Glossary of terms for Hepatitis CAcetaminophen: Component of many over-the-counter pain killers (such as Tylenol*) and cold medications; reduces fever and sensitivity to pain Acute: short-term infection. Acute hepatitis C infection should resolve within 6 months of initial infection. ALT: alanine aminotransferase. This is a type of enzyme normally found in the liver. When liver cells are injured this enzyme leaks into the blood. Therefore, persistently abnormal levels of this enzyme in the blood indicate that the liver may be inflamed or damaged. Amino acids: nitrogen-containing molecules. Proteins, both in food and in human tissue, are made up of chains of various amino acids. There are 22 known amino acids and the sequence characteristics of each protein. Analogue: in chemistry, a compound with a structure similar to that of another compound but differing from it with respect to certain components or structural makeup, which may have a similar or opposite action metabolically Anemia: decreased ability of the blood to carry oxygen from the lungs throughout the body. This is measured as hemoglobin or red blood cell count. Antibody: a type of immune protein molecule that is produced when bacteria, a virus or a foreign protein substance enters your body. A specific antibody is produced against each invader. Antigen: any substance that stimulates the immune system to produce antibodies, eg. hepatitis C virus is an example of an antigen Anti-HCV Test: a blood test that looks for and measures antibodies to the hepatitis C virus. A positive anti-HCV result does NOT indicate immunity to hepatitis C. Rather it indicates that you have been exposed to the hepatitis C virus and likely still have the infection. Antiviral drugs: drugs that work against a virus, such as the hepatitis C virus Antiviral: a substance or process that destroys a virus or prevents it from reproducing Ascites: swelling of the abdomen due to an accumulation of fluid AST: aspartate aminotransferase. An enzyme that is normally found in liver cells that can leak out of these cells and make its way to the blood when liver cells are injured. The ALT is felt to be a more specific indicator of liver inflammation, as AST is also found in other organs such as the heart and skeletal muscle. Autologus blood donation: pre-donation and storage of a patient's own blood a few weeks before elective surgery. This way, if the patient needs a transfusion during surgery they can receive their own blood and not someone else's. Bile: a substance secreted by the liver that helps in the digestion of fats. It is stored in the gall bladder until required. Bilirubin: a yellow substance formed when red blood cells age and break down. The liver normally breaks down bilirubin for excretion. However, if the liver is not functioning properly bilirubin may accumulate in the blood stream causing jaundice. Body fluids: any liquid in the body such as blood, urine, saliva, sputum, tears, semen, breast milk or vaginal secretions Bone marrow: the inside of bone where blood cells are formed Carrier: a person who has a virus in his/her system but who may not necessarily have symptoms or show signs of illness. This person can, however, pass the virus on to other people and make them sick. CAT Scan: computerized axial tomography; a special kind of x-ray for looking at the soft organs in the body, such as the liver. A three-dimensional image of a body structure is constructed by computer from a series of cross-sectional images made along an axis. Also referred to as a CT scan. Chronic: long-term infection. Chronic hepatitis C infection persists longer than 6 months and usually for years. Cirrhosis: scarring of the liver as it attempts to protect itself from inflammation. Blood cannot flow freely through scarred liver tissue and thus the liver cannot perform its normal functions. Clinical trial: a scientifically controlled study done with human subjects to investigate the effectiveness, safety and ideal dosage of a new drug or treatment Combination therapy: use of two or more medications at once. For hepatitis C, combination therapy with interferon and ribavirin is now the standard treatment. Consensus interferon: a type of synthetic interferon that may be an alternative for people who do not respond to interferon alone (See question 6.2.4.) Contraindication: a specific circumstance when the use of certain treatments could be harmful Cryptogenic cirrhosis: cirrhosis of unknown origin Diagnosis: determining the presence of a specific disease or infection usually based on evaluating a patient's symptoms and results from laboratory tests Dialysis: a treatment for kidney disease that removes waste from blood. Used when the kidneys cannot perform their normal waste removal function. (Also called hemodialysis.) Edema: abnormal accumulation of fluid in your arms, hands, legs, feet and face EIA: enzyme immunossay. A test that detects the presence of antibodies to the hepatitis C virus, EIA is used for initial testing. Because false positive results are possible, supplementary tests (such as RIBA) are needed to confirm diagnosis. ELISA: enzyme-linked immunosorbent assay; another name for the EIA test. Enzyme: a cellular protein whose shape allows it to hold together several other molecules in close proximity to each other. In this way, enzymes are able to induce chemical reactions in other substances with little expenditure of energy and without being changed themselves. Basically, an enzyme acts as a catalyst. Esophagus: a muscle lined tube extending from your throat to your stomach Fatigue: feeling extremely tired and lacking energy Gallstones: solid lumps of cholesterol crystals or pigment material that form in the gall bladder or bile ducts. They may obstruct the flow of bile and cause pain. Gamma-globulin: a type
