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National Hepatitis C Program
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Basics

Glossary

Click on an underlined letter to find the terms that start with that letter.

A  B   C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z

A

Acquired Immune Deficiency Syndrome (AIDS): A severe disorder caused by the HIV retrovirus. It effects your immunity by making you more susceptible to infections and to certain rare cancers. It is mostly transmitted by exposure to contaminated blood and semen.

Alanine aminotransferase (ALT): An enzyme released from liver cells. A blood test that reveals ALT levels above normal may indicate liver damage.

Alanine aminotransferase (ALT): levels and aspartate aminotransferase (AST) levels rise during periods of liver damage, when these enzymes leak out of broken cells. The actual numbers are not as important as how much they increase over time. Many patients with hepatitis C have raised ALT and AST levels, and many patients have normal ALT and AST levels. For those with elevations, one goal of treatment is to get the levels back to normal.

Albumin: A group of proteins made in the liver, and which play an important role in ensuring the maintenance of a normal blood volume.

Albumin (Alb): is a protein made by the liver to keep body fluids in balance. Low levels can indicate poor health and nutrition or a failing liver.

Alkaline phosphatase (AlkPhos): is an enzyme made in the liver's bile ducts and also in bone, kidneys, and intestines. High levels can indicate liver or bone disease.

Alpha-fetoprotein (AFP): is a test used to help diagnose liver cancer.

Anemia: is a shortage of red blood cells that can cause fatigue and other symptoms. Anemia may occur in people on interferon treatment.

Antibodies: are proteins produced by the body to fight infections. The presence in the blood of an antibody to hepatitis C means that the virus is present as well.

Antibody: A protein molecule produced by cells of the immune system in response to a foreign body, such as a virus or bacteria. Antibodies circulate in the blood to protect against infection.

Anti-HCV: (antibody to hepatitis C virus) The antibody directed against the hepatitis C virus (HCV). Its presence in the bloodstream often indicates HCV infection. This antibody has not been shown to protect people against hepatitis C.

Ascites: Fluid within the abdomen, often caused by cirrhosis.

Ascites: is fluid buildup in the abdomen due to high blood pressure in the liver.

Aspartate aminotransferase (AST): An enzyme released from liver cells. A blood test that reveals AST levels above normal may indicate liver damage.

Assay: A test or analysis.

B

bDNA (branched DNA) assay: One of the two tests that reveal the presence in the bloodstream of minute quantities of DNA and RNA, such as RNA fragments from hepatitis C virus.

Biochemical response (BR): Refers to patient's response to interferon therapy by normalization of ALT.

Bilirubin: A bile pigment that is also created by the breakdown of heme pigments. Usually collected by the liver cells, its presence in blood or urine is often a sign of liver damage.

Bilirubin (T bili): is produced by the liver when it recycles red blood cells. Normally it is processed for removal from the body, so high bilirubin is usually a bad sign. At very high levels, your skin can actually turn yellow (jaundice).

Blood-borne substances: Those substances that are present in the blood and are carried by it throughout the body. Blood-borne substances, such as viruses, can be passed on to others through blood transfusions, needle sharing, and even sharing a toothbrush if both people have bleeding gums.

Breakthrough response: A "breaking through" of the virus while on therapy. Detection of virus during therapy in those who had initially lost virus during treatment.

C

Carrier: A person in apparent good health, who has been infected with an organism and is capable of infecting and/or causing disease in others. Individuals persistently infected with hepatitis B and C without evidence of liver injury are considered "carriers."

Chronic infection: An infection that persists and that returns after it had seemed to be cured. Disease is defined as evidence of liver injury by abnormality in serum ALT and/or liver histology.

Cirrhosis of the liver: The result of long-standing inflammation and damage in the liver, such as may be caused by a hepatitis C infection or alcohol. It is characterized by excess formation of scar tissue, also called fibrosis, and results in the loss of liver cells and increased resistance of blood flow.

Cirrhosis: is the condition of having extensive scar tissue in the liver (see fibrosis). Permanent damage may have been done as a result of infection or alcohol abuse, and healthy liver cells have been replaced with scar tissue.

Concomitant event: An event, such as a medical condition, that occurs at the same time as another.

D

DNA (deoxyribonucleic acid): A component in cells of all living matter that carries hereditary genetic information. DNA helps determine what an organism will be as it develops to maturity, i.e. a virus, a human.

E

Edema: The puffiness that occurs from abnormal amounts of fluid in the spaces between cells in the body, especially just below the skin.

ELISA (enzyme-linked immunosorbent assay): This is a test that provides information on the presence or amount of antibodies in the bloodstream. This test is sometimes referred to as an "EIA."

Encephalopathy: A variety of brain function abnormalities experienced by some patients with liver disease. These most commonly include confusion, disorientation, and insomnia, and may progress to coma.

Encephalopathy: is damaged brain function caused by cirrhosis. It can lead to coma.

End treatment response (ETR): Refers to response to medications at the end of therapy regime.

Enzymes: Naturally occurring chemical substances in the human body that help a chemical reaction take place. High levels of these enzymes in blood may be a marker of disease.

