HD8 Hepatitis Flashcards
parenteral vs enteral transmission,
which heps are transmitted with each?
parenteral: via a way over then digestive system (Hep, B , C and D)
enteral: (Hep A and E)
Whats an acute mode of liver damage?
Infection of the hepatocytes with direct killing by effector lymphocytes
What is an effector lymphocyte?
a lymphocyte that has been induced into a form (e.g. cytotoxic Tc cell) capable of mounting a specific immune response
What is the mode of chronic liver damadge?
Low level chronic immune damage with additional direct cytopathic effects (structural changes in host cells that are caused by viral invasion) and the sequelae of chronic damage, fibrosis and repair (cirrhosis)
For Hep A, mention if its relevant, and how it would be manadged or what it is? Acute: Chronic: Carrier: Prevention:
acute: self limiting illness (sorts itself out); hospitalisation may not be neccessary. Rarely fatal
chronic: nil
carrier: nil
Prevention: Vaccination (reduced herd immunity, super-added infeciton)
For Hep B, mention if its relevant, and how it would be manadged or what it is? Acute: Chronic: Carrier: Prevention:
Acute: Self Limiting Illness (resolves spontaneously with or without specific treatment); Hospitalization may not be needed
Chronic: sAg positive (+/- eAg) or negative with ongoing liver damage and abnormal LFTs (liver function rests) (raised ALT) , Cancer risk ++ (is a DNA virus and interacts with oncogenic cells), DNA presence of virus postiive beyond 6 months, fulminant liver failure
Chronic symptoms: features of chronic liver disease, ascites (accumulation of poteint contaning fluid within abdomen) , skin thinning, weight loss, variceal bleeding, can be asymptomatic
Carrier: Vertical transmission; Low risk, high infectivity
Prevention: Vaccine, in preganancy caesarian used
What type of virus is Hep B?
2) What determines symptoms and effects of Hep B?
1) DNA virus (therefore integrates in the human genome)
2) the host response (which is different in different people)
What are responses percentage of the population do you get in the adult population to Hep B?
95% of people will clear the virus normally
5% will fail to clear the virus and develop chronic hepatitis
0.1% will develop fulminant liver failure
What is fulminant liver failure?
2) What pecentage of Hep B patient’s develop it?
severe impairment of hepatic functions or severe necrosis of hepatocytes in the absence of preexisting liver disease
2) 0.1%
What are the risk factors of infection with Hep B in adult infection?
- Sexual transmission (risk relatively high)
- IV drug abuse
- Blood transfusion
- “Soft” blood contact
- Professional Exposure
What is the clinical course of adult infection wiht Hep B?
Incubation period” up to 6 weeks
“Flu-like” symptoms 1-2 weeks
Jaundice (other symptoms resolve) 2-4 weeks
Resolution (or continuation= chronic)
When is Hep B defined as chronic and not acute?
at 6 months
2) risk of developing cirrhosis and hepato-cellular carcinoma.
What is the acute symptoms of hep B?
- Lethargy
- Jaundice & dark urine
- Liver pain
What is the chronic symptoms of hep B?
- General Features of Chronic Liver Disease
- Ascites (accumulation of protein-containing (ascitic) fluid within the abdomen)
- Skin thinning
- Weight Loss
- Variceal Bleeding
- Can be totally asymptomatic
What are the Liver function tests results from Hep B?
Alkaline phosphatase (increase) Biliruben (increased) alanine aminotransferase (ALT) (increased) Albumin (decreases) PT (increased)
true or false
Degree of elevation of ALT and bilirubin predicts
severity of Hep B:
False
What is the normal range of PT and INR?
you are not taking blood thinning medicines, such as warfarin, the normal range for your PT results is: 11 to 13.5 seconds. INR of 0.8 to 1.1.29
What antigens are looked at to detect Hep B? What does their presence mean?
HepBsAg (surface antigen) marker of viral presence present in acute and chronic disease and carrier state
HepBeAg (e antigen) marker of degree of viral load in chronic disease and carrier state
What antibodies are looked at to detect Hep B? What does their presence mean?
