Factor VIII concentrates and the immune system—laboratory investigations

1995 ◽  
Vol 6 (Sup 2) ◽  
pp. S65-S79 ◽  
Author(s):  
M. Wadhwa ◽  
T. W. Barrowcliffe ◽  
A. R. Mire-Sluis ◽  
R. Thorpe
Keyword(s):  
Immune System ◽  
Factor Viii ◽  
Factor Viii Concentrates ◽  
Laboratory Investigations

Changes in Platelet Function and Platelet Counts During Substitution Therapy in Haemophiliacs and Produced by Plasmapheresis in Patients Suffering from Inhibitors

1979 ◽  
Author(s):  
E. Dumitrescu ◽  
I. Ambrus ◽  
Kh. Nienhaus ◽  
B. Podolsak ◽  
E. Wenzel
Keyword(s):  
Factor Viii ◽  
Platelet Function ◽  
Clinical Signs ◽  
Bleeding Complications ◽  
Substitution Therapy ◽  
Drug Induced ◽  
Platelet Counts ◽  
Before And After ◽  
Factor Viii Concentrates ◽  
Laboratory Investigations

We noticed a systematic increase in small platelets (evaluated by electronical analysis of platelet volune distribution, using the Coulter Counter equipment, Wenzel 1977) during substitution therapy in patients suffering from haemophilia (N = 60). Laboratory investigations on these patients were performed before substitution and then 30 min., 60 min., 120 min. and 24 hours after infusion of factor-VIII-concentrationa (Inmuno, Schwab, Behring, factor-VIII-concentrates 20 U/kg b.w.). The same investigations were performed before and after plasmapheresis using a Hemonetric cell separator (N = 7}. in 48 of the patients, the clinical signs were insignificant (bleeding time, according to Duke, was found to be normall, although the platelet changes ware considerable (decrease in platelet count and increase of the percentage of platelets smaller than 4.5 μ3). However, significant test results were noticed in a haemophiliac patient suffering from inhibitory- and drug-induced platelet disorders during and after plasmapheresis. We observed bleeding complications only in 2 cases (Duke; 7 min. and 9 min.). Yet, a coneiderable decrease in platelet counts was observed as well as a significant increase in the percentages of small platelets (4.5 μ3, N = 48) in all cases. Controlling platelet function in haemophiliacs following substitution therapy could be essential as well as controlling the usual hemolysis parameters after plasmapheresis.

Automation of Two-Stage Factor VIII Assay

1978 ◽  
Vol 39 (02) ◽  
pp. 455-465 ◽  
Author(s):  
Yvonne Stirling ◽  
D J Howarth ◽  
Marguerite Vickers ◽  
W R S North ◽  
T W Meade
Keyword(s):  
Factor Viii ◽  
Optical Density ◽  
Electric Circuit ◽  
Clotting Time ◽  
Two Stage ◽  
Laboratory Error ◽  
Premature Closure ◽  
Factor Viii Concentrates ◽  
Experimental Findings ◽  
Automated Methods

SummaryTwo automated methods for two-stage factor VIII assays have been compared with one another, and evaluated in practice. The Depex method records the clotting time when an electric circuit is completed by the formation of a fibrin thread across a hook-type electrode; the Electra method is based on an optical density technique of clot detection. The two methods gave comparable results for measured levels of factor VIII when haemophilic or “normal” plasmas were assayed. Results from the two methods in practice also suggest that both are valid at low and “normal” factor VIII levels. The Electra method is also probably suitable for assays of concentrates; however, the Depex method appears to give falsely high values in these circumstances, and experimental findings suggest that the reason may be that increased viscosity due to the high fibrinogen levels in factor VIII concentrates causes premature closure of the circuit between the two ends of the Depex electrode. The main advantage of the Depex method is that, provided 3 or 4 machines are available, a given number of assays can be completed more quickly than on Electra. The main advantages of Electra are that it is probably subject to less laboratory error than Depex, and that it is suitable for assaying concentrates as well as haemophilic and “normal” plasmas.

The Recovery of Factor VIII from Fresh-Frozen, Indated and Outdated Human Plasma

1976 ◽  
Vol 36 (01) ◽  
pp. 071-077 ◽  
Author(s):  
Daniel E. Whitman ◽  
Mary Ellen Switzer ◽  
Patrick A. McKee
Keyword(s):  
Factor Viii ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
The United States ◽  
Fresh Frozen Plasma ◽  
Red Cross ◽  
Random Samples ◽  
Fresh Frozen ◽  
Factor Viii Concentrates ◽  
Frozen Plasma

SummaryThe availability of factor VIII concentrates is frequently a limitation in the management of classical hemophilia. Such concentrates are prepared from fresh or fresh-frozen plasma. A significant volume of plasma in the United States becomes “indated”, i. e., in contact with red blood cells for 24 hours at 4°, and is therefore not used to prepare factor VIII concentrates. To evaluate this possible resource, partially purified factor VIII was prepared from random samples of fresh-frozen, indated and outdated plasma. The yield of factor VIII protein and procoagulant activity from indated plasma was about the same as that from fresh-frozen plasma. The yield from outdated plasma was substantially less. After further purification, factor VIII from the three sources gave a single subunit band when reduced and analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. These results indicate that the approximately 287,000 liters of indated plasma processed annually by the American National Red Cross (ANRC) could be used to prepare factor VIII concentrates of good quality. This resource alone could quadruple the supply of factor VIII available for therapy.

