14 DAY TRIAL // Researchers have discovered a new "gateway" that could allow them to devise a therapy for the diseases of the immune system, such as AIDS.
The Mayo Clinic-led study, conducted with colleagues in Toronto and Baltimore and reported in the early online edition of the February 1 Journal of Immunology, found that when a baby's immune system is deficient, some type of protective system goes into action.
The researchers studied 20 patients who as infants underwent heart transplantation and had their thymus (a small glandular organ that is situated behind the top of the breastbone, serving as the site of T cell differentiation. The thymus increases gradually in size and activity until puberty, becoming vestigial thereafter removed, Dictionary.com). As a result the infants were deficient in T cells, the cells depleted in AIDS patients that are crucial to fighting viruses and cancer tumors.
They found that over a 10-year-period the infant transplant patients resisted the same infections that often kill adult AIDS patients. The transplant patients maintained their health even with low T cell counts.
"We are very excited by this result. This will be the first step to discovering how to make the immune system work in patients who have severe defects in their immune systems or who have cancer," says Jeffrey Platt, M.D., the Mayo transplant researcher who led the team.
"We were struck by the fact that when a heart transplant is carried out in very young infants, the thymus that produces T cells is removed and a drug is given that depletes T cells. Yet the infants don't get the same diseases that adult AIDS patients do, even though the transplanted infants are basically a model of AIDS," Dr. Platt added.
If this ability of infant-transplant patients' immune systems can be identified and enlisted to fight viruses without T cells, it perhaps could be therapeutically manipulated in adult patients to arrive at new and better treatments for various diseases involving immune system deficiencies.