There is a need for precision medicine to better predict future risk for exacerbations in pregnant women with asthma, according to an editorial published in Respirology.
Based on the premise that severe asthma exacerbations in pregnancy are likely underestimated, and that such exacerbations are associated with worse outcomes for both the baby and mother, so based on research, precision medicine is needed to better predict risk at an individual level to more effectively target clinical management and improve outcomes. Some research discusses the use and benefits of biomarkers of eosinophilic inflammation and type 2 (T2)-mediated immunity such as sputum eosinophils and fractional exhaled nitric oxide (FeNO).
Consistent findings in the literature demonstrate benefits in guiding corticosteroids in severe asthma with sputum eosinophils, but the lack of technical support limits its adoption. Although not specifically powered to assess perinatal outcomes, a double-blind, randomized trial of inflammatory marker–based management of asthma in pregnancy showed that FeNO-guided management resulted in a normalization of birth weights and reduced rates of neonatal hospital admissions and preterm births.
Based on a post hoc analysis conducted that compared responses between those with and without eosinophilic airway inflammation, there was more atopy and exacerbation frequency prepregnancy in those with eosinophilic asthma compared with those with noneosinophilic asthma. This was consistent with the view that eosinophilic inflammation and elevated FeNO are associated with increased risk for poor control and exacerbations. According to the researcher of the study, an FeNO-guided algorithm “probably better targets treatment to phenotype, such that more women with eosinophilic asthma receive inhaled corticosteroids, and more women with non-eosinophilic asthma receive long-acting beta-agonist.”
“FeNO-guided therapy for asthma during pregnancy is promising with improved outcomes but will need further validation before widely recommended in guidelines,” the researcher of the study concluded. “The concept that using biomarker-directed therapy targeting eosinophilic inflammation in asthma during pregnancy simply reduces eosinophil-mediated exacerbations is challenged by the findings of the post hoc analysis and underscores the need for further mechanistic understanding and clinical trials to ensure adoption of precision medicine approaches for asthma in pregnancy.”
Brightling CE. Asthma exacerbations during pregnancy: a need for precision medicine [published online December 16, 2019]. Respirology. doi: 10.1111/resp.13761