Assessing the immune system and HIV infection
People who have HIV have regular blood teats to determine how well they are doing from an HIV perspective. One of the blood tests done assesses the persons CD4 counts. HIV is a retrovirus, meaning it needs cells from a "host" in order to make more copies of itself (replication). In the case of HIV, CD4 cells are the host cells that aid HIV in replication. HIV attaches to the CD4 cells, allowing the virus to enter and infect the CD4 cells, damaging them in the process. The fewer functioning CD4 cells, the weaker the immune system and therefore the more vulnerable a person is to infections and illnesses.
A viral load test (using PCR) is also done which is a quantitative measurement of HIV nucleic acid (RNA) that provides important information that is used in conjunction with the CD4 cell count:
- to monitor the status of HIV disease,
- to guide recommendations for therapy,
- and to predict the future course of HIV.
Evidence shows that keeping the viral load levels as low as possible for as long as possible decreases the complications of HIV disease, slows the progression from HIV infection to AIDS, and prolongs life.
HIV Medications (HAART)
1996 was a pivotal point in HIV care where new treatments became available. Prior to then the life expectancy of a person with HIV did not look favourable. The treatment of HIV/AIDS has evolved in the last 20 years since the beginning of the epidemic from no treatment to treatment with a single drug (AZT) to dual-drug therapy and, now, to highly active antiretroviral therapy (HAART). HAART is defined as treatment with at least three active anti-retroviral medications (ARV’s), typically two nucleoside or nucleotide reverse transcriptase inhibitors (NRTI’s) plus a non-nucleoside reverse transcriptase inhibitor (NNRTI) or a protease inhibitor (PI) or another NRTI called abacavir (Ziagen). HAART is frequently called the drug “cocktail”. The purpose of HAART is to provide a potent way of suppressing viral replication in the blood while attempting to prevent the virus from rapidly developing resistance to the individual ARV’s (antiretrovirals). Suppressing viral replication with HAART allows the body time to rebuild its immune system and replenish the destroyed CD4 or T cells. HAART has been clearly shown to delay progression to AIDS (and potentially death). If HAART is stopped HIV becomes detectable in the blood once again. HAART is not a cure and a cure is still a long way off.
At the present time, there are seven NRTI’s, three NNRTI’s and six PI’s to choose from that have been that are used in Australia. What combination of drugs to start in a person who is “naive” to therapy (has never been on HAART) depends on the viral load and the patient’s life circumstances, as the various ARV's. Decisions on when to commence medications and what to type is quite complex and the prescribing doctor takes into account a lot of factor.
Failure of HAART
“Failure” of therapy can occur, defined as having a detectable viral load in the blood. Sometimes, the viral load rises only transiently and at low levels, called “blips”. This can occur if the viral load was measured while the person was ill or recently got a vaccine. Blips are not a reason to switch therapy, as the viral load will frequently become undetectable if measured a gain after a few weeks. Failure of HAART is a sustained and high rise in the viral load. People fail their HAART regimens for various reasons: non-adherence to the regimen, side effects from the medications, and development of resistance of HIV to the various medications in the regimen. When this happens, the regimen has to be switched. The doctor can do some blood tests that help determine which type of HAART medication to be switched to.
Medical specialists, psychologists and other allied health professionals
HIV can be quite complex to manage. Frequently people with HIV need to referred to specialists to deal with co-morbidities (other medical condition in addition to HIV). Psychologists can be of benefit for mental illness's, stress management and dealing with loss and grief issues. Allied health care workers may include:
- social worker
- exercise physiologist
Your General Practitioner is able to refer you to an allied health care worker. In some instances Medicare may fund some consultations.
It is important to have a therapeutic relationship with your health care team. If you trust them communication improves as does your health outcomes. If you don't feel you have good rapport or trust with them it may be beneficial to change to another professional if possible. However as HIV is a life long illness ideally you should build a relationship over an extended period.