Glossary

PT (prothrombin time; pro-time) – PT testing measures the amount of time it takes for blood to clot. When the liver is damaged, its ability to make clotting factors is impaired. If this time increases – referred to as a prolonged PT interval – it shows that the liver is not working so well.

compensatory mutation – this refer to an additional mutation, usually in the context of the fitness of a virus. For example, the mutations that stop a drug form working often stop the virus from reproducing as well. Additional mutations that return the virus to it’s former fitness are called compensatory mutations. They compensate for the reduced viral fitness. See revertant mutation.

elite controller (EC) – if your viral load stays undetectable for more than five years without ART you are an elite controller.

Elite controllers also have a very good CD4 count (always above 500 cells/mm³) that stays at a similar level over many years.

Even with this good immune response, ART is still generally recommended in the long-term.

This is because over decades – some ECs have been undetectable for more than 20 years – there is a concern that low level HIV in different body compartments like the brain, might lead to accumulative serious damage that isn’t easy to detect until it is too late.

This is a real concern, though evidence is limited because of the rarity of ECs.

See: long-term slow progressor (LTSP)/long-term non-progessor (LTNP).

viral load test – a test that detects whether a virus is present (qualatitive) or that measures the amount of virus (quantitative).

This is usually in a sample of blood, but a viral load test can also be used to check viral levels in other samples including genital fluid, semen or spinal fluid.

Results are given as the number of copies of virus in a millilitre of blood (copies/mL).

enzyme – a protein produced in the body that triggers or speeds up other chemical reactions.