The term AIDS is said for the advance stages of the HIV infection. CDC's definition of AIDS is with people who have less than 200 CD4 positive T cells per cubic millimeter of blood. These T cells are the ones that signal the other immune cells to perform their certain function, to fight everyday diseases. T lymphocytes play a major role in defense against intracellular pathogens such as viruses, protozoa and intracellular bacteria, and are also involved in immunity to extra cellular pathogens by providing "help" for the antibody response (Browning). These .
CD4 T cells are usually called the "helper" cells. These cells enhance the activation of the natural killer cells, cytotoxic T cells, and in the activation of microphages (Browning). Natural killer cells is a type of white blood cell that contains granules (small particles) with enzymes that can kill tumor cells or microbial cells (harmful cells). Cytotoxic cells are cells that are poisonus cell killing cells, in other words these cells help protect the body from bad cells. Microphages are like neutrophile with an irregular nucleus that ingests bacteria. These are just three examples of what the CD4-T cells are responsible for activating. Without these CD-4 T cells, those cells together with many other white blood cells will not be activated to perform their action. Picture the body as a territory with an army isolated in a camp (gland), CD4-T cells are watch dogs that are trained to activate these cells to leave the camp and attack foreign invaders (diseases). The army is divided into groups specialized in killing different types of invaders. So when the CD-4 T cells identify what invader is invading private territory, it informs a specialized white blood cell to engage battle in order to keep the body in homeostasis. .
Diagnosis & Symptoms.
Usually people get blood tests to figure out if the are HIV positive or not. Unfortunately, HIV antibodies do not appear in the blood tests for one to three months following the infection, it maybe will take 6 months until the number of antibodies is in a large enough amount to trigger the threshold detectable by the blood test.
