In a previous study [38], we recruited a total of 1006 subjects and divided them into VTE group, risk factor groups and control (non- risk factor) group without a difference in age. Flow cytometry was performed to detect the expression of the core proteins in venous thrombi. The normal range of integrins β1, β2 and β3 were generated from healthy people.

Compared with that in the control group, the integrin β1 expression in VTE group and subjects with different risk factors (acute infection, malignancy and autoimmune diseases) increased markedly (P<0.001, <0.01). However, compared with the control group, the integrin β1 expression in trauma /surgery group was not significantly dif f erent (P>0.05). The elevated expression of integrin β1 in VTE group, acute infection group, malignancy group and autoimmune diseases group was highly consistent with the increased core protein expression in thrombi, indicating that VTE patients shared the same protein expression with patients with acute infection, malignancy and autoimmune diseases. However, similar elevations of protein expression were not found in patients with trauma /surgery.

Compared with the control group, the integrin β2 expression in VTE group increased signif i cantly (P <0.05). However, compared with control group, the integrin β2 expression in subjects with different risk factors (acute infection, malignancy and autoimmune diseases,trauma /surgery group) was not significantly different (P>0.05), suggesting no same elevation of protein expression was found in patients with acute infection group,malignancy group and autoimmune diseases group, trauma /surgery group.

Compared with control group, the integrin β3 expression in VTE group was elevated (P<0.05). However, the integrin β3 expression in different risk factor groups(acute infection, malignancy, autoimmune diseases, trauma/ surgery) were not signif i cantly dif f erent (P>0.05).

We found that integrins β2 and β3 are the proteins to distinguish patient with VTE from patients with risk factors, and are also the key proteins for determining the occurrence of VTE. The increased integrin β1 is the characterized expression in patients with risk factors. However this increased expression of integrins β1, β2 and β3 was not found in patients following trauma or surgery, calling into question that such patients may have no VTE risk.