Antibody: proteins produced by the immune system to fight specific bacteria, viruses, or other antigens.
Chemokine antagonist: (also known as CCR5, short for chemokine receptor 5). This new class of HIV drugs blocks HIV from attaching onto the CCR5 receptor on the T-cell, making it hard for the virus to enter T cells.
Enzyme: a protein made in the body that can change one substance into another.
Genetic material: used to store a person's biological blueprint in the body.
Genotypic resistance testing: a test that looks at a person's HIV genes to see if there have been changes (mutations) to HIV. When changes in these HIV genes occur, HIV drugs are not as effective.
Growth hormone: a substance secreted by one part of the body that stimulates cells in another part of the body.
Integrase inhibitor: a new class of HIV reed that blocks the action of integrase, an enzyme that inserts genetic material from the virus into a person's cells.
Lipoatrophy: the loss of fat under the skin, especially in the limbs and cheeks, that appear as dents in the skin.
Lipodystrophy: changes in the body fat, such as loss of fat in the arms and legs, and a buildup of fat in the gut or at the back of the neck.
Mutation: occurs when a gene is damaged or changed in such a way as to alter the genetic material carried by that gene.
Opportunistic infection: a disease or infection caused by an organism that is usually harmless but becomes activated when a person's immune system is weakened or damaged.
Osteopenia: refers to bone mineral density that is lower than normal but not low enough to be classified as osteoporosis.
Osteoporosis: a disease that weakens bones, increasing the risk of sudden and unexpected fractures.
Osteonecrosis: the destruction (necrosis) of bone tissue, often due to an interference with the supply of blood to the bone.
Placebo: a pill or substance with no effect on the body, such as a sugar pill. It is often used to compare with a real medication to see what the medications real effect might be.
Primary infection: the period soon after being infected HIV when the virus multiplies rapidly and causes flu-like symptoms.
Regimen: a treatment plan for drugs or medications, including the dose, the schedule of treatments.
Resistance (resistant): a genetic change that allows HIV to reproduce itself in the presence of an HIV medication.
Toxicity: the degree to which a substance is poisonous or dangerous.
Triglyceride: a type of fat found in the blood that the body uses to store energy.
Virologic failure: an increase in vial load.