A photographically monitored enhanced luminescence enzyme immunoassay for factor VIII related antigen

1986 ◽  
Vol 6 (4) ◽  
pp. 212-214
Author(s):  
Wang Hong-xing ◽  
G. H. G. Thorpe ◽  
L. J. Kricka ◽  
J. George
Keyword(s):  
Factor Viii ◽  
Enzyme Immunoassay ◽  
Factor Viii Related Antigen ◽  
Enhanced Luminescence

scholarly journals Enhanced luminescence enzyme immunoassay for factor VIII related antigen.

1985 ◽  
Vol 38 (3) ◽  
pp. 317-319 ◽  
Author(s):  
H X Wang ◽  
J George ◽  
G H Thorpe ◽  
R A Stott ◽  
L J Kricka ◽  
...  
Keyword(s):  
Factor Viii ◽  
Enzyme Immunoassay ◽  
Factor Viii Related Antigen ◽  
Enhanced Luminescence

A Simple Enzyme-Immunoassay (EIA) Test for Factor VIII-Related Antigen (VIIIAGN)

1979 ◽  
Vol 42 (03) ◽  
pp. 848-854 ◽  
Author(s):  
Paul M Ness ◽  
Herbert A Perkins
Keyword(s):  
Factor Viii ◽  
Enzyme Immunoassay ◽  
Hemophilia A ◽  
Single Sample ◽  
Healthy Controls ◽  
Von Willebrand's Disease ◽  
Factor Viii Related Antigen ◽  
Von Willebrand’S Disease ◽  
Increased Sensitivity

SummaryAn enzyme immunoassay (EIA) system has been developed to measure factor VIII- related antigen (VIIIAGN). This assay gives similar results to the commonly used Laurell electroimmunodiffusion (EID) assay for VIIIAGN as shown by comparison of both techniques with samples from healthy controls, patients with hemophilia A, and patients with von Willebrand’s disease. The assay also has a greater precision than the EID technique as demonstrated by multiple assays of aliquots of a single sample. The use of this EIA test for VIIIAGN is simple and employs inexpensive reagents and equipment. The use of expensive antisera is minimized. EIA for VIIIAGN has the advantage of increased sensitivity compared to Laurell EIA.

Amperometric Enzyme Sensor-Based Enzyme Immunoassay for Factor VIII-Related Antigen

1983 ◽  
Vol 16 (16) ◽  
pp. 1279-1289 ◽  
Author(s):  
Reinhard Renneberg ◽  
Werner Schößler ◽  
Frieder Scheller
Keyword(s):  
Factor Viii ◽  
Enzyme Immunoassay ◽  
Enzyme Sensor ◽  
Factor Viii Related Antigen

Enzyme immunoassay for factor VIII-related antigen.

1982 ◽  
Vol 28 (6) ◽  
pp. 1356-1358 ◽  
Author(s):  
J Cejka
Keyword(s):  
Regression Analysis ◽  
Factor Viii ◽  
Enzyme Immunoassay ◽  
Immunosorbent Assay ◽  
Present Method ◽  
Solid Phase ◽  
Enzyme Linked Immunosorbent Assay ◽  
Plasma Samples ◽  
Factor Viii Related Antigen ◽  
Elisa Technique

Abstract I describe a simple enzyme-linked immunosorbent assay (ELISA) for the quantitation of Factor VIII-related antigen in plasma with use of commercially available peroxidase-labeled antiserum and solid-phase support. Regression analysis of 85 plasma samples analyzed by this technique (y) and by a commonly used electroimmunoassay (Anal. Biochem. 15: 45-52, 1966) (x) gave the equation y = 0.223 + 0.77x (r = 0.973). The present method was also compared with enzyme immunoassay in which a phosphatase-labeled antiserum prepared in our laboratory was used; the correlation between the two assays was very good. The simplicity and specificity of the ELISA technique should make it a useful alternative to the more difficult and time-consuming Laurell method.

scholarly journals Factor-VIII-related antigen: measurement by enzyme immunoassay.

