Acute—Any condition that is severe and sudden in
Acute hepatitis C—The initial stages of hepatitis
C infection; the acute phase of infection can last up to 6 months. Some people
may experience jaundice (yellowish eyes and skin that occurs as a result of the
liver becoming inflamed), fatigue, nausea, and increases in serum ALT levels. A
small percentage of people with acute hepatitis C are able to clear the virus
naturally from the bloodstream and recover on their own. However, more than 80%
develop chronic (long-term) hepatitis C.
Alanine aminotransferase (ALT)—An enzyme that is
found mainly in the liver and in other tissues of the body. When the liver is
damaged, this enzyme is released into the bloodstream. ALT levels can be
measured to determine if the liver is damaged or diseased.
Alcoholism- An illness marked by consumption of
alcoholic beverages at a level that interferes with physical or mental health,
and social, family, or occupational responsibilities.
Alopecia—Thinning or loss of hair.
Anorexia—A decreased appetite or aversion to
Antibody—A protein produced by the immune system
in response to the presence of an antigen (foreign substance). It defends the
body against substances identified by the immune system as potentially
Antigen—A substance that triggers an immune
response because the body recognizes it as foreign (different from normal body
Antigenic—Provoking an immune response or
reacting with specific antibodies.
Anti-inflammatory—Counteracting or suppressing
Antiviral—A substance that fights viruses.
Ascites—An abnormal buildup of fluid in the
abdomen usually due to cirrhosis and portal hypertension.
Assay—A test that identifies either antigens or
antibodies to diagnose an infection.
Autoimmune disorders—Conditions in which the
immune system mistakenly identifies cells of the body as foreign material,
producing an immune response against the body itself.
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Bacteria—Tiny organisms that often form colonies
and live in soil, water, organic matter, or the bodies of plants and animals.
While not all bacteria are harmful, some cause disease.
Bile—A yellow-green fluid that is made by the
liver to help digest fat. The principal components of bile are cholesterol, bile
salts, and the pigment bilirubin.
Blood-borne virus—A virus that circulates in the
blood and can be transmitted from one person to another during blood-to- blood
contact (eg, through shared needles).
Branched DNA signal amplification—A laboratory
test that can detect the genetic material (DNA) of a virus in a blood sample,
and quantify how much of that genetic material is present.
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Chronic—A condition that frequently recurs or
continues for a long time.
Chronic hepatitis C—A persistent hepatitis C
infection with periodic evidence of HCV RNA in the blood for at least 6 months.
The diagnosis is usually made by blood tests showing detectable viral levels in
Cirrhosis—A condition in which the liver does not
function normally due to scarring. Healthly liver cells are replaced with
non-functioning scar tissue. Alcohol accounts for approximately 50% of all
Community-acquired infection—An infection that
occurs through contact with an infectious agent in the community.
Compensated liver disease—Advanced liver disease
that is stabilized.
DNA (deoxyribonucleic acid)—The abbreviation for
deoxyribonucleic acid, the genetic material of nearly all forms of life. DNA is
used to store the genetic information of all living creatures.
Elevated liver enzymes—The presence of abnormal
blood serum levels of liver enzyme as a result of some for of injury to the
liver. Liver enzymes are special proteins found in liver cells responsible for
triggering various metabolic reactions.
Enzyme—A protein molecule in a plant or animal
that causes specific biochemical reactions in every stage of metabolism. For
example, certain enzymes aid in digestion.
Enzyme Linked Immunosorbent Assay (ELISA)—An
immunoassay is a test in which a substance is identified by its ability to
produce an immune response (by binding to specific antibodies). In an enzyme
immunoassay, an enzyme is used to highlight or label either the substance in
question or the antibody that is produced in response to it.
Exposure—Coming in contact with infectious agents
(bacteria or viruses).
False-positive—Test result that incorrectly
indicates the presence of a disease. Certain tests have higher false-positive
rates than others.
Fatigue—Feelings of being very tired or lacking
Fibrosis—Scarring of the liver.
Fulminant hepatic failure—Acute liver failure
resulting from some injury to the liver resulting in the development of hepatic
encephalopathy within six weeks. This form of liver failure is associated with a
high rate of death.
Gastroenterologist—A doctor who specializes in
disorders of the stomach, intestines, and all related organs, including the
Genotype—A unique set of genetic information that
codes for and determines specific characteristics about an organism. There are 6
known major genotypes of the hepatitis C virus, some of which are more prevalent
in specific parts of the world.
Half-life—The time required for half the amount
of a substance (such as a drug or toxin) introduced into the body to be
eliminated by the body through natural processes.
HCV—The abbreviation for the hepatitis C
HCV RNA—The abbreviation for hepatitis C virus
ribonucleic acid. RNA is the genetic material of hepatitis C virus and is a
chemical that is very similar to DNA. The hepatitis C RNA contains the
information that the hepatitis C virus needs to function.
Hemodialysis—A medical procedure that uses a
special machine (a dialysis machine) to separate and cleanse the blood.
Hepatic—Relating to the liver.
Hepatitis—Any inflammation of the liver.
Hepatitis A—Liver disease caused by the hepatitis
A virus, contracted through food or water contaminated by fecal matter. The
hepatitis A virus belongs to the Picornaviridae family of viruses.
Hepatitis B—Liver disease caused by the hepatitis
B virus, passed through sexual activity or contact with infected blood or blood
products. The hepatitis B virus belongs to the Hepadnaviridae family of
Hepatitis C—Liver disease caused by the hepatitis
C virus, passed through contact with infected blood or blood products. The
hepatitis C virus belongs to the Flaviviridae family and the Hepacivirus genus
Hepatocyte—Special cells found in the liver.
