Population differences in von Willebrand factor levels affect the diagnosis of von Willebrand disease in African-American women

Authors

  • Connie H. Miller,

    Corresponding author
    1. Hematologic Diseases Branch, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
    • Hematologic Diseases Branch, NCID, Centers for Disease Control and Prevention, 1600 Clifton Road, Mailstop D-02, Atlanta, GA 30333
    Search for more papers by this author
  • Anne Dilley,

    1. Hematologic Diseases Branch, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
    Search for more papers by this author
  • Lisa Richardson,

    1. Hematologic Diseases Branch, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
    Search for more papers by this author
  • W. Craig Hooper,

    1. Hematologic Diseases Branch, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
    Search for more papers by this author
  • Bruce L. Evatt

    1. Hematologic Diseases Branch, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
    Search for more papers by this author

  • This article is a U.S. Government work and, as such, is in the public domain in the United States of America.

Abstract

Diagnosis of von Willebrand disease (vWD) is based on a panel of laboratory tests that measure the amount and function of von Willebrand factor (vWF). In population studies, vWF is higher in African Americans than Caucasians. Bleeding time, factor VIII activity (FVIII), vWF antigen (vWF:Ag), “vWF activity” ELISA (vWF:Act), ristocetin cofactor (vWF:RCof), and ristocetin-induced platelet aggregation (RIPA) were measured on 123 women with menorrhagia and 123 randomly selected control women; 70 cases and 76 controls were African American. Among controls, African Americans had significantly higher levels of vWF:Ag (mean 120 vs. 102 U/dl, P = 0.017). Among all subjects, African Americans had higher levels of vWF:Ag (mean 123 vs. 103, P = 0.001), vWF:Act (mean 101 vs. 89, P = 0.006), and FVIII (mean 118 vs. 104, P = 0.008). VWF:RCof did not differ between races (93 vs. 94 U/dl). RIPA was reduced in African Americans (P < 0.0001). In both races, women with type O blood differed significantly from those with other ABO types in vWF:Ag, vWF:Act, FVIII, and vWF:RCof. Based on criteria of two or more tests below race- and ABO-specific reference ranges, 6.5% of menorrhagia cases and 0.8% of controls were classified as having vWD, or its phenocopy. Among Caucasians, no controls and 7 cases (15.6%) were classified as affected, and in African Americans, 1 control (1.3%) and 1 case (1.4%) were so classified. Racial differences in vWF further complicate the issues surrounding diagnosis of vWD. The finding of increased vWF:Ag not accompanied by increased vWF:RCof has implications for understanding the structure-function relationships of vWF. Am. J. Hematol. 67:125–129, 2001. Published 2001 Wiley-Liss, Inc.

Ancillary