Cerebral venous thrombosis and plasma concentrations of factor VIII and von Willebrand factor: a case control study

Background

High plasma concentrations of factor VIII (FVIII) and von Willebrand factor (VWF) have been recently associated with a moderately increased risk of venous thrombosis, but their roles in cerebral sinus and venous thrombosis (CSVT) have not been addressed. To determine whether elevation of FVIII and VWF is more frequent in CSVT, we analysed plasma levels of FVIII and VWF in a case control study.

Methods

The study population consisted of 25 consecutive patients (of whom nine were excluded) admitted for CSVT to the Department of Neurology, Amiens University Hospital, France, from January 1997 to December 2002, for a general screening for thrombophilia. Sixty‐four healthy subjects matched for age and sex formed the group control.

Results

Mean FVIII (CSVT: 167.3 (SD 48.8)?IU/dl; control group: 117.9 (39.8)?IU/dl; p?=?0.001) and VWF levels (CSVT: 165.4 (76.5)%; control group: 108.5 (27.8)%; p?=?0.01) were significantly higher in the CSVT group. Using the 95th percentile of the control group as the cut off value, elevated FVIII (>190?IU/dl) occurred in 25% (4/16) (p?=?0.005) and elevated VWF (>168%) in 37.5% (6/16) of patients with CSVT (p<0.001). Using previously reported cut off values (>150?IU/dl or >150%) showed the same results (FVIII: p?=?0.005; VWF: p?=?0.009).

Conclusion

Our study suggests that elevation of plasma factor VIII levels is the most common prothrombotic risk factor for CSVT. Elevation of VWF is also associated with an increased risk of CSVT but its effect seems to be partly mediated through FVIII.Cerebral sinus and vein thrombosis (CSVT) is a rare localisation of venous thromboembolic disease. It generally occurs in young or middle‐aged adults and accounts for approximately 1% of strokes.¹ Many coagulation disorders have been associated with CSVT.^2,3,4Several prospective studies showed that high concentrations of factor VIII (FVIII) are associated with a moderately increased risk of venous thromboembolism (VTE).^5,6 The role of increased levels of von Willebrand Factor (VWF) in VTE remains unclear.^5,7 Recent studies suggest that the effect of VWF is fully explained by FVIII concentrations.⁵ Indeed, the ABO blood group, which regulates plasma concentrations of both FVIII and VWF, may also play a role in susceptibility to thrombosis.^8,9,10The increased risk of VTE with elevated levels of FVIII or VWF has been observed in previous studies.^5,6,7,11 However, they did not specifically include patients with CSVT^7,9 or they were incomplete.¹²The aim of our study was to assess plasma levels of FVIII, VWF and other thrombophilic factors in patients with CSVT in a case control study.