Lecture 17 - Liver Pathology 2 Flashcards

1
Q

What are some examples of liver disease associated with metabolic syndrome?

A
  • Non-alcoholic fatty liver disorder (NAFLD)
  • Non-alcoholic steatohepatitis (NASH)

These look like Steatohepatitis and Steatosis under the microscope, but the sufferer is a non-drinker

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which people are most commonly affected by non-alcoholic liver disease?
Which other disorders are associated with it?

A

Middle aged women

Associations:
• Obesity
• Hypertension
• Diabetes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the underlying cause of non-alcoholic, metabolic liver disease?

A

Central obesity: aka big belly
Men: more than 94 cm
Women: more than 80 cm

In Asians it is even less, because they are often shorter

\+ two of the following features:
• Raised serum Triglyceride (TG) level
• Reduced serum HDL cholesterol
• Raised BP
• Raised fasting blood glucose (FBG)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the metabolic and inflammatory cascade of Central Obesity

A

Dyslipidaemia

Systemic inflammation

Endothelial dysfunction → hypertension

Insulin Resistance

NASH / NAFLD

Polycystic ovary syndrome; infertility

Atherosclerosis

Obstructive sleep apnoea

Disordered fibrinolysis

Hypertension

Type 2 Diabetes Mellitus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the different categories of metabolic liver disease?

A
  • Acquired: NAFLD, NASH

* Genetic: hereditary storage diseases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are liver ‘storage diseases’?

Give some examples

A

Genetic metabolic liver diseases

  • Genetic haemochromatosis
  • Wilson’s disease
  • α1-antitrypsindeficiency
  • Tyrosinaemia
  • Glycogen storage disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is genetic Haemochromatosis?

A

Hereditary iron overload

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is Wilson’s disease?

A

Copper overload

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is alpha-1-antitrypsin?

What is it needed for?

A

A protease inhibitor

Needed to inhibit all the proteases released by neutrophils in inflammation

→ If this isn’t controlled more inflammation and fibrosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Compare most common cause of hereditary storage disease cirrhosis in:
• Adults
• Children

A

Adults: Haemochromatosis
• Because adults are using less iron
• More is accumulating

Children: α1-antitrypsin deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the categories of hepatitic liver injury?

A

Infectious
• Viral hepatitis
Immunological
• Autoimmune hepatitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the definition of the ‘Hepatitic histological pattern’?

What are the causes of Hepatitic histological pattern?

Describe the morphology

A

“Diffuse inflammation of the liver accompanied by features hepatocellular injury and regeneration”

Causes:
• Viral hepatitis
• Idiosyncratic reactions to therapeutic drugs

Morphology:
1. Parenchymal degeneration
• aka damage to liver cells:
• Ballooning hepatocytes

  1. Cell death
    • Apoptosis
    • Necrosis
  2. Inflammatory reaction
    • Mononuclear inflammatory cell infiltration
    • Hyperplasia of Kupffer cells
    • Macrophages
  3. Mesenchymal reaction
    • This is HSCs
  4. Regeneration of hepatocytes
    • Hypertrophy
    • Mitosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the changes to the following in acute viral hepatitis:
• Liver lobules
• Hepatocytes

A

Liver lobules:
• Complete disarray; loss of order
• Inflammatory infiltrate: pigmented macrophages
• Sinusoids are hard to see

Hepatocytes:
• Apoptosis
• Necrosis
• Ballooning degeneration
• Regeneration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the features of resolving hepatitis?

How long does the acute stage last?

How long until it is completely resolved?

A

In most forms of viral hepatitis, it starts to resolve after 6 weeks
There will be residual cells for about 3 months

Inflammation remains in the portal tracts

Sinusoids are open again

Still some pigmented macrophages in zone 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the evolution of Acute Viral Hepatitis

A
  1. Early stage
  2. Fully developed stage
    • Parenchymal damage
    • Necrosis
  3. Later stage
    • Still have Pigmented macrophages
  4. Residual changes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are pigmented macrophages and when are they seen?

What does this indicate

A

Seen in viral hepatitis

Macrophages filled with ceroid & iron

Indicates that they are filled with lipids from the plasma membranes of the cells that have just undergone necrosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which types of necrosis are seen in Hepatitic pattern in viral hepatitis?

