Immune System Glitch Linked to Greater Risk of Death
MONDAY June 4, 2012 -- People with a certain flaw in their immune system are up to four times more likely to die than people who don't have this "glitch," a new study indicates.
Researchers from the Mayo Clinic explained that people whose immune system produced too much of an antibody molecule known as a free light chain, are far more likely to die from a serious illness, such as cancer, diabetes or heart disease.
In conducting the study, the researchers examined blood samples taken from nearly 16,000 people aged 50 and older. They found those with levels of free light chains that fell in the top 10 percent had a roughly four times greater risk of death than those with lower levels of the molecule. After taking differences in age, gender and kidney function into account, those with the highest levels of the molecule still had double the risk of dying.
The study authors explained that high levels of free light chains indicate a greater response by the immune system to infection, inflammation or another serious disorder.
Although high levels of free light chains may signal immune system stimulation, the researchers noted it should not be used as a diagnostic tool.
"We do not recommend this test as a screening test, because it will only cause alarm," study author Dr. Vincent Rajkumar, a Mayo Clinic hematologist, said in a news release. "We do not know why this marker is associated with higher rates of death. We do not have a way of turning things around. Therefore, I would urge caution in using this test until we figure out what to do about it and what these results mean."
The study authors concluded that more research is needed to determine exactly why free light chains are associated with a greater risk of death and if specific treatment options should be explored.
The study was published in the June issue of Mayo Clinic Proceedings.
The U.S. National Institutes of Health provides more information on the immune system and disorders.
Posted: June 2012