Glossary
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LATENCY

The period when an infecting organism is in the body but is not producing any clinically noticeable ill effects or symptoms. In HIV disease, clinical latency is an asymptomatic period in the early years of HIV infection. The period of latency is characterised in the peripheral blood by near normal CD4 counts. Recent research indicates that HIV remains quite active in the lymph nodes during this period. Cellular latency is the period after HIV has integrated its genome into a cell's DNA but has not yet begun to replicate.

LENTIVIRUS

"Slow" virus characterised by a long interval between infection and the onset of symptoms. HIV is a lentivirus as is the simian immunodeficiency virus (SIV) that infects non-human primates.

LESION

A general term to describe an area of altered tissue (e.g. the infected patch or sore in a skin disease).

LIPODYSTROPHY

A disturbance in the way the body produces, uses and distributes fat. Lipodystrophy is also referred to as "buffalo hump," "protease paunch," or "Crixivan potbelly." In HIV disease, lipodystrophy has come to refer to a group of symptoms that seem to be related to the use of protease inhibitor drugs. How protease inhibitors may cause or trigger lipodystrophy is not yet known. Lipodystrophy symptoms involve the loss of the thin layer of fat under the skin, making veins seem to protrude; wasting of the face and limbs; and the accumulation of fat on the abdomen (both under the skin and within the abdominal cavity) or between the shoulder blades. Women may also experience narrowing of the hips and enlargement of the breasts.

Logs (log10)

Short for logarithm. The number of times ten must be multiplied with itself to equal a number. For example, 100,000 is 5 logs (10 x 10 x 10 x 10 x 10). Logs are used to express viral load results and changes in viral load.

LONG-TERM NONPROGRESSORS

Individuals who have been living with HIV for at least 7 to 12 years (different authors use different time spans) and have stable CD4+ T cell counts of 600 or more cells per cubic millimeter of blood, no HIV-related diseases, and no previous antiretroviral therapy.

LYMPHADENOPATHY SYNDROME (LAS)

Swollen, firm, and possibly tender lymph nodes. The cause may range from an infection such as HIV, the flu, or mononucleosis to lymphoma (cancer of the lymph nodes).

Lymphocyte

White blood cells.

LYMPHOID INTERSTITIAL PNEUMONITIS (LIP)

A type of pneumonia that affects 35 to 40 percent of children with AIDS, which causes hardening of the lung membranes involved in absorbing oxygen. LIP is an AIDS-defining illness in children.

LYMPHOMA

Cancer of the lymphoid tissues. The types of lymphomas most commonly associated with HIV infection are called non-Hodgkin's lymphomas or B cell lymphomas. In these types of cancers, certain cells of the lymphatic system grow abnormally. They divide rapidly, growing into tumours.