title: Detection of IgM to hepatitis B core antigen in a reductant containing, chemiluminescence assay.
abstract: The Abbott PRISM(R) hepatitis B core (HBc) antigen assay is an automatic in vitro competitive chemiluminescence immunoassay for the detection of total antibody to HBc (anti-HBc) antigen in human serum or plasma. The assay utilizes cysteine solution as a reducing reagent in order to maximize specificity. To help understand the effect of cysteine on detection of anti-HBc antigen, we separated and purified anti-HBc IgM and IgG from human plasma using size exclusion, protein A/G, and affinity chromatography techniques. We showed that cysteine affected the reactivity of anti-HBc IgM with recombinant HBc (rHBc) antigen but not the reactivity of anti-HBc IgG. Anti-HBc IgM treated with cysteine yielded byproducts which were reactive in the PRISM HBcore assay. Reduction-sensitive factor (RSF) - IgM fraction from serum known to be non-specific for anti-HBc activity, similarly treated with cysteine, was no longer reactive in the PRISM HBcore assay. We showed that cysteine treatment is effective against non-specific IgM in human blood. Also, the inclusion of cysteine in the PRISM HBcore assay does not compromise the detection of HBc specific antibodies.
authors.affiliation: Abbott Diagnostics Division, Building AP1A, D-93E, Abbott Laboratories, 100 Abbott Park Road, Abbott Park, IL 60064, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Cheng
authors.forename: N
authors.initials: N
authors.lastname: Dubovoy
authors.forename: M E
authors.initials: ME
authors.lastname: Hayes-Rogers
authors.forename: J
authors.initials: J
authors.lastname: Stewart
authors.forename: D
authors.initials: D
authors.lastname: Shah
mesh_terms: D000918:Antibody Specificity; D002846:Chromatography, Affinity; D003545:Cysteine; D005069:Evaluation Studies as Topic; D006510:Hepatitis B Antibodies / Q000032:analysis* / Q000097:blood; D006512:Hepatitis B Core Antigens / Q000276:immunology*; D006801:Humans; D007118:Immunoassay / Q000379:methods* / Q000706:statistics & numerical data; D007075:Immunoglobulin M / Q000032:analysis* / Q000097:blood; D007202:Indicators and Reagents; D008163:Luminescent Measurements; D010084:Oxidation-Reduction; D012680:Sensitivity and Specificity
chemical_list: D006510:Hepatitis B Antibodies; D006512:Hepatitis B Core Antigens; D007075:Immunoglobulin M; D007202:Indicators and Reagents; D003545:Cysteine