HepBsAb (surface antibody) Marker of immunity
(nb vaccinated patients)
HepBeAb (e antibody) Markers of low risk in chronic
HepBcAb (core antibody) hepatitis patients
Describe results for patients with acute Heb B:
1) sAg
2) eAg
3) eAb
4) sAb
1) positive
2) positive
3) negative (but will develop when disease resolves)
4) negative (but will develop when disease resolves)
What is looked for to screen for patients with Hep B?
2) what do the positive and negative results of this mean?
Screen patients by sAg.
-ve = no Hep B
+ve =do full markers to assess risk
What % of chilren born by vaginal delivery will be infected and become chronic carriers?
50%
Children born by vaginal delivery that become infected or carriers of Hep B:
will not develop liver disease (they have no immmune response to the virus)
true
Children born by vaginal delivery that become infected or carriers of Hep B:
• will not be infectious (very)
false
Children born by vaginal delivery that become infected or carriers of Hep B:
•• might be at risk of liver cancer
true
Whats the aim of therapy of Hep B?
The aim of therapy is to clear HBV in patients with chronic hepatitis thereby reducing the risk of cirrhosis (and HCC= Hepatocellular carcinoma)
What antivirals are used in therapy of Hep B?
interferon, lamivudine, adefovir
What immuno-stim is used in Hep B therapy?
interferon
What operation can a chronic Hep B pt undergo?
2) What is the issue with this?
1) liver transplant
2) high re-infection risk
Is Hep C
RNA or DNA?
RNA
Does Hep C integrate into the human genome?
no
Is Hep C infection the same in every patient?
yes, it follows a single clinical pattern (chronic)
What is the normal host response to Hep C?
Viral clearance with clinical resolution (no acute illness) occurs in less than 20% of infected individuals
What is the excessive host response to Hep C?
doesn’t occur
What is no host response to Hep C?
No equivalent carrier state? So are they just a carrier?
What is inadequate host response to Hep C?
Chronic hepatitis (viraemic ++ (a virus or viruses present in the bloodstream))
What are the 3 risk groups to Hep C?
1) iv Drug Abusers
2) Receivers of blood products
3) Factor X (unknown)
What are the presentations of Hep C?
- Abnormal LFT ? cause
- iv drug abusers for screening blood donors
- screening of recipients of blood products
What is the prevention of Hep C?
risk modulation NOT vaccination
What is advice to families of Hep C pt?
“casual” transmission is rare
What s the treatment of Hep C?
Interferon 3MU 3x/week for 12 months. +/- Ribavirin (old)
Novel tx:
-previ=protease inhibitor= affects replication and assembly
-asvir=NS5A = inhibitorsaffects replication and assembly
-buvir= NS5B inhibitor = affects nucleotides and non-nucleotides
There are novel protease and polymerase inhibitors
What is the result of Hep C treatment?
2) what are the risks are increased in Hep C in a patient with an inadequate host immune response ?
95% clearance in
2) chronic hep and hepatocellular carcinoma
What are the pros of Hep C treatment?
Potential Cure (cf HIV)
reduced progression to cirrhosis even if virus not cleared
? Reduced risk of HCC even if virus not cleared
What are the cons of Hep C treatment?
Sustained response rate less than clinical trails is 95%, but lower in practice
Length and nature of treatment
Side effects
Costs
How does Hep E present?
Acute hepatitic episode
Severe in pregnant women
Fulminant liver failure
How is Hep E investigated?
ALT thousands (low levels are normal) Hep E serology (slow
How is Hep E prevented?
Risk modulation NOT vaccination
What advice is given to families of Hep E pt?
Food hygeine (barbecue & pigs)
What is the treatment of Hep E?
Supportive & Transplant rarely
What is the risk of viral hep to pts in dentistry?
- Bleeding in the patients with chronic liver disease
- (platelet aspects and clotting factor aspects)
- Infection in a non-infected patient
What is the risk of viral hep to dentists?
infection by an infected patient
