Hepatitis B Flashcards
What is the aetiology of hepatitis B? (And ways of transmission)
Sexual - transmitted when body fluids come into contact with broken skin or mucous membrane (mouth, genitals or rectum)
Parenteral - due to contaminated needles or instruments that come into contact with patient’s blood
Mother to child transmission
Common associations - Hepatitis C and HIV positive individuals, travelers to regions where HBV is endemic
What is the pathophysiology of acute infection of HBV?
In acute infection, the cellular immune response causes damage to hepatocytes.
Hepatitis B-infected hepatocytes express viral peptides on their surfaces → detection of the HBV-derived peptides by lymphocytes and the subsequent activation of CD8+ T cells that attack the infected hepatocytes → hepatic inflammation with destruction of hepatocytes
What is the pathophysiology of chronic infection?
Caused by viral persistence due to failing immune clearance, which promotes:
Persistent hepatic inflammation → necrosis, mitosis, and regeneration processes → cirrhosis and cellular dysplasia → HCC (hepatocellular carcinoma)
Integration of HBV DNA into the host genome → altered expression of endogenous genes, chromosomal instability → HCC
HBV proteins fulfill numerous immune-modulating functions that allow them to elude detection by the immune system and avoid clearance.
What are the clinical features of acute HBV?
Incubation period 1-6 months
Clinical course - serum sickness like syndrome can develop during prodromal period 1-2 weeks after infection - rash, arthalgias, myalgias, fever
Subclinical hepatitis
Symptomatic hepatitis - fever, skin rash, arthalgias, myalgias, fatigue, nausea, anorexia, jaundice, RUQ pain
What are the clinical features of chronic HBV?
Most are asymptomatic carriers
Unspecific symptoms - fatigue, malaise, nausea, poor appetite, unspecific abdominal pain, hepatic failure
What can the physical exam reveal for patients with HBV?
Low grade fever
Jaundice
Hepatomegaly
Spleen omega lymph
Palmar erythema (rare)
Spider nevi (rare)
What can the physical exam reveal in chronic HBV patients?
Hepatomegaly
Palmar erythema
Spider angiogram
Which symptoms may patients with cirrhosis develop?
Ascites
Jaundice
History of variceal bleeding
Peripheral oedema
Gynecomastia
Testicular atrophy
Abdominal collateral veins
What is the d/d for hepatitis B?
Alcoholic hepatitis
Autoimmune hepatitis
Cholangitis
Cirrhosis
Hemochromatosis
Hepatic carcinoma
Hepatitis A
Hepatitis C
Hepatitis D
Hepatitis E
Viral hepatitis
Primary sclerosing cholangitis
Wilson disease
What is the diagnosis for HBV?
Screening for hepatitis B antigen (HBsAg) used most frequently to screen for the infection - usually appears 1-3 months after infection or vaccination
Shortly after this antigen, another antigen called hepatitis B e antigen (HBeAg) will appear - indicates long term clearance o HBV and thus pops transmission
If host can fight off infection, eventually HBsAg will become undetectable and IgG antibodies will appear to hepatitis B surface antigen and core antigen
Look at picture for a table for serology of HBV
DA
What is the testing algorithm for HBV?
Screening - measure HBsAg and anti HBc-IgM
If HBsAg is positive - measure HBeAg and HBV DNA to determine transmissibility
What are additional lab tests that should be done for HBV?
LOOK AT PICTURES
What is the treatment for HBV? q
Lifestyle changes - weight loss
Cessation of substance use eg alcohol
Discontinuation of hepatotoxic medication
What is the antiviral treatment for HBV?
Acute HBV - treat the liver failure, pharmacological therapy not recommended for acute HBV
Chronic HBV - nucleoside/nucleotide analogs eg Tenofovir, entecavir etc. Pegylated interferon Alfa
Liver transplant
