Week 17 - Hepatitis C Flashcards

(58 cards)

1
Q

Outline Herpes Simplex Type 1 and 2

A

Herpes simplex type 1
Cutaneous exposure
Belongs to Herpesviridae family of viruses
Acute infection
Do you clear infection?
Establishment of latent infection in dorsal root ganglia innervating the mucosal areas involved in acute infection
Virus never eliminated
Why are symptoms severe in some cases? – immunodeficiency
Herpes simplex type 2 genital herpes

Diagnosis is usually based on symptoms.
Genital infection, take a swab and send for laboratory testing using PCR for DNA amplification

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2
Q

Outline Varicella Zoster virus

A

Varicella Zoster virus chickenpox Also belongs to the Herpesviridae familyDiagnosis of chickenpox is usually based on symptoms. Can take a swab of the base of the ulcer and carry out PCR.Virus Latency in dorsal root gangliaReactivations in shinglesOnce infected virus is never completely cleared

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3
Q

Outline Cytomegalovirs

A

Very common, stays in lymphocytes

Can cause hearing, visual, intellectual impairment, can be passed to foetus

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4
Q

Outline Epstein Barr vieus

A

Causes glandular fever, in herpesviridae group, latent in lymphocytes, passed through saliva, blood, semen
Can diagnose with IgM antibody test

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5
Q

Key structural points on viruses

A
Size - small
You can’t see the virus under light microscope. Need electron microscope
Shape – a large number are icosahedral
Can be enveloped or non enveloped
The nucleic acid – DNA or RNA
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6
Q

How do Hepatitis B viruses evade immune response?

A

Immune response targets surface antigen, other antigens are able to cause infection as not all viruses are complete and they are able to escape detection

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7
Q

What are the cancer causing mechanisms of Hepatitis B?

A

Hepatitis B virus no oncogenes. How does it cause cancer?
Long latency period between HBV infection and the development of hepatocellular carcinoma
Integrated viral DNA may cause the cell to produce altered proteins. These altered proteins in turn can activate oncogenes
Alternatively increased chronic inflammation may increase cell turnover and regeneration. This can lead to activation of cellular growth genes

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8
Q

What is the strongest risk factor for Hepatitis C?

A

Drug use / sharing needles

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9
Q

What does a patient require to be infected with Hepatitis D?

A

Co-exists with Hepatitis B virus

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10
Q

Examples of viruses your body can clear

A

Common cold – rhinovirus
Influenza
Diarrhoea – rotavirus norovirus
Sore throat - adenovirus

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11
Q

What is key in vaccine design?

A

Knowing which antigens are key for attachment to other cells and targeting those

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12
Q

List viruses that cause human disease

A

PICTURE IN FOLDER

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13
Q

Describe the structure of hepatitis B

A

PICTURE IN FOLDER

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14
Q

Describe the structure of hepatitis C

A

PICTURE IN FOLDER

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15
Q

Describe how viruses evade the immune response and cause chronic infection

A

Proteins can change (like flu)
Or different types of the same virus
Humoral and cell mediate immune response both take time so virus is at an advantage
Body attacks surface antigen, but may not attack the more dangerous core antigens

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16
Q

Compare the routes of transmission and risk factors of hepatitis A, B, D, C and E viruses

A

PICTURE IN FOLDER

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17
Q

Describe the long-term complications of chronic hepatitis B

A

The risk for chronic infection varies according to the age at infection and is greatest among young children. Approximately 90% of infants and 25%–50% of children aged 1–5 years will remain chronically infected with HBV. By contrast, approximately 95% of adults recover completely from HBV infection and do not become chronically infected (10).

When chronic, causes hepatocellular carcinoma

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18
Q

Describe the long-term complications of chronic hepatitis C

A

PICTURE IN FOLDER

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19
Q

Simply describe the role of cell mediated immune response in defence against infectious organisms

A

PICTURE IN FOLDER

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20
Q

Why do we need cell-mediated immunity?

A

B-cells are not enough

Need cell mediated to help fight antigens on the INSIDE of the cell (antibodies help prevent binding on OUTSIDE)

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21
Q

What are come intracellular microbes that cell mediated response helps to address? (3)

A

intracellular bacteria (following phagocytosis)
Viruses
Parasites

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22
Q

Types of T cells (4) and roles

A

PICTURE IN FOLDER

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23
Q

How do T cells recognise antigens?

A

Cannot recognise antigens in free form - they need to be taken up and presented by APC

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24
Q

What do T cells recognise on the pathogen?