Describe them

A

Spotty (focal) necrosis
• 2-10 hepatocytes necrosis
• collections of lymphocytes and pigmented macrophages

Confluent necrosis
• en masse death of tracts hepatocytes

Piecemeal necrosis
• Hepatocyte death at interface of connective tissue & liver parenchyma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the three grades of increasing severity of confluent necrosis seen in viral hepatitis?

A

Zonal:
• just in one of the zones

BHN: Bridging hepatic necrosis
• Bridging between two vascular structures (i.e. portal tracts and central veins)

MLN: Multilobular hepatic necrosis
• Lots of neighbouring lobules disappear at once

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the parenchyma of the liver?

A

The hepatocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is pan lobular necrosis?

A

Many or all lobules undergoing necrosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe the order of events that can occur after BHN

A
  1. BHN
  2. Passive septum
  3. Active septum
  4. Bridging fibrosis

and if inflammation continues:

  1. Cirrhosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which malignancies are seen in the liver?

A

Hepatocellular carcinoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Compare progression to cirrhosis in NAFLD & NASH with alcoholic FLD and SH

A

Alcoholic fatty liver disease and hepatosteatosis more likely to develop into cirrhosis:
• Only 3-4% get cirrhosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What percent of sufferers of NAFLD progress to HCC?

A

less than 0.5% go on to get HCC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the end stage of hereditary storage diseases?
Cirrhosis
26
Which inflammatory cells infiltrate in non-alcoholic hepatitis?
Mononuclear cells | Hardly ever neutrophils (as is seen in alcoholic hepatitis)
27
Where is inflammation seen in hepatitis?
* Portal tracts | * Lobules
28
What leads to cell death in viral hepatitis?
Not the virus that kills hepatocytes It is the immune cells that are responsible
29
What happens to bile in acute viral hepatitis
Ballooned cells are unable to secrete bile Bile remains in the cytoplasm → Bile pigment in liver cells
30
What happens in chronic viral hepatitis?
Lasts more than 3 months • Virus persists → Persistent inflammation and hepatocellular injury Most important feature: fibrosis (periportal and bridging) Eventually: → Cirrhosis
31
What is cholestasis? | When is it observed?
Bile plugs | Observed in acute hepatitis
32
What are passive septa?
Collapsing of septa Seen in lobular lesions in more severe cases
33
What is piecemeal necrosis? | Where is the necrosis occurring?
Immune mediated cell death • Lymphocytes reacting against liver cells 'Interface necrosis': • Necrosis occurs at the interface of hepatocytes w/ connective tissue
34
Where are stem cells seen in viral hepatitis?
Around portal tracts | Attempting to regenerate tissue
35
Describe what happens to blood flow in BHN
BHN: Bridging hepatic necrosis • Occurs in viral hepatitis Fibrosis bridges form between portal tracts and ventral veins The blood now has a path go lower resistance between these two structures, and will flow through here. The other regions will be prone to ischemia, because they are no longer getting adequate blood supply
36
What are the differentiating factors in acute and chronic hepatitis?
``` Acute: • Ballooning degeneration of hepatocytes • Bridging necrosis • Steatosis • Inflammatory cell infiltrates (macrophages) • Apoptosis ``` ``` Chronic: • Bridging fibrosis • Steatosis • Lymphocyte aggregates • Macrophage aggregates ```
37
What is seen macroscopically in cirrhosis?
Macronodules all over the liver | • all nodules are within centrimetes in length
38
What is seen macroscopically in HCC?
Green patches | • Bile unable to escape the cancerous cells, because they aren't connected to anything
39
What are the different viruses than can cause hepatitis? Which are the most frequent causative agents of viral hepatitis? Which virus most commonly causes chronic liver disease?
Hepatitis A-E ``` Causative agent of viral hepatitis in order of frequency: • HBV • HAV • HCV Very low: • HEV • HDV ``` Chronic infection: (in order of frequency) • Hep C: 80% • Hep B: 5% • Hep D: 5%
40
Why can't an individual get rid of Hep B infection?
dsDNA genome of the virus is incorporated into the genome of the host Cannot be cured, but can be controlled with drugs
41
How are Hep A & E transmitted?
Faecal-oral route
42
