Study looks at medical spread of Alzheimer's

Sep 09, 2015, 4:45 PM EDT
Barrie Page Hill, right, shares a moment with her mother Bobbie Wilburn, 79, March 15, 2014, in Arlington, Texas.
Joyce Marshall/Fort Worth Star-Telegram/MCT via Getty Images
A team of British scientists found evidence that the biological seeds of Alzheimer's disease could be passed on through medical procedures. Research published points to evidence that suggested that one of the signifiers of Alzheimer's could have spread to a group of patients via a hormone treatment that is now banned. Reuters reports:
"This was very surprising," said John Collinge, a University College London professor and director of the Prion Unit who led the studies and published them in the journal Nature.
The growth treatment, using human-derived hormones, is no longer used due to the risk of contamination. But Collinge said studies are now needed into whether other procedures, such as blood transfusions and the repeated use of surgical instruments, pose a risk.
"We do need to ask that question," he said, noting that previous experiments on laboratory mice and monkeys have already shown that transmission of the Alzheimer's protein is theoretically possible. "There is evidence from animal studies that it is not implausible."
Researchers performed the autopsies to see if there was anything else unusual about the brains of these individuals. "And what we found, very much to our surprise, is that four of them had really quite significant deposition of Alzheimer amyloid protein in their brains," Collinge said.
Amyloid protein is what forms the sticky plaques that appear in the brains of people with Alzheimer's. But the individuals in the study had died far too young (the oldest was just 51) to have so much amyloid in their brains.
So the researchers began searching for an explanation. And they concluded that the growth hormone had been tainted with a second protein from the human pituitary glands — one that caused amyloid to build up quickly.
There's no way this could happen now, because growth hormone hasn't been made from brain tissue since the 1980s. Also, the people in the study did not have full-blown Alzheimer's, only the amyloid deposits that typically appear before problems with memory and thinking.
But the finding could have implications for surgeons operating on the brains of people with Alzheimer's, says Lary Walker, a neuroscientist at Emory University and the Yerkes National Primate Research Center.