HIV Glossary Terms
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Adherence
The ability to stay on treatment and take meds as prescribed.
AIDS (acquired immune deficiency syndrome)
In the United States, AIDS (Acquired Immune Deficiency Syndrome) is a diagnosis made by a doctor when an HIV+ person:
- Has a CD4 cell count less than 200 (per cubic millimeter of blood), or
- Has a specific infection, cancer or condition (opportunistic infection or disease) associated with HIV infection
(For a complete list of AIDS-defining illnesses, please visit www.cdc.gov/hiv/dhap.htm .)
AIDS Service Organization (ASO)
A community-based social services organization or agency that offers a range of support and education programs for people living with and affected by HIV/AIDS.
Anemia
A lowered number of red blood cells that can result in decreased energy and increased fatigue (feeling tired).
Antibodies
A part of the immune system that "tags" or destroys viruses, bacteria, etc. An HIV antibody test is positive when antibodies that are specific to the virus are detected.
A type of medicine (drug or "med") that blocks a virus's ability to make copies of itself. HIV is a kind of virus called a retrovirus, so all of the HIV drugs or meds are considered antiretroviral drugs.
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Bilirubin
Occurs in liver bile, urine and blood and is used to determine the health of the liver. An elevated or increased level of bilirubin can mean that the liver is diseased or weakened.
Body fat redistribution
Changes in body fat (often called lipodystrophy syndrome) that can result in a paunch, a hump at the back of the neck, facial thinning and loss of fat in the arms and legs.
Body fluids
Any fluid in the human body including blood, urine, saliva, tears, semen, vaginal secretions and breast milk. HIV needs to infect certain cells in the body—especially CD4 cells—so fluids that contain higher levels of those cells will have levels of HIV that make it infectious (able to be passed to another person). The body fluids that can pass HIV to another person are blood, semen, vaginal secretions and, less often, breast milk, especially when blood is found in breast milk as a result of dry or cracked nipples occurring during breastfeeding.
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A kind of immune system cell that helps protect the body against infections. Also known as "T helper cells," CD4 cells activate other parts of the immune system response by telling other cells to perform their specific roles in fighting infection. Destruction of CD4 cells by HIV is the main way the virus weakens the immune system. A decreasing CD4 cell count means that an HIV+ person is at greater risk of getting opportunistic infections and illnesses.
The measurement of CD4 cells per cubic millimeter (about a teaspoon) in your blood.
Cholesterol is a fat-like substance found in the bloodstream and in all of the body's cells used for producing cell membranes and some hormones, as well as serving other needed bodily functions. Low-density lipoprotein (LDL) cholesterol, or "bad" cholesterol, can increase the risk of heart attack and stroke if it's too high. High-density lipoprotein (HDL), or "good" cholesterol, protects against heart disease by carrying cholesterol away from the arteries.
Generally, two or more classes of antiretroviral drugs used in combination to block stages of the viral replication process (the process by which HIV makes copy of itself) and decrease the amount of virus in the body.
Cross-resistance
Occurs when one HIV med causes resistance to one or more of the other HIV meds in the same class ("family") of drugs, even if the person hasn't yet taken it. When one HIV med can no longer recognize HIV and attack it, other HIV meds that work almost the same way may not be able to recognize and target the virus either.
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Detectable
Having a viral load that can be detected (more than 50 or 400 copies of virus per milliliter of blood, depending upon the viral load test that is performed.
Diarrhea
Uncontrolled, loose and frequent bowel movements. There are many possible causes of diarrhea in persons living with HIV—infections, bacteria, parasites, diet, medications and problems with the intestine. HIV-related diarrhea can be life-threatening because of the dangerous loss of fluid (dehydration).
Drug resistance
The ability of bacteria, viruses and other illness-causing agents to adapt to treatments and continue to grow or multiply. When HIV becomes resistant (less sensitive) to an HIV med (as determined by a genotype or phenotype resistance test ) it is necessary to change treatment.
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Fusion inhibitors
A kind of HIV med that blocks HIV outside the CD4 cell , stopping the viral replication process before it starts.
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Gastrointestinal (GI)
Relating to the stomach and intestines.
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HAART (Highly Active Antiretroviral Therapy)
The aggressive treatment of HIV infection through combination therapy to reduce the amount of virus and get to undetectable (fewer than 400 or fewer than 50 copies of virus per milliliter of blood).