Can Hep C be treated?
Yes | Since about 5 years we have very good treatments that can cure the infection
43
How are Hep B & C transmitted?
Blood (parenteral) IVDU: Intravenous drug users Hep B: • often sexually transmitted
44
Which viruses do we have a vaccine for?
HBV Don't have a vaccine for HCV
45
What is the prognosis for Hep A & E? What about Hep B? What about Hep C?
Hep A & E: 99% recovery Hep B: 95% recovery Hep C: 15-20% (80% chronic infection)
46
What are the risk factors for Hep B infection?
``` In order of risk: • Heterosexual intercourse • Injecting drug use • Homosexual activity • Health care workers ```
47
Describe the structural features of the Hep B virus
Genome: dsDNA Envelope HBsAg: Hep B surface antigen HBcAg: Hep B core antigen • aka 'e' antigen • Can circulate in the blood stream • Can cross the placenta
48
Describe the features of HBcAg Why do neonates predominantly get chronic hepatitis?
'e' antigen • Can cross the placenta * Does not cause infection of the foetus * Tolerises the child to the infection * When the child is born, if they swallow some of the blood, they will be tolerant to the virus → Chronic hepatitis * Virus is there, but at lower levels * Not attacking anything
49
Compare acute vs. chronic viral hepatitis frequency in neonates and adults
Acute • Adults: 90% • Neonates: 2% Chronic: • Adults: 10% • Neonates: 98%
50
Describe global prevalence of HBV carrier infection
Highest: • Africa • SE Asia • China Middle: • South America • Russia • Australia Low: • Europe • USA
51
Describe the potential outcomes for HBV infection in adults
90% Recovery A large proportion are in a Healthy carrier state • They do not know they are infected • Transmitting the disease to many people unknowingly
52
What is the major histological sign of HBV infection?
Ground glass hepatocytes
53
Where are HBsAg and HBcAg kept in cells?
HBsAg: cytoplasmic inclusions HBcAg: nucleus
54
Describe reactivation of Hep B in children who got it from their mothers
Reactivation of the virus around age of 25 Immune system has learnt to recognise the virus as foreign The peptide is presented on the cell membrane to CTLs
55
Describe the mechanism of hepatocyte necrosis in HBV infection
1. HBV infected hepatocyte 2. HBcAg presented on HLA class I 3. CD8+ T cell recognises peptide on HLA-1 as foreign 4. CD8+ T cell releases perforins and kills the cell
56
Describe worldwide prevalence of Hep C
High: • Egypt, Africa in general • South America • China
57
What are the sequelae of Hep C infection?
Chronic infection → 30% cirrhosis (20 years) → 15% HCC (30 years)
58
What is METAVIR?
Fibrosis scoring system F0: no fibrosis F1: Stellate enlargement of portal tracts w/o septa F2: enlargement of portal tracts w/ rare septa F3: numerous septa w/o cirrhosis F4: cirrhosis
59
Which drugs can reverse fibrosis?
Anti-fibrotic agents
60
What is autoimmune hepatitis?
Mainly in females HLA-A1 HLA-B8 HLA-DR3 HLA-DR4 High Ig levels Circulating auto antibodies • to smooth muscle • to nuclear antigens
61
How can autoimmune hepatitis be treated?
Patients respond very well to corticosteroids
62
What type of necrosis is seen as a hallmark of autoimmune hepatitis?
Piecemeal necrosis • Lymphocytes • Plasma cell infiltrate Lymphocytes have lost tolerance to liver cells
63
List some of the acquired aetiologies of cirrhosis
``` • Alcoholic • Viral hepatitis • Autoimmune hepatitis • Cryptogenic (don't know the cause) • Primary biliary cirrhosis • Secondary biliary cirrhosis • Drug induced • Toxins (e.g. fungal, alkaloids) • Venous outflow obstruction (obstruction in vena cavae, blood gets backed up to the liver) ```
64
List some risk factors for HCV
* Male gender * IVDU * Heterosexual and homosexual contact
65
When do most deaths due to HCV occur?
Around the ages of 50-80 This is 30 years after exposure, because the infection has been chronic for all this time
66
Describe the changes in prevalence of HCV in Australia over the last 30 years
Epidemic in the late 70's Peaked around 2014 We think it will now start to drop off, because we have a very good curative treatment
67
What is the hallmark of chronic hepatitis?
Fibrosis: • Bridging fibrosis (between portal tracts and central veins) • Periportal fibrosis
68
If hepatitis isn't resolved and becomes chronic, what happens to bridging necrosis?
Becomes bridging fibrosis
69
Which Hepatitis viruses are transmitted by the faecal-oral route? How are the other transmitted?
Faceal-oral: HAV and HEV The others are transmitted parenterally