Rabbit Antibodies Against the Procoagulant Activity (VIII:C) of Human Factor VIII

1981 ◽  
Vol 46 (04) ◽  
pp. 699-705 ◽  
Author(s):  
T H Tran ◽  
G A Marbet ◽  
F Duckert
Keyword(s):  
Factor Viii ◽  
Human Factor ◽  
Gel Filtration ◽  
Procoagulant Activity ◽  
Solid Matrix ◽  
Factor Viii Activity ◽  
Physiological Conditions ◽  
Human Factor Viii ◽  
Plasma Factor ◽  
Factor Viii Antigen

SummaryThe procoagulant activity VIII:C was separated from factor VIII antigen (VIIIR:Ag) by gel filtration in the presence of 0.25 mol/l calcium chloride. Antibodies (anti-VIII:C) were obtained by immunization of rabbits with VIII:C. The last step of the purification procedure of antibodies consists of an adsorption on VIIIR:Ag-Sepharose 2 BCL as immunoadsorbent to remove contaminating traces of antibodies against VIIIR:Ag. The anti- VIII:C titer remains unchanged during this adsorption (29 Bethesda units per mg). In solution, anti-VIII:C neutralies factor VIII activity (in plasma, cryoprecipitate or in purified form) and the fragment VIII:C without reacting with VIIIR:Ag. Once immobilized on a solid matrix, i.e.2% agarose, it loses over 95% of its inhibitory capacity. The immobilized anti-VIIIR:Ag binds stoichiometrically the antigen and the activity of plasma factor VIII. These results together suggest that factor VIII is composed of 2 different entities, but undissociated under physiological conditions. Immunophysical analyses as a function of pH and temperature of anti-VIII:C and its complex with factor VIII show properties similar to those of homologous antibodies. The antigen determinants of VIII:C (VIII:CAg) are destroyed at low pHs or high temperatures, and VIII:C can no more form a complex with anti-VIII:C. Purified anti-VIII:C is also used in a two-stage assay to detect VIII:CAg or cross-reacting material in some severe haemophiliacs.

Concentration-dependent dissociation of factor VIII in 1 M NaCl

1976 ◽  
Vol 230 (2) ◽  
pp. 434-440 ◽  
Author(s):  
Sussman ◽  
W Rosner ◽  
HJ Weiss
Keyword(s):  
Factor Viii ◽  
Human Factor ◽  
Gel Filtration ◽  
Procoagulant Activity ◽  
Void Volume ◽  
Gradual Transition ◽  
Human Factor Viii ◽  
Factor Viii Concentrates ◽  
High Concentrations ◽  
Dilution Curves

Plasma, cryoprecipitate, Hemofil, and human factor VIII concentrate were dissolved in 1.0 M NaCl and chromatographed on Bio-Gel A-5m. With high concentrations of factor VIII the activity eluted as a symmetrical peak in the void volume; with a low factor VIII concentration the procoagulant activity was retarded. Dilution curves were performed for several human factor VIII concentrates. When the concentration of factor VIII was decreased, elution patterns showed a gradual transition from a peak in the void volume to a peak with a Ve/Vo of 1.7. Cryoprecipitate exhibited a similar behavior in 1.0 M NaCl, but the percent dissociation was greater than expected at high concentrations of factor VIII. When gel filtration was performed with 0.25 M CaCl2, significant dissociation occurred at all concentrations of factor VIII tested. The behavior of factor VIII in 1.0 M NaCl closely fit a theoretically derived curve for the dissociation of a protein from its binder. We conclude that the dissociation of factor VIII in 1 M NaCl is dependent on the concentration and purification of the procoagulant protein.

scholarly journals Effects of Plasmin on Human Factor VIII (AHF)

Blood ◽  
1973 ◽  
Vol 41 (1) ◽  
pp. 105-111 ◽  
Author(s):  
R. Pasquini ◽  
E. J. Hershgold
Keyword(s):  
Factor Viii ◽  
Gel Electrophoresis ◽  
Human Factor ◽  
Gel Filtration ◽  
Antigenic Determinants ◽  
Hemorrhagic Diathesis ◽  
Activity Assay ◽  
Factor Viii Activity ◽  
Immunologic Reactivity ◽  
Human Factor Viii

