• Posted August 15, 2025

Youthful Immunity: A Double-Edged Sword for Seniors

The Fountain of Youth may not be all it’s cracked up to be, researchers say.

A genetic “fountain of youth” actually might increase seniors’ risk of developing autoimmune diseases like rheumatoid arthritis, lupus, celiac disease and psoriasis, a new study says.

Essentially, seniors who maintain “immune youth” are less likely to suffer from infection and disease, but they pay a price for that youthfulness, researchers reported Aug. 14 in the journal Nature Aging.

“These patients have very young immune systems despite being in their 60s and 70s, but the price they pay for that is autoimmunity," lead researcher Dr. Cornelia Weyand, a rheumatologist and clinician-scientist at the Mayo Clinic in Rochester, Minn., said in a news release.

The research team discovered this cellular fountain of youth in more than 100 seniors seeking treatment at the Mayo Clinic for an autoimmune disease called giant cell arteritis. 

The condition causes inflammation of the lining of arteries. Left untreated, it can cause blindness.

The diseased tissue of these patients contained specialized immune cells called stem-like T cells, researchers said.

These immune cells behaved like young stem cells, which usually aid in healing and growth. However, in these patients, the immune cells were causing autoimmune disease, in which the immune system mistakenly attacks healthy organs and tissues.

Researchers also found that immune checkpoint inhibitors — proteins that regulate the immune system and prevent it from attacking healthy cells – weren’t working properly in these patients.

The results indicate that immune aging is not all bad, but instead serves as a sophisticated mechanism that helps a person’s immune system adapt as they grow older to prevent the development of autoimmune disease.

"Contrary to what one may think, there are benefits to having an immune system that ages in tandem with the body," co-lead researcher Dr. Jörg Goronzy, a Mayo Clinic researcher on aging, said in a news release. "We need to consider the price to pay for immune youthfulness. That price can be autoimmune disease."

The team now is developing new diagnostic tests that could help identify people with high numbers of these youthful immune stem cells. These folks might have a higher risk of autoimmune diseases later in life.

More information

Yale School of Medicine has more on aging and immunity.

SOURCE: Mayo Clinic, news release, Aug. 14, 2025