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16 Cards in this Set
- Front
- Back
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When looking at infected blood with electron microscopy, one will notice the Dane particle spheres, as well as longer filamentous structures. TRUE/FALSE
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TRUE. These structures are composed of the envelope and some capsid proteins that have dissociated from the intact virion.
This part of the virus is called the hepatitis B surface antigen(HBsAg) and is imporatnt because antibodies against this component are protective. having anti-HBsAg menas the patient is immune against HBV. |
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Removing HBsAg leaves the viral core, which is called hepatitis B core antigen(HBcAg) and is also antigenic. TRUE/FALSE
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TRUE. However, antibodies against the core are not protective.
During active infection and viral growth, a soluble component of the core is released. This is called HBeAg. This is found dissolved in the serum, and is a marker for active disease and a highly infectious state. Infected mothers who have no HBeAg will rarely infect the neonate. |
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HBV may spread via a very wide parenteral route, needle sticks, blood spray, sexual contact and perinatal transmission. TRUE/FALSE
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TRUE.
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HBV can cause both an acute and chronic hepatitis. TRUE/FALSE
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TRUE. There are app. 200 million carriers of HBV in the world.
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Liver injury appears to occur from a cell mediated immune system attack on HBV. TRUE/FALSE
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TRUE. Viral antigens on the surface of infected hepatocytes are targets for cytotoxic T cells.
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There is a 200X increase in the risk of developing primary hepatocellular carcinoma in HBV carriers. TRUE/FALSE
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TRUE.
With chronic infection the HBV DNA becomes incorporated into the hepatocyte DNA and triggers malignant growth. |
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Is there an established protocol of therapy?
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1. Serologic testing on donor blood is used for prevention.
2. Active immunization; recombinent vaccine. The gene coding for HBsAg is cloned in yeast. Risk from the vaccine is practically non existant, because it contains only the surface envelope and proteins(no DNA or capsid). It is given to all infants at birth, 2, 4, and 15 mos. It is given as 3 injections to adolescents, and high risk workers. |
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Are there any other drugs used for HBV?
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Lamivudine, the anti HIV drug suppresses HBV DNA to undetectable levels, but most will relapse if the drug is discontinued.
Interferon alpha, suppressed HBV DNA and HBeAg in 50% of treated patients and might prevent cirrhosis. |
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How is the Hepatitis delta Virus transmitted?
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This RNA virus is transmitted parenterally and can only replicate with the help of HBV.
Infact, the delta virus helical nucleocapsid actually uses HBV's envelope, HBsAg |
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HBV and HDV both are transmitted together parenterally and cause an acute hepatitis similar to that caused by HBV. TRUE/FALSE
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TRUE. Antibodies to HBsAg will be protective against both, ending the infection.
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Does HDV infect a person who has chronic HBV infection?
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Yes. This results in acute hepatitis in a patient already chronically infected with HBV. The patient with chronic HBV cannot make antiHBsAg and so remains chronically infected with both HBV and HDV.
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Most of the cases(about 90%) of non-A and non-B hepatitis are caused by HCV. TRUE/FALSE
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TRUE. It is transmitted parenterally and has been identified as an enveloped icosahedral RNA virus. It causes acute and chronic hepatitis.
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Is there arelationship between HCV and Cirrhosis?
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Yes. A large percentage of these develop chronic hepatitis and eventual Cirrhosis. Hepatocellular carcinoma can develop in patients with chronic active HCV infection and Cirrhosis.
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Is there a treatment available?
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For patients with chronic active HCV, treatment with alpha-interferon can sometimes result in resolution of liver inflammation(app. 50% will respond).
Treatment with ribavirin only temporarily normalized liver enzymes in 1/3 of patients. |
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Why is Hepatitis E virus(HEV) often referred to as non A hepatitis?
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It shares similarities with HAV. HEV is also transferred by the fecal oral route. The E stands for Enteric.
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What is Hep. G virus?
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It is an RNA virus in the flavivirus family. It is transmitted via parenteral and transfusion routes. It does not necessarily cause liver disease.
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