Studies of Cross-Reactivity of Acquired Factor VIII Inhibitor Activity in Hemophilic Plasma

Abstract

The plasma of a hemophilic patient with acquired factor VIII inhibitory activity was found to be time and temperature dependent, resistant to heat and stable on storage at -20°. Studies revealed cross-reactivitiy with 11 different mammalian plasmas but no cross-reaction was found with chicken plasma. The inhibitory activity of the plasma studied was neutralized by fresh normal plasma and normal serum but not by aged normal plasma or hemophilic plasma (20 patients). Comparison of the present findings with other reports suggest a difference in cross-reactivity of acquired inhibitors and inhibitory activity induced by immunization of animals. ^* This investigation was supported by a graduate training grant (TI-AM-5344) from the National Institute of Arthritis and Metabolic Diseases, and research grants from the National Heart Institute (RG-HE-07418), the National Institute of Child Health and Human Development (RG-HD-00568), National Institutes of Health, United States Public Health Service and the Chicago and Illinois Heart Associations.