Development of an anti-EPO antibody detection kit based on lab-on-a-chip and bridging antibody technologies

Immunogenicity is a major concern in the use of biological drugs. In particular, antibody-mediated pure red cell aplasia (PRCA) is a rare condition that is caused by administration of recombinant erythropoietin. There are numerous assay platforms for detect EPO anti-drug antibody (ADA), and most have appropriate assay sensitivity, but in need of improvement in terms of assay turnaround time and user accessibility. Here, the new method was developed based on lab-on-a-chip technology and bridging ELISA. The FREND™ Cartridge is equipped with a microfluidic lateral flow channel, enabling easy, fast and accurate immunoassays with small sample volumes. Biotinylated EPO was immobilized on the avidin-coated solid phase of the test zone in the FREND™ cartridge. Initially, ADA in the serum sample binds to the detector conjugate (EPO-HRP-anti HRP antibody-FL bead) in the conjugation zone, and it flows into the test zone prepared with capture complex (avidin-biotinylated EPO). Unbound detector complexes are captured in the reference zone. The FREND™ system detects and quantifies the fluorescence signals in each zone and then calculates the concentration of EPO ADA in the sample. The FREND™ EPO ADA kit may be useful in local clinics as a rapid method for monitoring patients administered recombinant erythropoietin.