scholarly journals Noncoagulation inhibitory factor VIII antibodies after induction of tolerance to factor VIII in hemophilia A patients

Blood ◽  
1990 ◽  
Vol 75 (2) ◽  
pp. 378-383 ◽  
Author(s):  
IM Nilsson ◽  
E Berntorp ◽  
O Zettervall ◽  
B Dahlback
Keyword(s):  
Factor Viii ◽  
Hemophilia A ◽  
Protein A ◽  
Gel Filtration ◽  
Tolerance Induction ◽  
Factor Ix ◽  
High Dose ◽  
Void Fractions ◽  
Igg4 Antibody ◽  
Induction Of Tolerance

Abstract We recently described tolerance induction with factor VIII/IX, cyclophosphamide, and high-dose intravenous IgG in hemophilia A or B patients with coagulation inhibitory antibodies. Circulating noninhibitory antibodies complexed with factor IX have been demonstrated in tolerant hemophilia B patients. Similar findings are now described in six tolerant hemophilia A patients. Complexes between factor VIII and the ‘tolerant’ antibody were demonstrated by subjecting plasma to gel filtration chromatography, void fractions containing factor VIII/vWF complexes being collected and adsorbed to protein A. Using 125I-labeled F(ab')2 fragments against IgG subclass and factor VIII antigen, complexes between an IgG4 antibody and factor VIII were found to adsorb to protein A. After infusion of factor VIII to tolerant patients, all factor VIII circulated in complex with IgG4 antibody. In three of the patients, the ‘tolerant’ antibodies inhibited an ELISA specific for factor VIII light chain but, unlike the pretolerant antibodies, did not bind radiolabeled factor VIII heavy chain. Although after induction of tolerance the patients still have circulating IgG4 antibodies against factor VIII, the antibodies differ in specificity, lack coagulation inhibitory activity, and do not enhance the rate of elimination of factor VIII.

scholarly journals Noncoagulation inhibitory factor VIII antibodies after induction of tolerance to factor VIII in hemophilia A patients

Blood ◽  
1990 ◽  
Vol 75 (2) ◽  
pp. 378-383
Author(s):  
IM Nilsson ◽  
E Berntorp ◽  
O Zettervall ◽  
B Dahlback
Keyword(s):  
Factor Viii ◽  
Hemophilia A ◽  
Protein A ◽  
Gel Filtration ◽  
Tolerance Induction ◽  
Factor Ix ◽  
High Dose ◽  
Void Fractions ◽  
Igg4 Antibody ◽  
Induction Of Tolerance

We recently described tolerance induction with factor VIII/IX, cyclophosphamide, and high-dose intravenous IgG in hemophilia A or B patients with coagulation inhibitory antibodies. Circulating noninhibitory antibodies complexed with factor IX have been demonstrated in tolerant hemophilia B patients. Similar findings are now described in six tolerant hemophilia A patients. Complexes between factor VIII and the ‘tolerant’ antibody were demonstrated by subjecting plasma to gel filtration chromatography, void fractions containing factor VIII/vWF complexes being collected and adsorbed to protein A. Using 125I-labeled F(ab')2 fragments against IgG subclass and factor VIII antigen, complexes between an IgG4 antibody and factor VIII were found to adsorb to protein A. After infusion of factor VIII to tolerant patients, all factor VIII circulated in complex with IgG4 antibody. In three of the patients, the ‘tolerant’ antibodies inhibited an ELISA specific for factor VIII light chain but, unlike the pretolerant antibodies, did not bind radiolabeled factor VIII heavy chain. Although after induction of tolerance the patients still have circulating IgG4 antibodies against factor VIII, the antibodies differ in specificity, lack coagulation inhibitory activity, and do not enhance the rate of elimination of factor VIII.

TOLERANCE INDUCTION IN HIGH-RESPONDING HEMOPHILIACS WITH F VIII ANTIBODIES BY MEANS OF COMBINED TREATMENT WITH IgG, CYCLOPHOSPHAMIDE AND F VIII

1987 ◽  
Author(s):  
I M Nilsson ◽  
E Berntorp ◽  
O Zettervall
Keyword(s):  
Hemophilia A ◽  
Combined Treatment ◽  
Protein A ◽  
Tolerance Induction ◽  
Antibody Concentration ◽  
High Dose ◽  
Anamnestic Response ◽  
High Concentrations ◽  
High Responders ◽  
Tolerant State

