Prevention and treatment of factor VIII inhibitors in murine hemophilia A

Blood ◽  
2000 ◽  
Vol 95 (4) ◽  
pp. 1324-1329 ◽  
Author(s):  
Jiahua Qian ◽  
Mary Collins ◽  
Arlene H. Sharpe ◽  
Leon W. Hoyer
Keyword(s):  
T Cell ◽  
Factor Viii ◽  
Antibody Formation ◽  
Hemophilia A ◽  
Major Complication ◽  
Primary Response ◽  
Inhibitory Antibody ◽  
Intravenous Injections ◽  
Antibody Titers ◽  
Viii Inhibitor

Inhibitory antibody formation is a major complication of factor VIII replacement therapy in patients with hemophilia A. To better understand the pathogenesis of this immunologic reaction, we evaluated the role of T-cell costimulatory signals for antifactor VIII antibody formation in a murine model of hemophilia A. Repeated intravenous injections of factor VIII in these factor VIII–deficient mice induced an antifactor VIII inhibitor antibody response. This response was shown to be T-cell dependent by its absence in hemophilic mice also deficient for the T-cell costimulatory ligand B7-2. In separate experiments, injection of murine CTLA4-Ig completely blocked the primary response to factor VIII in hemophilic mice with intact B7 function. This reagent also prevented or diminished further increases in antifactor VIII when given to hemophilic mice with low antifactor VIII antibody titers. These studies suggest that strategies targeting the B7-CD28 pathway are potential therapies to prevent and treat inhibitory antifactor VIII antibodies. Moreover, because the development of antibodies to replaced proteins may limit the success of many human gene therapy approaches, our results may be broadly applicable.

Immunomodulation of Transgene Responses Following Naked DNA Transfer of Factor VIII into Hemophilia A Mice.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1279-1279
Author(s):  
Peiqing Ye ◽  
David J. Rawlings ◽  
Arthur R. Thompson ◽  
Hans D. Ochs ◽  
Carol H. Miao
Keyword(s):  
Gene Expression ◽  
T Cell ◽  
Immune Responses ◽  
Factor Viii ◽  
Hemophilia A ◽  
Dna Transfer ◽  
Secondary Response ◽  
Inhibitory Antibody ◽  
Naked Dna ◽  
Human Factor Viii

Abstract Naked DNA transfer of liver-specific, high-expressing plasmid pBS-HCRHPI-FVIIIA in Rag2(−/ −) SCID mice produced persistent high-level gene expression of human factor VIII (hFVIII) (Miao, Hum. Gene Ther. 2003). However, in immunocompetent hemophilia A mice, a robust humoral immune response against FVIII that followed gene transfer led to complete inhibition of circulating FVIII activity (Ye, Mol. Ther. 2004). Transient immunomodulation strategies were explored to prevent the formation of inhibitory antibody formation. Eight groups of mice (n=8) were treated by naked DNA transfer of plasmid pBS-HCRHPI-FVIIIA. Each group were subjected to treatment with single or combined immunosuppressive regimen: CyclosporineA (CSA) daily for 14 days; Rapamycin daily for 14 days; Mycophenylate mofetil (MMF) daily for 14 days; combination of CSA and MMF; combination of Rapamycin and MMF; a monoclonal antibody (MR1) against murine CD40 ligand on days -1, 1, 2, 7, & 14; recombinant murine Ctla4Ig on days 1 & 2; and combination of MR1 and Ctla4Ig. Combination regimens were given using the same combined schedule and dosages. All animals treated with immunosuppression had delayed or no immune responses against hFVIII except the group treated with CSA only. The most effective treatment was observed in animals treated with the combination of Ctla4Ig and MR1. Seven of 8 animals failed to develop detectable inhibitors. One animal developed transient low-titer antibodies. This group of animals produced persistent, therapeutic levels of hFVIII gene expression for over 6 months. Tolerized animals were subsequently challenged by the T dependent antigen, bacteriophage Φx174, and exhibited a normal primary and secondary response including amplification and isotype switch. These results strongly suggest that transient immunomodulation strategies to disrupt B- and T- cell interactions at the time of plasmid injection is effective to promote long-term immune tolerance that is specific for FVIII without altering subsequent immune responses to other T cell dependent antigens.

