Thromb Haemost 1981; 45(01): 068-072
DOI: 10.1055/s-0038-1650131
Original Article
Schattauer GmbH Stuttgart

Altered Serum Factor Vlll-Related Antigen (VIII: AGN)/von Willebrand Factor (VIII: vWf) in Haemophiliacs with Inhibitors to Factor VIII Procoagulant Activity (VIII: C)

Authors

  • J O Ballard

    The Division of Hematology, Department of Medicine, The Pennsylvania State University School of Medicine, Hershey, Pennsylvania, U.S.A
  • J C Sanders

    The Division of Hematology, Department of Medicine, The Pennsylvania State University School of Medicine, Hershey, Pennsylvania, U.S.A
  • M E Eyster

    The Division of Hematology, Department of Medicine, The Pennsylvania State University School of Medicine, Hershey, Pennsylvania, U.S.A
Further Information

Publication History

Received 16 October 1980

Accepted 11 December 1980

Publication Date:
04 July 2018 (online)

Summary

Inhibitors to factor VIII (anti-F VIII) developing in patients with classic haemophilia have apparent specificity for the factor VIII procoagulant activity (VIII: C), rather than the factor VIII-related antigen (VIII :AGN) and von Willebrand factor (VIII :vWf) regions of the factor VIII complex.

Since procoagulant function is absent following in vitro clotting, but serum retains VIII: AGN/vWf properties, we searched for differences in VIII :AGN and VIII :vWf of inhibitor serum that might relate to the presence of anti-F VIII.

Rocket immunoelectrophoresis and the washed platelet ristocetin assay were performed on the plasma and serum of nine haemophiliacs with inhibitors, 23 non-inhibitor haemophiliacs and six normal subjects. Unlike normal and non-inhibitor haemophilic sera, that from five of nine inhibitor patients demonstrated absent VIII : vWf and significantly lower VIII: AGN (p <0.05). Furthermore, VIII: AGN of faster mobility was detected on crossed immunoelectrophoresis of the sera of three inhibitor patients. Thrombin clotting of plasma from haemophiliacs with high titer anti-F VIII was associated with a greater loss of VIII: vWf than seen with non-inhibitor haemophilic plasma. This effect was independent of the presence of platelets.

These data indicate that in vitro clotting is associated with alteration in the serum VIII: AGN/vWf of some haemophiliacs with anti-F VIII.