On December 13, researchers at the University of California at San Francisco said they had identified a derivative of thalidomide that seems to rejuvenate the immune systems of aging people. When they tested the drug in small doses on cell cultures taken from 13 patients, it stimulated the production of proteins called "cytokines." That may, in turn, reduce the age-related inflammation that causes overall health to deteriorate.
Thalidomide was the anti-nausea drug that was famously pulled from the market in 1961, after it caused severe birth defects in children. Lately a derivative of the drug called lenalidomide has been embraced as a therapy for some cancers and for leprosy. And Dr. Edward J. Goetzl of UCSF has been studying the drug as a potential immunity booster.
In a UCSF statement announcing the study, which will be published in the January edition of the journal Clinical Immunology, Goetzl asked a tantalizing question. "If, at age 50, your cytokine levels are the same as they were at 25, you'll probably stay healthy as you age," he said. "But if they're heading downhill, we need to do something about it. If you could take a low-dosage pill with no side effects, wouldn't you do it?"
My guess is that most anti-aging proponents would answer that with a resounding "yes!" Anti-aging, after all, is an industry that has latched onto everything from human growth hormone to the red wine supplement resveratrol as elixirs against getting old.
But as is the case with all those anti-aging treatments, lenalidomide has not actually been proven to slow the aging process.
That's why Goetzl regretted his statement as soon as he saw it in print. "We don't think this is a drug for aging," Goetzl told me in a phone interview a few days after the UCSF press release was released. "We're not at this stage thinking of this for healthy seniors." When he made the statement, Goetzl explains, he was theorizing about what might be possible far in the future -- provided scientists can prove out their suspicions about cytokines in aging people.
In the study, Goetzl's team found that tiny doses of lenalidomide stimulated the production of a type of cytokine called IL-2 sevenfold in young people and an astonishing 120-fold in older people. The aging folks regained youthful levels of IL-2 for a full five days.
But don't go scrambling for a lenalidomide prescription just yet, Goetzl warns. The current study merely observed cytokine changes in cell cultures. And as Goetzl puts it, "Just because something looks great in the test tube doesn't mean it works when you give it to people."
So he and his team are now working on designing tests of lenalidomide in actual people, with the goal of defining whether the drug actually helps them fight diseases, and if so, how. For example, they're considering giving lenalidomide to seniors before they get their annual flu shot and just after, to see if they produce more antibodies against the flu virus than they would if they just had the shot. They may also design studies to test whether the drug boosts the effectiveness of standard treatments given to seniors who are fighting age-related cancers.
Goetzl says he's not interested in studying lenalidomide as a way to turn healthy seniors back into thirty somethings. Still, he says, he's been inundated with emails and phone calls from healthy people wanting to sign up for his studies. "I don't want to give people false hope," says the scientist, who adds that at age 70, he sort of understands why people might be looking for the fountain of youth. "We try to be practical. We're not thinking about longevity."
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