Hepatic
Related to the liver.
Hepatitis
Inflammation of the liver which can be caused by bacterial or viral infection, parasites, alcohol or drug use (including some over-the-counter drugs) or a transfusion of the wrong kind of blood. Many cases are not health- or life-threatening. Severe hepatitis can cause hardening of the liver and long-term (chronic) liver problems.
Hepatitis A
Caused by the hepatitis A virus. Hep A can be spread by direct contact through food or water that is contaminated with feces. There is a vaccine available for hepatitis A.
Hepatitis B
Caused by the hepatitis B virus (HBV). Hepatitis B affects the liver and can cause serious liver damage. HBV infection can happen by coming into direct contact with the blood or body fluids of an infected person. As with HIV, you can become infected with HBV by having unprotected sex or sharing needles with an infected person.
Hepatitis C
Caused by the hepatitis C virus (HCV). Hepatitis C affects the liver and can cause liver damage. HCV infection happens by coming into direct contact with the blood of an infected person. About 40% of patients living with HIV are also co-infected with HCV because both viruses are spread in similar ways—especially through sharing needles. Having HIV and HCV causes more rapid progression to liver damage and failure. There is no vaccine for hepatitis C.
HIV (human immunodeficiency virus)
The virus that weakens the human immune system and creates the conditions that makes an AIDS (acquired immune deficiency syndrome) diagnosis possible. HIV attacks the immune system, infecting cells in the body—especially CD4 cells—lowering the number of cells ( CD4 cell count ) needed to help fight infections.
HIV disease
Gradual weakening of the immune system because of HIV infection.
Hyperlipidemia
An increase in levels of triglyceride and cholesterol in the blood that can lead to heart and vascular (blood vessel) disease and/or pancreatitis (inflammation of the pancreas).
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The human body's complex system of fighting infection including the skin, white blood cells, lymph nodes, antibodies and other cells and molecules in the body.
Immunodeficiency
A breakdown and weakening of the immune system that causes a person to become more vulnerable to infections and diseases.
Infection
The state or condition in which the body or part of the body in invaded by an infectious agent (bacteria, viruses, fungus, parasites) that grows and harms the body (active infection).
Infectious
An infection that is transmitted during intimate, close contact (for example, unprotected sex). HIV is infectious—not contagious. A contagious infection can be passed through casual contact like coughing or sneezing. HIV is passed only through intimate contact with blood, semen or vaginal secretions. HIV is not passed through sharing food, spitting, sharing utensils, making contact with toilet seats, shaking hands, hugging, kissing, etc.
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Lipid
Any group of fats and fatlike compounds, including sterols (eg, cholesterol), fatty acids and other substances.
Lipodystrophy
A syndrome believed to be associated with antiretroviral therapy and generally referred to as a redistribution of body fat. Lipodystrophy may be defined as an increased amount of fat around the gut or stomach, the base of the neck and the breasts, as well as decreased fat in the legs, arms and face. Lipodystrophy is often associated with high levels of cholesterol, triglycerides, insulin or glucose in the blood.
Liver function test (LFT)
A test that measures blood levels of several enzymes produced by the liver. An elevated liver function test result (increased levels of liver-related enzymes) is a sign of possible liver disease.
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Mutation
When HIV changes during the replication process (the process of making copies). These changes mean that the new virus in the body is different from the original—and the changed virus may eventually be less sensitive to certain HIV meds ( antiretroviral drugs ).
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NNRTI (Non-nucleoside reverse transcriptase inhibitors
A kind of HIV med that blocks HIV from making copies of itself early in the process. NNRTIs block the reverse transcriptase enzyme that makes it possible for HIV to transfer its genetic material into the CD4 cell's genetic material. NNRTIs are similar to NRTIs , although they work in a slightly different way.
NRTI (Nucleoside reverse transcriptase inhibitor)
A kind of HIV med that blocks HIV from making copies of itself early in the replication process. NRTIs block the reverse transcriptase enzyme that makes it possible for HIV to transfer its genetic material into the CD4 cell's genetic material. NRTIs are similar to NNRTIs , although they work in a slightly different way.
