Inflammation and platelet activation in peripheral arterial occlusive disease

Objectives: Epidemiological evidence indicates that inflammation accompanies the progression of atherosclerosis. Aim of the cross-sectional study was to define relations between platelet activation and inflammation in patients with mild to severe (stages II–IV) peripheral arterial obliterative disease (PAOD) and matched controls. The effect of chronic administration of low dose aspirin was investigated.Design and Methods: Subjects were studied in a single occasion. C-reactive protein (CRP) and two indices of in vivo platelet activation were measured: the urinary excretion of 11-dehydro-TXB2 by immunoassay and circulating platelet-monocyte aggregates (PMA) by flow cytometry. Results: Plasma PMA and urinary 11-dehydro-TXB2 were significantly increased in PAOD patients compared to controls (p<0.01 for all). A positive correlation between 11-dehydro-TXB2, and CRP was found in the study population (rs=0.63, p<0.001). Using logistic regression analysis, CRP was the only independent correlate of 11-dehydro-TXB2 (βCRP = 11.9; p<0.01), whereas only the presence of PAOD was an independent predictor of high PMA levels (βPAOD = 13.7; p=0.001). Chronic administration of aspirin reduced 11-dehydro-TXB2 but not PMA and CRP.Conclusions: There is evidence that platelet activation in patients with PAOD is related to the vascular disease and dependent on the severity of inflammation.