A medication that is already in use has been discovered to restore the immune system, stopping the steady decline in immunity and health as people age.
The research team has found that extremely low doses of the drug lenalidomide can stimulate the body's immune-cell protein factories, which decrease production during aging, and rebalance the levels of several key cytokines-immune proteins that either attack viruses and bacteria or cause inflammation that leads to an overall decline in health.
In 2009, Edward J. Goetzl of the University of California studied a group of 50 elderly adults through the National Institute on Aging, examining their levels of key cytokines and discovered that truly healthy 70-80-year-old women had the same levels, as did healthy 20-year-olds.
However, some elderly men and frail women who showed increased levels of inflammatory diseases and weakened defenses against infections tended to have lower levels of the first two cytokines, which are protective, and higher levels of inflammatory cytokines.
The team focused on three classes of drugs, among them the one that includes lenalidomide - a derivative of thalidomide, said Goetzl.
They found that extremely low levels of lenalidomide optimally stimulated IL-2 production in the young people (21-40 years) roughly sevenfold, but stimulated IL-2 production in patients over age 65 by 120-fold, restoring them to youthful levels for up to five days.
The researchers also found that lenalidomide had many other beneficial effects on the elderly participants' T cells, including better migration throughout the body, more efficient patrolling activity and longer survival after defending the body against an infection.
The findings would appear in the January issue of the journal Clinical Immunology.