title: FVIII/VWF ratio is not a reliable predictor of VWD in children.
abstract: Adults with von Willebrand Disease (VWD) are known to have a ratio of factor VIII activity (FVIII:C) to von Willebrand factor antigen (VWF:Ag) greater than 1. We, however, noted healthy children with ratios that are unexpectedly high. Though the FVIII:C/VWF:Ag ratio differs significantly between healthy children and VWD patients in some age groups, the substantial overlap of observed ranges suggests that a ratio threshold-based screening approach alone cannot reliably discriminate between these groups. The diagnostic performance of this ratio is poor for VWD in children, which may decrease its value as a screening tool in the pediatric population.
authors.affiliation: Department of Pediatrics, Section of Hematology/Oncology/Bone Marrow Transplantation at The Children's Hospital Colorado and University of Colorado Anschutz Medical Campus, Aurora, Colorado.
authors.forename: Brian R
authors.initials: BR
authors.lastname: Branchford
authors.forename: Katherine
authors.initials: K
authors.lastname: Ruegg
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Villalobos-Menuey
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Jacobson
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Di Paola
authors.forename: Marilyn
authors.initials: M
authors.lastname: Manco-Johnson
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood*; D001780:Blood Coagulation Tests; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005169:Factor VIII / Q000032:analysis*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D055815:Young Adult; D056725:von Willebrand Disease, Type 1 / Q000097:blood / Q000175:diagnosis*; D014841:von Willebrand Factor / Q000032:analysis*
chemical_list: D015415:Biomarkers; D014841:von Willebrand Factor; D005169:Factor VIII
keywords: factor VIII; reference range; von Willebrand disease; von Willebrand factor