A32-40 Type-2 Inflammation and Disease Progression in Mild to Moderate Asthma in the General Population

Rationale

Whether type-2 inflammation in mild to moderate asthma is associated with disease progression remains unclear. We tested the hypothesis that elevated type-2 inflammatory biomarkers - blood eosinophil count (BEC) and fractional exhaled nitric oxide (FeNO) - are associated with accelerated disease progression in individuals with mild to moderate asthma.

Methods

We included 103,033 randomly selected individuals aged ≥20 years from the Copenhagen General Population Study, of whom 14,881 attended a follow-up examination after 10 years. Among these, 1141 individuals with asthma were identified and classified by disease severity based on symptoms and airflow obstruction assessed using pre- and post-bronchodilator forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC). BEC was measured at baseline and follow-up, while FeNO was available in a subset of 213 individuals measured at follow-up only. Associations of elevated BEC (≥300 cells/μL) and FeNO (≥20 ppb) with annual FEV1 decline were assessed using multiple linear regression analyses, and with exacerbation risk using Cox regression, adjusted for age, sex, body mass index, smoking status, tobacco consumption (pack-years), inhaled corticosteroid use, exacerbation history, and asthma severity.

Results

Adjusted FEV1 decline over 10 years was 26.5 mL/year (95% confidence interval [CI]:24.5-28.5) for BEC <300 cells/μL versus 32.9 mL/year (29.7-36.1) for BEC ≥300 cells/μL. Corresponding FEV1 declines were 18.8 mL/year (13.2-24.3) for FeNO <20 ppb versus 34.8 mL/year (26.7-42.8) for FeNO ≥20 ppb. During up to 8.7 years of follow-up (median 6.0 years), 328 exacerbations were recorded. Adjusted HR for exacerbation was 1.20 (95% CI:0.94-1.51) for BEC ≥300 cells/μL versus BEC <300 cells/μL, and was 1.66 (1.03-2.66) for FeNO ≥20 ppb versus FeNO <20 ppb. No interaction between BEC or FeNO and asthma severity was observed for FEV1 decline or exacerbation risk.

Conclusions

Type-2 inflammation indicated by elevated BEC and FeNO is associated with accelerated FEV1 decline and increased exacerbation risk in individuals asthma in the general population including those with mild to moderate disease.

Funding

The study was funded by Sanofi.

This abstract is funded by: Sanofi