Researchers at the University of Pittsburgh have identified distinct asthma endotypes in youths aged six to 20 by analyzing nasal epithelial gene expression. The study, “Transcriptomic Profiles in Nasal Epithelium and Asthma Endotypes in Youth,” marks a significant advancement in asthma research and could lead to more targeted and effective treatments.
The study, which was published in JAMA Network, included 459 participants from three separate cohorts of predominantly Puerto Rican and Black youths, revealing three mutually exclusive asthma profiles: T helper 2 (T2)-high, T helper 17 (T17)-high and T2-low/T17-low.
In addition to determining whether nasal epithelial gene expression could be used to identify asthma endotypes in youths, researchers aimed to better understand which endotypes are most prevalent. The analysis leveraged data from three existing U.S. studies: “Stress and Treatment Response in Puerto Rican and African American Children With Asthma (STAR),” “Epigenetic Variation and Childhood Asthma in Puerto Ricans (EVA-PR)” and “Vitamin D Kids Asthma (VDKA).”
Gene expression meta-analysis identified 3,516 and 2,494 different genes for the T2-high and T17-high profiles, respectively. The T17-high profile was associated with interleukin 17 and neutrophil signaling pathways. The T2-high profile was associated with interleukin 13 signaling pathways.
In ranking the prevalence of endotypes, researchers concluded that T17-high asthma was found in 35% to 47% of participants and T2-low/T17-low asthma was present in 30% to 38% of participants. T2-high asthma was the least common subtype, present in 23% to 29% of participants.
The study also highlighted significant differences in clinical characteristics among the endotypes. Participants with the T2-high profile had higher median total immunoglobulin E (IgE) and blood eosinophil levels compared to those with T2-low profiles. At least 50% of participants in all profiles had one or more positive allergen-specific IgEs. These findings are crucial for developing effective asthma therapies tailored to specific endotypes.
Researchers emphasized the importance of characterizing asthma endotypes based on T2 and T17 cell types to improve therapies for diverse groups of youths with asthma as well as the prospect of improving quality of life.
