Treatments and Progression of AIDS : Why is it different between patients?

Acquired immune deficiency syndrome or acquired immunodeficiency syndrome (AIDS or Aids) is a type of disease caused by HIV virus. A HIV patient shows many symptoms and infections as a result of body immune system damage. Within years, it will progressively deteriorates the body with more opportunistic infections and tumours as the body is left more and more vulnerable.

The use of genetic testing is now widely used to determine why HIV virus attacks people differently. Some example questions brought up by scientists are why is there only one person infected with the disease if there are two of them exposed to the virus, and if both are infected with HIV virus, why is that one show symptoms within two years but another only shows after decades later?

One discovery that has been recently reported regarding genetics and HIV is the number of copies of a normal human gene, CCL3L1, which encodes the protein MIP-1 a P. On average across population, each person possesses 2 copies of this gene, even though there are people having seven or more copies if this gene in their chromosomes. Research result has concluded that people with fewer copies of this gene have a higher risk of HIV virus attack. And among those who are infected, patients with fewer copies also develop more rapid progression of AIDS. Researchers also noted that people that possess one or no copies of this gene have 69% to 97% greater risk of acquiring HIV.

Another study found that protection against HIV may come from specific combinations of alleles that humans carry. Rare immune system alleles tend to provide greater protection against HIV. This is proven as HIV patients that have much lower viral loads than other patients carry particular rare gene variants (viral load refers to the number of viral particles in blood plasma and this is a way of measuring progression of HIV). This means that HIV has adapted to attack the dominant alleles in the population, which is the more common immune system alleles system. Research also proves that these people who confer the greatest protection have the least common gene variants in the population. An example given is based on African-American patients who were underrepresented in the study. They possessed less common immune system alleles and they are the ones who gave measured lower viral loads in their body

In response to the many possible factors regarding HIV attack and the possible reactions towards AIDS medication, there should be a better prediction of each individual patient’s risk of developing drug resistance, toxicity and long-term efficacy of therapy. One best way to be able to predict accurately is a simple genetic blood test and screening and this will help physicians to decide when to start therapy in an HIV-positive person, and what drugs to start treatment with so that proper treatment is achieved in each individual patient.

Links :

http://en.wikipedia.org/wiki/AIDS

http://www.infectiousdiseasenews.com/200511/genetics.asp

http://www.emaxhealth.com/53/2006.html