Abstract Highly purified, fibrinogen-free human factor VIII was incubated with plasmin, and the liberated split products of the factor VIII were analyzed by gel filtration, acrylamide gel electrophoresis, bioassay, and for immunologic reactivity. At least three fragments retaining different antigenic determinants are released from the factor VIII after prolonged digestion and at least three new fragments are seen in acrylamide gel electrophoresis. The split products were not anticoagulant in the factor VIII activity assay. In fact, the breakdown products in the hydrolysate increased the factor VIII activity of normal plasma mixed with it. Therefore, it is not likely that the factor VIII split products formed in fibrinolytic states contribute actively to the hemorrhagic diathesis.

The Fractionation Properties of Human Factor VIII (Antihaemophilic Factor)

1960 ◽  
Vol 04 (02) ◽  
pp. 253-260 ◽  
Author(s):  
Franco Gobbi
Keyword(s):  
Factor Viii ◽  
Human Factor ◽  
Maximum Yield ◽  
Factor Vii ◽  
Precipitation Method ◽  
Salting Out ◽  
Human Factor Viii ◽  
Plasma Factor ◽  
Two Factors ◽  
Thromboplastic Activity

SummaryThe fractionation properties of human Factor VIII (antihaemophilic factor, AHF, antihaemophilic globulin) have been studied using a plasma of congenital afibrinogenaemia as a starting material.From a fibrinogen-free plasma, Factor VIII does not precipitate with ethanol at a final concentration of 8%; on the contrary the maximum yield is reached at an ethanol concentration of 25%.With a precipitation method carried out by a one to ten dilution of plasma with distilled water and acidification by N/10 hydrochloric acid to a pFI 5.2, Factor VIII does not precipitate with the euglobulin fraction; when normal plasma is used, such a precipitation is almost complete.With the salting-out fractionation method by ammonium sulphate, Factor VIII precipitates at a concentration between 25 and 33% of saturation either from fibrinogen-free and from normal human plasma.A non-specific thromboplastic activity appears in the fractions prepared by every method. This activity, which is probably due to the activation of seric accelerators, is easily removed by Al(OH)s adsorption. Thus, in order to insure the specificity of Factor VIII assays, the preliminary adsorption of the fractions is indispensable before testing their antihaemophilic activity.Fibrinogen and Factor VIII have different and definite precipitation patterns. When these two factors are associated the fractionation properties of AHF appear quite modified, showing a close similarity to those of fibrinogen. This fact can explain the technical difficulties encountered in the attempt to purify the antihaemophilic factor, and the lack of reproducible procedures for removing fibrinogen without affecting Factor VII.

scholarly journals Factor VIII/von Willebrand factor in subendothelium mediates platelet adhesion

Blood ◽  
1985 ◽  
Vol 65 (4) ◽  
pp. 823-831 ◽  
Author(s):  
VT Turitto ◽  
HJ Weiss ◽  
TS Zimmerman ◽  
II Sussman
Keyword(s):  
Factor Viii ◽  
Von Willebrand Factor ◽  
Vessel Wall ◽  
Platelet Adhesion ◽  
Human Factor ◽  
Rabbit Aorta ◽  
Human Factor Viii ◽  
Plasma Factor ◽  
Von Willebrand ◽  
Willebrand Factor

