Increased expression of serine palmitoyl transferase and ORMDL3 polymorphism are associated with eosinophilic inflammation and airflow limitation in aspirin-exacerbated respiratory disease

Patients with aspirin-exacerbated respiratory disease (AERD) are known to have poor clinical outcomes. The pathogenic mechanisms have not yet been completely understood. We aimed to assess the involvement of the de-novo synthetic pathway of sphingolipid metabolism in patients with AERD compared to those with aspirin tolerant asthma (ATA). A total of 63 patients with AERD and 79 patients with ATA were enrolled in this study. Analysis of mRNA expression of serine palmitoyl transferase, long-chain base subunit 2 (SPTLC2) and genotyping of ORMDL3 SNP (rs7216389) was performed. Significantly higher levels of SPTLC2 mRNA expression were noted in patients with AERD, which showed significant positive correlations with peripheral/sputum eosinophil counts and urine LTE4 (all P