Of 10 patients with hemophilia A and antibodies, 7 have been rendered tolerant by means of combined treatment with high-dose IgG i.v., cyclophosphamide and F VIII. When the initial antibody concentration exceeded 10 Bethesda inhibitor units per ml, the treatment was preceded by antibody adsorption to protein A. Six of the tolerant patients were originally classified as high-responders. After one week of the combined treatment, VI11:C dropped and the inhibitor reappeared in low titer. The F VIII infusions being continued alone, the inhibitor disappeared in the following week and VIII:C increased satisfactorily after infusion, while VIII:Ag (assayed immunoradiometrically) reached very high concentrations. In one patient the treatment had to be repeated once. Except for transient leukopenia, no side effects occurred. Earlier treatments with F VIII in combination with cyclophosphamide gave high anamnestic response. In two of the remaining three non-tolerant patients, anamnestic response decreased dramatically after two courses of the combined treatment. The tolerant state seems to be stable, as the tolerant patients have now been on regular prophylaxis with F VIII concentrate for periods varying from four months to four years. The half-life of infused F VIII is normal, while that of VIII:Ag is prolonged. On the basis of similar findings in hemophilia B patients, we believe the VIII:Ag to have become modi Tied and complexed to a 'new' antibody which lacks VIII:C inhibitory activity. It is known that modified antigen may act as a tolerogen. The tolerant state may thus be sustained by maintaining consistent concentrations of the modified antigen by means of the F VIII treatment. We conclude that the combined treatment described here is a safe and effective method of tolerance induction in hemophilia A patients.

ITI with high-dose FIX and combined immunosuppressive therapy in a patient with severe haemophilia B and inhibitor

2009 ◽  
Vol 29 (02) ◽  
pp. 155-157 ◽  
Author(s):  
H. Hauch ◽  
J. Rischewski ◽  
U. Kordes ◽  
J. Schneppenheim ◽  
R. Schneppenheim ◽  
...  
Keyword(s):  
Nephrotic Syndrome ◽  
Immunosuppressive Agents ◽  
Tolerance Induction ◽  
Intravenous Immunoglobulins ◽  
Factor Ix ◽  
High Dose ◽  
Allergic Reactions ◽  
Success Rates ◽  
Serious Infections ◽  
History Of

SummaryInhibitor development is a rare but serious event in hemophilia B patients. Management is hampered by the frequent occurrence of allergic reactions to factor IX, low success rates of current inhibitor elimination protocols and the risk of development of nephrotic syndrome. Single cases of immune tolerance induction (ITI) including immunosuppressive agents like mycophenolat mofetil (MMF) or rituximab have been reported. We present a case of successful inhibitor elimination with a combined immune-modulating therapy and high-dose factor IX (FIX). This boy had developed a FIX inhibitor at the age of 5 years and had a history of allergic reactions to FIX and to FEIBA→. Under on-demand treatment with recombinant activated FVII the inhibitor became undetectable but the boy suffered from multiple joint and muscle bleeds. At the age of 11.5 years ITI was attempted with a combination of rituximab, MMF, dexamethasone, intravenous immunoglobulins and high-dose FIX. The inhibitor did not reappear and FIX half-life normalized. No allergic reaction, no signs of nephrotic syndrome and no serious infections were observed.

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.

scholarly journals In Hemophilia Α Plasma Treated with Emicizumab, Factor IX Activation By Factor VIIa Drives Thrombin Generation

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 17-17
Author(s):  
Dougald Monroe ◽  
Mirella Ezban ◽  
Maureane Hoffman
Keyword(s):  
Factor Viii ◽  
Tissue Factor ◽  
Plasma Levels ◽  
Thrombin Generation ◽  
Hemophilia A ◽  
Factor Viia ◽  
Factor Ix ◽  
Factor X ◽  
Dose Dependent