The present studies were undertaken to determine whether factor VIII/von Willebrand factor (vWF) present in the vessel wall (in addition to that in plasma) may mediate the attachment of platelets to subendothelium. Subendothelium from everted rabbit aorta was exposed to human citrated blood flowing through an annular perfusion chamber at 40 mL/min (wall shear rate of 2,600 s-1 for five minutes). The vessel segments were incubated at 37 degrees C for one hour with various dilutions of either goat-anti-rabbit factor VIII/vWF serum or an IgG fraction prepared from the serum. Control segments were incubated with serum or IgG from a nonimmunized goat. Values of platelet contact (C), platelet adhesion (C + S), and thrombus formation (T) on the subendothelium were evaluated by a morphometric technique. Compared with vessels incubated with fractions prepared from a normal goat, a significant decrease in platelet adhesion (C + S), ranging from 45% to 65%, was observed on vessels incubated with various dilutions (1:5 to 1:50) of either serum or IgG fractions of goat-anti-rabbit factor VIII/vWF. A similar decrease in platelet adhesion was observed with vessels incubated with an F(ab')2 fragment against rabbit factor VIII/vWF prepared in the goat. When goat-anti-rabbit factor VIII/vWF IgG was added to rabbit blood (1:75 dilution), platelet adhesion was reduced to the same extent (65%) on normal rabbit vessels and on vessels pre-incubated with goat-anti-rabbit factor VIII/vWF. Immunofluorescence studies revealed the presence of rabbit factor VIII/vWF in the subendothelium of rabbit aorta and the continued binding of the goat-anti-factor VIII/vWF antibodies on subendothelium during the perfusion studies. No uptake of human factor VIII/vWF on the rabbit subendothelium was observed by this immunologic technique; human factor VIII/vWF was found to be entirely associated with the attached human platelets. Thus, factor VIII/vWF in the vessel wall may mediate platelet attachment to subendothelium in a manner similar to that of plasma factor VIII/vWF.

Human factor VIII procoagulant activity and phospholipid interaction

1981 ◽  
Vol 678 (1) ◽  
pp. 132-136 ◽  
Author(s):  
A LAJMANOVICH ◽  
G HUDRYCLERGEON ◽  
J FREYSSINET ◽  
G MARGUERIE
Keyword(s):  
Factor Viii ◽  
Human Factor ◽  
Procoagulant Activity ◽  
Human Factor Viii

scholarly journals The Activation of Factor VIII by Thrombin

Blood ◽  
1965 ◽  
Vol 26 (4) ◽  
pp. 500-509 ◽  
Author(s):  
A. H. ÖZGE-ANWAR ◽  
G. E. CONNELL ◽  
J. F. MUSTARD
Keyword(s):  
Factor Viii ◽  
Human Factor ◽  
Experimental Approach ◽  
Factor Viii Activity ◽  
Clotting Factors ◽  
Activation Effect ◽  
Activation Reaction ◽  
Human Factor Viii

Abstract The activation of human factor VIII by thrombin has been demonstrated by a new experimental approach. This method permitted investigation of the interaction of thrombin and factor VIII in the absence of most other clotting factors. The activation effect of thrombin is susceptible to inhibition by diisopropylfluorophosphate. Trypsin cannot replace thrombin in the activation reaction, and it destroys factor VIII activity rapidly.

Correction of the coagulation defect in hemophilia A mice through factor VIII expression in skin

Blood ◽  
2000 ◽  
Vol 95 (9) ◽  
pp. 2799-2805 ◽  
Author(s):  
Steven S. Fakharzadeh ◽  
Yue Zhang ◽  
Rita Sarkar ◽  
Haig H. Kazazian
Keyword(s):  
Transgenic Mice ◽  
Factor Viii ◽  
Hemophilia A ◽  
Systemic Disease ◽  
Factor Viii Activity ◽  
Human Factor Viii ◽  
Plasma Factor ◽  
Transgenic Lines ◽  
Rag 1 ◽  
Involucrin Promoter

To test the hypothesis that factor VIII expressed in the epidermis can correct hemophilia A, we generated transgenic mice in a factor VIII–deficient background that express human factor VIII under control of the involucrin promoter. Mice from 5 transgenic lines had both phenotypic correction and plasma factor VIII activity. In addition to the skin, however, some factor VIII expression was detected in other tissues that have stratified squamous epithelia. To determine whether an exclusively cutaneous source of factor VIII could correct factor VIII deficiency, we grafted skin explants from transgenic mice onto mice that are double knockouts for the factor VIII and RAG-1 genes. Two graft recipients had plasma factor VIII activity of 4% to 20% of normal and improved whole blood clotting compared with factor VIII–deficient mice. Thus, expression of factor VIII from the epidermis can correct hemophilia A mice, thereby supporting the feasibility of cutaneous gene therapy for systemic disease.

scholarly journals A large region (approximately equal to 95 kDa) of human factor VIII is dispensable for in vitro procoagulant activity.

