Hepatitis Virus Flashcards
- picornavirus, aka enterovirus 72
- small nonenveloped
- replicates exclusively in cytoplasm
hepatitis A
- infectious naked viral RNA
- synthesis of polyprotein, one of proteins synthesized is RNA dependent RNA polymerase
hepatitis A
- discrete onset of symptoms (nausea, anorexia, fever, malaise, abdominal pain)
- jaundice or elevated AST/ALT
- confirm with positive IgM antibody
acute hepatitis A
incubation period of hepatitis A?
complications?
chronic seqeualae?
average 30 days
fulminant, cholestatic, relapsing hepatitis
no chronic
hepatitis A transmission?
close personal contact, contaminated food and water, blood exposure
hepatitis A vaccine is ________ adsorbed onto aluminum hydroxide, given to persons ______ and older, has two doses
inactivated
12 months and older
- ssRNA genome, hepeviridae
- seven genotype, 4 cause human disease
- generally transmitted fecal oral
hepatitis E
incubation of hepatitis E?
highest fatality group with hepatitis E?
illness severity?
chronic sequelae?
40 days
pregnant women, 15-25% fatality
increased with age
none
- flavivirus, enveloped (+)ssRNA
- replication confined to cytoplasm
hepatitis C
HCV virus genome?
E1 and E2 envelope proteins, capsid protein
transmission of HCV?
- percutaneous: IV drug use, transfusion, needlestick
- permucosal: perinatal, sexual (low incidence)
incubation of hep C? acute illness (jaundice)? chronic infection? chronic hepatitis? cirrhosis?
6-7 weeks mild 75-85% 70-85%, most symptomatic 10-20%
factors promoting severity of hep C?
alcohol, age >40 years at time of infection, HIV coinfection, male gender, chronic HBV infection
in hepatitis B
- envelope protein known as _____
- nucleocapsid protein known as _____
- _______ necessary for replication of viral genome
- early antigen known as ______
- _______ linked to hepatocellular carcinoma
- surface antigen (HBsAg)
- core antigen (HBcAg)
- reverse transcriptase
- HBeAg
- X protein
hepatitis B virion and particles?
virion (Dane particle)
secreted filaments
spherical particles
________ is not incorporated into virions and is secreted from the cell
HBeAg
secreted from the cell and observed in plasma at early times post infection, altered antigenic structure due to disulfide bond, development of antibodies correlates with reduction in HBV viremia
HBeAg
hepatitis B incubation period?
jaundice?
chronic infection?
premature mortality from chronic liver disease?
60-90 days
more likely if older than 5
more likely if under 5
15-25%
transmission of hepatitis B? highest concentration in body fluids?
sexual, parenteral, perinatal
blood, serum, wound exudates
marker of infectivity of hepatitis B?
HBsAg surface antigen
marker of immunity when found in serum for hep B?
marker of past or current infection?
anti-HBsAg
anti-HBcAg
IgM anti-HBc indicates _______ infection with HBV
recent (4-6mo)
IgG anti-HBc indicates _______ infection with HBV
old
indicates active HBV infection, can only be present if HBsAg is positve
HBeAg
HBsAg negative
anti-HBc negative
anti-HBs negative
susceptible to HBV infection
HBsAg negative
anti-HBc positive
anti-HBs positive
immune due to natural infection
HBsAg negative
anti-HBc negative
anti-HBs positive
immune due to vaccine
HBsAg positive
anti-HBc positive
IgM anti-HBc positive
anti-HBs negative
acutely infected
HBsAg positive
anti-HBc positive
IgM anti-HBc negative
anti-HBs negative
chronically infected
HBsAg negative
IgM anti-HBc positive
anti-HBs negative
4 interpretations:
- resolved HBV infection
- susceptible w/ false positive anti-HBc
- low level chronic infection
- resolving an acute infection
in asymptomatic carrier HBV, liver is normal except scattered hepatocytes with _________, containing HBV particles, filamentous and spherical forms
ground glass cytoplasm
in chronic persistent hepatitis, viral hepatitis leads to liver cell destruction, inflammation confined to ______
portal tracts
in chronic active hepatitis, a ___________ inflammatory infiltrate extends from portal areas, leading to _______ and hallmark apoptotic bodies called ________
mononuclear
piecemeal necrosis
councilman bodies
in HCV, influx of cytotoxic T cells into liver doesn’t occur for _____, (other viruses 1 week), implicated in the pathogenesis of viral hepatitis
2-3 months
patients with weak CTL responses generally have ________
less liver damage
small ssRNA, circular genome, codes for one protein and one mRNA
hepatitis D
hepatitis D is a ______ virus, which requires coinfection with HBV that provides ______
defective
HBsAg
replication of the hep D genome occurs in the ______, and acquires HBsAg at the _______
nucleus
golgi complex
hepatitis D modes of transmission?
percutaneous (IV drug use), permucosal sexual contact
- severe acute disease and higher incidence of fulminant hepatits than HBV alone
- low risk of chronic infection
HDV Co-infection
- usually develop chronic HDV infection
- high risk of severe chronic liver disease (70-80%)
- higher risk of fulminant hepatitis than HBV alone
HDV superinfection
hepatitis B vaccine is based on the concept that antibodies to _______ of HBV are protective, given as series of 3 ______ doses
surface glycoproteins
intramuscular
treatment options for chronic hep B?
- pegylated interferon alpha-2a
- 3TC lamivudine
- adefovir dipivoxil
- entecavir
- telbivudine
- tenofovir
HBV and HCV are linked to 70-80% of cases of what cancer?
hepatocellular carcinoma
major predisposing factor for HBV and HCV induced HCC is development of?
cirrhosis
role of HBV and HCV in carcinogenesis?
- chromosome instability –> loss of tumor suppressor genes
- insertional mutagenesis: disruption of cell cycle control genes
- hep b protein X: transactivates host genes, blocks tumor suppressors, interacts with mitogenic paths
