Abstract Rationale Asthma is a heterogeneous disease characterized by chronic airway inflammation. In recent years, asthma management has evolved toward the anti-inflammatory reliever (AIR) strategy, which combines inhaled corticosteroids (ICS) with rapid-acting bronchodilators (RABDs) for symptom relief resulting in reduced exacerbation risk. Notably, the anti-inflammatory effect of AIR therapy at the very moment of symptom onset has never been investigated. This study aimed to compare the effect of the ICS plus SABA versus SABA alone on airway inflammation and lung function, at the time of/following the use of the rescue medication due to asthma symptoms. Methods We conducted a single-center, randomized, cross-over phase II study. Adults with mild to moderate asthma (GINA steps 1-3) were randomized 1:1 to receive inhaled corticosteroids plus salbutamol as rescue therapy, or rescue salbutamol alone for a maximum of three symptomatic episodes or for 4 weeks, with at least 1-week washout between the two cross-over periods. At the onset of asthma symptoms, i.e. before the use of the rescue medication, patients measured FeNO (FeNO Breath®), PEF and FEV1 (Microlife®), and scored respiratory symptoms by a visual analog scale (VAS). All measurements were repeated after the use of the rescue medication and at predefined intervals minutes up to 36 hours post-dose. Results A total of 21 patients were included in the study (mean age 35.6 years; 47.6% female). Overall, 49 symptomatic episodes were recorded, each characterized by a significant decrease in FEV1 (-0.70 L vs stable condition; p=0.003). As shown in Figure 1, after the rescue medication use, FeNO progressively increased in the SABA arm compared with SABA + ICS, with a difference of + 4.43 ppbat 8-15 min (p=0.052), followed by significant increases at 30-60 min (+6.30 ppb; 95% CI 1.91-10.68; p=0.005), 11-25 h (+8.93 ppb; 2.35-15.51; p=0.008), and 26-36 h (+10.63 ppb; 0.42-20.85; p=0.041). After the bronchodilation peak (30-60min), the total FEV1 decline was of 0.47L and 0.28L in the SABA and ICS+SABA group respectively (p = 0.003). Conclusions The AIR strategy (ICS + SABA) reduces airway inflammation compared with SABA alone during symptomatic episodes, as demonstrated by significant differences in FeNO levels, and reduces post- bronchodilation decline in FEV1 following rescue medication use. These findings support the concept of an acute anti-inflammatory effect of ICS when used on demand. This abstract is funded by: none
Baraldi et al. (Fri,) studied this question.