The clinical and laboratory findings of von Willebrand's disease (prolonged bleeding time, low factor VIII, and abnormal platelet activity) are discussed, and a protocol for management of patients with low factor VIII levels (such as hemophilia carriers and subjects with hemophilia A or von Willebrand's disease) undergoing open-heart surgery is proposed.
It is concluded that consideration of both the level of factor VIII activity and the ratio of factor VIII activity to factor VIII-related antigen is of some value in detecting carriers of haemophilia.
However, there was a discrepancy between the factor IX antigen determined by the neutralization test and the factor IX procoagulant activity in the patients of both hemophilia BM and hemophilia B+.
The activity of factor IX in a definite carrier of hemophilia B was significantly lower than that of factor VIII in a definite carrier of hemophilia A.3.
Examination of Factor VIII activity and Factor VIII-related antigen revealed that the Factor VIII activity/Factor VIII-related antigen ratio was significantly decreased in their mother and maternal grandmother consistent with the carrier state of hemophilia.
Estimation of the titer of procoagulant antihemophilic factor (AHF) and the concentration of AHF-like antigens, as detected by heterologous antiserum, provides a method for diagnosis of the carrier state of classic hemophilia.
However, the maternal grandfather was known to have been a bleeder and the propositus' mother, his sister and his aunt had low-normal factor VIII levels and were probably hemophilia A carriers.
A circulating anticoagulant against factor VIII activity was demonstrated in the plasma of a boy from a family with both factor VIII deficiency and prolonged bleeding time.
Hemorrhagic diathesis in multiple obligate carriers in these families is not readily explained by the Lyon hypothesis, and suggests that these families may be exmaples of an unusual allelic form of hemophilia A or that they may be transmitting several independent genes affecting VIII AHF levels.
Carriers of hemophilia can often be detected because their plasmas contain a disproportionately high concentration of antihemophilic factor, measured immunologically, compared with the titer of procoagulant antihemophilic factor.
A pregnant woman, whose mother was an obligate heterozygote for hemophilia, had factor VIII levels and a G6PD phenotype that failed to indicate clearly whether or not she was heterozygous for hemophilia.
Close linkage between the loci for G6PD and hemophilia A allows prenatal diagnosis of hemophilia in the fetuses of certain women who are heterozygous for two electrophoretic types of G6PD.
All of fourteen patients with severe classic haemophilia and twelve of fifteen obligate carriers had a pre-peak ("rocket") above the sample well when factor VIII-related antigen was examined by crossed immunoelectrophoresis.
The patient's haemophilia was studied with a newly developed immunological technique determining the plasma antigen associated with Factor VIII activity, and was found to be a genetic variant of moderately severe haemophilia A.
Sources of variability in antihemophilic factor (factor VIII) procoagulant titers and precipitating antigen levels among obligate carriers of classic hemophilia.
There was also no statistical difference between VIIICAg/VIIIRAg (or VIIIC/VIIIRAg) ratios obtained from carriers of severe compared to mild haemophilia.
Sources of variability in antihemophilic factor (factor VIII) procoagulant titers and precipitating antigen levels among obligate carriers of classic hemophilia.
There is much evidence to indicate that inhibitors to Factor VIII in patients with classical hemophilia are the result of an immunological response to exposure to material (VIII:C or VIII:CAg) that is absent or present in reduced amounts in these patients.
Individuals with blood group A, B, AB had significantly higher levels of factor VIII related antigen (EIA) and (RIA), and ristocetin cofactor, compared with blood group O. Obligate carriers with severe haemophilia A in their families had more bleeding symptoms than corresponding group with moderate haemophilia.