Lecture 41 - hepititis

Question 1

viral hepatitis

Answer 1

• Yellow skin due to jaundice
• too much bilirubin, increased production of bilirubin or decreased conjugation in liver, or decreased excretion from liver

-Swollen - odematious, - liver makes proteins, albumin low, and so fluid leaks out (albumin cannot be made as much)

Cannot tell if acute or chornic liver failure

Question 2

Most common cause of hepatitis

Answer 2

• alcohol - most common
• viral, drugs, autoimmune ec.t

Viral - hepatitis virus, epstein barr virus however there are other problems with this

Question 3

Hep A

Answer 3

Hep A - rna, fecal oral route, less common in developed world - never chronic - does not lead to liver fibrosis or cancer
-most are asymptomatic

Hep B - DNa virus, blood borne virus, extremly contagious , acute, chronic, cirrhosis, cancer

• also asymptomatic symptoms
• will get infection if mother passes to baby and will result in chornic infection
• when adults infected, quite uncommon to become chronic

Hep C - rna, blood borne,
acute, chronic, cirrhosis, cancer  
-generally infects adults 
-mostly due to intravenous drug use 
-can cause liver cirhossis and cancer, but less so than hep B

Can cure hep C

Question 4

Hep B

Answer 4

• partially double stranded DNA virus
• enveloped
• hepaptotropic DNA virus
• has a surface protein , as virus replicates in liver there is alot of viral antigen that doesnt get incorportaed into intact viral particles
• this spils out of liver and into blood - can detect this in the blood
• also vaccination against hep B made with this antigen

-hep B uses reverse transcriptase
-drugs can be used against this
-also has an X gene to hyjac hepatocyte cell
to increase protein synthesis ect.
-excess surface antigen made compared to other proteins so spills out into blood

• acute hep b - viral replicaiton for many months, person does not know they are infected
• then in adult the cytotoxic t cell reponse occurs and get damage to liver cells , and can overcome this - get jaundice ect. now

First thing we do - test surface antigen (doesnt tell us if acute or chornic)
early antigen - found ealry in replication cycles - means they are highly infectious
-only make antibodies against surface antigens if you have already been vaccinated or if have been infected and cleared the virus
-anti - core antibodies- someone with acute often has this
-someone with acute hiv will have very high levels of dna in blood

Question 5

Hep C

Answer 5

• viral repliacation inside liver cell does not damage liver cell
• normally destorys the host cell
• it is the cytotoxic T cell response that cause damage
• immune system finds it hard to clear
• dna is not stored in nucleus

Antibody against HCV - doesnt tell us weather if you had it in the past, or have it now or have cleared it

• do PCR _ then have hep c and shoudl treat to stop spreading and reduec cirrosis
• will have chornci if have eviednce of the hep C surface antigen for more than 6 moths

Question 6

Hep A transmission

Answer 6

get vaccine before travel

most common from travel

Question 7

Clinical features

Answer 7

CHronic hep B - outcoems are not very good 1/5 will develop cirhosis and liver failure
-die in 5 years

Hep C - if someone has acute, treat

Question 8

Clinical features

Answer 8

CHronic hep B - outcoems are not very good 1/5 will develop cirhosis and liver failure
-die in 5 years

Hep C - if someone has acute, treat