Click on any of the words below for a definition.
Active Liver Damage
Acute Hepatitis B
Adverse Event
Alanine Aminotransferase (ALT)
Antibody
Antigen
Antiviral Drug
Baraclude (entecavir)
Cirrhosis
Clinical Trial
Compensated Liver Disease
Decompensated Liver Disease
Dose
Drug Resistance
Enzyme
Epivir (lamivudine)
HBV DNA
HBV DNA Polymerase
Healthy Chronic Carrier
Hepatitis B Virus (HBV)
Hepatocellular Carcinoma
Histology Improvement
Interferon
Nucleotide Analog
Perinatal (Vertical) Transmission
Placebo
Prescribing Information
Replication
Resistance
Resistance Mutations
Side Effects
Viral Replication
Active Liver Damage:
Moderate-stage liver disease in which active viral replication, liver
inflammation and elevated levels of the liver enzyme alanine aminotransferase (ALT) may occur.
This condition may produce early signs of cirrhosis.
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Acute Hepatitis B:
Active and symptomatic infection of the liver from which patients generally recover within six months,
clearing the virus from their blood and developing immunity.
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Adverse Event:
The development of an undesirable or harmful side effect during drug therapy.
(see Side Effects)
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Alanine Aminotransferase (ALT):
A liver enzyme found in the blood. Elevated levels of ALT indicate liver disease severity and the presence of liver inflammation.
A normalization or reduction in ALT levels signifies increased and improved liver function,
the halt of disease progression and liver damage, and a reduced risk of progressive liver
disease.
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Antibody:
A protein that your immune system makes in response to a foreign substance.
Antibodies can be produced in response to a vaccine or to a natural infection.
Antibodies usually protect you against future infections.
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Antigen:
A foreign substance in the body, such as the hepatitis B virus.
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Antiviral Drug:
A substance used to kill a virus or inhibit its replication.
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Baraclude (entecavir):
An orally administered antiviral drug designed to stop hepatitis B virus replication by blocking HBV DNA polymerase. Entecavir is the generic name for Baraclude™ (drug brand name).
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Cirrhosis:
A condition in which specific diseases or conditions cause the liver to become permanently injured and scarred.
The scar tissue that forms in cirrhosis harms the structure of the liver, blocking the flow of blood through the organ.
The loss of healthy liver tissue slows the liver’s ability to process nutrients and hormones necessary for normal liver function.
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Clinical Trial:
Test that is intended to evaluate how well a drug will work in humans.
Clinical trials are often conducted with many people and compare a treatment or a way
of treating a disease with either a sugar pill or other, approved
treatments.
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Compensated Liver Disease:
A serious disease of the liver in which liver cells are damaged by HBV but the liver continues to function. This condition often leads to decompensated liver disease, which can result in death.
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Decompensated Liver Disease:
Cirrhosis of the liver which is accompanied by fluid buildup in the
abdomen.
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Dose:
The recommended amount of a drug to be
taken.
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Drug Resistance:
When a virus is able to adapt, grow and multiply in the presence of the drugs designed to control it. A virus is considered resistant to a drug when that drug is no longer effective against it.
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Enzyme:
A substance found in a living cell that is capable of producing certain
chemical changes.
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Epivir (lamivudine):
An orally administered antiviral drug designed to stop hepatitis B virus replication by blocking HBV DNA polymerase. Lamivudine is the generic name for Epivir-HBV® (drug brand name).
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HBV DNA:
Genetic sequence found in carriers of HBV. HBV DNA in the blood indicates the presence and severity of the virus in chronic hepatitis B patients. Elevated levels of HBV DNA can cause liver damage and affect overall liver function.
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HBV DNA Polymerase:
An enzyme that is a part of the hepatitis B virus replication process.
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Healthy Chronic Carrier:
A person who has HBV in the liver and blood, but who does not exhibit obvious physical signs or symptoms of infection. Chronic carriers can pass the virus on to others and have an increased risk of developing liver diseases such as cirrhosis or liver cancer.
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Hepatitis B Virus (HBV):
A virus that causes inflammation of the liver; HBV is typically transmitted through contact with contaminated blood during sexual contact or while sharing needles.
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Hepatocellular Carcinoma (HCC):
Cancer of liver cells, which often results from chronic hepatitis B infection; specimens derived from a liver biopsy will appear fragmented and paler than normal tissue, indicating the presence of the disease. It also is referred to as primary liver cancer.
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Histology Improvement
Improvements in liver histology are indicated by reductions in necroinflammatory activity and scarring of the liver, as well as by improvements in the condition of the liver tissue when viewed under a microscope. This is the most clinically significant indication that a therapy has slowed or reversed the progression of liver disease. If the liver tissue is improved, it can significantly reduce the risk of liver cancer or eliminate the need for liver transplantation.
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Interferon:
A naturally occurring substance in the body that stimulates the immune system. Artificial forms of interferon created in a laboratory can be used as treatments for diseases like hepatitis B and C.
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Nucleotide Analog:
A chemically engineered nucleotide (the natural building block of the nucleic acids DNA and RNA — the source of all genetic information in human cells and viruses) that acts as a substitute building block in the viral replication process, inhibiting the replication of HBV. The nucleotide analog adefovir dipivoxil inhibits an enzyme known as HBV DNA polymerase, helping to prevent the virus from replicating in an infected person.
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Perinatal (Vertical) Transmission:
Transmission of an infectious disease from mother to child. In the case of HBV, transmission occurs via a mother’s milk, through the placenta or during childbirth.
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Placebo:
Sugar pill used in comparison to a drug in studies of the safety and effectiveness of a drug.
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Prescribing Information:
Also referred to as the package insert, product label, or product information, this document is the primary reference for information about a prescription drug. The prescribing information is approved by the US Food and Drug Administration.
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Replication:
The process by which viruses make copies of themselves. In the case of hepatitis B, the hepatitis B virus uses liver cells (hepatocytes) to make copies of itself.
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Resistance:
When a virus is able to adapt, grow and multiply in the presence of the drugs designed to control it. A virus is considered resistant to a drug when that drug is no longer effective against it.
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Resistance Mutations:
Mutations are alterations in the genetic code of an organism that arise by accident or in direct response to the presence of an antagonistic substance, such as a drug. Although many harmless mutations may be generated, a mutation is called a resistance mutation if the change in the genetic code renders the organism less susceptible to treatment with medication. In the case of HBV, the appearance of resistance mutations may allow the virus to replicate more freely even in the presence of an active drug.
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Side Effects:
Reactions caused by a drug in a person’s body other than what the drug was designed to do (for example, nausea from a drug that is taken to fight hepatitis B).
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Viral Replication:
The process whereby a virus enters a living host, multiplies and reproduces by generating copies of itself.
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