Asthma biologics are leaving low-income and racial/ethnic minority children behind
Published: September 15, 2021
Asthma is a complex disease with multiple and often overlapping clinical and biological subtypes, commonly referred to as endotypes. Some asthma/allergy subtypes are characterized by objective biomarkers including eosinophil and immunoglobulin E (IgE) levels. Some asthma endotypes are characterized by obesity or poor response to commonly used asthma drugs such as albuterol and inhaled corticosteroids. Still, more asthma endotypes have yet to be clearly defined. Clinicians need to be able to delineate these clinical asthma endotypes to treat their patients accurately and effectively. However, clinical translation remains a challenge for frontline clinicians who care for patients with asthma. A recent revolution in science and medicine is the introduction of asthma biologic therapies. These therapies target known asthma blood biomarkers to reduce asthma symptoms, but they have strict dosing and eligibility criteria based on the biomarkers they target, which differ by race/ethnicity. The current lack of information on asthma therapeutic-associated blood biomarkers in racially/ethnically diverse pediatric populations can leave clinicians uncertain about the choice of biologic therapy for the patients who need this therapy most.
In a recent issue of The Journal of Allergy and Clinical Immunology (JACI), Wohlford, Huang, Elhawary, and colleagues investigating known peripheral blood biomarkers and asthma endotypes examined population-specific eligibility for corresponding biologic therapies using data from two asthma case-control studies of minority children: the Genes-environments & Admixture in Latino Americans study (GALA II) and the Study of African Americans, Asthma, Genes, & Environments (SAGE). Participants were age 8-21 and recruited across the United States and Puerto Rico. Asthma cases were defined by physician diagnosis, and asthma controls were healthy children with no history of lung disease. Parents and grandparents of study participants must have self-identified as Hispanic/Latino (GALA II) or African American (SAGE).
Wohlford, Huang, Elhawary, et al. found population-specific associations of IgE and eosinophils with asthma outcomes after controlling for age, sex, obesity status, socioeconomic status, and medication use. They also demonstrated that the eosinophilic asthma endotype was associated with worse clinical asthma outcomes in Puerto Ricans, while the allergic asthma endotype was associated with worse asthma control and an increased number of exacerbations in Mexican Americans. These findings suggested that clinical eligibility for novel biomarker-driven asthma therapies differed across racial/ethnic minority children. When examined, Wohlford, Huang, Elhawary, et al. alarmingly found 51.3% of African Americans and 26.8% of Puerto Ricans age 12 and older with moderate-to-severe asthma in their population would not have qualified for eosinophilic asthma-directed therapies due to a too low eosinophil count while 17.2% of African Americans, 21.2% of Mexican Americans, and 31.4% of Puerto Ricans with moderate-to-severe, allergic asthma had pre-treatment IgE either too low to qualify or too high to recommend a dose for allergic asthma-directed therapy.
Selecting the correct biologic asthma therapy for a given patient remains a struggle for frontline clinicians who treat children with asthma. This clinical problem is compounded in racially/ethnically diverse populations with the lack of clinical and biomedical research in these groups. While biologic therapies represent a new dawn in asthma care, that dawn has not yet risen for all patients. Current and future asthma therapeutics must be studied in patients of diverse racial/ethnic backgrounds to bring maximal benefits to all.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.
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