In a December 2009 study published in the Public Library of Science Genetics Journal, researchers identified several naturally occurring genetic abnormalities that can cause an HIV-positive individual to exhibit greater control over viral load and slower disease progression.

Researchers also found certain gene variants that had previously been reported to provide HIV resistance to be ineffective.

Individuals who are able to maintain the virus at undetectable levels without the use of treatment are known as HIV elite controllers. Though rare, elite controllers, also known as long term non-progressors, possess a genetic makeup that gives them natural resistance to the virus.

Without treatment, HIV patients usually develop AIDS within eight to twelve years following HIV infection. However, elite controllers often survive 20 to 25 years without progressing to AIDS and without any HIV symptoms.

The study hoped to address genetically why some individuals experience faster virus progression compared to others.

Central to their research was the major histocompatibility complex (MHC) region, found in most vertebrates. The MHC is widely known to play an important role in the immune system and its defense mechanisms.

The genes found in the MHC region provide instructions for the creation of proteins that help the immune system identify foreign pathogens in the human body.

The research conducted in this experiment focused on a few different genetic variants, and their impact on HIV-1 infection.

It was found that the presence of one variant, dubbed rs9264942, leads to increased protein production. This results in a certain degree of HIV-1 infection control.

The researchers also examined another variant, rs2395029, located on a different gene. This gene acts as an indicator of another genetic variance, HLA-B*5701.

Of all the variants examined, HLA-B*5701 provides the greatest protection against the HIV-1 virus.

Additionally, the researchers looked at a gene deletion mutation. Individuals possessing this mutation are known to have almost complete protection against HIV-1 infection.

Combined, their results explain 13 percent of the variability seen in HIV-1 viremia, or viral infiltration of the bloodstream. By taking gender, age, and population dynamics into account as well, this amount can increase to 22 percent.

The investigation did not find any association between other non-MHC gene variants and HIV-1 disease progression, despite previous reports.

Additional research is needed, not only to further understand this natural immunity, but also to account for more of the variance. Because the study was conducted among a group of mostly adult Caucasian males, the study will need to be performed in other ethnic, gender, or age groups as well.

It is worthwhile to study elite control, as the results could provide information vital to the creation of better treatments, or even a cure for the HIV virus.

For more information regarding this study, please see the published article at the Public Library of Science.