title: Validation of a sample pretreatment protocol to convert a drug-sensitive into a drug-tolerant anti-infliximab antibody immunoassay.
abstract: A meta-analysis revealed that up to 51% of patients treated with infliximab develop anti-drug Abs (ADA) which are associated with loss of response. Detection of ADA is strongly influenced by assay technique since drug-sensitive ADA assays are not able to detect ADA in the presence of drug and therefore underestimate ADA development. In addition, the lack of a calibrator antibody that can be used in a drug-sensitive and drug-tolerant assay hampers an adequate comparison among different assays. Here we present a sample pretreatment protocol to convert the bridging assay, originally developed as a drug-sensitive assay, into a drug-tolerant assay, allowing use of the same assay and calibrator antibody MA-IFX10F9. Using the sample pretreatment protocol, the bridging assay detects antibodies towards infliximab in samples containing up to 5-fold infliximab over anti-infliximab. Analysis of consecutive serum samples from infliximab treated patients revealed that the drug-tolerant assay detects ADA development up to 40 weeks earlier compared to the drug-sensitive assay. In conclusion, the sample pretreatment protocol can be implemented in various assay formats and allows determination of ADA in the presence of drug, providing the possibility for early treatment optimization. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Therapeutic and Diagnostic Antibodies, KU Leuven, Leuven, Belgium.
authors.forename: Thomas
authors.initials: T
authors.lastname: Van Stappen
authors.affiliation: Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Therapeutic and Diagnostic Antibodies, KU Leuven, Leuven, Belgium.
authors.forename: Els
authors.initials: E
authors.lastname: Brouwers
authors.affiliation: Department of Gastroenterology, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Séverine
authors.initials: S
authors.lastname: Vermeire
authors.affiliation: Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Therapeutic and Diagnostic Antibodies, KU Leuven, Leuven, Belgium.
authors.forename: Ann
authors.initials: A
authors.lastname: Gils
mesh_terms: D000328:Adult; D000906:Antibodies / Q000097:blood* / Q000276:immunology*; D018501:Antirheumatic Agents / Q000276:immunology*; D004342:Drug Hypersensitivity / Q000097:blood* / Q000276:immunology*; D016903:Drug Monitoring; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006801:Humans; D000069285:Infliximab / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity
chemical_list: D000906:Antibodies; D018501:Antirheumatic Agents; D000069285:Infliximab
keywords: ELISA; immunogenicity; infliximab; therapeutic drug monitoring