BMJ ◽  
1976 ◽  
Vol 1 (6016) ◽  
pp. 994-996 ◽  
Author(s):  
A Bartlett ◽  
K M Dormandy ◽  
C M Hawkey ◽  
P Stableforth ◽  
A Voller
Keyword(s):  
Factor Viii ◽  
Enzyme Immunoassay ◽  
Factor Viii Related Antigen

Factor VIII-Related Activities in Normal, Haemophilic and von Willebrand’s Disease Platelet Fractions

1978 ◽  
Vol 40 (02) ◽  
pp. 288-301 ◽  
Author(s):  
P Meucci ◽  
I R Peake ◽  
A L Bloom
Keyword(s):  
Factor Viii ◽  
Electrophoretic Mobility ◽  
Concanavalin A ◽  
Freezing And Thawing ◽  
Von Willebrand's Disease ◽  
Factor Viii Related Antigen ◽  
Von Willebrand’S Disease ◽  
Normal Plasma ◽  
Significant Difference ◽  
Ristocetin Cofactor

SummaryFactor VIII-related activities have been studied in platelet fractions in order to try to reconcile the conflicting findings of other workers, and to extend the studies. In platelets from 16 normal subjects procoagulant factor VIII was not detected. The amount of factor VIII-related antigen (FVIIIR: AG) in the cytosol per mg of protein was about twice that in the membrane fraction and about ten times that in the debris fraction. There was no significant difference between the amount of FVIIIR: AG and ristocetin cofactor (RistCof) activity in each fraction. The findings in haemophilic platelets were similar. In von Willebrand’s disease (vWd) one serverely affected patient had no detectable factor VIII related activities in any platelet fraction. In 5 patients with intermediate vWd results were normal. In a further 5, with more prolonged bleeding times, no FVIIIR: RistCof was detected in platelets, despite a normal amount of FVIIIR: AG in the cytosol and debris. The electrophoretic mobility of cytosol FVIIIR: AG was increased in all normals and patients, while that in the membrane and debris fractions had normal mobility. Cytosol FVIIIR: AG eluted later than normal FVIIIR: AG on gel filtration on Sepharose 2B, and also showed reduced antibody binding in an immunoradiometric assay. Precipitation of FVIIIR: AG by concanavalin A was incomplete in all platelet fractions from normals, and even more reduced in vWd platelet fractions. The results suggest the possibility of two types of platelet FVIIIR: AG.A factor VIII-related antigen was shown to be associated with normal washed platelets by immunofluorescence techniques (Bloom et al. 1973). Since then, several studies have been reported on the localisation of factor VIII related antigen (FVIIIR: AG), factor VIII procoagulant activity (FVIII: C) and factor VIII related ristocetin cofactor activity (FVIIIR: RistCof) within the platelets. Initially, Howard et al. (1974) indicated that FVIIIR: AG was firmly bound to the platelet membrane, and noted that in lysed platelets the level of FVIIIR: AG as measured by electroimmunodiffusion was higher than that in whole platelet suspensions. However, further studies by Nachman and Jaffe (1975) showed that FVIIIR: AG was also present to a considerable extent in the granules, and they detected none in the platelet cytosol. Bouma and colleagues (1975) were, however, able to find FVIIIR: AG and FVIIIR: RistCof in the cytosol upon freezing and thawing platelets. This FVIIIR: AG had an electrophoretic mobility comparable to that of normal plasma. They also noted that platelets which were air dried apparently had a granular FVIIIR:AG localisation by immunfluorescence; however, intact platelets in suspension did not stain by this method.Recently Ruggeri et al. (1977) and Sultan et al. (1977) have also found FVIIIR: AG in the cytosol, and the former authors reported it to have increased electrophoretic mobility when compared to normal plasma FVIIIR:AG. Results concerning the localisation of FVIIIR: AG in normal platelets have thus been conflicting. Similarly, in the few reports available concerning platelet FVIIIR: AG in von Willibrand’s disease variable results have also been obtained (Ruggeri et al. 1977, Howard et al. 1974, Shearn et al. 1974 and Bouma et al. 1975).In this study we report on the localisation of factor VIII-related activities in normal, haemophilic and von Willebrand’s disease platelets using available standard techniques as well as precipitation of FVIIIR: AG with the plant lectin concanavalin A, a procedure which has been shown to detect abnormal forms of FVIIIR:AG in certain types of von Willebrand’s disease (Peake and Bloom 1977).

