Some aging adults have ‘youthful’ immune systems

Most people’s immune systems slow down with age, making it harder to fight infections and disease. But Mayo Clinic researchers have found that some people in their 60s and 70s still have what looks like a youthful immune system — a phenomenon they call “immune youth.”

Dr. Cornelia Weyand, a Mayo Clinic rheumatologist and lead author of a new paper in Nature Aging, says her team wants to learn why. 

“We are studying why some individuals have a ‘fountain of youth’ in their immune systems. We want to learn from them,” she said.

The discovery came while studying patients with giant cell arteritis, a serious autoimmune disease that affects arteries, including the aorta. In these patients, researchers found special “stem-like” immune cells that usually help the body heal and grow. But in this case, the cells were fueling the disease.

Autoimmune diseases

That means having a “younger” immune system may not always be a blessing. 

“These patients have very young immune systems despite being older,” Weyand said. “But the price they pay for that is autoimmunity.”

Autoimmune diseases occur when the body’s defense system mistakenly attacks healthy tissues.

Weyand’s colleague, Dr. Jörg Goronzy, points out that immune systems that age in step with the body may actually protect against this kind of damage. 

“Contrary to what one may think, there are benefits to having an immune system that ages,” he said.

In other words, while aging may weaken the immune system, it may also lower the risk of developing harmful autoimmune conditions.

What’s Next

The Mayo Clinic team is now developing new tests to spot people who have higher numbers of these immune stem cells, which could make them more likely to develop autoimmune disease later in life.

The work is part of Mayo’s Precure initiative, which focuses on finding ways to predict and stop disease before it starts.