[[pl:Wirus_nabytego_niedoboru_odporno%B6ci]] HIV is an abbreviation for human immunodeficiency virus, which is a frequently mutating retrovirus that attacks the human immune system and which has been shown to cause acquired immune deficiency syndrome (AIDS).
A small minority of scientists continue to question the connection between HIV and AIDS and even the very existence of HIV (see Duesberg hypothesis).
HIV causes disease by infecting the CD4+ T cells. These are a subset of leukocytes (white blood cells) that normally coordinate the immune response to infection. By using CD4+ T cells to replicate itself, HIV spreads throughout the body and at the same time depletes the very cells that the body needs to fight the virus. Once a HIV+ individual's CD4+ T cell count has decreased to a certain threshold, they are prone to a range of diseases that the body can normally control. These opportunistic infections are usually the cause of death.
Treatment
Patients today are given a complex regime of drugs that attack HIV at various stages in its life cycle. These are known as antiretroviral drugs. They include:
- Protease inhibitors (PIs) inhibit production of protease, an enzyme used directly by HIV, and so prevent virus replication.
- Reverse transcriptase inhibitors (RTIs) inhibit production of reverse transcriptase, an enzyme HIV needs to reproduce. Lack of this enzyme prevents HIV from building RNA and DNA. They come in three forms:
Many problems are involved in establishing a course of treatment for HIV. Each effective drug comes with side effects, often serious and sometimes life-threatening in themselves. Common side effects include extreme nausea and diarrhea, liver damage, and jaundice. Any treatment requires regular blood tests to determine continued efficacy (in terms of T-cell count and viral load) and liver function.