title: Elimination of complement interference can improve the diagnostic performance of the VIDAS CMV IgG assay in acute cytomegalovirus infections.
abstract: In this study we showed that complement factors are responsible for assay interference in the VIDAS cytomegalovirus (CMV) immunoglobulin G (IgG) assay. Three different serum treatments were applied to show the cause of interference: heat treatment (56 °C), adding cobra venom factor, and adding EDTA. Elimination of complement interference by EDTA treatment of serum was prospectively evaluated on 215 CMV IgM positive samples and a sensitivity increase of the VIDAS CMV IgG assay was noticed. On average the CMV IgG level increased 100% after EDTA treatment of the serum. In paired serum samples from 38 patients we could show that serum treatment with EDTA can make the CMV IgG level changes more obvious in recent CMV infections. Since the CMV IgG avidity II assay on VIDAS depends on the determination of CMV IgG, the CMV IgG avidity was also evaluated in this study but only a limited effect of the complement interference was observed.
authors.affiliation: Algemeen Medisch Laboratorium (AML), Sonic Healthcare, Antwerpen, Belgium. Electronic address: mario.berth@aml-lab.be.
authors.forename: Mario
authors.initials: M
authors.lastname: Berth
authors.affiliation: Algemeen Medisch Laboratorium (AML), Sonic Healthcare, Antwerpen, Belgium.
authors.forename: Sofie
authors.initials: S
authors.lastname: Willaert
mesh_terms: D000915:Antibody Affinity / Q000276:immunology; D016022:Case-Control Studies; D003165:Complement System Proteins / Q000276:immunology*; D003587:Cytomegalovirus / Q000276:immunology*; D003586:Cytomegalovirus Infections / Q000175:diagnosis* / Q000276:immunology*; D006801:Humans; D007118:Immunoassay / Q000379:methods* / Q000592:standards; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D015203:Reproducibility of Results
chemical_list: D007074:Immunoglobulin G; D003165:Complement System Proteins
keywords: Complement; Cytomegalovirus; IgG avidity; Immunoassay; Interference; Serology