifestations:
–Hepatic fibrosis
– Cholangitis 
– Portal hypertension
• esophageal varices
• GI bleeding

25

ARPKD morphology

size and number of cysts:

kidney is smooth or lobulated:

Location of cysts:

 

 Smooth kidney with numerous small cysts in both cortex and medulla
• Cut section – cylindrical cysts extending radially through cortex 

26

27

• Microscopically – cysts lined by cuboidal epithelium; may see epithelial hyperplasia
• Glomeruli normal

ARPKD

28

How many peopl are affectd with ADPKD (autosomal dominant)

what do we look for in family Hx?

 

• Affects 1:400 - 1:1000 Americans
• Family history absent in 25-40%
–new mutations
– late-onset renal failure

29

ADPKD

• 90% have mutation of______ gene on ____
• Others have mutation of PKD2 gene on chr. 4
• Patients with PKD2 mutations vs PKD1 pts

PKD1

chr. 16

progress to renal failure at a later age than PKD1

30

Cysts in ADPKD

• Abnormal differentiation of_______ cells and high proliferation rate
• Secretion of fluid into cysts and we end up with:

Percent of nephrons with cystic dialation:
 

epithelial

loss of connection to functioning nephrons

1-2% but cysts are HUGE

31

Cysts in ADPKD

•_______ extracellular matrix
•_____ fibrosis

Abnormal

Interstitial

32

Clinical manifestations of ADPKD

• Renal manifestations– hematuria and mild proteinuria and hypertension
– progressive renal failure
• 50% reach ESRD by age 57-73 
– infections
– stones
– pain

33

Two main extrarenal manifestations of ADPKD

• hepatic cysts (40%)
• intracranial aneurysms (10-30%) = Berry aneurysms

• cardiac valvular abnormalities
• arterial aneurysms (aorta, coronaries)
• IVC thrombosis
• inguinal & umbilical hernias
• pancreatic cysts

34

ADPKD: Diagnosis
• Patients present in several different ways:
– symptomatic presentation:

-asymptomatic presentation:


 

-typically flank pain & hematuria
– multiple bilateral cysts noted incidentally on imaging study or 
screening due to family history with ultrasound:

35

In order to be diagnosed with ADPKD in asymptomatic patient

• Age <30:
• Age 30-59: 
• Age >60:

• Age <30: at least 2 cysts
• Age 30-59: at least 2 cysts in each kidney
• Age >60: at least 4 cysts bilaterally

36

ADPKD – Treatment goals
 

• Slow the progression to ESRD
– Control BP and tx infections
• Identify and manage extrarenal manifestations
• Control pain
• Renal replacement therapy when necessary

37

Pt come sin with heaturia. There is no history of family kidney diseasea. She has recurrent UTIs and history of stones. Imaging showsd ilated medullary and papillary collecting 
ducts. Dx?

Medullary Sponge Kidney
• No inheritance pattern
• Dilated medullary and papillary collecting ducts
• Spongy appearance on pyelogram
• Complicated by:
– Recurrent urinary tract infections
– Kidney stones
– Hematuria

38

Whats this nasty nasty?

Medullary Sponge Kidney

39

• Develop in 50% of patients on dialysis and depends on duration of dialysis
– more likely with more years on dialysis
• Usually asymptomatic, but may present with bleeding or pain

Acquired cystic disease

40

41

Describe the cysts seen in acquired cystic disease and their location

• Clear, fluid-filled cysts that are uni- or multilocular cysts
• Cortex (usually), may involve corticomedullary junction and medulla
 

42

Acquired cystic disease is associated with:

• Increased incidence of papillary renal cell carcinoma

43

Indications for a renal biopsy

– Persistent glomerular hematuria
– Persistent nephrotic range proteinuria
– Unexplained renal failure
– Renal transplant rejection

 

44

• Contraindications of renal biopsy
 

 

– Bleeding disorders
– Anatomic abnormalities (e.g. solitary kidney)

45

• Complications of renal biopsy
 

– Self limited gross hematuria (10%)
– Hematoma formation (80% of cases)
– Hemorrhage (1-2% of cases)
• Surgery requiring (0.3% of cases)
– Death (1/8000 cases)