New research suggests that a common immune-system gene may lead to the earlier onset of Alzheimer’s disease symptoms.
Scientists at the University of California, Los Angeles, examined 207 Alzheimer’s patients for a gene called HLA-A2, which is a common gene connected with the immune system.
Patients who had versions of that gene experienced Alzheimer’s symptoms on average three years sooner than Alzheimer’s patients who have no HLA-A2, UCLA’s Dr. Gary Small reports in the August edition of the journal Neurology.
The study is far from proof that the A2 version of the human leukocyte antigen, or HLA, gene actually is to blame. Small acknowledges that the gene may be a signal of a hidden gene nearby that is doing the damage. And if HLA-A2 is the culprit, nobody knows just why because the gene’s exact function in regulating the immune system remains a mystery.
“If this holds up, it will be very helpful in studying patient groups that have the antigen and that don’t, and trying to work out what the gene product is doing in the brain,” Small said.
Zaven Khachaturian of the Alzheimer’s Association called Small’s finding “provocative, because it strengthens the argument for the import role the immune system may play in the expression of Alzheimer’s disease.”