Achievement of clinical remission in asthma subgroups based on the combination of FeNO and blood eosinophil counts

<bold>Aims and Objectives:</bold> Clinical remission (CR) has been focused on as an achievable treatment goal. However, what asthma phenotype is favorable to achieve CR remains unclear. Fraction of exhaled nitric oxide (FeNO, F) and blood eosinophil counts (b-EOS, b-E) are recognized as type 2 biomarkers of asthma. Here, we examined the rates of CR in the subtypes of asthmatics based on two type 2 biomarkers. <bold>Methods:</bold> Asthmatics were classified into four subgroups according to 27ppb of F and 265/μl of b-E, based on our previous study (Front Pharmacol. 2022). CR was defined by ACT ≥ 20 or no symptoms, no use of oral corticosteroids (OCS), and no severe acute exacerbations (SAEs) for a year. The rates of CR were compared among the four subgroups. <bold>Results:</bold> One hundred eleven asthmatics were divided into 26 of the low (lo)-F/lo-b-E, 23 of the high (hi) F/lo-b-E,31 of the lo-F/hi-b-E, and 31 of the hi-F/hi-b-E subgroup. The hi-b-E subgroups achieved higher rates of no OCS use (p=0.005). The lo-F/hi-b-E achieved the highest rates of no SAEs among them (p=0.04). The rates of no symptoms did not differ between the four subgroups. The lo-F/hi-b-E showed the highest rates of CR (p=0.02). <bold>Conclusion:</bold> Asthmatics with low-FeNO and high b-EOS are likely advantageous to reach clinical remission.