Platelet activation markers overexpressed specifically in patients with aspirin-exacerbated respiratory disease

BACKGROUND:Aspirin-exacerbated respiratory disease (AERD) is characterized by respiratory reactions on ingestion of COX-1 inhibitors and cysteinyl leukotriene overproduction. The hypersensitivity reaction is induced by low doses of aspirin that inhibit COX-1 in platelets. OBJECTIVE:We sought to explore the role of platelets in the pathogenesis of AERD in patients under stable conditions and during an aspirin challenge test. METHODS:Stable patients with AERD (n = 30), aspirin-tolerant asthma (ATA; n = 21), or idiopathic chronic eosinophilic pneumonia (n = 10) were enrolled. Platelet activation was estimated based on expression levels of P-selectin (CD62P), CD63, CD69, and GPIIb/IIIa (PAC-1) in peripheral platelets; percentages of circulating platelet-adherent leukocytes; and plasma levels of soluble P-selectin (sP-selectin) and soluble CD40 ligand (sCD40L). RESULTS:In the stable condition, expression of all surface markers on platelets, the percentage of platelet-adherent eosinophils, and the plasma levels of sP-selectin and sCD40L were significantly higher in patients with AERD compared with those in patients with ATA. P-selectin and CD63 expression on platelets and plasma sP-selectin and sCD40L levels were positively correlated with the percentage of platelet-adherent eosinophils. Among these markers, P-selectin expression and plasma sP-selectin levels positively correlated with urinary concentrations of leukotriene E4. Additionally, plasma sP-selectin and sCD40L levels were negatively correlated with lung function. In contrast, platelet activation markers in patients with AERD did not change during the aspirin challenge test. CONCLUSION:Peripheral platelets were activated more in patients with stable AERD compared with those in patients with stable ATA, patients with idiopathic chronic eosinophilic pneumonia, and control subjects. Platelet activation was involved in cysteinyl leukotriene overproduction and persistent airflow limitations in patients with AERD.