of protein in blood plasma that provides immunity to certain viruses, such
as hepatitis A and hepatitis B (also called immune globulin or
immunoglobulin) Genotype: an identifiable stain of the hepatitis C virus. There are 11 major hepatitis C genotypes and more than 90 subtypes. HCV: hepatitis C virus; the virus that causes hepatitis C HCV RNA: the actual viral material of hepatitis C Hemochromatosis: a disease in which too much iron is absorbed from the intestine and the excess iron accumulates in various organs. The liver is the first organ to store iron, but when its storage capacity is exhausted, iron may accumulate in the heart, pituitary gland and elsewhere in the body. If untreated, damage to the liver, heart and pancreas may eventually cause death. Hemoglobin: the component of red blood cells that carries oxygen Hemophilia: an inherited disease that affects mostly males and prevents normal blood clotting. It is treated by lifelong injections of a synthetic version of the clotting factor lacking in persons with the disease. The new recombinant clotting factor replaces the natural product, which was extracted from people's blood. Hemophiliac: a person who has hemophilia Hepatitis: inflammation or swelling of the liver Hepatitis A: a liver disease caused by the hepatitis A virus and spread through contaminated food and water Hepatitis B: a liver disease caused by the hepatitis B virus and spread through direct contact with blood or body fluids or sexual contact with an infected person Hepatitis C: a liver disease caused by the hepatitis C virus (HCV) and spread through direct blood-to-blood contact with an infected person Hepatocellular carcinoma: liver cancer Hepatomegaly: enlarged liver HIV: a disease in which the human immunodeficiency virus (HIV) weakens the person's immune system. HIV is the virus that causes AIDS (acquired immune deficiency syndrome). Hyperglycemia: an abnormally high level of sugars in the blood Immune system: the natural defense mechanism in the body that reduces susceptibility to a disease Immunity: a body's resistance to the effects of a deleterious agent, such as a virus. A person may have developed immunity to one virus, but not another. Immunization: an injection with a vaccine that causes the body to develop immunity against a certain virus or bacterial infection Immunocompromised: used to describe people who lack normal natural levels of immunity. This could include people with HIV infection or people who are taking immunosuppressive drugs (such as transplant patients). Immunoglobulin: a type of blood plasma that provides immunity to certain viruses, such as hepatitis A and hepatitis B (also called gamma-globulin) Incidence: the number of new cases of a disease occurring in a given population over a certain period of time Incubation period: time it takes for the virus to develop sufficient copies of itself in a body before symptoms and signs of the disease occur and before it can be detected through blood tests In vitro: outside the living body and in an artificial environment In vivo: in the living body of a plant or animal Interferon: one of a
number of antiviral proteins that modulate immune response. Interferon
alpha (IFNa) is secreted by an infected cell and strengthens the defenses
of nearby uninfected cells. A manufactured version of IFNa (trade names
Roferon, Intron A) is an HPB approved treatment for Kaposi's sarcoma,
hepatitis B virus and hepatitis C virus. Jaundice: yellow discolouration of the skin and eyes as a result of a build-up of bilirubin in the blood. May be a symptom of many liver diseases. Liver biopsy: a diagnostic procedure used to obtain a small amount of liver tissue, which can be examined under a microscope to help identify the cause or stage of liver disease. Under local anesthetic, a needle is inserted and a small piece of liver is removed. Liver function tests: blood tests used to assess the general state of the liver or biliary system, and to reflect the presence of damage or inflammation. Common LFTs include ALT, AST and bilirubin. Liver Transplant: a life-saving operation to replace a diseased liver with a healthy, donated liver Mutation: the ability of a virus to change its outer coating and therefore not be recognized and attacked by antibodies NAT: nucleic acid testing. Testing that allows direct detection of specific HCV RNA in serum, plasma or tissues, independent of the host's immune response. Viral nucleic acid detected in the plasma or serum reflects active HCV replication in the liver. NAT-based detection of HCV RNA is performed in two major ways. The most common is target amplification, an example of which is the polymerase chain reaction (PCR). The other major approach involves signal amplification, and includes the branched chain DNA technique. Nausea: feeling sick to your stomach and wanting to vomit Nucleic acid: molecules in living cells, which carry hereditary information. The presence of DNA and RNA, the chief types of nucleic