Immunodominant T-cell epitopes in the factor VIII C2 domain are located within an inhibitory antibody binding site

2004 ◽  
Vol 92 (09) ◽  
pp. 522-528 ◽  
Author(s):  
David Okita ◽  
Brenda Diethelm-Okita ◽  
Bianca Conti-Fine ◽  
Kathleen Pratt ◽  
Jiahua Qian ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Factor Viii ◽  
Human Monoclonal Antibody ◽  
Cell Epitope ◽  
Major Complication ◽  
C2 Domain ◽  
T Cell Epitopes ◽  
Inhibitory Antibody ◽  
Human Factor Viii

SummaryFormation of inhibitor antibodies to factor VIII (FVIII) is a major complication of FVIII replacement therapy for hemophilia A patients, and it occurs through a T-cell dependent process. The C2 domain of FVIII contains epitopes that are recognized by antibody inhibitors. We have examined regions of the C2 domain that form epitopes for T cells in mice congenitally deficient in FVIII. We obtained CD4+ T cells from mice immunized by intravenous infusion of therapeutic doses of recombinant human FVIII (rFVIII), or by subcutaneous injections of rFVIII or recombinant human C2 domain in adjuvant. In all cases, the T cells recognized most strongly and consistently two overlapping peptides that spanned residues 2191 to 2220 of the C2 domain. Analysis of the crystal structure of human factor VIII C2 bound to a human monoclonal antibody, BO2C11, showed these residues also constitute part of a human alloimmune B-cell epitope (Spiegel et al., Blood 2001; 98: 13-19).This region includes one of the “hydrophobic spike” protrusions, consisting of M2199 and F2200, as well as the basic residues R2215 and R2220. These residues contribute to membrane binding and to association with von Willebrand factor (vWF).These findings suggest that a major T-cell epitope in the C2 domain recognized by hemophilic mice is located within the same region that binds to inhibitors, vWF, and activated membranes.

scholarly journals Induction of tolerance to factor VIII inhibitors by gene therapy with immunodominant A2 and C2 domains presented by B cells as Ig fusion proteins

Blood ◽  
2005 ◽  
Vol 105 (12) ◽  
pp. 4865-4870 ◽  
Author(s):  
Tie Chi Lei ◽  
David W. Scott
Keyword(s):  
B Cells ◽  
Factor Viii ◽  
B Cell ◽  
Hemophilia A ◽  
Humoral Response ◽  
Retroviral Vectors ◽  
Inhibitory Antibody ◽  
C2 Domains ◽  
Antibody Titers ◽  
A2 Domain

Abstract Up to 30% of patients with hemophilia A given therapeutic factor VIII (fVIII) can make inhibitory antibodies, the majority of which are reactive with its C2 and A2 domains. We have previously demonstrated that antigen-specific tolerance to several antigens can be induced by lipopolysaccharide (LPS)-activated B-cell blasts transduced with immunoglobulin (IgG)-antigen fusion constructs. To apply this system to hemophilia A inhibitor formation, we created retroviral vectors expressing fVIII amino acids S2173-Y2332 (C2 domain) and S373-R740 (A2 domain) in frame with an IgG heavy chain backbone. These vectors were transduced into B-cell blasts to induce tolerance in both naive and fVIII-primed hemophilic (E16 fVIII-/-) mice. Thus, treatment of E16 fVIII-/- mice with B cells expressing fVIII C2 and A2 domains led to tolerance in terms of specific humoral response (including inhibitory antibody titers) and cellular responses to fVIII and its C2 or A2 domains. Moreover, a significant reduction in immune responses to fVIII could be achieved in immunized hemophilic mice with existing anti-fVIII titers. This hyporesponsive state persisted for at least 2 months and withstood additional challenge with fVIII. Further experiments, in which mice were treated with a depleting monoclonal anti-CD25, suggested that a regulatory T cell may be required for the tolerogenic effect of transduced B cells. These findings demonstrate that B-cell presentation of fVIII domains on an Ig backbone specifically prevents or decreases existing antibodies in hemophilia A mice. (Blood. 2005;105:4865-4870)

Relationship of Major Histocompatibility Complex Class II Genes to Inhibitor Antibody Formation in Hemophilia A

1990 ◽  
Vol 64 (04) ◽  
pp. 564-568 ◽  
Author(s):  
Lloyd E Lippert ◽  
Lyman Mc A Fisher ◽  
Lawrence B Schook
Keyword(s):  
Major Histocompatibility Complex ◽  
Factor Viii ◽  
Antibody Formation ◽  
Rflp Analysis ◽  
Class Ii ◽  
Major Histocompatibility ◽  
Odds Ratios ◽  
Inhibitory Antibody ◽  
Histocompatibility Complex ◽  
Hla Dr

