January 1, 1970 (Vol. , No. )
If you saw the movie The Awakening, you may have noticed the film’s subtltle, A Hidden Power Emerges from Within. In a real world take on that idea, scientists in the Gladstone Institute of Virology and Immunology at UCSF awakened the relatively sleepy thymus of adults and, in doing so, have given new hope for stimulating the compromised immune systems of HIV patients. HIV, of course, attacks the immune system in its cycle of infection and lowers the levels of T-cells involved in helping to fight off infections. One set of these cells, known as CD-4, are dangerously low, even in patients responding successfully to anti-viral therapy. With the aim of boosting the levels of these critical immune system cells, Laura Napolitano and colleagues treated HIV patients undergoing therapy with Growth Hormone (GH), a compound shown previously to stimulate the thymus in older mice. The thymus, which is a source of T-cells, has its function diminish with aging. Two groups of patients were studied. Each had similar levels of CD-4 cells, detectable HIV in the blood, age, and their thymuses were similar in mass at the beginning of the study. One group was given GH for a year in addition to other ongoing therapies and then had the therapy stopped. The other group did not receive the therapy for the first year for comparison and then received the treatment. As reported in the March, 2008 Journal of Clinical Investigation, the results were striking. Thymic masses increased significantly when GH was given and the number of CD-4 cells increased 30%. Enhanced function occurred for at least three months after the therapy was discontinued and the benefits appeared to last for as long as a year after the GH therapy was stopped. Researchers caution that additional studies are necessary to evaluate the health benefits of GH therapy, so GH should not be used as a treatment at this time.