Evaluation of elevated FVIII in patients with thrombophilia

An increased tendency for the blood to clot is referred to as the hypercoagulable state or thrombophilia which includes various inherited and acquired clinical disorders or mixed conditions. There are many studies suggesting that elevated factor VIII may be a common and independent risk factor for thrombotic events. We tried to assess the level of factor VIII in patients with idiopathic thrombosis. Materials and Methods Our cases were the patients with idiopathic venous thrombosis having referred for hypercoagulable studies to Coagulation Lab in Iranian Blood Transfusion Organization. The inclusion criterion was the occurrence of thrombotic event confirmed by objective diagnostic methods coupled with three months of follow-up without any other disorder. Our controls were from healthy blood donors and matched with the cases on sex, ethnicity, and age. Plasma of a healthy person was used to establish the normal reference range according to which our patients are compared. Factor VIII levels were measured using a one-staged assay, the PTT based Diagonistica Stago on the STA compact automated coagulation factor analyzer. SPSS and Chi-square were finally used for data analysis. Results One hundred fifty two cases and 130 controls enrolled. The mean factor VIII level for cases was 157.26 IU/dl (SD±53.8) with the minimum level of 66 and maximum of 364 IU/dl. For controls, the mean factor VIII level was 111.78 IU/dl (SD± 29.68) with the minimum level of 42 and the maximum of 195 IU/dl. These levels were statistically significant and higher in the case group. The elevated FVIII level was higher in females than males (35.3% vs 23.8%) and increased with age. The normal range in the control group varied within 52-171 IU/dl, which is higher than the normal level of 50-150 IU/dl. Conclusions There are many studies showing that increased FVIII level may be an independent risk factor for thrombosis. Our results suggested elevated FVIII level in 28.9% of the patients with thrombosis compared to 3.1% in the control group. So, factor VIII measurement is recommended to be practiced in routine thrombophilia screening programs