Lecture 41 - hepititis Flashcards
viral hepatitis
- 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
Most common cause of hepatitis
- alcohol - most common
- viral, drugs, autoimmune ec.t
Viral - hepatitis virus, epstein barr virus however there are other problems with this
Hep A
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
Hep B
- 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
Hep C
- 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
Hep A transmission
get vaccine before travel
most common from travel
Clinical features
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
Clinical features
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