Scientists Discover Potential Blood Test for Asthma Diagnosis and Severity

Scientists at Rutgers Health have discovered that a simple blood test could diagnose asthma and determine its severity, a breakthrough that could transform how the disease is identified and monitored.

The paper, which will appear in the Journal of Clinical Investigation, found that patients with asthma have dramatically elevated levels of a molecule called cyclic adenosine monophosphate (cAMP) in their blood - sometimes up to 1,000 times higher than in people without asthma.

"What we discovered is a specific transporter, a protein on the membrane of airway smooth muscle cells, allows cAMP to leak into the blood," said Reynold Panettieri, one of the study's senior authors and vice chancellor for Translational Medicine and Science at Rutgers University. "For decades, we believed that an enzyme called phosphodiesterase was the critical factor in decreasing cAMP. We now refute that and say this transporter simply leaks it out."

The finding has significant implications for the roughly 1 in 20 Americans with asthma. Currently, diagnosing asthma requires sophisticated breathing tests, typically found only at specialists, that can be challenging for young children.

"It's really difficult to do lung function tests in kids under the age of 5," said Panettieri, who is also director of the Rutgers Institute for Translational Medicine and Science. "However, our data suggests that if you just did a pinprick, maybe you could diagnose kids who can't access or do lung function tests."

The research team analyzed blood samples from 87 asthma patients and 273 participants without asthma. They found that cAMP levels were consistently higher in the blood of asthma patients and correlated with disease severity, potentially offering doctors a new tool for monitoring patient conditions.

The discovery could be particularly valuable in urban areas, where asthma rates are higher.

"If you look at city dwellers, about 1 in 15 people has asthma," said Panettieri. "It's incredibly common - the number one reason kids go to the emergency room."

The researchers are working with companies to develop a point-of-care test for doctors' offices. Initial attempts to create a simple lateral flow device - similar to a pregnancy test - proved not sensitive enough, but the team is exploring more sensitive fluorescent markers.

"We would anticipate maybe in the next six months, we'll have nailed the fidelity of it, get it into our intellectual property and patent the test itself, and then in a year to two, it could become available," Panettieri said.

Beyond diagnosis, the discovery of the cAMP transporter mechanism could lead to new therapeutic approaches. Asthma medications such as albuterol work by increasing cAMP levels in airway smooth muscle cells, causing them to relax and airways to open. "By targeting the newly discovered transporter, future treatments might prevent the loss of cAMP, potentially making existing medications more effective," said Steven An, professor of pharmacology at Robert Wood Johnson Medical School and the first author of the study.

The next phase of research will involve studying larger groups of patients to better understand how cAMP levels relate to different asthma subtypes.

"Every disease we study or treat is not one disease," Panettieri said. "There are different aspects and attributes within a disease entity."

Members of the team plan to study hundreds or thousands of patients to understand who has the highest cAMP levels and how that affects their asthma, potentially leading to more personalized treatment approaches.

While current treatments for asthma, such as inhaled steroids and bronchodilators, are effective for many patients, the disease remains poorly controlled in others. The development of this blood test could help doctors better identify which patients need more aggressive treatment and monitor their response to therapy more accurately.