Knowledge of Blood Group Decreases von Willebrand Factor Panel Testing in Children

摘要

Von Willebrand factor (VWF) and Factor VIII:C testing are often initiated in the evaluation of pediatric patients with a concern for a bleeding disorder. Subjects with O blood group are known to have significantly lower baseline von Willebrand factor (VWF) values than subjects with non-O blood groups and thus are more likely to fall within a low VWF category (low VWF or disease) than any other blood group. Repeat VWF panel (VWF antigen [VWF:Ag], VWF ristocetin cofactor [VWF:RCo], and Factor VIII:C drawn on same date and at same time) testing has been advocated to help improve clinician diagnostic ability, but there is little evidence to suggest that it does. In subjects with low VWF, knowledge of blood group might not only be useful in decreasing overall VWF panel testing but also help in the diagnosis of patients with true bleeding disorders. We aimed to determine if the timing of blood group testing influenced the number of VWF panels performed.