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10.13 Hepatitis B and D
at 2:00 by Dr. Foster
54
Microbiology
Professional
10/15/2011

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Term
What are downey cells?
Definition
a reactive lymphocyte with distinctive morphology that is commonly associated with viral infections. Not typically observed in circulating blood. Nucleus of a reactive lymhpocyte can be round, elliptic, indented cleft or folded and the cell with be enlarged with abundent vacuoles. Cytoplasm is often gray to pale blue in color
Term
Along with EBV infection, what other infection is a cofactor for development for development of burkitt's lymphoma in africa?
Definition
malaria (P. falciparum is highly mitogenic for B cells)
Term
T/F ALl forms of Burkitt's lymphoma contain a dysregulated form of the c-myc oncogene activated thru a chromosomal translocation onto the immunoglobulin locus
Definition
true
Term
What is the viral family of hepatitis B?
Definition
hepadnavirus
Term
Describe the virion and genome of hep B.
Definition
enveloped; pleomorphic structure; smallest of enveloped animal viruses. DNA virus with nuclear replicaiton
Term
T/F Hepatitis B uses reverse transcriptase to replicate.
Definition
true
Term
What disease procesess are associated with hep b infection?
Definition
acute and chronic hepatitis; HCC
Term
How do you diagnose hep B?
Definition
Hep B surface antigen means you are currently infectted
Hep B core antigen antibody means you currently are or have been infected
PCR for E antigen (a secreted protein that determines severity of liver infection)
also, liver fxn tests and histology
Term
How do you treat hep B?
Definition
RT inhibitors and interferon; hep B immunoglobulin
Term
How is hep B transmitted?
Definition
birth (esp HBeAg+ moms), blood (IVDU, health care workers, tatoos), sexual contact (also sharing personal items
Term
How does Hep B help evade the immune system?
Definition
produces 22nm spheres and filamentous tubes consisting solely of HBsAg which outnumber virions by about 1000:1
Term
Describe the stability of HBV.
Definition
although it has an envelope, HBV is remarkably soluble to organic solvents, heat, and pH.
Term
Describe the antigenic parts of hep B.
Definition
surface= HBsAg and internal= HBcAg, HBeAg
Term
T/F Antibodies against HBsAg confer life-long immunity.
Definition
true, although these ab/ag complexes can cause type III hypersensitivity during acute infection
Term
How long is the incubation period for hep B?
Definition
45-180 days
Term
What are the symptoms of hepatitis B?
Definition
tiredness with loss of appetite, abdonimal discomfort, vomiting, joint pain, dark urine, clay colored bowel movements, jaundice
Term
T/F For both HBV and HCV there is very little cytopathic effect.
Definition
true
Term
T/F Like HCV, HBV targets monocytes and lymphocytes before targeting hepatocytes.
Definition
false!!! HBV goes straight to hepatocytes
Term
What causes and who gets chronic hepatitis from hep B?
Definition
a weak cell-mediated immune response; infants and very young patients
Term
What percent of patients below the age of 5 show symptoms when infected with hep B? What percent develop chronic disease?
Definition
10%; 30-90%
Term
What percent of patients older than 5 develop chronic disease after HBV infection? What percent display clinical symptoms?
Definition
30-50% display clinical symptoms
2-10% develop chronic disease
Term
What percent of pts chronically infected with hep B get liver cirrhosis?
Definition
25%
Term
What percent of patients with liver cirrhosis from HBV develop liver failure or HCC?
Definition
25%
Term
How many people are affected by chronic HBV?
Definition
affects between 350-500 million people worldwide; chronic hep B accounts for about 1million deaths per year. 10th leading cause of deaths world wide
Term
How many people in the US have chronic hep b?
Definition
1-1.25 million people
Term
How many people in the US die each year form hep B complications?
Definition
4,000-5,000
Term
T/F Hepatitis B chronic infection leads to severe chronic liver disease.
Definition
false, progression of chornic hepatitis is highly variable from mild asymptomatic infection to severe chronic liver disease
Term
What percent of pts iwth chronic hep B infection have complications including liver cirrhosis and HCC?
Definition
15-25%
Term
What are the serological characteristics of chronic hep B infection?
