A novel diagnostic test using just a nasal swab could transform how doctors diagnose and treat childhood asthma. Researchers at the University of Pittsburgh have developed this non-invasive approach that, for the first time, allows physicians to precisely identify different subtypes of asthma in children without requiring invasive procedures.
Until now, determining the specific type of asthma a child has typically required bronchoscopy, an invasive procedure performed under general anesthesia to collect lung tissue samples. This limitation has forced doctors to rely on less accurate methods like blood tests and allergy screenings, potentially leading to suboptimal treatment choices.
“Because asthma is a highly variable disease with different endotypes, which are driven by different immune cells and respond differently to treatments, the first step toward better therapies is accurate diagnosis of endotype,” says senior author Dr. Juan Celedón, a professor of pediatrics at the University of Pittsburgh and chief of pulmonary medicine at UPMC Children’s Hospital of Pittsburgh, in a statement.
3 subtypes of asthma
The new nasal swab test analyzes the activity of eight specific genes associated with different types of immune responses in the airways. This genetic analysis reveals which of three distinct asthma subtypes, or endotypes, a patient has: T2-high (involving allergic inflammation), T17-high (showing a different type of inflammatory response), or low-low (exhibiting minimal inflammation of either type).
The research team validated their approach across three separate studies involving 459 young people with asthma, focusing particularly on Puerto Rican and African American youth, populations that experience disproportionately higher rates of asthma-related emergency room visits and complications. According to the researchers, Puerto Rican children have emergency department and urgent care visit rates of 23.5% for asthma, while Black children have rates of 26.6% — both significantly higher than the 12.1% rate among non-Hispanic white youth.
The findings, published in JAMA, challenge long-held assumptions about childhood asthma. While doctors have traditionally believed that most cases were T2-high, the nasal swab analysis revealed this type appears in only 23-29% of participants. Instead, T17-high asthma accounted for 35-47% of cases, while the low-low type represented 30-38% of participants.
“These tests allow us to presume whether a child has T2-high disease or not,” explained Celedón. “But they are not 100% accurate, and they cannot tell us whether a child has T17-high or low-low disease. There is no clinical marker for these two subtypes. This gap motivated us to develop better approaches to improve the accuracy of asthma endotype diagnosis.”
Precision medicine for patients
This breakthrough carries significant implications for treatment. Currently, powerful biological medications exist for T2-high asthma, but no available treatments specifically target T17-high or low-low types. The availability of this new diagnostic test could accelerate research into treatments for these previously understudied forms of asthma.
“We have better treatments for T2-high disease, in part, because better markers have propelled research on this endotype,” said Celedón. “But now that we have a simple nasal swab test to detect other endotypes, we can start to move the needle on developing biologics for T17-high and low-low disease.”
The test could also help researchers understand how asthma evolves throughout childhood and adolescence. Celedón noted that one of the “million-dollar questions in asthma” involves understanding why the condition affects children differently as they age.
“Before puberty, asthma is more common in boys, but the incidence of asthma goes up in females in adulthood. Is this related to endotype? Does endotype change over time or in response to treatments? We don’t know,” he says. “But now that we can easily measure endotype, we can start to answer these questions.”
Dr. Gustavo Matute-Bello, acting director of the Division of Lung Diseases at the National Heart, Lung, and Blood Institute, emphasizes the potential impact of this diagnostic advancement. “Having tools to test which biological pathways have a major role in asthma in children, especially those who have a disproportionate burden of disease, may help achieve our goal of improving asthma outcomes,” he says. “This research has the potential to pave the way for more personalized treatments, particularly in minority communities.”
Source : https://studyfinds.org/simple-nasal-swab-could-revolutionize-childhood-asthma-treatment/