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Opportunistic infections (OIs)
Infections and illnesses that happen when a person's immune system is weakened by HIV infection. These illnesses are not common in people with functioning immune systems. People with advanced HIV disease or an AIDS diagnosis can have infections of the lungs, brain, eyes and other organs. Opportunistic infections that can occur in people with AIDS include Pneumocystis carinii pneumonia (PCP), candidiasis (yeast infections or thrush), cancers and Mycobacterium avium complex (MAC). (For a complete list of AIDS-defining illnesses, please visit www.cdc.gov/hiv/dhap.htm .)
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Inflammation of the pancreas that can cause severe pain and serious illness. The pancreas is a gland found behind the stomach that helps with digestion and produces insulin. The beginning of pancreatitis can be predicted by rises in blood levels of the pancreatic enzyme, amylase.
Protease inhibitor (PI)
A kind of HIV med that stops HIV from making copies of itself by blocking the last step in the process. HIV's protease enzyme breaks apart long strands of viral protein into the smaller, separate proteins that make up the core of new virus. Protease inhibitors keep the enzyme from cutting up the long viral chain—and if the larger HIV proteins are not broken apart they can't make themselves into new HIV particles that can leave the CD4 cell and infect other cells.
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The process by which a virus, like HIV, makes copies of itself.
When HIV in your blood changes in a way that causes one or more HIV medicines to stop working. Resistance is one of the main reasons why HIV medicines stop working.
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Sexually Transmitted Diseases (STD)
An infection spread by passing infection- or illness- causing organisms from one person to another through sexual contact. There are more than 20 STDs, including HIV, herpes, gonorrhea, syphilis, genital warts, chlamydia, hepatitis B, trichomoniasis and chancroid. If left untreated, some STDs can lead to certain kinds of cancers, fertility problems, neurological (brain) problems and death.
Effects of a medicine that are usually undesirable—including things like headache, diarrhea, fatigue, liver or kidney problems, rash and/or other problems that can make taking the medicine difficult or not possible.
Symptom
Any noticed change in the body or its functions that is a sign of disease or stages of a disease.
Synergy
An interaction between two or more drugs that enhances or produces an effect greater than the effects of the drugs on their own.
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T cell
See also CD4 cell . T cells are white blood cells made in the thymus gland in the body. White blood cells participate in the immune system response. There are three very different types of T cells: helper, killer and suppressor. These cells are responsible for organizing certain immune responses, "policing" the immune system to find infected cells, stimulating antibodies and cell- killing T cells and then shutting down an immune response if it has effectively cleared out the invading organisms. An HIV+ person's immune system does not function properly because HIV takes over the helper CD4 cells to make more HIV, and the killer T cells (T8 or CD8 cells) continue to try to shut the immune system.
Transmission
As related to HIV infection: HIV is passed from an infected person to the sexual or needle-sharing partner(s) through unprotected anal, vaginal or oral sex and through sharing contaminated needles and "works" (those items used for setting up and injecting drugs like heroin and cocaine). It is possible to pass HIV during pregnancy and childbirth and through breastfeeding. HIV transmission through blood transfusion is rare in developed countries with careful screening of blood products. HIV cannot be transmitted by donating blood.
Compound made up of fatty acid and glycerol. Elevations in triglyceride levels (especially in combination with increased cholesterol levels) have been associated with clogged arteries—an underlying cause of some heart diseases and stroke. Recent observations and studies have shown that some patients taking HIV meds may experience very high triglyceride levels.
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Undetectable
When the amount of HIV in blood (viral load) is less than 400 or less than 50 copies per milliliter of blood (both measurements are considered undetectable and differ only in the kind of test used to determine the amount of virus in the blood). It is generally agreed that having an undetectable viral load, or a significantly lowered viral load, is one way to slow HIV disease progression. Even when a viral load is undetectable, it is still possible to pass HIV through unprotected sex, sharing needles and other risk behaviors.
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Viral load
The amount of HIV RNA (its genetic material) in the blood, measured in copies per milliliter of blood plasma. Viral load is considered a significant sign of the risk of HIV disease progression. The lower the viral load, the longer it takes to progress to the conditions that make an AIDS diagnosis possible. Viral load testing is one factor used to decide when to start or change HIV combination therapy .
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Sources
The information provided here is based on information provided in the Glossary of HIV/AIDS-Related Terms, 4th Edition, published by the HIV/AIDS Treatment Information Service and available at http://www.aidsinfo.nih.gov
For additional information about HIV/AIDS, please visit the resources section of this Web site.
This information does not include everything you may need to know about HIV and does not take the place of talking with your healthcare provider.
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