Available online 28 January 2023, 113436

Accurate anti-drug antibody (ADA) detection requires dissociation from the drug.

Anti-idiotype/Fc bridging facilitates detection of IgG4 and low-affinity ADAs.

Europium labeling enables fluorescence-based detection of ADAs immobilized on beads.

Eu-chelate fluorescence allows assays to be performed in a 96-well plate format.

Accurate anti-drug antibody (ADA) measurements in patient sera requires dissociation of ADA-drug complexes combined with sensitive and specific ADA detection. Bridging type immunoassays are often used despite several disadvantages associated with this approach. A good drug-tolerant alternative is the acid-dissociation radioimmunoassay (ARIA), but this method is not easily implemented in most labs as specialized facilities are required for working with radioactive materials. We describe an innovative method for ADA detection that combines the advantages of antigen binding tests like the ARIA with the convenience of regular immunoassays. This acid-dissociation lanthanide-fluorescence immunoassay (ALFIA) involves dissociation of ADA-drug complexes, followed by binding to an europium-labeled drug derivative and subsequently an IgG pulldown on Sepharose beads. After europium elution, detection is achieved by measuring time-resolved fluorescence originating from europium chelate complexes. We measured anti-adalimumab ADA levels in sera of 94 rheumatoid arthritis patients using the ALFIA and showed this method to be highly drug tolerant, sensitive and specific for anti-adalimumab ADAs.

Anti-drug antibodies (ADA)

Adalimumab

Drug-tolerant assay

Europium chelate fluorescence

Filter plate

Radioimmunoassay

© 2023 Elsevier B.V. All rights reserved.