Hepatologist—A doctor who specializes in liver
Histologic response—Improvement in the liver due
to a reduction in inflammation.
Histology—The study of tissue under a
Immunocompromised—A situation where the immune
system is weakened or not functioning normally because of illness or an
Inflammation—An immune system response to
infection, irritation, or other injury, which usually results in redness,
warmth, swelling, and pain in the affected area.
Immunoregulatory—Controlling immune response
Insomnia—Inability to sleep.
Interferon—A protein that is secreted by cells in
the body as a response to viral infections. Alpha interferon is one specific
type of this protein. It was genetically engineered to be used in the treatment
of viral hepatitis and other viral diseases.
Invasive—Any procedure involving entry into the
living body, including entry by incision or insertion of an instrument.
Jaundice—A yellowing of the skin, whites of the
eyes, tissues, and certain body fluids, which can result from certain liver
diseases, including hepatitis C, or from excessive breakdown of red blood cells
due to internal hemorrhage or various other conditions.
Liver—A large, dark-red organ in the human body
located in the mid-abdomen region. The liver performs many important functions,
such as processing food into fuel for the body and cleaning alcohol and poisons
from the blood.
Liver biopsy—A tiny sample of the liver is
removed (with a needle) and examined in a laboratory.
Liver cancer—A malignant tumor of the liver.
Contributing factors to the development of liver cancer include viral hepatitis;
chronic liver disease; hemochromatosis (an inherited liver disease that affects
how the body processes iron); known liver carcinogens; and toxins (mycotoxins)
found in foods in parts of Africa and Asia. Avoiding known liver carcinogens and
preventing and treating viral hepatitis may be beneficial in reducing the risk
of liver cancer.
Liver failure—A condition of severe end-stage
liver disease, which is accompanied by a decline in mental status that may range
from confusion to coma. Other features include tremor (shaking movements
resulting from involuntary contracting and relaxing of muscles) and
gastrointestinal bleeding, with vomiting of blood or blood in the stool.
Liver inflammation—A biological response to
cellular injury that may affect liver function.
Lymphocytes—White blood cells that play a role in
defending the body against disease.
Malaise—A feeling of weakness or discomfort.
Metabolism—The process in which the body breaks
down or builds carbohydrates, fats, and proteins for use as a source of
Metabolic reactions—Processes and chemical
changes in living cells by which energy is provided for vital functions.
Monotherapy—Therapy with one drug or agent.
Neutropenia—An abnormal decrease in the number of
neutrophils, types of white blood cell. If present, individuals may be at risk
Noninvasive—Any procedure that does not involve
penetration (as by surgery or hypodermic needle) of the skin.
Pegylation—A process that helps proteins,
including interferon, remain in the body longer.
Polymerase Chain Reaction (PCR)—A testing
technique that can identify the DNA or RNA (ie, the primary genetic material) of
a specific organism. This type of test can identify hepatitis C virus RNA in a
blood sample, and is the most specific test for hepatitis C infection.
Protein—Molecules involved in structures,
hormones, enzymes, muscle contraction, and immune system responses.
Qualitative HCV Polymerase Chain Reaction (PCR)—A
testing technique that can identify the DNA or RNA (ie, the
material) of a specific organism. This type of test can identify hepatitis C
virus RNA in a blood sample, and is the most specific test for hepatitis C
Recombinant Immunoblot Assay (RIBA)—A qualitative
test used to detect antibodies to specific antigens. In testing for antibodies
to hepatitis C, RIBA has historically been used to confirm results of a positive
enzyme linked immunosorbent assay (ELISA).
Ribonucleic Acid (RNA)—The abbreviation for
ribonucleic acid, a form of genetic material. Life forms (with the exception of
some viruses) use RNA as a temporary messenger molecule to carry information
that is permanently stored in DNA.
Ribavirin—A medication, often prescribed with
alpha interferons, to make the alpha interferon more effective against the
hepatitis C virus. It is taken as a capsule by mouth.
Serum—A clear liquid part of blood.
Solid Organ Transplant—An operation in which a
vital organ of the body is surgically removed from one person and placed into
another person. Solid organs that can be transplanted include: heart, lung,
liver, kidney, pancreas, and intestine.
Spleen—An organ located near the stomach that
stores blood, disintegrates old blood cells, filters foreign substances from the
blood, and produces a type of immune cells called lymphocytes.
Sporadic infection—(In the context of hepatitis
C) an infection in which the cause is unknown.
Sustained virologic response (SVR)—The virus
remains at undetectable levels in the blood for 6 or more months after the end
Transmission—The way a disease is transferred or
spread from one person to another.
Universal precautions—A set of guidelines
developed by the U.S. Centers for Disease Control intended to decrease the risk
of spreading illness and disease in healthcare settings. Specifically, universal
precautions are to be used when coming into contact with certain types of body
fluids, such as blood, semen, and vaginal fluids. When handling these fluids,
all measures to avoid exposure should be taken, including wearing gloves and
other protective covers; avoiding injury; and proper disposal of affected
Viral load—The amount of viral particles present
in a milliliter (one-thousandth of a liter) of blood.
Virologic response—A reduction in the amount of
virus in the blood to an undetectable level.
Virus—A micro-organism smaller than a bacteria,
which can only grow and reproduce within living cells. Viruses cause many human
infections, and are responsible for various diseases. Viruses can mutate, or
change, in each infected person, which makes treatment more difficult.
White blood cells—Cells the body makes to help