[Heparin cofactor II (HCII) activity and antigen assay and their significance in thrombotic diseases]

To study the plasma HCII activity and antigen level variations and their relationship with arterial and deep venous thrombotic diseases.

Seventy-five patients with brain infarction (BI), 50 myocardial infarction (MI), 36 deep venous thromboembolic disease (DVT) and 50 healthy controls were entered in this study. Plasma HCII activity was measured with chromogenic substrate method and the HCII antigen level by Western blotting assay. Plasma antithrombin (AT) activity was detected for the HCII deficiency individuals with DVT using chromogenic substrate method.

There was no significant difference in the mean plasma HCII activity and antigen levels between BI group [(99.97 +/- 21.14)% and 0.96 +/- 0.24], MI group [(98.18 +/- 29.35)% and 0.95 +/- 0.20] and healthy controls [(96.80 +/- 20.11)% and 0.93 +/- 0.19]. The plasma HCII activity and antigen concentrations in patients with DVT [(89.57 +/- 17.12)% and 0.87 +/- 10.18] tended to be decreased as compared with healthy controls, but they were not significant. No significant difference was found for the prevalence of HCII deficiency between patient groups and control group. The HCII deficiency individuals with DVT had normal AT activity and fibrinogen concentration.

Plasma HCII deficiency may not be the risk factor for arterial thrombosis in the Han population of Hunan Chinese. It is needed to further confirm if decreased plasma HCII is correlated with venous thrombosis.