Phenotypes of allo- and autoimmune antibody responses to FVIII characterized by surface plasmon resonance.
PLoS One
; 8(5): e61120, 2013.
Article
em En
| MEDLINE
| ID: mdl-23667433
ABSTRACT
Evidence of antibody isotype/subtype switching may provide prognostic value regarding the state of immune responses to therapeutic proteins, e.g. anti-factor VIII (FVIII) antibodies that develop in many hemophilia A patients, clinically termed "inhibitors". A sensitive, high- information-content surface plasmon resonance (SPR) assay has been developed to quantify IgG subtype distributions and the domain specificity of anti-drug antibodies. Plasma samples from 22 subjects with an allo- or auto-immune reaction to FVIII were analyzed. Pre-analytical treatment protocols were developed to minimize non-specific binding and specific matrix interference due to von Willebrand factor-FVIII interactions. The dynamic range for IgG quantification was 0.2-5 µg/ml (â¼1-33 nM), allowing characterization of inhibitor-positive samples. Subtype-specific monoclonal antibodies were used to quantify the IgG subtype distribution of FVIII-specific antibodies. Most samples obtained from multiply-infused inhibitor subjects contained IgG4 antibodies. Several distinct phenotypes were assigned based on the IgG subtype distribution IgG1, IgG4, IgG1 & IgG4, and IgG1, IgG2 & IgG4. An IgG1-only response was found in mild/moderate HA subjects during early FVIII infusions, and analysis of serial samples followed antibody class switching as several subjects' immune responses developed. Competition studies utilizing a recombinant FVIII-C2 domain indicated 40-80% of FVIII-specific antibodies in most samples were directed against this domain.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fenótipo
/
Fator VIII
/
Imunoglobulina G
/
Ressonância de Plasmônio de Superfície
/
Hemofilia A
/
Formação de Anticorpos
Tipo de estudo:
Guideline
/
Prognostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Revista:
PLoS One
Assunto da revista:
CIENCIA
/
MEDICINA
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Estados Unidos