Enzyme immunoassay (EIA): A test that provides information on the presence or amount of antibodies in the bloodstream. This test is sometimes referred to as an "ELISA."

Epidemiology: Investigation of the causes of, and ways to control, diseases.

F

False-positive: A test result that mistakenly gives a positive reading.

Fibrosis: is the first stage of scar formation in the liver. Scar tissue is an attempt to contain areas of the liver that have been damaged by alcohol, hepatitis C, or other factors.

Flavivirus: A group of related viruses, including the viruses that cause yellow fever. Hepatitis C is a hepacivirus related to flavivirus.

G

Genotype: A pattern of genetic information that is unique to a group of organisms or viruses. Doctors may determine the genotype of hepatitis C to help decide the best treatment.

H

Hepatic: Related to the liver.

Hepatitis: Inflammation (swelling) of the liver.

HCV RNA (hepatitis C virus ribonucleic acid): Fragments of the replicating hepatitis C virus (HCV). These can be detected using sophisticated testing to determine the level of hepatitis C virus present in the serum.

Hepatocellular carcinoma (HCC): Cancer of the liver cells that has progressed into a tumor.

Hepatocellular carcinoma (HCC): is liver cancer.

I

Interferons (IFN): are a group of proteins made by the body that have antiviral, antitumor, and immune system activity. They are also produced synthetically for treatment of medical conditions.

Intravenous drug abuse (IVDA): Acquiring an addiction to narcotic-type drugs that require intravenous administration. The intravenous use and abuse of recreational and other illegal drugs is a common route of transmission for hepatitis C infection.

J

Jaundice: A condition characterized by yellowness of the skin and eyes. Jaundice is a symptom of many disorders, including: obstruction of bile passageways by a gallstone; disease of the liver due to viral infection, alcoholism, or poisons; or breakdown of red blood cells.

N

Neutropenia :means a decreased number of a type of white blood cells that fight infections in the body. Interferon treatment can cause neutropenia.

P

Polymerase chain reaction (PCR): is a test used to determine the number of virus particles in the blood.

Portal hypertension: is high blood pressure in and around the liver. It is often caused by cirrhosis, and it can result in variceal bleeding and ascites.

Prothrombin time (PT): is a test that measures how long your blood takes to clot. Prothrombin helps the blood to clot, so time increases if the liver is not making enough of it.

Q

Quasispecies: One or more sub-populations of a virus occurring within a single genotype in an individual.

R

Recombinant DNA: Genetic material that has been altered and recombined through insertion of new DNA sequences using bioengineering. Many drugs are now produced using recombinant DNA methods.

Recreational drugs: Illegal drugs, such as marijuana, cocaine, and heroin that are used by people addicted to the drugs, or, if not addicted, who feel the effects of the drugs outweigh the risk factors associated with them.

Remission: Partial or complete disappearance - or a lessening of the severity - of symptoms of a disease. Remission may happen on its own or occur as a result of a medical treatment.

RIBA (recombinant immunoblot assay): A test that confirms the presence of HCV antibodies in the bloodstream.

Risk factors: Certain behaviors (such as intravenous drug use or transfusions) linked to the development of an infection such as hepatitis.

RNA (ribonucleic acid): Molecules, found in all cells, that translate DNA genetic information into proteins.

S

Serology: A branch of medical testing that focuses on serum, particularly immune factors in serum.

Seronegative: When the suspected substance being searched for, such as the antibody to hepatitis C virus, does not show up in a blood test.

Seropositive: When the suspected substance being searched for, such as the antibody to hepatitis C virus, does show up in a blood test.

Seroprevalence: The frequency of a seropositive substance in a group of people.

STD (sexually transmitted disease): A communicable disease transmitted by sexual intercourse or genital contact.

Sustained response (SR): A response to therapy that continues over a long time period.

Sustained viral response: Means that six months after the end of interferon treatment, the virus is no longer detectable in the blood.

T

Thrombocytopenia: is a low level of platelets in the blood, sometimes caused by interferon treatment.

Transaminase: A term for alanine aminotransferase (ALT) and aminotransferases (AST).

Transmission: Passing an infection or disease from one person to another.

True-positive: A test result that accurately gives a positive reading.

V

Variceal bleeding: is bleeding from enlarged veins in the esophagus (called varices). Varices form as a result of high blood pressure in the liver.

Viral load: is the amount of virus particles in a milliliter of blood.

Viral load: The measurement of the amount of a given virus in the bloodstream.

Viremia: The presence of a given virus in the bloodstream.

Virologic Response (VR): Refers to patients' loss of detectable HCV RNA during or after medication therapy.

W

White blood cell count (WBC), hematocrit (HCT), and platelets (PLT): are all components of the blood. A low WBC count is called leukopenia. A low HCT count is called anemia and represents a lack of red blood cells. A low platelet count is called thrombocytopenia. These abnormalities can develop as complications of liver disease or as side effects of HCV treatments. A complete blood count (CBC) tests all of these types of blood cells.