THROMBOSIS AND HEMOSTASIS Quantitation of anti–factor VIII antibodies in human plasma
نویسندگان
چکیده
The presence of antibodies (Abs) in hemophilia A patients can potentially influence the therapeutic qualities of factor VIII (fVIII) administration. Much work has been focused on the presence of inhibitory antibodies, whereas the quantitation of noninhibitory anti-fVIII antibodies has been largely undetermined. Our objective was to develop a sensitive and specific fluorescencebased immunoassay (FLI) for the quantitation of anti-fVIIIAbs in human plasma. Affinity-purified human anti-fVIIIAb, isolated from a hemophilia A subject, was used as a calibrator with a detectability limit of 40 ( 1.5) pM. The calibrator and the human plasma anti-fVIIIAb were captured on recombinant fVIII (rfVIII)– coupled microspheres and probed with mouse anti–human Ig–R-phycoerythrin. Plasma samples from 150 healthy donors and 39 inhibitor-negative hemophilia A subjects were compared with 4 inhibitor-positive hemophilia A plasma samples with inhibitor titers of 1 BU/mL (94.6 0.8 nM), 11 BU/mL (214.3 7.1 nM), 106 BU/mL (2209.4 84.9 nM), 140 BU/mL (2417.7 3.8 nM) as measured by the Nijmegen method. We also describe the validation of a mouse anti–human fVIIIAb as a surrogate calibrator. Four healthy individuals (3%) showed detectable antifVIIIAb in the range of 0.6 to 6.2 nM, whereas 13 (33%) of the 39 inhibitor-free hemophilia A subjects were positive for anti-fVIIIAb in the range of 0.5 to 20 nM. The method may be useful for therapeutic management of hemophilia A patients. (Blood. 2009;113:2587-2594)
منابع مشابه
Rituximab for Treatment of Hemophilia A with High-Responder Inhibitors
Background: The development of inhibitors is a complication factor replacement therapy in hereditary factor VIII deficiency. Several management options are available for the treatment of inhibitor. Rituximab, a monoclonal antibody against CD20, reduces inhibitor level in rare bleeding disorders. The aim of this study was to evaluate the effectiveness of rituximab in lowering or eliminating the ...
متن کاملHigh expression reduces an antibody response after neonatal gene therapy with B domain-deleted human factor VIII in mice.
BACKGROUND Gene therapy could prevent bleeding in patients with hemophilia A, but might induce antibodies that block factor VIII (FVIII) function. OBJECTIVES To test the efficacy of gene therapy in the newborn period for preventing a response to human FVIII (hFVIII) because of immaturity of the immune system. METHODS Varying doses of a retroviral vector (RV) expressing a B domain-deleted hF...
متن کاملEvaluation of Normal Range of Bleeding Scores in Healthy Iranian Adults using the International Society on Thrombosis and Hemostasis Bleeding Assessment Tool
Background: Bleeding assessment tools are key components in the evaluation of patients suspicious for bleeding disorders. The exact determination of the normal ranges of ISTH-BAT (International Society on Thrombosis and Hemostasis –Bleeding Assessment Tool) in the healthy population is a crucial step for determining who needs to be referred for further coagulation laboratory examinations. We ai...
متن کاملHEMOSTASIS, THROMBOSIS, AND VASCULAR BIOLOGY In vivo neutralization of a C2 domain–specific human anti–Factor VIII inhibitor by an anti-idiotypic antibody
Factor VIII (FVIII) administration elicits specific inhibitory antibodies (Abs) in about 25% of patients with hemophilia A. The majority of such Abs reacts with FVIII C2 domain. mAbBO2C11 is a high-affinity human monoclonal antibody (mAb) directed toward the C2 domain, which is representative of a major class of human FVIII inhibitors. Anti-idiotypic Abs were raised to mAbBO2C11 to establish th...
متن کاملHEMOSTASIS, THROMBOSIS, AND VASCULAR BIOLOGY Antigenicity of putative phospholipid membrane-binding residues in factor VIII
Most inhibitory antibodies to human factor VIII (fVIII) bind to epitopes in the A2, ap-A3, or C2 domains. The anticoagulant action of antibodies to the C2 domain is due to inhibition of binding of fVIII to phospholipid. The x-ray structure of the human fVIII C2 domain shows a putative hydrophobic, 3-prong, phospholipid membrane-binding site consisting of Met2199/ Phe2200, Val2223, and Leu2251/L...
متن کامل