Platelet activity measured by plasma levels of beta-thromboglobulin and platelet factor 4 in seasonal allergic rhinitis during natural pollen exposure

Background: Upon activation, platelets release mediators with potent inflammatory properties in IgE-mediated immune responses. Moreover, the atopic state leads towards functional abnormalities of these cells. Objective: The aim of our study was to examine the degree of activation of circulating platelets in patients with seasonal allergic rhinitis (SAR) during the symptomatic period, to improve the understanding of platelet function in atopy. Subjects and Method: Plasma levels of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) - specific markers of platelet activation were measured by enzyme-linked immunoassay in 20 patients suffering from SAR and in 15 healthy, nonatopic subjects. Results: There were no significant differences in peripheral blood platelet numbers and plasma levels of beta-TG and PF4 in SAR patients when compared with control subjects. Conclusion: It seems that increased in vivo platelet activity, assessed by measuring plasma beta-TG and PF4, may not occur during allergic inflammation that is associated with SAR.