Definition
production of S, E, and C antigens are sustained. Antibodies against S antigen are no longer detected meaning NO PROTECTION
Term
What serological test can you perform to determine whether your patient with chronic hep c is at a higher risk of developing HCC?
Definition
high HBsAg increases risk of HCC
HBsAg and HBeAg double positive increases their risk even more
Term
What percent of deaths in HBsAg carriers are caused by liver cirrhosis or HCC?
Definition
50%
Term
How does infection with Hep B lead to cancer?
Definition
there is destruction of hepatocytes as a result of the immune reponse to the virus. This results in regeneration via cell division of liver cells that may ultimately cause the cancer. An HBV protein X isknown to activate the src kinase and may also interact with p53. Also, HBV genomes can integrate near myc gene
Term
How do you initially diagnose someone with acute hep B infection?
Definition
initially by clinically symptoms and elevated liver enzymes
Term
What are you testing for when you get a hep B panel?
Definition
detection of antigen: HBsAg and HBcAg detection of antibodies: HBsAg, HBeAg, and HBcAg
Term
What is the histological appearance of a liver biopsy of someone with hep b?
Definition
ground glass hepatocytes. HBsAg expression causes observed cytoplasmic abnormalities. only observed in chronic infections
Term
If a patient is neg for HBsAg, positive fo ranti-HBcAg, and positive for anti-HBsAg then...
Definition
pt is immune to HBV as result of previous exposure
Term
If patient is negative for HBsAg, negative for anti-HBcAg, and positive for anti-HBsAg, then the patient is...
Definition
immune to HBV because of vaccination
Term
If a patient has + HBsAg, + anti-HBcAg, + anti-HBcAg IgM, and negative for anti-HBsAg?
Definition
acute HBV infection. antibodies for HBSAg may be undetectable by being complexed with decoy particles
Term
What if patient is + HBsAg, + anti-HBcAg, - anti-HBcAg IgM, and - for anti-HBsAg...
Definition
chornic HBV infection
Term
If patient is - HBsAg, + anti-HBcAg, and - for anti-HBsAg...
Definition
patient in recovery phase and anti-HBsAg is complexed with particles or below detection levels. also could be false positive
Term
Describe the hep B vaccine.
Definition
subunit vaccine produced in yeast and engineered to express HBsAg
Term
How do you prevent verticle transmission of hep b?
Definition
when mother is HBsAg+, you give vaccine along with HBV immune globulin (HBIG-passive immunization)
Term
How do you treat someone with hep B?
Definition
passive immunization with HBIG immediately after exposure. IFN-alpha or pegylated IFN alpha. Nulceotide that inhibits reverse transcriptase
Term
What the nucleotide analogs that inhibit RT and can be used to treat hep B infection?
Definition
lamivudine (epivir), adefovir dipivoxial (hepsera), entecavir, and telbivudine
Term
What type of virus is hep D? (genome, virion, classification)
Definition
enveloped, satellite virus
circular ssRNA genome
Term
What types of disease does Hep D cause?
Definition
acute and chronic hepatitis; exacerbates severe hepatic diseaes
Term
How is hep D transmitted?
Definition
perenteral; IVDU; sexually, but less efficient
Term
How do you diagnose hep D?
Definition
presence of delta antigen in liver; delta antigen in blood (pre-clinical)
Term
How do you treat hep D?
Definition
eliminate pt's hep B
Term
Why does hep D need hep B coinfection?
Definition
outer envelope protein of hep D is HBsAg so hep B needs to make HBsAg for hep D so hep D can infect other cells
Term
Where does hep D replicate?
Definition
inner core contains an extensively base-paired circular RNA genome associated with delta antigen that targets RNA to nucleus. Replicates in nucleus nucleus using host RNA polymerase II
Term
What does the hep D genome encode?
Definition
has one open reading frame that encodes 2 proteins: small and large delta antigens
Term
What is the serology of acute infection with hep D?
Definition
breif appearance of delta antigen in blood, brief appearance of anti-delta IgM, with little or no IgG, anti-HBsAg titers are high and persist after clearance
Term
What is the serology of chronic hep D infection?
Definition
breif appearance of IgM followed by high titers of anti-delta IgG. Delta antigen persists in the liver but it is rapidly cleared from serum. Anti-delta IgG persists at high level. HDV RNA detectable long term
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