Circulating platelet-neutrophil aggregates as risk factor for deep venous thrombosis.

Background Platelet-neutrophil aggregates (PNAs) are fundamental mechanisms linking hemostasis and inflammatory processes. Elevated level of PNAs have been reported in inflammatory diseases and coronary artery diseases. However, studies on the correlation between PNAs formation and deep venous thrombosis (DVT) are not available. Methods A total of 92 participants were involved in this study, including 32 cases with DVT and 60 cases without DVT. Blood samples coagulated by K2-EDTA or sodium citrate were prepared for blood cell count and blood smears. PNAs and platelet activation were measured using flow cytometry. The correlation between platelet activation level and PNAs level was analyzed by linear regression. Receiver operating characteristic (ROC) analysis was performed, assessing the prognostic performance of PNAs to predict potential risk of DVT occurrence. Results PNAs was found in the blood smears of patients with DVT. Significant increased level of PNAs was identified in DVT group (medium 8.43%, interquartile range [IQR] 4.11%-15.69%), compared with that in control group (5.16%, IQR 2.40-9.60, p<0.01). The DVT group also showed a dramatic elevated level of total platelet activation (medium 16.06%, IQR 6.04-22.05) vs. control group (11.26%, IQR 5.54-19.99, p<0.05). The PNAs level was correlated with total platelet activation (r2=0.58, p<0.0001). A significantly high odds ratio (OR) of DVT occurrence was identified when the level of PNAs was higher than 7.4% (OR 3.60, 95% confidence interval [CI] 1.463-8.838, p<0.01). Conclusions An elevated level of PNAs was associated with risk of DVT occurrence, which might be a suitable marker predicting DVT development.