IgA inhibitor to factor VIII/von Willebrand factor |
| |
| Authors: | Harvey R. Gralnick Morris A. Flaum Craig M. Kessler Harvey Zimbler Barry S. Coller |
| |
| Affiliation: | Hematology Service, Clinical Pathology Department, Clinical Center, National Institutes of Health, Bethesda, Md.;Hematology Section, Ochsner Clinic, New Orleans, La.;Division of Hematology-Oncology, Department of Medicine, George Washington University Medical Center, Washington, D.C.;Department of Hematology-Oncology, Berkshire Medical Center, Pittsfield, Mass.;Hematology Section, Department of Medicine, State University of New York, Stony Brook, N.Y. |
| |
| Abstract: | A 60-year-old Black female presented with a haemorrhagic diathesis and an acquired factor VIII/von Willebrand factor (VIII/vWf) inhibitor. This inhibitor was classified as an IgA immunoglobulin and was active not only against factor VIII coagulant (VIII:C) activity but also against plasma von Willebrand factor (vWf). The purified IgA also interacted with normal platelets to inhibit ristocetin-induced platelet aggregation (RIPA). In contrast, studies with haemophilia A plasma and platelets revealed that the inhibitor did not react significantly with these plasmas or platelets. The significant differences in the inhibition of vWf assay both of the plasma and the platelets of the haemophilia A patients suggests that part of the haemorrhagic diathesis may be related not only to the inhibition of VIII:C but also to interference with platelet function. In addition, these studies suggest that there may be significant differences in the factor VIII-related antigen (VIII R:Ag) on platelets in haemophilia A patients compared to normal. |
| |
| Keywords: | |
|
|
