IgE antibodies to chimeric or humanized IgG therapeutic monoclonal antibodies as a screening test for anaphylaxis
The present invention provides an assay for detecting serum IgE antibody levels to cetuximab and to other proteins. The present invention further provides a method for predicting whether a subject will respond adversely to cetuximab treatment. The present further provides a method for detecting sensitivity to compounds comprising galactose-alpha-1,3-galactose.
1. A method of identifying whether a compound comprises the oligosaccharide moiety galactose-alpha-1,3-galactose, said method comprising:
combining the compound with an IgE antibody which binds specifically to galactose-alpha-1,3-galactose to form a complex comprising the galactose-alpha-1,3-galactose of the compound bound specifically IgE antibody; and
detecting the presence of the complex, wherein the presence of the complex indicates that the compound comprises the oligosaccharide moiety galactose-alpha-1,3-galactose.
2. A method of screening a sample, for the presence or amount of IgE antibodies specific for alphaGal, comprising;
(a) contacting the sample with a known amount of an isolated compound comprising the moiety galactose-alpha-1,3-galatose (alphaGal) that specifically binds to said IgE antibodies in the sample, so as to form complexes between alphaGal moieties on said compound and said IgE antibodies; and
(b) detecting the presence or amount of said complexes, wherein the presence or amount indicates that the sample comprises said IgE antibodies.
3. The method of claim 2 wherein the presence or amount of IgE is detected by reacting the complex with a secondary enzyme-labeled anti-IgE antibody.
4. The method of claim 2 , wherein the sample is screened for the presence of IgE antibodies specific for alphaGal.
5. The method of claim 2 , wherein the sample is screened for the amount of IgE antibodies specific for alphaGal.
6. The method of claim 2 , wherein said biological sample is selected from the group consisting of blood, serum, and plasma.
7. The method of claim 2 , wherein said sample is a human sample.
8. The method of claim 1 or 2 , wherein said compound is a protein.
9. The method of claim 8 , wherein said protein is an antibody.
10. The method of claim 9 , wherein said antibody is a therapeutic antibody.
11. The method of claim 2 , wherein said IgE antibody cross-reacts with alphaGal moieties on cetuximab or on the F(ab′) 2 fragment cetuximab.
12. The method of claim 11 , wherein said IgE antibody which forms complexes with alphaGal moieties is measured using an ImmunoCAP assay.
13. The method of claim 12 , wherein said ImmunoCAP assay is a modified ImmunoCAP) assay using streptavidin bound to the solid phase.
14. The method of claim 13 , wherein the level of said IgE is expressed in IU/ml.