An experimental blood test can predict whether seniors have long to live, a new study says.
The genetics-based blood test predicted two-year survival with accuracy as high as 86% among hundreds of seniors, researchers reported Feb. 24 in the journal Aging Cell.
The test is based on PIWI-interacting RNA (piRNA), a class of genetic molecules that regulate development, regeneration and immune response in the human body.
“The combination of just a few piRNAs was the strongest predictor of two-year survival in older adults — stronger than age, lifestyle habits or any other health measures we examined,” said senior researcher Dr. Virginia Byers Kraus, a professor of medicine, pathology and orthopaedic surgery at Duke University in Durham, North Carolina.
“What surprised us most was that this powerful signal came from a simple blood test,” Kraus said in a news release.
For the study, researchers measured piRNAs found in blood samples taken from nearly 1,300 seniors 71 and older.
Results showed that lower levels of certain piRNAs were strongly linked to longer survival.
Specifically, a set of six piRNAs alone predicted the odds that a senior would live beyond two years with up to 86% accuracy. Participants who lived longer consistently had lower levels of these piRNAs.
“We know very little about piRNAs in the blood, but what we’re seeing is that lower levels of certain specific ones is better,” Kraus said. “When these molecules are present in higher amounts, it may signal that something in the body is off‑track. Understanding why could open new possibilities for therapies that promote healthy aging.”
These piRNAs outperformed age, cholesterol, physical activity and more than 180 other clinical measures in predicting short-term survival, researchers found.
Lifestyle factors became more influential when predicting longer-term survival, but piRNAs continued to provide valuable insights into a person’s biology, researchers added.
“These small RNAs are like micromanagers in the body, helping control many processes that affect health and aging,” Kraus said. “We are only beginning to understand how powerful they are.”
The team next plans to study how treatments, lifestyle changes or medications might alter a person’s piRNA levels. They also plan to compare piRNA levels in blood to those found in tissues, to better understand how the molecules function.
“This research suggests we should be able to identify short-term survival risk using a practical, minimally invasive blood test — with the ultimate goal of improving health as we age,” Kraus said.