Is There Any Basophil Activation in Peripheral Blood in AERD Patients?

Rationale: Cysteinyl leukotriene (cysLT) overproduction is considered as one of the most important mechanisms underlying the pathogenesis of aspirin-exacerbated respiratory disease (AERD). Many studies have shown that eosinophils and mast cells play some important roles in the pathogenesis of AERD. However, there has been no study in which the relevance of basophils, which also release cysLT, to AERD pathogenesis was evaluated. We have explored CD203c expression on basophils from AERD patients in stable condition and its relevance to cysLT overproduction.

Methods: We examined 17 AERD patients and 20 aspirin-tolerant asthma (ATA) patients whose aspirin sensitivity was determined by the aspirin challenge test. We used flow cytometry to compare the spontaneous expression levels of surface markers on basophils from patients with stable asthma and healthy controls (HCs). Longitudinal changes in these expression levels were measured after basophil stimulation by IgE-dependent or IgE-independent (IL3 stimulated) mechanisms and compared with patients’ asthma status.

Results: The spontaneous CD203c expression level on basophils from AERD patients was similar to those from ATA patients and HCs (p value=0.198). The level of anti-IgE induced expression of CD203c increased significantly on basophils from ATA patients compared with those from AERD patients and HCs (p value = 0.002). However, there were no significant differences in the level of CD203c expression on IL3-stimulated basophils among the three groups (p value=0.283).

Conclusions: The expression level of CD203c, which is a biomarker of basophil activation, is not elevated in stable AERD patients compared with stable ATA patients.