Observations on hemophilia, parahemophilia, and coexistent hemophilia and parahemophilia; alterations in the platelets and the thromboplastin generation test.

Abstract

Abstract Cases of parahemophilia and of coexistent hemophilia and parahemophilia are described. The coexistence of these two defects suggests a common step in the syntheses of antihemophilic factor and proaccelerin. That the hemophilic platelets are deficient in antihemophilic activity and parahemophilic platelets in proaccelerin-like activity has been confirmed. These defects were correctible by incubating the abnormal platelets with normal plasma. The defect measured in the thromboplastin generation test was exaggerated in parahemophilia by the use of parahemophilic platelets and a substrate of parahemophilic plasma. The significance of these observations in relationship to the mechanisms measured by this test is discussed.