Bleeding Symptoms and von Willebrand Factor Levels: 30-Year Experience in aTertiary Care Center

摘要

Correlations between bleeding symptoms and von Willebrand factor (VWF) levels may help topredict hemorrhagic severity in the Westerners with von Willebrand disease (VWD), but datain Asians are lacking. In this study, Thai patients with VWF levels <50 IU/dL withoutany secondary causes were enrolled from 1988 to 2018 to determine the relationship betweenVWF levels and hemorrhagic manifestations. According to the current concept, wereclassified VWD and low VWF by VWF levels ≤30 and 30 to 50 IU/dL, respectively. Type 2VWD was diagnosed if VWF activity to antigen ratio was ≤0.6. Bleeding severity wasdetermined by the condensed MCMDM-1VWD bleeding score (BS). Among 83 patients, VWFactivities showed negative correlations with BS ( .001), which werehigher in type 2 (median: 7, interquartile range [IQR]: 5-11) compared with type 1 VWD(median: 3, IQR: 2-4) and low VWF (median: 4, IQR: 2-8). Bleeding symptoms wereindistinguishable between type 1 VWD and low VWF using the 30 IU/dL cutoff point. However,VWF ristocetin cofactor activity or gain-of-function mutant glycoprotein Ib bindingactivity <36.5 IU/dL and VWF collagen binding activity <34.5 IU/dL could predictincreased bleeding risk (BS ≥3) by 92.3% specificity and 70.0% sensitivity( < .0001).