1986 ◽  
Vol 83 (16) ◽  
pp. 5939-5942 ◽  
Author(s):  
J. J. Toole ◽  
D. D. Pittman ◽  
E. C. Orr ◽  
P. Murtha ◽  
L. C. Wasley ◽  
...  
Keyword(s):  
Factor Viii ◽  
Human Factor ◽  
Procoagulant Activity ◽  
Large Region ◽  
Human Factor Viii

scholarly journals Clinical experience with polyelectrolyte-fractionated porcine factor VIII concentrate in the treatment of hemophiliacs with antibodies to factor VIII

Blood ◽  
1984 ◽  
Vol 63 (1) ◽  
pp. 31-41 ◽  
Author(s):  
PB Kernoff ◽  
ND Thomas ◽  
PA Lilley ◽  
KB Matthews ◽  
E Goldman ◽  
...  
Keyword(s):  
Factor Viii ◽  
Clinical Experience ◽  
Human Factor ◽  
Intermediate Level ◽  
Human Factor Viii ◽  
Plasma Factor ◽  
Post Infusion ◽  
Clinical Responses ◽  
Circulating Antibodies

Circulating antibodies to factor VIII (anti-VIII, “inhibitors”) occurring in patients with hemophilia neutralize porcine factor VIII less readily than human factor VIII in vitro. Over an 18-mo period, 8 patients with anti-VIII were treated with 45 courses (297 infusions) of polyelectrolyte-fractionated porcine factor VIII concentrate (PE porcine VIII). Where no anti-PE porcine VIII was detectable, mean post- infusion rise in plasma factor VIII was 1.29 U/dl/units infused/kg. Above 13 Old Oxford units of anti-PE porcine VIII and 48 Bethesda units of anti-human VIII, there were no postinfusion rises in plasma factor VIII. Where postinfusion rises were detected, clinical responses were good and conventional methods could be used to guide dosage. Ten percent of infusions were followed by febrile reactions, but these were usually mild and decreased in frequency and severity with increasing exposure. Multiple and prolonged courses of therapy were given to some patients without evidence of loss of clinical or laboratory efficacy. PE porcine VIII could provoke anamnestic rises of anti-VIII in susceptible patients, but appeared to have a lower immunogenic potential than human VIII. PE porcine VIII is a rational and effective therapeutic alternative for patients with anti-VIII, particularly those with intermediate level inhibitors who cannot be managed effectively using human factor VIII.

scholarly journals Studies of the human factor VIII/von Willebrand's factor protein. II. Identification and characterization of the von Willebrand protein

Blood ◽  
1975 ◽  
Vol 46 (3) ◽  
pp. 417-430
Author(s):  
HR Gralnick ◽  
BS Coller
Keyword(s):  
Factor Viii ◽  
Human Factor ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Related Protein ◽  
Human Factor Viii ◽  
Von Willebrand’S Factor ◽  
Von Willebrand ◽  
Identification And Characterization

The purified factor VIII-related protein we have previously characterized from normal cryoprecipitate possesses both procoagulant activity and vWf activity. We have attempted to isolate and characterize this protein from three patients with severe vWd. This protein is absent or markedly diminished in amount in these vWd patients, as judged by gel filtration, polyacrylamide-gel electrophoresis, and immunoprecipitation assays. Likewise, the procoagulant and vWf activities are deficient. As vWf activity is one of the major biologic functions of either the normal or hemophilic factor VIII-related protein, the purified protein should be designated the f VIII/vWf protein.

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