A variant of von Willebrand's disease with abnormal expression of factor
VIII procoagulant activity
RR Montgomery, WE Hathaway, J Johnson, L Jacobson and W Muntean
Reports on variants of von Willebrand's disease are numerous, but many of
these are based on tests that will show marked fluctuations with time and
tests that might not be similar in affected family members. This report
describes 8 patients with a new variant of von Willebrand';s disease in
which there is a normal APTT, slightly reduced one-stage factor VIII:C
assay (VIII:C-1), and a drastically reduced two- stage factor VIII:C assay
(VIII:C-2). The VIII:C in this variant is more readily adsorbed to AI(OH)3.
This variability in VIII:C assays and excessive adsorption to AI(OH)3 are
corrected by the addition of either hemophilic plasma or hemophilic
factor-VIII-related antigen. This variant is stable with restudy on
multiple occasions and is inherited in a stable fashion in three
generations of one family. The multimeric structure of the VIIIR:Ag appears
normal, although the concentration is moderately reduced. The differences
in functional activity, the adsorption to AI(OH)3, and the differences
between functional and antigenic (VIII:C Ag) assays of VIII:C support that
this is a functional abnormality of type I von Willebrand's disease.
Volume 60,
Issue 1,
pp. 201-207,
07/01/1982
Copyright © 1982 by The American Society of Hematology
