Glossary
of Common Hepatitis B Terms
Active Liver Damage
Acute Hepatitis B
Adverse Event
Alanine Aminotransferase (ALT)
Antiviral Drug
Cirrhosis
Clinical Trial
Compensated Liver Disease
Decompensated Liver Disease
Dose
Drug Resistance
Enzyme
HBV DNA
HBV DNA Polymerase
Healthy Chronic Carrier
Hepatitis B Virus (HBV)
Hepatocellular Carcinoma
Histology Improvement
Interferon
Epivir (lamivudine)
Nucleotide Analogue
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.
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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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Antiviral
Drug:
A drug that is effective in slowing the growth of a virus.
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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:
Drug resistance occurs when viruses acquire ways to survive
the effects of the drugs that were designed to weaken them.
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Enzyme:
A substance found in a living cell that is capable of producing certain chemical
changes.
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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.
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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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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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Nucleotide
Analogue:
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 analogue adefovir
dipivoxil inhibits an enzyme known as HBV DNA polymerase, preventing 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 the 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 U.S.
Food and Drug Administration.
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Replication:
The process by which viruses make copies of themselves using host cells. 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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