Background.Recently a novel bifunctional antibody (emicizumab) that binds both factor IXa (FIXa) and factor X (FX) has been used to treat hemophilia A. Emicizumab has proven remarkably effective as a prophylactic treatment for hemophilia A; however there are patients that still experience bleeding. An approach to safely and effectively treating this bleeding in hemophilia A patients with inhibitors is recombinant factor VIIa (rFVIIa). When given at therapeutic levels, rFVIIa can enhance tissue factor (TF) dependent activation of FX as well as activating FX independently of TF. At therapeutic levels rFVIIa can also activate FIX. The goal of this study was to assess the role of the FIXa activated by rFVIIa when emicizumab is added to hemophilia A plasma. Methods. Thrombin generation assays were done in plasma using 100 µM lipid and 420 µM Z-Gly-Gly-Arg-AMC with or without emicizumab at 55 µg/mL which is the clinical steady state level. The reactions were initiated with low (1 pM) tissue factor (TF). rFVIIa was added at concentrations of 25-100 nM with 25 nM corresponding to the plasma levels achieved by a single clinical dose of 90 µg/mL. To study to the role of factor IX in the absence of factor VIII, it was necessary to create a double deficient plasma (factors VIII and IX deficient). This was done by taking antigen negative hemophilia B plasma and adding a neutralizing antibody to factor VIII (Haematologic Technologies, Essex Junction, VT, USA). Now varying concentrations of factor IX could be reconstituted into the plasma to give hemophilia A plasma. Results. As expected, in the double deficient plasma with low TF there was essentially no thrombin generation. Also as expected from previous studies, addition of rFVIIa to double deficient plasma gave a dose dependent increase in thrombin generation through activation of FX. Interestingly addition of plasma levels of FIX to the rFVIIa did not increase thrombin generation. Starting from double deficient plasma, as expected emicizumab did not increase thrombin generation since no factor IX was present. Also, in double deficient plasma with rFVIIa, emicizumab did not increase thrombin generation. But in double deficient plasma with FIX and rFVIIa, emicizumab significantly increased thrombin generation. The levels of thrombin generation increased in a dose dependent fashion with higher concentrations of rFVIIa giving higher levels of thrombin generation. Conclusion. Since addition of FIX to the double deficient plasma with rFVIIa did not increase thrombin generation, it suggests that rFVIIa activation of FX is the only source of the FXa needed for thrombin generation. So in the absence of factor VIII (or emicizumab) FIX activation does not contribute to thrombin generation. However, in the presence of emicizumab, while rFVIIa can still activate FX, FIXa formed by rFVIIa can complex with emicizumab to provide an additional source of FX activation. Thus rFVIIa activation of FIX explains the synergistic effect in thrombin generation observed when combining rFVIIa with emicizumab. The generation of FIXa at a site of injury is consistent with the safety profile observed in clinical use. Disclosures Monroe: Novo Nordisk:Research Funding.Ezban:Novo Nordisk:Current Employment.Hoffman:Novo Nordisk:Research Funding.

scholarly journals Sustained expression of therapeutic levels of human factor VIII in mice

Blood ◽  
1996 ◽  
Vol 87 (11) ◽  
pp. 4671-4677 ◽  
Author(s):  
S Connelly ◽  
JM Gardner ◽  
RM Lyons ◽  
A McClelland ◽  
M Kaleko
Keyword(s):  
Factor Viii ◽  
Adenoviral Vector ◽  
Human Factor ◽  
Hemophilia A ◽  
Coagulation Factor ◽  
High Dose ◽  
Specific Enzyme ◽  
Adult Mice ◽  
Human Factor Viii

Deficiency of coagulation factor VIII (FVIII) results in hemophilia A, a common hereditary bleeding disorder. Using a human FVIII-encoding adenoviral vector, Av1ALAPH81, we have demonstrated expression of therapeutic levels of human FVIII in mice sustained for more than 5 months after vector administration. Administration of a high dose (4 x 10(9) plaque-forming units [pfu]) of Av1ALAPH81 to mice resulted in a peak expression of 2,063 ng/mL of human FVIII in the mouse plasma, with levels decreasing to background by weeks 15 to 17. Normal FVIII levels in humans range from 100 to 200 ng/mL and therapeutic levels are as low as 10 ng/mL. Alternatively, administration of 8- to 80-fold lower vector doses (5 x 10(8) pfu to 5 x 10(7) pfu) to normal adult mice resulted in expression of FVIII at therapeutic levels sustained for at least 22 weeks. Detailed analysis of vector toxicity indicated that the high vector dose caused a dramatic elevation of liver-specific enzyme levels, whereas an eight-fold lower vector dose was significantly less hepatotoxic. The data presented here demonstrate that administration of lower, less toxic vector doses allow long-term persistence of FVIII expression.

ITI Treatment is not First-Choice Treatment in Children with Hemophilia A and Low-Responding Inhibitors: Evidence from a PedNet Study

2020 ◽  
Vol 120 (08) ◽  
pp. 1166-1172
Author(s):  
H. Marijke van den Berg ◽  
Maria Elisa Mancuso ◽  
Christoph Königs ◽  
Roseline D'Oiron ◽  
Helen Platokouki ◽  
...  
Keyword(s):  
Hemophilia A ◽  
Real Life ◽  
Tolerance Induction ◽  
High Dose ◽  
Severe Hemophilia ◽  
Limited Data ◽  
Treatment Regimens ◽  
First Choice ◽  
Lost To Follow Up

