CysLT₁-R expression following allergen provocation in asthma and allergic rhinitis

Abstract 

Cysteinyl leukotrienes (CysLTs) contribute to allergic and inflammatory diseases through CysLT₁-R. We aimed to assess CysLT₁-R mRNA expression in induced sputum of rhinitics with or without asthma before and following allergen challenges. Both groups underwent nasal and “low dose” lung allergen challenges. Asthmatics also underwent “standard” lung challenge. Sputum was obtained before and at different time-points following the challenges for CysLT₁-R, 5-lipoxygenase (5-LO), and eotaxin mRNA assessments. At baseline, there was no difference in mediator levels between groups. An increase in CysLT₁-R mRNA (p=0.04) and a trend towards an increase in 5-LO and eotaxin (p=0.06 for both) at 24h post-nasal challenge were observed. Following “low dose” lung allergen challenge, there was a trend towards an increase in CysLT₁-R (p=0.07). In conclusion, CysLT₁-R gene expression changes can be detected in sputum following allergen challenges. No difference was observed between groups, suggesting that changes in CysLT₁-R expression occur whether or not the subject has concurrent asthma.

Keywords: CysLT₁-R, Asthma, Allergic rhinitis, Allergen provocation, Induced sputum