LTNP / LTSP – See: long-term non-progressor.

life cycle

life cyle – the steps for an organism to reproduce or replicate. The HIV life cycle includes: Attachment and binding to a CD4 cell). Fusion or joining the cell. Reverse transcription. When the single strand RNA becomes a double strand …

long-term non-progressor (LTNP)

long-term non-progressor (LTNP) – An HIV positive person whose CD4 count stays above 500 copies/mm3 with very low viral load for more than five years, without using ART. Some LTNPs have kept their CD4 count above 500 for more than …

low level resistance

low level resistance – when there is some resistance but it does not have any significant impact on how well a drug works.  The HIV drug is still sensitve and is  considered active.

late breaker

late breaker – in research, this is a study presented at a medical meeting that was submitted to the conference organisers after the main programme had been decided. There are usually only a few dozen late-breakers, where the last minute …


lymphoma – name for a cancer in the lymphatic system. Cancer: lymphoma and sarcoma


lymphocyte – medical term for a white (clear) immune cell in blood, lymph or lymph tissue. Two main types of lymphocyte are B cells and T cells. CD4 cells and CD8 cells are both types of T cells. Sometimes a …

lumbar puncture

lumbar puncture – taking a sample of spinal fluid by inserting a needle into the body at the base of the spine. Also called a spinal tap.

log value

log value – a number expressed as a factor of 10 – ie 2 logs = 10 x 10=100; 3 logs = 10 x 10 x 10=1000. This measurement is used when needing to include very large and very small …


lipodystrophy – body fat changes, including fat loss (from arms, legs, buttocks and face) and/or fat gain (in abdomen, breasts and shoulders). The lipodystrophy syndrome also includes metabolic changes in lipid and glucose metabolism.


lipoatrophy – fat loss in your arms, legs or face. Lipoatrophy is a type of lipodystrophy.


lipid – medical term for fat. The term ‘blood lipids’ refers to cholesterol and triglyceride levels in blood.


lesion – damage to a part of the body.


latent – not active at present, resting. Latently infected CD4 cells are CD4 cells that are infected with HIV but which are resting. HIV drugs do not work on resting cells.

lactic acidosis

lactic acidosis – dangerous build up of lactate in the blood.


lactate – waste product produced when sugar is turned into energy by the body.

Lymph node

lymph node – small bodies in the lymphatic system, particularly at the neck, armpit, and groin, that filter bacteria and foreign particles. During infection, lymph nodes may become swollen with white blood cells (lymphocytes) fighting the infection.

Lymph system

lymph (or lymphatic) system – vessels, nodes, organs and clear fluid, that are part of the immune system.