ACUTE & CHRONIC HEPATITIS Flashcards
Acute hepatitis is defined as…
Acute parenchymal liver damage that resolves within 6 months, or can progress to chronic hepatitis and rarely acute hepatic failure
Chronic hepatitis is defined as…
Hepatitis lasting longer than 6 months. Chronic viral hepatitis is the main cause of chronic hepatitis, cirrhosis and hepatocellular carcinoma.
Who does Hep A (notifiable disease in UK) commonly affect and how does it spread?
Children & young adults. Faecal-oral route and arises from contaminated water and food.
Clinical features of Hep A & E (only acute infection)
Non-specific symptoms ie nausea and anorexia prior to jaundice. Many recover at this stage, commonly children.
After 1-2 weeks, jaundice occurs with dark urine and pale stool. Enlarged liver, splenomegaly. Recovers within 3-6weeks.
What are the investigation (biochemistry, blood test and serology) results in Hep A?
Biochem: Raised AST & ALT precedes jaundice
Bilirubin reflects degree of jaundice. AST reaches maximum 1-2 days after jaundice
Bloods: Leukopenia, raised ESR and prolonged PT
Serology: Anti-HAV IgM = acute infection; IgG antibodies common over 50yrs
What are the management for Hep A infection?
Good hygiene, killed by boiling water for 10 mins.
Active vaccination
How is Hep B transmitted?
Vertical transmission: mother to child during parturition. Mosts common way.
Horizontal transmission: mainly children through abrasions and close contact. HBV can survive on household items.
HBV transmitted via intravenous route (blood transfusion, drug users, tattooists). Sexual intercourse esp MSM. Virus found semen and saliva.
Which HBV antigens are present in blood?
Antigens: HBsAg appears in blood 6 weeks to 3 months after acute infection and then disappears.
Which antibodies are produced against HBV and when?
Antibody: Anti-HBs (surface protein) appears late and indicates immunity.
Anti-HBc (core protein) first antibody to appear. High titres of IgM anti-HBc suggests acute & continuing viral replication. IgM anti-HBc may be the only serological indicator of recent infection before rise in anti-HBs and after HBsAg decrease.
Anti-HBe appears after anti-HBc = related to decreased infectivity.
What are the clinical features of Hep B infections in adults?
Hep B infection in children is likely to be acute or chronic?
If perinatally acquired, Hep B infection is chronic not acute.
In adults, acute infection more common - nausea, anorexia, jaundice, hepatosplenomegaly. Serum sickness-like immunological syndrome i.e. rashes and polyarthritis affecting small joints unto 25% of cases. Fever.
What is the investigation for Hep B?
What are the specific tests for Hep B?
Investigation same as Hep A ==> bilirubin, AST/ALT raised, ESR raised, leukopenia, prolonged PT.
HBsAg cleared rapidly in acute infection so anti-HBc IgM is diagnostic. Patients must be tested for both HBsAg and anti-HBc antibodies if HBV suspected.
What is the prevention of HBV?
Avoid risk factors
Vaccination - HBV vaccine added to UK childhood vaccination programme.
What is Hepatitis D mechanism of action?
How is HDV diagnosed?
Hep D is activated in presence of HBV.
HDV always occurs as co-infection with HBV.
Diagnosis: confirmed by serum IgM anti-HDV in the presence of IgM anti-HBc.
How is Hep C transmitted?
HCV transmitted via blood - v common in haemophilia before blood screening. Common in intravenous drug users.
What is the clinical features of Hep C?
Acute infections mostly asymptomatic. Flu-like symptoms with jaundice and raised serum aminotransferases noticeable in routine blood test. Most patients don’t present till years later with chronic liver disease.
What are the serology/ DNA tests for HCV?
HCV RNA can be detected from 1-8 weeks after the infection.
Anti-HCV antibodies present 8 weeks from infection.
Prognosis of HCV
~90% asymptomatic patients develop chronic liver disease.
What are the clinical features of chronic hepatitis C infection?
Malaise & fatigue
Extrahepatic manifestation ie arthritis, cryoglobulinaemia with or without glomerulonephritis
Higher incidence of diabetes and associated with Lichen Planus
Progressive fibrosis leading cirrhosis (risk factors for exacerbation = excess alcohol, HIV, obesity & diabetes)
Once cirrhosis is developed, some go on to decompensated cirrhosis and risk of HCC.
Acute hepatic failure is defined as…
Acute liver injury with encephalopathy and deranged coagulation (INR>1.5) in a patient with previously normal liver.
Jaundice ==> encephalopathy varies from:
- Hyperacute - 7 days
- Acute - 8-24 days
- Subacute - 21-26 weeks