Platelet proinflammatory activity in clinically stable patients with CF starts in early childhood

Background: Early onset chronic inflammation is present in CF. Platelets may contribute to inflammation by cytokine release and interaction with leukocytes. Methods: Parameters of platelet proinflammatory function (soluble CD62P, soluble CD40L, the percentage of platelet leukocyte aggregates, platelet CD62P) and platelet procoagulatory function (PAC-1-binding to activated integrin alpha(IIb)beta(3) and expression of integrin alpha(IIb)beta(3)=CD41a) were measured in patients and controls. Results: Levels of sCD62P, sCD40L were increased in CF irrespective of age and activity of inflammation. The number of platelet leukocyte aggregates was elevated in older CF patients. PAC-1-binding to platelets decreased with growing activity of inflammation. Exocytosis of CD41a upon platelet activation was reduced. Conclusion: In CF, platelet proinflammatory activity is increased at very young age already and might promote inflammation and tissue damage. On the other hand, platelets seem to downregulate the activation of their most important integrin (alpha(IIb)beta(3))for clot formation. (C) 2010 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.