Tissue localization and synthesis of factor-VIII-related antigen in the human foetus

Human fetal tissue research: practice, prospects, and policy

Tissue from human fetal cadavers has long been used for medical research, experimental therapies, and various other purposes. Research within the last two decades has led to substantial progress in many of these areas, particularly in the application of fetal tissue transplantation to the treatment of human disease. As a result, clinical trials have now been initiated at centers around the world to evaluate the use of human fetal tissue transplantation for the therapy of Parkinson's disease, insulin-dependent diabetes mellitus, and a number of blood, immunological and, metabolic disorders. Laboratory studies suggest a much wider range of disorders may in the future be treatable by transplantation of various types of human fetal tissue. A combination of characteristics renders fetal tissue uniquely valuable for such transplantation, as well as for basic research, the development of vaccines, and a range of other applications. Although substitutes for human fetal tissue are being actively sought, for many of these applications there are at present no satisfactory alternatives. Important issues remain unresolved concerning the procurement, distribution, and use of human fetal cadaver tissue as well as the effects of such use on abortion procedures and incidence. These issues can be addressed by the introduction of appropriate guidelines or legislation, and need not be an impediment to legitimate research and therapeutic use of fetal tissue.

Coagulation activation and hyperviscosity in infection

A serial study of coagulation activation and whole-blood viscosity was performed on 37 patients with local or systemic bacterial infection, malaria, or a viral infection. Thrombocytopenia, without consumption of coagulation factors, was the main feature of benign tertian malaria and viral infection, whereas in septicaemia and malignant tertian malaria it was associated with activation of coagulation and fibrinolysis. Patients with evidence of intravascular coagulation showed the highest levels of factor VIII related antigen which did not correlate with fibrinogen and probably reflected vascular endothelial cell damage rather than an acute-phase protein reaction. Hyperviscosity, which has been implicated in the pathogenesis of endotoxic shock and cerebral malaria, occurred in parallel with the acute-phase rise in plasma fibrinogen. There was, however, no evidence to implicate hyperviscosity as a major causative factor in the pathogenesis of septic shock or severe infective illness.

Factor VIII activity and factor VIII related antigen in newborns

Factor VIII procoagulant activity and factor VIII related antigen were examined in 20 full-term and preterm newborn infants during the first days of life. The control group involved 15 adults volunteers. Factor VIII activity was estimated by a one-stage test and factor VIII related antigen was determined by immunelectrophoresis according to Laurell, using our own rabbit antiserum. The following results were obtained:--Factor VIII activity during the first 3 days of life did not differ from the normal range of the adult controls.--The concentration of factor VIII related antigen in newborns was markedly higher than in adults on the first, and to a lesser extent on the second, day of life.--The antigen concentration decreases on the second and following days of life to adult levels. The cause of this discrepancy cannot be completely explained but possible reasons are discussed.

Immunoradiometric assay of procoagulant factor-VIII antigen in plasma and serum and its reduction in haemophilia. Preliminary studies on adult and fetal blood

An immunoradiometric assay (I.R.M.A.) for antihaemophilic factor (factor VIII) has been developed which is based on a human inhibitor to procoagulant factor VIII (FVIIIC) which arose in a polytransfused haemophiliac. The assay detected and measured the antigen related to FVIIIC (FVIIICAg) in normal plasma and serum but failed to detect any antigen in samples from five patients with severe haemophilia. In a sixth patient with severe haemophilia a non-parallel dose-response curve was obtained. FVIIICAg was also present in plasma and serum from six samples of cord blood and in two samples of fetal serum obtained after termination of pregnancy. The assay may, therefore, be used to measure FVIIICAg in small serum samples and provides a potential practical method for prenatal diagnosis of haemophilia.