acid, allow cells to replicate themselves. Nucleoside analogue: an artificial copy of a nucleoside. When incorporated into a virus DNA or RNA during viral replication, the nucleoside analogue acts to prevent production of a new virus. An example of a nucleoside analogue is ribavirin, the drug used in combination with interferon to treat hepatitis C. Nucleoside: a building block of nucleic acids. Nucleosides are nucleotides without the phosphate group. PCR: polymerase chain reaction. PCR is a method to test for HCV RNA, the actual viral material of hepatitis C. There are two types of test for HCV RNA by PCR. Qualitative tests give a positive or negative result and are recommended for patients who are anti-HCV positive with normal ALT levels, and to determine response to treatment. Quantitative tests give the viral concentration or viral load, and are not routinely recommended for patients. Pegasys: type of pegylated interferon PEG-Intron: type of pegylated interferon Pegylated interferon: a form of interferon that stays in the body longer. Pegylated interferon is created by attaching polymers to interferon. This allows the interferon to become more water-soluble and to remain inside the body longer, accounting for its enhanced activity. This reduces the frequency of injections. Pegylated interferon is under review for approval in Canada. Platelet: fragments of blood cells that are necessary for blood clotting (coagulation). Platelets are released when damage occurs to a blood vessel. By forming into clots, they stem the flow of blood from the damaged blood vessel. Polymerase: any of several enzymes that catalyze the formation of DNA or RNA using pre-existing DNA or RNA as a template (pattern). Porphyria: the inability of cells to convert porphyrins to heme in a normal manner. Porphyrins are chemical compounds that are stepping stones along the pathway that leads to the formation of heme in humans, and to chlorophyll in plants. Protease inhibitor: a type of antiviral drug that acts by inhibiting the virus' protease enzyme. This prevents the virus from replicating itself. Protease: an enzyme that breaks down proteins, including viral proteins Quasispecies: closely
related variants of a single genotype within a single individual, which
arise from mutations that occur during viral replication. The quasispecies
may have an impact on how the virus reacts in an individual and on the
natural history of the infection. Rebetron: trade name for the combination therapy of interferon alfa-2b plus ribavirin used for the treatment of hepatitis C. RIBA: recombinant immunoblot assay is a supplementary test used to confirm findings when an EIA test is positive. Measures presence of various antibodies to hepatitis C in the blood. Ribavirin: one of a group of drugs called nucleoside analogues that prevent viruses from multiplying. Ribavirin is used in combination with interferon alfa-2b in the treatment of hepatitis C. Seroconversion: the development of antibodies to a particular antigen Serologic test: any of a number of tests done using the clear portion of blood. Often refers to a test that determines the presence of antibodies to antigens such as viruses. Spider nevi: asymptomatic, spider-like marks that may develop in patients with advanced cirrhosis of the liver. The mark consists of a central arteriole, radiating from which are numerous small vessels resembling a spider's legs. Common sites are the necklace area, face, forearms and the back of the hands. (Also called vascular spiders, arterial spiders, spider telangiectasis or spider angioma.) Spleen: a large organ situated in the upper part of the abdominal cavity on the left side. The spleen breaks down red blood cells and sets free hemoglobin, which the liver then converts into bilirubin. In addition, the spleen performs many more important functions. Splenomegaly: an enlarged spleen Steroid: a member of a large family of structurally similar lipid molecules. Different classes of steroids perform different functions. Anti-inflammatory steroids can reduce swelling, pain and inflammation. Teratogenicity: tendency to produce birth defects. Teratogenicity is a potential side effect of some drugs, including ribavirin. Titre: a laboratory
measurement of the concentration of a given compound in solution. (Also
spelled "titer".) Vaccine: a solution of killed or inactive viruses or bacteria, or synthetically, genetically engineered antigenic material. Usually administered by injection, a vaccine can stimulate an immune response and thus give a person protection against contracting a disease. Currently there is no vaccine against hepatitis C. Varices: large, swollen blood vessels in the stomach and esophagus. In people with severe liver damage the normal flow of blood through the liver is blocked. Blood from the intestines is then re-routed around the liver, primarily through the small blood vessels in the stomach and esophagus. These can become enlarged and swollen (varices) and eventually rupture, causing internal bleeding. Virus: a tiny microorganism, smaller than bacteria, which cannot replicate itself without a host and can cause sickness in humans that cannot be treated with antibiotics. This glossary of terms was taken from the "Hepatitis C Question and Answer Manual" produced by the Canadian Liver Foundation and is used with permission. |
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