Asthma, the most common chronic disease in children, affects 1 in 10 kids in the United States. Yet, diagnosing the underlying causes of asthma remains a challenge, particularly when it comes to identifying the immune system pathways driving the disease. Now, researchers have developed a non-invasive nasal swab test that could revolutionize how asthma is diagnosed and treated in children.
A Game-Changer in Asthma Diagnosis
Traditionally, identifying the subtype—or endotype—of asthma has been an invasive and complex process. Doctors often rely on indirect markers from blood tests, lung function exams, and allergy assessments to infer a child’s asthma type. But these methods are not entirely accurate, and some subtypes remain undetectable with current tools.
“Asthma is a highly variable disease with different endotypes, driven by distinct immune cells, which respond differently to treatments,” explained Dr. Juan Celedón, chief of pulmonary medicine at UPMC Children’s Hospital of Pittsburgh. “The first step toward better therapies is accurate diagnosis of endotype.”
The new nasal swab test changes this by directly analyzing genetic markers linked to asthma’s immune drivers. It identifies three main asthma subtypes:
- T2-high, caused by T helper 2 cells, which is linked to severe inflammation.
- T17-high, driven by T helper 17 cells, which lacks targeted treatments.
- Low-low, where neither T2 nor T17 cells dominate, making it the least understood subtype.
How the Test Works
In the study, published in the Journal of the American Medical Association, researchers collected nasal samples from nearly 460 children. The samples were analyzed for eight genes associated with T2 and T17 immune cells. The children, primarily Puerto Rican and African American—groups disproportionately affected by asthma—were part of three U.S. studies.
The nasal swab test accurately identified the asthma subtype for each child, offering a reliable, non-invasive alternative to invasive tissue sampling under anesthesia.
This breakthrough is particularly impactful for children with T2-high asthma, as it can guide them toward biologic therapies that specifically target the immune cells driving their condition. Approximately 29% of the children in the study were classified as T2-high.
Implications for Asthma Treatment
Currently, biologic treatments exist only for T2-high asthma. Dr. Celedón hopes that this simple, accurate diagnostic tool will spur research into therapies for the other two subtypes, especially T17-high and low-low.
“We’ve made strides in T2-high treatments because reliable markers have propelled research,” Celedón said. “Now, with this nasal swab test, we can begin advancing treatments for T17-high and low-low asthma as well.”
A Tool for Future Research
The test also holds promise for answering long-standing questions about asthma progression. “Why do some kids see their asthma worsen at puberty, while others stay the same or improve?” Celedón asked. “We know asthma is more common in boys before puberty, but in adulthood, its prevalence shifts to women. Does endotype play a role? Does it change over time or in response to treatment? With this test, we can finally start exploring these questions.”
Looking Ahead
With its potential to improve diagnosis, tailor treatments, and unlock new avenues of research, this nasal swab test marks a significant step forward in managing childhood asthma. By making precise diagnosis accessible and non-invasive, it offers hope for better care and outcomes for millions of children worldwide.