HIV is a virus that attacks the immune system, our body’s natural defense against illness. If HIV is left untreated, a person’s immune system will get weaker and weaker until it can no longer fight off life-threatening infections and diseases.
What is ART?
ART are medications that treat HIV. The drugs do not kill or cure the virus. However, when taken in combination they can prevent the growth of the virus. When the virus is slowed down, so is HIV disease. Antiretroviral drugs are referred to as ARV. Combination ARV therapy (cART) is referred to as highly active ART(HAART).
Goals of ART
- Improvement the quality life and prolongation of life
- Reduction of HIV related morbidity and mortality
- Great reduction in viral load (<50 copies/ml) for as long as possible to stop or delay disease progression
- Restoration and preservation of immune function
- Minimization of drug side effects
- Reduction of HIV transmission
How are the drugs used?
Antiretroviral drugs are usually used in combinations of three or more drugs from more than one class. This is called “Combination Therapy.” Combination therapy helps prevent drug resistance.
- Manufacturers of ARVs keep trying to make their drugs easier to take, and have combined some of them into a single tablet regimen.
What is drug resistant?
When HIV multiplies, many of the new copies have mutations: they are slightly different from the original virus. Some mutant viruses keep multiplying even when you are taking ARV drugs. When this happens, the virus can develop resistance to the drug and ART may stop working.
- If only one or two ARV drugs are used, it is easy for the virus to develop resistance. For this reason, using just one or two drugs is not recommended. But if two or three drugs are used, a successful mutant would have to “get around” all of the drugs at the same time. Using combination therapy means that it takes much longer for resistance to develop.
Can these drugs cure HIV?
ARVs reduce the viral load, the amount of virus in your bloodstream, but are not a cure. A blood test measures the viral load. People with undetectable viral loads stay healthier longer. They are also less likely to transmit HIV infection to others.
- Some people’s viral load is so low that it is “undetectable” by the viral load test. This does not mean that all the virus is gone, and it does not mean a person is cured of HIV infection.
When to Start ART
All HIV positive patients regardless of WHO clinical stage and at any CD4 count.
Regimens of ART
There are three regimens of ART
- First line regimens
- Second line regimens
- Third line regimens
Monitoring response to ART
Clinical assessment and laboratory tests play a key role in assessing individuals before ART is initiated and then monitoring their treatment response and possible toxicity of ARV drugs.
Laboratory tests used for ART response are
- CD4 count
- HIV viral load
The CD4 count is a test that measures how many CD4 cells you have in your blood. These are a type of white blood cell, called T-cells, that move throughout your body to find and destroy bacteria, viruses, and other invading germs.
What Does HIV Do to CD4 Cells?
HIV damages your immune system because it targets CD4 cells. The virus grabs on to the surface of a cell, gets inside, and becomes a part of it. As an infected CD4 cell multiplies so it can do its job, it also makes more copies of HIV.
Those new bits of virus find and take over more CD4 cells, and the cycle continues. This leads to fewer and fewer HIV-free, working CD4 cells.
HIV can destroy entire “families” of CD4 cells, and then the germs these cells fight have easy access to your body. The resulting illnesses are called opportunistic infections because they take advantage of your body’s lack of defense.
What the Results Mean
A normal CD4 count is from 500 to 1,400 cells per cubic millimeter of blood. CD4 counts decrease over time in persons who are not receiving antiretroviral therapy. At levels below 200 cells per cubic millimeter, patients become susceptible to a wide variety of opportunistic infections, many of which can be fatal.