Hepatitis Flashcards
What is hepatitis?
a complex disease that involves inflammation of the liver
What causes hepatitis?
- microbes (parasites, viruses, bacteria, fungi), especially viruses
- drugs (hepatotoxic drugs - whether prescription, OTC, illicit)
- autoimmune (low incidence)
What causes hepatitis A, B and C?
Hepatitis A, B and C viruses.
How is hepatitis A spread?
oral-fecal route
How is hepatitis B spread?
saliva, sex, serum/blood products
How is hepatitis C spread?
blood and blood products, possible to be spread through sex
What is the incubation period for hepatitis A?
15-50 days
What is the incubation period for hepatitis B?
28-160 days
What is the incubation period for hepatitis C?
15-160 days
Which forms of hepatitis can have carrier states?
- no carrier state for hepatitis A
- sometimes carrier state for hepatitis B
- often carrier state for hepatitis C
Which forms of hepatitis are chronic?
- hepatitis A is usually acute, not chronic
- a small percentage of hepatitis B is chronic (10-15%)
- hepatitis C is most often chronic (80% of cases), with a pattern of exacerbation and remissions
What problem often results from hepatitis C?
cirrhosis
What are the two mechanisms of injury that occur in hepatitis?
1) immune response causes inflammation and necrosis (this damages hepatocytes as well as blood vessels and ducts)
2) viral injury - the virus targets hepatocytes and causes them to lyse, decreasing liver function
What lab tests would be abnormal in someone suffering hepatitis?
ALT and AST are liver enzymes that escape into the blood when hepatocytes are damaged. These will be elevated in a person suffering hepatitis.
How long does it take the liver to heal after it has been damaged by hepatitis virus?
Around 4 months
The symptoms of viral hepatitis are split into three phases - what are they?
1) prodromal stage
2) clinical stage (5-10 days after the prodromal stage)
3) recovery stage
What are the symptoms of viral hepatitis that occur during the prodromal stage?
- lack of energy, lethargy, myalgia
- fever
- abdominal pain (due to hepatomegaly, the inflamed liver stretches the liver capsule causing pain)
- anorexia, nausea and vomiting
What manifestations occur during the clinical stage of viral hepatitis?
- previous manifestations worsen (lethargy, fever, abdominal pain, anorexia, nausea and vomiting)
- jaundice (from accumulation of bilirubin since liver breaks down bilirubin further to make bile)
- pruritis (from deposition of bile salts in the skin)
What occurs during the recovery stage of viral hepatitis?
- acute manifestations subside in the first few weeks
- complete recovery needs 4 months/16 weeks (time required to regenerate hepatocytes)
How is hepatitis treated?
minimize liver workload to allow hepatocytes ability to regenerate:
- rest (decrease energy requirement)
- change diet (small meals high in calories, limit fat content so liver doesn’t have to make so much bile)
- NO alcohol or other hepatotoxic drugs
- relieve symptoms (ex. pruritis)
- post exposure prophylaxis (PPE, increase hygiene to prevent spread, for Hep A & B can give antibodies or vaccine, for Hep C give antiviral drugs)
What is autoimmune hepatitis?
a severe, chronic form of hepatitis
What causes autoimmune hepatitis?
complex trait:
- involves HLA genes on chromosome 6 as well as other genes
- involves an environmental trigger (viruses, chemical agents)
What is type 1 autoimmune hepatitis? What antibodies are involved?
- more common form
- 30% of cases are females under 40 yrs
- the antibodies inflict damage to the liver: antinuclear antibodies (ANAs) target all cells with DNA, RNA, and anti-smooth muscle antibodies target the smooth muscle in blood vessels and ducts in the liver
What is type 2 autoimmune hepatitis? What antibodies are involved?
- most often affects kids 2-14 yrs old
- 2 different antibodies:
1) antibodies against cytosol
2) antibodies against microsomes