SummaryApproximately 14% of transfused hemophiliacs develop an anti-factor VIII inhibitory antibody which specifically neutralizes factor VIII procoagulant activity. In this study an association of the major histocompatibility complex (MHC) with inhibitor antibody formation was evaluated by restriction fragment length polymorphism (RFLP) analysis using BamHI, EcoRI, HindII, PstI, PvuII and TaqI digested genomic DNA probed with DP beta, DQ alpha, DQ beta and DR beta class II MHC gene probes. The RFLP patterns for 16 non-inhibitor and 11 inhibitor hemophiliac patients were analyzed. These 24 enzyme:probe combinations generated 231 fragments. Fifteen (15) fragments associated with the inhibitor phenotype; odds ratios ranged from 5.1 to 45 and lower bounds of 95% confidence intervals were > 1.000 for all 15 fragments. Five (5) fragments associated with non-inhibitors, with odds ratios ranging from 6.4 to 51.7. This report establishes a MHC related genetic basis for the inhibitor phenotype. No statistically significant differences in the distribution of serologically defined HLA-DR phenotypes were observed between the inhibitor and non-inhibitor groups.

scholarly journals A Clinical and Experimental Study of Acquired Inhibitors to Factor VIII

Blood ◽  
1965 ◽  
Vol 26 (6) ◽  
pp. 805-818 ◽  
Author(s):  
HAROLD R. ROBERTS ◽  
MARGARET B. SCALES ◽  
JOHN T. MADISON ◽  
WILLIAM P. WEBSTER ◽  
GEORGE D. PENICK
Keyword(s):  
Experimental Study ◽  
Factor Viii ◽  
Mode Of Action ◽  
Exchange Transfusion ◽  
Hemophilia A ◽  
Retroperitoneal Hematoma ◽  
Factor Viii Inhibitor ◽  
Viii Inhibitor ◽  
Potent Factor

Abstract Factor VIII inhibitors which developed in four patients with hemophilia A are described. These inhibitors are apparently specific for Factor VIII and are capable of inducing a transient hemophilic state when injected into dogs. The genesis, properties, and mode of action of these inhibitors can be explained on an immunologic basis and it seems most likely that they represent an antibody to Factor VIII. One hemophilia A patient, with retroperitoneal hematoma and a potent Factor VIII inhibitor, was successfully treated by an exchange transfusion followed by administration of purified porcine Factor VIII.

MODERN POSSIBILITIES OF SUBSTITUTION THERAPY AND HEMOPHILIA A PREVENTION IN CHILDREN

2021 ◽  
Vol 100 (2) ◽  
pp. 182-187
Author(s):  
P.A. Zharkov ◽  
Keyword(s):  
Factor Viii ◽  
Half Life ◽  
Hemophilia A ◽  
Safety Data ◽  
Residual Activity ◽  
Recombinant Factor Viii ◽  
Substitution Therapy ◽  
Life Effectiveness ◽  
Intravenous Injections ◽  
Prophylactic Use

Currently, the prophylactic use of factor VIII concentrate is the «gold standard» for treatment of an uncomplicated severe hemophilia A without inhibitors. However, there are a number of difficulties associated with frequent intravenous injections to maintain the activity of factor VIII above 1% in children and adolescents, which cannot but affect the adherence of patients to this type of treatment. The article discusses modern approaches to extend the half-life of recombinant factor VIII allowing to reduce the frequency of infusions and increase the residual activity of the deficient factor. On the example of efmoroctocog alpha, the first recombinant factor VIII concentrate registered in our country with a prolonged half-life, effectiveness and safety data of this class of drugs approved for use in children is presented.

scholarly journals Neutralizing and Non-Neutralizing Anti-FVIII Antibodies in Black and White Hemophilia A Subjects: A Natural History Profile

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1131-1131 ◽  
Author(s):  
Kathleen P. Pratt ◽  
Devi Gunasekera ◽  
Pooja Vir ◽  
Robert Peters ◽  
Siyuan Tan ◽  
...  
Keyword(s):  
B Cell ◽  
Hemophilia A ◽  
African Ancestry ◽  
Full Length ◽  
Inhibitory Antibody ◽  
B Cell Epitopes ◽  
Black African ◽  
Coagulation Inhibitors ◽  
Antibody Titers ◽  
Linear B