Calculation of Predictive Odds for Possible Carriers of Haemophilia

1975 ◽  
Vol 34 (03) ◽  
pp. 740-747 ◽  
Author(s):  
C. R. M Prentice ◽  
C. D Forbes ◽  
Sandra Morrice ◽  
A. D McLaren
Keyword(s):  
Biological Activity ◽  
Factor Viii ◽  
Factor Viii Related Antigen ◽  
Using Data ◽  
The Individual ◽  
Betting Odds

SummaryBetting odds for possible carriers of haemophilia have been calculated using data derived from normal and known carrier populations. For each possible carrier the concentration of factor VIII-related antigen and factor VIII biological activity was measured and used to determine the probability of the individual being a carrier. The calculations indicated that, of the 32 possible carriers, 11 were likely to be normal (odds of more than 5:1) while 11 were likely to be haemophilia carriers (again odds of more than 5:1).

Factor VIII : C and Factor VIII R: Ag in Argentine Hemorrhagic Fever

1981 ◽  
Vol 46 (02) ◽  
pp. 525-527 ◽  
Author(s):  
Felisa C Molinas ◽  
Julio I Maiztegui
Keyword(s):  
Factor Viii ◽  
Normal Values ◽  
Hemorrhagic Fever ◽  
Plasma Samples ◽  
Two Dimensional ◽  
Plasma Infusion ◽  
Factor Viii Related Antigen ◽  
Clinical Forms ◽  
Argentine Hemorrhagic Fever ◽  
Immune Precipitation

SummaryFactor VIII procoagulant activity (F VIII: C) and factor VIII related antigen (F VIII R: Ag) were investigated in 35 patients with Argentine hemorrhagic fever. Since the results obtained in the three clinical forms of the disease were not significantly different, they were tabulated altogether. F VIII: C was low in early stages of the disease but increased progressively in later days (days 5–6:0.54 ± 0.10 I.U./ml; days 13–14:0.95 ± 0.13 I.U./ml). In contrst, the levels of F VIII R: Ag were high all along the disease and they returned to normal values during the convalescence period (days 5–6; 2.58 ± 0.54 I.U./ml; day 30: 1.30 ± 0.14 I.U./ml). The levels of F VIII R: Ag were similar in samples drawn before (11 cases) or after (10 cases) the treatment with immune plasma infusion. Plasma samples from 12 patients were studied by two-dimensional immunelectrophoresis. The only abnormality found was increased height of the immune precipitation arc.

The Effects of Age, Gene Source and Familial Severity on Factor VIII in Normals and Haemophilia Carriers: Analysis by Multiple Regression

1983 ◽  
Vol 50 (03) ◽  
pp. 722-725 ◽  
Author(s):  
Bruce M Duncan ◽  
Lynn J Tunbridge ◽  
John V Lloyd
Keyword(s):  
Factor Viii ◽  
Multiple Regression ◽  
Analysis Of Covariance ◽  
Severe Haemophilia ◽  
Factor Viii Related Antigen ◽  
Defective Gene ◽  
Coagulant Activity

SummaryThere are conflicting views on the effects of age, gene source and familial severity on levels of factor VIII in carriers of haemophilia. Different workers have found that factor VIII increases with age, is higher in paternal carriers, and is higher in carriers from families with more severe haemophilia. Other workers have disagreed with these findings. In this study we explored some of the causes of this conflict. We measured factor VIII related antigen and factor VIII coagulant activity on 40 normal females and 48 carriers, and analysed the results by multiple regression and analysis of covariance. Our results indicated that both factor VIII coagulant activity and factor VIII related antigen increased with age, but were unaffected by the familial severity of haemophilia or whether the defective gene came from the mother or the father. We found that the conflicting reports of previous authors were due to high inter-correlations of the studied variables.

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