Wednesday, June 24, 2009

HIV and Aging - June 24, 2009

Over the past few years there has been more attention paid to the possibility of aging and being HIV+ at the same time. That was originally seen as a non-sequitor since the diagnosis of infection with HIV was equated with a considerably shortened life span. In the last ten years of Anti Retroviral Therapy [ART], that truism has changed and people with HIV keeping a “healthy” lifestyle and being on ART are advised that they can live pretty much a “normal” lifespan.

Of course, this is our first go round at this disease and as conditions change and people are living longer; new information is constantly being discovered, keeping the need for an open mind about this disease and its accepted truths as paramount.

Concepts and details about longevity are no exception.

Now we go to observe longevity at a cellular level, at the T-cell or immune cell level, to be exact.

Every cell contains a tiny cellular clock called a telomere, which shortens each time the cell splits in two. Located at the end of the cell’s chromosome, the telomere limits the number of times a cell can divide. Immune cells that fight HIV are under constant strain to divide in order to continue performing their protective functions. This massive amount of division shortens these cells’ telomeres prematurely, explains Dr. Rita Effros, Plott Chair in Gerontology, David Geffin School of Medicine at UCLA. So the telomeres of a 40-year-old person infected with HIV resemble those of a healthy 90-year-old person.

In common parlance, immune cells that battle HIV must constantly divide in order to continue performing their protective functions. The massive amount of division required to defend against the constant invasion of HIV cells prematurely shortens these cells' ends, or telomeres; ultimately exhausting the immune system. So the immune system of a person with HIV is rendered prematurely old, something that has been intuitively suspected but has never confirmed scientifically until now.

The good news is that this process of CD4 and CD8 [immune cells] senescence was originally found to be slowed down by invasive genetic work. But now, though the use of TAT2, a naturally occurring substance in the Chinese herb, astrulagus; the same positive result can be achieved. This work is still in early phases but offers hope for a natural therapy, different in impact from the many current HIV medicines and their often toxic side effects

Dr. Effros currently is examining the role of exercise, nutrition
and caloric intake on the immune system's ability to function effectively. All are seen to impact this process a great deal, as does smoking cigarettes; emphasizing yet again the importance of considered daily health and lifestyle choices for us all.

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