Definitions.

Anemia: low levels of red blood cells or hemoglobin in the blood, resulting in feelings of tiredness or fatigue.

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

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.