Acquired Immunodeficiency Syndrome (AIDS)

Acquired Immunodeficiency Syndrome (AIDS) is a condition associated with infection with Human Immunodeficiency Virus (HIV). The common subtypes for HIV are HIV-1 and HIV-2.

It is important to know that a positive test for HIV-1 or HIV-2 does not constitute a diagnosis for AIDS. This diagnosis requires evaluation of the clinical condition of the person as well as other laboratory tests that show immunodeficiency.  In other words, a person infected with HIV is HIV positive but may have NOT developed AIDS. 

AIDS is the result of damage to the immune system.  This syndrom can develop as HIV uses certain types of the infected person's white cells to multiply.  There is a schema in this article showing the multiplication cycle of HIV within a human white cell.  The white cells used by the virus to multiply can no longer function properly.  Therefore, the immune system of the infected person begins to suffer ultimately showing immunodeficiency.  These deficiencies, make the infected person susceptible to a number of other types of diseases. 

Some of the most commonly used tests used to diagnose AIDS, as well as check the effectiveness of drug therapy to control the disease follow:

HIV antibody– this is the most commonly used test for initial screening. It tests for the antibody against the HIV virus. This test may have false-positives (a false positive is a positive result for a test that is not really positive). Therefore, before giving an HIV diagnosis, most healthcare givers order a confirmatory test.

HIV Western Blot – This is a confirmatory test for HIV antibody.

CD4+ and CD8+ lymphocyte levels – These are tests that specifically measures the levels of these type of white cells. This in turn is directly related to the immunological status of the person.

HIV RNA (Viral Load) – this measures the actual amount of HIV activity in the blood. It is mostly used to check antiretroviral therapy (drugs against HIV).

HIV drug resistance – assists to find if the virus contracted is susceptible to a specific drug. Used to improve treatment protocols.

The Center for Disease Prevention and Control (CDC) has published easy to read fact sheets on all Sexually Transmitted Diseases and related conditions.

AIDS virus drawing

HIV Virus DrawingCredit: NIAIDCredit: NIAID

AIDS virus multiplication

HIV replication cycle(77286)Credit: NIAIDCredit: NIAID