Determinants of bleeding phenotype in adult patients with moderate or severe von Willebrand disease.

We performed a nation-wide cross-sectional study to evaluate determinants of bleeding symptoms in a large unselected cohort of adults with von Willebrand disease (VWD). VWD patients were included (n=664), based on lowest historically measured VWF:Ag and VWF:Act levels ≤30 U/dl. Menorrhagia (85%), cutaneous bleeding (77%), bleeding from minor wounds (77%) and oral-cavity bleeding (62%) occurred most frequently. Higher age was associated with a higher bleeding score (BS), determined according to Tosetto, in females. A 10 year increase in age was associated with 0.8 point (95% confidence interval [CI] 0.4–1.1) higher BS. Females had higher BS than males (median 12 vs. 10, p=0.012). BS differed significantly between VWD type 1, 2 and 3: median 9 (-2–31), 13 (-1–33) and 19.5 (1–35), respectively (p 30 IU/dl. In type 3 patients 1 IU/dl FVIII:C decrease was associated with 0.6 point (95% CI 0.1–1.1) BS increase (p=0.021). In conclusion, in VWD patients the bleeding phenotype is strongly associated with type of VWD and VWF and FVIII levels.