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IHD Part 2 306 > Hepatobilary system > Flashcards

Flashcards in Hepatobilary system Deck (85)
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1

Hepatitis: What are the causes of hepatitis? (infectious and non infectious)

infectious:
- viral - most common
- bacterial
- fungal
- parasitic

non infectious
- alcohol
-drugs
-autoimmune
- metabolic diseases

2

Hepatitis: What are the signs and symptoms of hepatitis?

Malaise
Jaundice - elevation of bile in the blood causes
Dark urine
Pale fatty stools
Serum & urine biochemistry, specific serological tests for HepA, B, C, D & E antibodies for viral hepatitis

3

Hepatitis: What is the structure of a virus?

Consist of a strand of nucleic acid, either DNA or RNA, surrounded by a protective protein coat (the capsid).

Sometimes they have a further membrane of lipid, referred to as an envelope, surrounding the protein.

4

Hepatitis: What is a complete virus called?

vision

5

Hepatitis: What are the major hepatitis viruses?

- do we have to know this, ask

6

Hepatitis: What is hepatitis A?

- RNA, belongs to group
Picornavirus

- Genotypes I - VII.
- Four associated with human disease I-III & VII; most being I (80%) & III

Jejunum-blood-liver, bile faeces

2- week incubation followed
by 4-10 day prodrome. Resolves in few weeks

Vaccine – formalin-killed virus

7

Hepatitis: What is the epidemiology of hepatitis A?

1.5 million cases worldwide; 6-7000 cases reported p.a. in UK
Children (3-5 years) often asymptomatic
Important in spread
- severity increases with age

8

Hepatitis: Which antibody is produced the first time a host is exposed to an antigen?

IgM

IgM will eventually decline, and then the host produces IgG, which lasts much longer

9

Hepatitis: Which antibody do you get in a secondary infection?

igG

Detection of IgM indicates acute or primary infection, IgG indicates past infection or immunity.

10

Hepatitis: In which phase is hepatitis A infective?

Asymptomatic phase

11

Hepatitis:What is chronic persistent hepatitis B?

Healthy carriers - can spread but no symptoms

12

Hepatitis: What is a Dane particle?

The whole outer vision (capsule) which is infective of the hep b virus

13

Hepatitis: What is HBE antigen used for?

Detect hep B infection

14

Hepatitis: What does the surface antigen split off to form in hep B?

The tubular and spherical forms

15

Hepatitis: What 4 genes are encoded by the hep B genome?

C, X, P, S

core protein - gene C
Dna polymerase - gene P
surface antigen - gene S
Gene x - regulatory?

16

Hepatitis: how can enzymes be used to determine whether liver cells are abnormal?

Liver cells happen to have lots of AST, ALT, and GGTP inside them. When cells die or are sick the enzymes leak out causing the blood level of these enzymes to rise, which is a way of determining if the cells in question are sick.

17

Hepatitis: What is laboratory diagnosis of hep B focused on?

detection of the hepatitis B surface antigen HBsAg

18

Hepatitis: What antigen is also seen in the initial phase of hep b infection?

hbeag

19

Hepatitis: What is high levels of hbeag an indication of?

HBeAg is usually a marker of high levels of replication of the virus.

The presence of HBeAg indicates that the blood and body fluids of the infected individual are highly contagious.

20

Hepatitis: What is chronic infection of hep b characterised by?

persistence of HBsAg for at least 6 months (with or without concurrent HBeAg). Persistence of HBsAg is the principal marker of risk for developing chronic liver disease and liver cancer (hepatocellular carcinoma) later in life.

21

Hepatitis: What is the epidemiology of hep b?

UK carriage approx. 0.1%
Carriage in Africa and Asia approx. 5%
Transmission; vertical, parenteral, sexual
>108 HBV/ml; 0.000001-0.00001ml blood;
Infection early in life > increased chance of chronicity
10% of chronic infection progress to chronic liver disease
Vaccine – genetically engineered HBsAg

22

Hepatitis:What is hep D caused by?

a ‘defective’ RNA virus which coexists with HBV

23

Hepatitis: What are the features of hep D?

Very small virus
Outer coat derived from HBsAg – cannot survive without HBV.
~5% HBV carriers are HDV positive.

24

Hepatitis: What is the delta antigen of hep D used for?

Used for diagnosis

25

Hepatitis: What hepatitis virus can only occur with HBV?

Hep D

Infection co-incident with HBV
- HDV influenced by replication of HBV
- rarely progressive or chronic

Superinfection on HBV disease
- ideal for rapid HDV replication
- commonly chronic

15 million HDV cases worldwide
- mainly iv drug users in UK

26

Hepatitis:What are the viral features of hep C?

Small enveloped SSRNA virus

Core of genetic material (RNA), surrounded by an icosahedral capsid

Two viral envelope glycoproteins, E1 and E2, are embedded in the lipid envelope - help it to attach to host cells of liver

27

Hepatitis: How is hep c released?

by budding

28

Hepatitis: What is hep c a member of? ( a family)

flaviviruses

29

Hepatitis: What is the epidemiology of HCV?

180 million carriers worldwide
- 5 million in Western Europe
- UK carriage ~0.08% (~40,000)


Transmission
- IV drug abuse needle sticks, tattoos, ear piercing
--80% iv drug users infected
- Previously
--blood products, haemodialysis, transplantation

minor routes - saliva; sexual; vertical

30

Hepatitis: Why is diagnosis of HCV unreliable?

antibody takes 6wk-6mnth to show up in blood) – 97% by 6mnth