Abstract Background Limited data exist on the clinical impact of low-responding inhibitors and the requirement for immune tolerance induction (ITI) treatment to establish tolerance, reduce bleeding, and improve outcome. The aim of this article is to describe the therapeutic management of children with severe hemophilia A and low-responding inhibitors and its effect on bleeding phenotype. Methods The REMAIN (Real-life Management of Inhibitors) study is a satellite study of the PedNet registry. It included unselected children with severe hemophilia A (factor VIII [FVIII] < 0.01 IU/mL) born between January 1, 1990 and December 31, 2009 who developed clinically relevant inhibitors and were followed-up for at least 3 years after the first positive inhibitor test. Results A total of 260 patients with inhibitors were identified and 68 of them (26%) had low-responding inhibitors (peak < 5 BU/mL). Five patients were lost to follow-up and 63 were included in this study. The median follow-up was 3.7 years (interquartile range: 3.0–7.5). ITI was started in 51/63 (81%) patients. The median time from ITI start to first negative inhibitor titer was similar with low-dose and high-dose ITI regimens (2.5 and 3.1 months, respectively). Ten of the 12 patients who did not receive ITI were treated with regular prophylaxis and reached a negative titer after a median of 6.5 months. Bleeding rate was low in all patients with no difference between treatment regimens. Conclusion In children with low-responding inhibitors negative titers were reached with regular FVIII treatment irrespective of the regimen (i.e., prophylaxis or ITI).

Induction of Tolerance to FVIII in Hemophilic Mice by Delivery of Apoptotic Syngeneic Fibroblasts Expressing a FVIII Transgene.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 768-768
Author(s):  
Rui-Jun Su ◽  
Laura Stewart ◽  
Angela Epp ◽  
Steven W. Pipe ◽  
Neil C. Josephson
Keyword(s):  
T Cell ◽  
Factor Viii ◽  
Cell Line ◽  
Resistance Gene ◽  
Hemophilia A ◽  
Foamy Virus ◽  
Tolerance Induction ◽  
Apoptotic Cells ◽  
Control Vector ◽  
Zeocin Resistance

Abstract In response to treatment with factor concentrates approximately 30% of patients with severe hemophilia A develop high titer inhibitory antibodies to Factor VIII. Inhibitor formation represents a major obstacle in treating patients of hemophilia A. We are investigating ways to prevent and treat inhibitors, in the mouse model of hemophilia A, through tolerance induction by infusion of FVIII vector modified apoptotic syngeneic fibroblasts. We generated a fibroblast cell line from a tail snip of a 129Sv−FVIIIKO mouse. We then transduced these cells with a bi−cistronic foamy virus vector expressing both the full length FVIII coding sequence and the zeocin resistance gene. Production of FVIII by these modified cells was confirmed by ELISA on cell culture medium. A cell line transduced with a control vector expressing only the zeocin resistance gene was also generated. Both vector modified cell lines were maintained under selective pressure and induced to apoptose by UV irradiation just prior to infusion into 129Sv−FVIIIKO mice. Mice were treated with two infusions of UV−irradiated FVIII expressing or control fibroblasts at three different weekly cell doses: 1 x 107, 2 x 106, or 2 x 105. Ten days later they were inoculated with 4 weekly intravenous doses of 0.2 μg albumin free recombinant human FVIII (ADVATE). An additional set of control mice were not given any apoptotic cells prior to inoculation with ADVATE. Blood was collected to determine anti−FVIII inhibitor titers one week after the final ADVATE dose. The Bethesda titers in mice treated with apoptotic FVIII expressing fibroblasts, at all 3 cell doses, were 3–5 fold lower than mice that received no cells prior to intravenous FVIII challenge (p &lt; 0.02 for all 3 cohorts, Welch’s t−test). A pair wise comparison with mice that received equivalent numbers of control apoptotic cells demonstrated significantly lower Bethesda titers in the mice given two weekly doses of 2 x106 FVIII expressing cells (436 ± 140BU versus 1230 ± 433BU, p = 0.04). In mice that received 1 x 107 and 2 x 105 apoptotic FVIII expressing cells there was a trend for the development of lower Bethesda titers when compared to mice that received an equivalent numbers of apoptotic cells modified by the control vector. Four months after treatment with ADVATE mice from the no cell group and both the 1 x 107 control and FVIII vector expressing groups were re−challenged with 4 additional weekly doses of ADVATE. T cell proliferation assays showed the highest stimulation index in mice that received no cells and the lowest index in mice that were treated with apoptotic FVIII expressing fibroblasts. Bethesda titer results from these re−challenged mice are currently pending. Our data show that anti−Factor VIII inhibitory antibody titers can be reduced by the prior infusion of apoptotic syngeneic cells stably transduced with a FVIII expressing foamy virus vector. Furthermore, the higher titers seen in mice treated with cells containing a control vector demonstrate that the effect is dependent on delivery of FVIII within the apoptotic cells. Moreover, the T cell stimulation data seen in the mice re−challenged 4 months after initial inoculation with FVIII indicate that the decrease in immune priming is due to the induction of durable tolerance. Future work will focus on elucidating the mechanisms of tolerance induction in this model and on combining apoptotic cell delivery with other immune modulators to optimize results.

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