Glossaries
Key Terms and Definitions
The terms and definitions in our glossaries are intended to provide you with a better understanding of words frequently used on this website and/or in reference to published articles and other sources. Information contained in our glossaries is no substitute for your healthcare professional's advice.
- ABC
- Abacavir.
- ADCC
- Antibody-dependent cellular cytotoxicity.
- ADR
- Adverse drug reaction.
- AIDS
- Acquired immunodeficiency syndrome.
- AIDS Dementia Complex (ADC)
- HIV encephalopathy.
- AIDS-Defining Condition
- AIDS-defining illness.
- AIDS-Defining Illness
- An opportunistic or malignant condition that is included in category C of the CDC (Centers for Disease Control) case definition and is a reason for an AIDS diagnosis. The 26 conditions include candidiasis, cytomegalovirus infection (CMV), Kaposis Sarcoma (KS), mycobacterium avium complex (MAC), pneumocystis jiroveci pneumonia (PCP), progressive multifocal leukoencephalopathy (PML), pulmonary tuberculosis, invasive cervical cancer, and wasting syndrome. cf: AIDS cf: Centers for Disease Control
- APV
- Amprenavir.
- ARS
- Acute retroviral syndrome.
- ATV
- Atazanavir.
- Abacavir (ABC)
- Generic name for Ziagen®. cf: nucleoside reverse transcriptase inhibitor
- Acquired Immunodeficiency Syndrome (AIDS)
- The late stage of HIV disease; AIDS involves the loss of function of the immune system as CD4 cells are infected and destroyed, allowing the body to succumb to opportunistic and malignant diseases. The CDC defines AIDS as a CD4 cell count below 200 cells/mm3 or the presence of at least one opportunistic illness in an HIV positive individual (Category C).
- Acute HIV Infection
- The initial stage of infection with HIV, prior to the development of antibodies. Acute HIV infection is characterized by a drop in CD4 Cell counts and an increase in HIV levels in the blood. Some, but not all, individuals experience flu-like symptoms during this period of infection. These symptoms can include fever, inflamed lymph nodes, sore throat, and rash. cf: seroconversion acute retroviral syndrome (ARS) asymptomatic HIV infection symptomatic HIV infection acquired immunodeficiency syndrome (AIDS)
- A combination of flu-like symptoms (e.g. fever, sore throat, skin rash, inflamed lymph nodes) that accompanies acute (primary) HIV infection in some patients. These symptoms may last from 7 to 10 days and then go away. Often used as a synonym to acute HIV infection. cf: acute HIV infection.
- Adherence
- Compliance.
- Adverse Drug Reaction (ADR)
- Any drug effect that is unwanted, unpleasant, or potentially harmful. These effects may be mild and may disappear when the drug is stopped or subside as the body adjusts to the drug (short-term ADR). Other ADRs, such as skin rashes, anemia, or organ damage, are more serious (long-term ADR).
- Adverse Effect
- Adverse drug reaction.
- Adverse Event
- Adverse drug reaction.
- Amino Acid
- An organic compound that is a basic structural unit of peptides and proteins.
- Antibody
- Also known as immunoglobulin. A protein produced by the body's immune system that recognizes and fights infectious organisms and other foreign substances that enter the body. Each antibody is specific to a particular piece of an infectious organism or other foreign substance.
- Antibody-Dependent Cellular Cytotoxicity (ADCC)
- An immune response in which antibodies bind to target cells and identify them for attack by other immune cells (natural killer cells and macrophages).
- Antigen
- Any substance that can stimulate the immune system to produce antibodies against it. Antigens include bacteria, viruses, proteins, and other foreign materials. The HIV contains various antigens (e.g. gp120, p24).
- Antigene Presenting Cell
- A cell (e.g. dendritic cell) that processes antigen proteins and displays the short peptide fragments on its surface in conjunction with major histocompatibility (MHC) proteins, enabling recognition by T-cells, which iniitiate an immune response.
- General term for treatment with antiretroviral drugs that reduce viral replication and hence the progression of disease. The antiretroviral therapy recommended for HIV infection is referred to as highly active antiretroviral therapy (HAART), which uses a combination of medications to attack HIV at different points in its life cycle. cf: highly active antiretroviral therapy cf: replication cycle
- Apoptosis
- Programmed cell death.
- Assembly
- A step in the replication cycle of HIV. HIV proteins and RNA accumulate on and associate with the inner surface of the plasma membrane. As assembly continues, the new HIV leaves the cell. cf: replication cycle.
- Asymptomatic HIV-Infection
- A period of varying length after acute infection with HIV during which there are no symptoms of HIV infection. At the same time there is ongoing viral replication and a steady deline in CD4 cells. cf: acute HIV infection symptomatic HIV infection acquired immunodeficiency virus (AIDS)
- Asymptomatic Phase
- Asymptomatic HIV-Infection.
- Attachment
- A step in the replication cycle of HIV. HIV's envelope protein binds to the cell surface molecule CD4, which allows binding of another envelope protein gp41 to a chemokine receptor (CCR5, CXCR4). Attachment is followed by fusion of HIV with the cell. cf: replication cycle
- Attachment Inhibitor
- A class of anti-HIV drugs designed to prevent binding of the viral envelope protein to the CD4 receptor of the host cell. cf: entry inhibitor cf: CD4 receptor
- Attenuated
- Weakened, made less virulent. An attenuated virus is a virus that is still alive but incapable of causing harm. cf: attenuation
- Attenuation
- Weakening or reducing the level of virulence of a pathogen. An attenuated virus still posseses immunological properties but has a diminished ability to cause disease. Used in vaccines.