AIDS (acquired immunodeficiency syndrome) is a disease caused by an infection with HIV (human immunodeficiency virus). This virus is transmitted via bodily fluids (such as blood and sexual fluids). Approximately 1 million people in the United States have HIV, according to Medline.
HIV Pathology
HIV infects a specific subtype of cells within the body called CD4+ T-cells (or CD4 positive T lymphocytes). T cells are white blood cells that are a part of the immune system's response to invading organisms. CD4 is a protein that can be found on some of these T cells. When HIV infects these cells, it kills them, which gradually depletes the immune system.
HIV Life Cycle
HIV, like all viruses, has to be inside a host cell to replicate. The first stage of HIV's life cycle, according to AIDSInfo, is the binding and fusion of the virus to the CD4+ T cells. Once the virus has infected the T cell, it converts its genetic material (RNA, which is similar to DNA) into DNA. The virus then incorporates this new DNA into the cell's DNA, which causes the cell to make more copies of the virus. The newly made copies of the virus then leave the cell to infect other CD4+ T cells.
Symptoms
Patients commonly do not have any symptoms immediately after being infected with HIV, the Mayo Clinic explains. Two to four weeks after the patient has been infected, the patient may develop an illness that resembles the flu. Symptoms may include a headache, the fever and swollen lymph nodes. Typically the patient will then have no symptoms until the disease progresses.
HIV and AIDS
It can take several years for HIV to develop into AIDS, according to Medline. This is because the body's immune system is able to make more CD4+ T lymphocytes to compensate for the ones killed by the virus. However, over time the immune system becomes seriously weakened, leading to AIDS. As the patient's immune system gets weaker, it becomes more susceptible to infections, which can ultimately be fatal as the immune system is unable to fight off pathogens.
Treatment
HIV infections cannot be cured, but according to the Mayo Clinic, the progression of the disease can be slowed. Patients with HIV are typically given a combination of drugs that either slow the virus's replication or block it from getting into the CD4+ T cells. HIV treatment is often called HAART, also known as Highly Active Anti-Retroviral Therapy. While a patient is being treated, the levels of HIV in the patient's blood will be monitored every three to four months.