A

They mostly recognise peptides

A small group recognise antigens that are not peptides

25
Difference in antigen presentation between CD4 and CD8 cells
``` CD4: MHC class II CD8: MHC class I Because of their specific structures ```
26
Describe shape of T cell receptor
PICTURE FROM FOLDER
27
What is the Major histocompatibility complex (MHC)? Where are they found?
Molecules that display peptides from different antigens MHC I: All nucleated cells MHC II: APCs - dendritic cells and macrophages
28
Describe antigen binding process
xxx
29
What is an antigen presenting cells (APCs)?
xxx
30
What is the process for T cell activation? (steps with APCs)
Signal 1 Signal 2 Signal 3 And then what.... XXX
31
What are the different pathways that antigens can be processed by?
Pathogens that live outside the cell | Pathogens that live inside the cytosol
32
How are pathogens that live outside the cells processed? (and what type of T cell, what is the pathogen likely to be?)
CD4, Bacteria | COPY PASTE SLIDE (add the invariant chain, HLA-DM role)
33
How are pathogens that live inside the cells processed? (and what type of T cell, what is the pathogen likely to be?)
CD8, virus | LOOK AT SLIDE
34
What are CD4 cells?
H-helper 1 and 2, Th17, Th1 - help phagocytes to kill ingested microbes Th2: XXX FROM SLIDE
35
What are CD8 cells?
xxx
36
Types of Regulatory T Cells?
xxx
37
How do we differentiate between Th cells?
They produce different cytokines Th1 - Intreferon gamma which activate phagocytes (macrophages) and stimulate IgG antibodies (they tell B cells to switch from IgM to IgG)
38
What are some Th1 mediated diseases? (2)
Granulomas, autoimmunity
39
What is the role of Tcells in supporting phagocytosis? Why is this necessary?
xxx | Make them better, especially important if phagocytes can be evades
40
What is the role of interferon in the th1-mediated immune response?
xxx
41
Outline the Th2 mediated immune response
xxx
42
Why are helminths difficult for the body to eliminate
They are too large for phagocytosis | They have a thick coat that is resistant to microbicidal activities of macrophage
43
Outline role of CD8 CTL cells - how do they function? What are the key cytolytic proteins? (2)
xxx
44
What are the general stages of clinical diagnosis of acute viral hepatitis?
Stage 1 - Usually asymptommatic, virus replicating Stage 2- Range of symptoms, many general Stage 3 - Worsening symptoms, hepatomegaly, dark urine and light stool Stage 4 - Symptoms and jaundice resole, liver enzymes return to normal
45
Factors required for clinical diagnosis of viral hepatitis
COPY AND PASTE FROM SLIDE
46
Laboratory tests for hepatitis
COPY AND PASTE FROM SLIDE
47
Outline the course, symptoms, prognosis, vaccination / treatment options for HEPATITIS A
PICTURE IN FOLDER
48
Outline the course, symptoms, prognosis, vaccination / treatment options for HEPATITIS B
PICTURE IN FOLDER | Spread via fluids
49
How does age at which HBV acquired affect likelihood of chronic infection?
At birth 90% | To 2-5% over 16yo
50
What is the signficance of picking up HBV surface antigen on test?
Patient as active HBV infection, but you don't know if it is acute or chronic
51
What is the signficance of a 'high infectivity' and 'low infectivity' chronic HBV patient?
Much more likely to develop serious long term complications such as hepatocellular carcinoma
52
If someone has been vaccinated, which one test is positive?
Anti-HBs (everything else should be negative)
53
What are the treatment options for hepatitis B?
Treatable in some patients - only in chronic patients (after 6 months of active infection) Pegylated interferon and/or antiviral agent
54
Outline the course, symptoms, prognosis, vaccination / treatment options for HEPATITIS C
PICTURE FROM FOLDER
55
Outline the course, symptoms, prognosis, vaccination / treatment options for HEPATITIS D
PICTURE FROM FOLDER | Detected by looking for HBV, and then looking for HDV RNA
56
Outline the course, symptoms, prognosis, vaccination / treatment options for HEPATITIS E
E stands for enteric (water bourne outbreaks, can be spread in pork) PICTURE FROM FOLDER
57
What are some other causes of viral hepatitis? (2)
Cytomegalovirus Epstein Barr virus Others??
58
Discuss lifestyle factors to manage viral hepatitis
``` Prevent further damage to liver Avoid alcohol, anything that can damage liver (inclu medications) Prevent spread Wash hands, hygiene techniques, careful food preparation No shared needles No donations, blood / organs Inform doctors / dentists / partners ETC ```