TY - JOUR
T1 - Phenotypes of Allo- and Autoimmune Antibody Responses to FVIII Characterized by Surface Plasmon Resonance
AU - Lewis, Kenneth B.
AU - Hughes, Richard J.
AU - Epstein, Melinda S.
AU - Josephson, Neil C.
AU - Kempton, Christine L.
AU - Kessler, Craig M.
AU - Key, Nigel S.
AU - Howard, Tom E.
AU - Kruse-Jarres, Rebecca
AU - Lusher, Jeanne M.
AU - Walsh, Christopher E.
AU - Watts, Raymond G.
AU - Ettinger, Ruth A.
AU - Pratt, Kathleen P.
N1 - Funding Information:
The authors have the following interests. Dr's. Pratt and Lewis are inventors on a patent describing the SPR methodology described in this study. Dr. Pratt received travel support from GE Health Sciences to present preliminary SPR studies at the 2011 DiPia meeting in Boston, Massachusetts. This study was partly funded by Bayer HealthCare LLC. The authors thank Dr. Jason Schuman (GE Health Sciences) for technical advice and Bill Church (Green Mountain Antibodies, Burlington, Vermont) for donations of monoclonal antibodies. Drs. Lewis and Pratt are inventors on the following patent: International Patent Application No. PCT/US2012/61/553,660, Title: Antibody Response Phenotyping, Filed: October 31, 2012, Inventors: Kathleen Pratt, PhD; Kenneth Lewis, PhD. There are no further patents, products in development or marketed products to declare. This does not alter the authors′ adherence to all the PLOS ONE policies on sharing data and materials, as detailed online in the guide for authors.
PY - 2013/5/10
Y1 - 2013/5/10
N2 - 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 (∼1-33 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.
AB - 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 (∼1-33 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.
UR - http://www.scopus.com/inward/record.url?scp=84877308750&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0061120
DO - 10.1371/journal.pone.0061120
M3 - Article
C2 - 23667433
AN - SCOPUS:84877308750
SN - 1932-6203
VL - 8
JO - PLoS ONE
JF - PLoS ONE
IS - 5
M1 - e61120
ER -