The most common complication in hemophilia A (HA) treatment, affecting 25-30% of severe HA patients, is the development of alloimmune inhibitors that foreclose the ability of infused factor VIII (FVIII) to participate in coagulation. Inhibitors confer significant pathology on affected individuals and present major complexities in their management. Inhibitors are more common in African American patients, and it has been hypothesized that this is a consequence of haplotype (H)-treatment product mismatch. F8 gene haplotypes H1-H5 are defined by combinations of nonsynonymous SNPs encoding FVIII sequence variants D1241E, M2238V and R484H. F8 haplotypes H2-H5 are more prevalent in individuals with black African ancestry, while >90% of the white population has the H1 haplotype. This study used a validated Luminex-based assay to determine total anti-FVIII antibody titers in plasma from 395 HA (189 black, 206 white) and 23 non-HA control subjects, measuring their binding to recombinant full-length H1 and H2 and B-domain-deleted (BDD) H1/H2, H3 and H4 FVIII proteins. Inhibitor titers were determined using a chromogenic Bethesda assay with the Nijmegen modification. Linear B-cell epitopes recognized by antibodies in human plasma samples were characterized using commercial peptide microarrays with imprinted 15-mer peptides spanning the FVIII A1, A2, C1 and C2 domains, with binding interactions detected using fluorescent-labeled anti-human IgG antibodies. Neither total nor inhibitory antibody titers correlated with F8 haplotype. FVIII peptides with the D1241E and M3348V polymorphisms showed low antibody reactivity, indicating they do not comprise linear B-cell epitopes. Similarly, antibodies from subjects with H3 and H5 haplotypes, who were necessarily infused with FVIII products having a different haplotype than that of their endogenous, (dysfunctional) F8 sequence, did not show haplotype-correlated differential binding to the three BDD-FVIII or full-length FVIII proteins, indicating the polymorphic M2238V or D1241E sites do not correspond to immunodominant, conformational B-cell epitopes. Interestingly, the BDD-FVIII proteins were significantly more reactive with antibodies in plasma than were two commercial full-length recombinant FVIII products. Overall, results of this study indicated that low-titer FVIII-reactive antibodies are readily detected in most HA subjects and in a majority of healthy non-HA controls. The observed stronger immunoreactivity of BDD-FVIII suggests that B-domain removal exposes novel B-cell epitopes, perhaps through conformational rearrangements of FVIII domains. Disclosures Pratt: Bloodworks NW: Patents & Royalties: inventor on patents related to FVIII immunogenicity; Grifols, Inc: Research Funding. Peters:Sanofi: Employment. Mann:Haematologic Technologies: Other: Owner; Stago: Consultancy; Novo Nordisk: Consultancy; Takeda: Consultancy; Shire: Consultancy; Baxalta: Consultancy.

Replacement Therapy in Hemophilia Patients with Inhibitors

1979 ◽  
Author(s):  
S.S. Shapiro
Keyword(s):  
Factor Viii ◽  
Antibody Titer ◽  
Hemophilia A ◽  
Double Blind Study ◽  
Cooperative Study ◽  
Double Blind ◽  
Antibody Titers ◽  
High Degree ◽  
High Treatment ◽  
Dependent Factor

Approximately 15% of patients with hemophilia A develop inhibitors to Factor VIII. These inhibitors have a high degree of specificity for Factor VIII procoagulant activity. Inhibitor patients seem to fall into 2 groups: roughly 3/4 are “strong” responders, whose Factor VIII antibody titer rises substantially after exposure to Factor VIII, while the remainder are “weak” responders, whose antibody level remains below 3-5 Bethesda units/ml despite exposure to Factor VIII. The latter group can be treated successfully with Factor VIII, although the dose required may be greater than in non-inhibitor patients. The “strong” responders can be treated with Factor VIII if their antibody titer is very low, although anamnesis will ensue within 3-4 days, reaching a maximum in 10-20 days. When antibody titers are high, treatment can be extremely difficult. Use of Factor VIII may still be possible, when combined with massive plasmapheresis; otherwise treatment with vitamin K-dependent factor concentrates may be attempted. A variety of such concentrates is available, both “non-activated” and “activated”. The former type of product may have become less useful for the treatment of inhibitor patients in recent years. The NTH Cooperative Study of Factor VIII Inhibitors in Hemophilia A has recently conducted a double-blind study of Konyne and Proplex in the treatment of Inhibitor patients. These results will be presented.

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