A Survey of the Effectiveness of Prothrombin Complex Concentrates in Controlling Hemorrhage in Patients with Hemophilia and Anti-Factor VIII Antibodies

1980 ◽  
Vol 44 (01) ◽  
pp. 039-042 ◽  
Author(s):  
Philip M Blatt ◽  
Doris Ménaché ◽  
Harold R Roberts
Keyword(s):  
Factor Viii ◽  
Ad Hoc ◽  
Hemophilia A ◽  
Working Party ◽  
International Committee ◽  
Factor Ix ◽  
Prothrombin Complex Concentrates ◽  
Factor Viii Concentrates

SummaryThe treatment of patients with hemophilia A and anti-Factor VIII antibodies is difficult. Between July 1977 and June 1978, a survey was carried out by an ad hoc working party of the subcommittee on Factor IX concentrates of the International Committee on Thrombosis and Hemostasis to assess the effectiveness of Prothrombin Complex Concentrates in controlling hemorrhage in these patients. The results are presented in this paper and, although subjective, support the view that these concentrates are not as effective in patients with inhibitors as Factor VIII concentrates are in patients without inhibitors.

A Higher than Expected Incidence of Factor VIII Inhibitors in Multitransfused Haemophilia A Patients Treated with an Intermediate Purity Pasteurized Factor VIII Concentrate

1993 ◽  
Vol 69 (02) ◽  
pp. 115-118 ◽  
Author(s):  
Kathelijne Peerlinck ◽  
Jef Arnout ◽  
Jean Guy Gilles ◽  
Jean-Marie Saint-Remy ◽  
Jos Vermylen
Keyword(s):  
Factor Viii ◽  
Randomized Trials ◽  
Specific Factor ◽  
Factor Viii Inhibitor ◽  
Haemophilia A ◽  
Viral Inactivation ◽  
Gradual Decline ◽  
Inhibitor Level ◽  
Factor Viii Concentrates ◽  
Viii Inhibitor

SummaryIn May 1990, 218 patients with haemophilia A regularly attending the Leuven Haemophilia Center were randomly assigned to a group receiving either of two newly introduced factor VIII concentrates: factor VIII-P, an intermediate purity pasteurized concentrate, or factor VIII-SD, a high purity concentrate treated with solvent-detergent for viral inactivation.Patients were followed from May 1990 until October 1991. Between August 1991 and October 1991 a clinically important factor VIII inhibitor was detected in five out of the 109 patients receiving factor VIII-P while none of the 109 patients receiving factor VIII-SD developed such antibodies. All patients acquiring an inhibitor had previously been clinically tolerant to transfused factor VIII with 200 to more than 1,000 days of exposure to factor VIII prior to May 1990. Patients with inhibitors were transfused daily with 30 U factor VIII-SD per kg body weight, which was associated with a gradual decline of the inhibitor level. In all patients the antibodies were relatively slow-acting and predominantly directed towards the light chain of factor VIII.This study demonstrates a higher than expected incidence of factor VIII inhibitors associated with the use of a specific factor VIII concentrate in multitransfused haemophilia A patients. It indicates the usefulness of evaluating newly introduced concentrates in prospective, randomized trials.

Circulating Anticoagulant (Antifactor VIII) Treated with Immunosuppressive Drugs

1969 ◽  
Vol 21 (02) ◽  
pp. 249-258 ◽  
Author(s):  
L. A Sherman ◽  
M. A Goldstein ◽  
H. S Sise
Keyword(s):  
Factor Viii ◽  
Conventional Therapy ◽  
Immunosuppressive Drugs ◽  
The Other ◽  
Not Given ◽  
Factor Viii Concentrates ◽  
Short Courses

SummaryThree cases have been presented who had a circulating antifactor VIII anticoagulant developing spontaneously in non-hemophilic subjects. Following two short courses of azathioprine in one case there were transient incomplete remissions of a degree not seen in the previous 4 months of observation. In the other two cases complete remissions were observed within three weeks of beginning administration of 6-mercaptopurine. In one of these, a brief relapse was retreated successfully. In 4 other cases not given these drugs and in cases reported in the literature, such a rapid remission was not seen to occur spontaneously and happened only infrequently in cases given corticosteroids. On the basis of this experience, we suggest that in the treatment of antifactor VIII, if the disorder shows no improvement with conventional therapy (blood, factor VIII concentrates, and corticosteroids), a trial with immunosuppressive drugs is warranted.

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