Nasal periostin expression is higher in asthma patients with versus without persistent airflow limitation

<bold>Introduction:</bold> One in three asthma patients have persistent airflow limitation (PAL), which is associated with lower quality of life and higher risk of exacerbations. In the current study, we used nasal brush transcriptome data to explore mechanisms associated with PAL in asthma patients. <bold>Methods:</bold> In ATLANTIS, a differential gene expression (DGE) analysis of 126 previously identified asthma-associated genes (ERJ 2022; 60: Suppl. 66, 687) was performed using EdgeR, adjusted for age and sex. Replication was done in a cohort (ARMSTRONG) of 20 asthma patients. <bold>Results:</bold> We included 95 asthma participants with and 204 without PAL (age 46 vs 43, male sex 51% vs 34%, FEV1 % pred 80 vs 96, FEV1/FVC % pred 76 vs 96, blood eos 0.25 vs 0.20 respectively) from whom nasal brush RNA-seq data were available. We found 3 higher and 5 lower expressed genes in asthma with versus without PAL (figure 1). We identified high expression of the gene <italic>POSTN</italic> in PAL, also replicated in nasal brushes of 9 patients with and 11 without PAL included in the ARMSTRONG study (ATLANTIS LogFC: 1.07, FDR: 0.001, AMSTRONG: logFC: 2.73, FDR: 0.03). <bold>Conclusion:</bold> We found higher nasal periostin expression to be associated with PAL in participants with asthma. Our findings suggest that periostin, associated with epithelial inflammatory responses and airway wall remodelling, is a feature of PAL in asthma. Figure 1: Results for DGE analysis in ATLANTIS <fig><object-id>erj;64/suppl_68/PA823/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>