Reduction of the inhibitory antibody response to human factor VIII in hemophilia A mice by mutagenesis of the A2 domain B-cell epitope.
Blood
; 104(3): 704-10, 2004 Aug 01.
Article
em En
| MEDLINE
| ID: mdl-15073030
ABSTRACT
Approximately 25% of patients with hemophilia A develop inhibitory antibodies after treatment with factor VIII. Most of the inhibitory activity is directed against epitopes in the A2 and C2 domains. Anti-A2 inhibitory antibodies recognize a 25-residue segment bounded by R484-I508. Several antigenic residues in this segment have been identified, including R484, R489, and P492. The immunogenicity of purified recombinant B domain-deleted (BDD) human factor VIII molecules containing mutations at R484A/R489A or R484A/R489A/P492A was studied in hemophilia A mice. Inhibitory antibody titers in mice receiving the R484A/R489A/P492A mutant, but not the R484A/R489A mutant, were significantly lower than in mice receiving control human BDD factor VIII. The specific coagulant activity and the in vivo clearance and hemostatic efficacy in hemophilia A mice of the R484A/R489A/P492A mutant were indistinguishable from human BDD factor VIII. Thus, the inhibitory antibody response to human factor VIII can be reduced by mutagenesis of a B-cell epitope without apparent loss of function, suggesting that this approach may be useful for developing a safer form of factor VIII in patients with hemophilia A.
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Base de dados:
MEDLINE
Assunto principal:
Fator VIII
/
Linfócitos B
/
Hemofilia A
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Ano de publicação:
2004
Tipo de documento:
Article