A new novel test can identify various types of asthma using a nasal swab.

 The swabs effectively identified various types of asthma in hundreds of Black and Puerto Rican children.

A 5-year-old boy inserts a swab stick into his nose for a Covid-19 self-test.

Jan. 3, 2025, 4:22 AM GMT+6

A recent study introduces a test that can identify different types of asthma using a nasal swab. Researchers hope this test could eventually help match patients with more effective treatments. The research specifically focused on Black and Puerto Rican children, who experience higher asthma rates and related deaths compared to white children.

Diagnosing asthma in children is complex, as the condition, which affects over 4.6 million U.S. children, is often divided into two categories. "T2-high" asthma, caused by inflammation from T helper 2 immune cells, was once considered the most common form. The second category, "T2-low" asthma, includes subtypes with less inflammation or inflammation from a different type of T cell.

For moderate to severe asthma cases, identifying the specific type can help doctors find the right treatment. However, existing tests are limited, often measuring immune cells or nitric oxide in breath. These tests typically only detect T2-high asthma and can't distinguish between other subtypes.

Researchers at the University of Pittsburgh developed a more accurate method by using nasal swabs and sequencing the RNA they contain. In individuals with two asthma subtypes, certain inflammation-related genes were more highly expressed, allowing the researchers to identify them. The third subtype was recognized by the absence of these genetic markers.

The study, published in JAMA, involved over 450 children and teens from Puerto Rico and Pittsburgh, predominantly Puerto Rican or non-Hispanic Black. The results showed that the nasal swab test could effectively identify asthma subtypes, revealing that T2-low asthma, often linked to air pollution, was the most common among the participants.

Black and Puerto Rican children are at greater risk for asthma and related deaths in the U.S. due to higher exposure to environmental triggers such as air pollution, mold, and dust.

Building on earlier research using nasal swabs to diagnose asthma, this study could significantly improve the process of matching children with appropriate treatments, according to Dr. Juan Celedón, one of the paper's authors and chief of pulmonary medicine at UPMC Children’s Hospital of Pittsburgh. He emphasized that this approach is a crucial step toward personalized medicine for asthma treatment. While steroids are typically the default treatment, severe cases may require additional therapies, which have mostly been designed for T2-high asthma. This nasal swab test could help identify individuals with T2-low asthma, making them eligible for new treatments being tested.

The study is significant as it highlights children of color, a group often underrepresented in asthma research. Dr. Gurjit Hershey, director of the asthma research division at Cincinnati Children’s Hospital, who was not involved in the study, noted the importance of focusing on Puerto Rican and Black children, who have been overlooked in previous studies dominated by white, European populations.

However, the test is not yet ready for widespread use. Dr. Celedón noted it would require FDA approval before it could be implemented in clinical settings. Additionally, Dr. Hershey cautioned that more research is needed to determine whether a child's asthma type remains consistent over time or changes due to environmental factors like pollution.

Dr. Jessica Hui, a pediatric allergist at National Jewish Health in Denver, also highlighted the challenges of implementing genetic sequencing, which is costly and requires specialized expertise. While this technology isn't ready for immediate use, she called it an exciting step forward for asthma treatment.