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)

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
› Author Affiliations
Further Information

Publication History

Received 16 October 1980

Accepted 11 December 1980

Publication Date:
04 July 2018 (online)

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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.