Surface plasmon resonance-based methodology for anti-adalimumab antibody identification and kinetic characterization

Abstract

Adalimumab (ADA) is a TNF-α blocker drug antibody fully humanized and thus indistinguishable in structure and function from natural human IgG1, used in the juvenile idiopathic arthritis (JIA) treatment. Immunogenicity against the drug has been frequently detected in treated patients, and the presence of anti-ADA antibodies is correlated to treatment failure or lower clinical remission. Herein, we measured by surface plasmon resonance (SPR) both the binding and the affinity of anti-ADA antibodies to the ADA-immobilized biosensor. The binding of anti-ADA antibodies was evaluated by testing sera from ADA-treated patients (n = 30), untreated patients (n = 9), and healthy donors (n = 20) in the SPR biosensor. The optimal cut-off point was defined using the receiver operating characteristic curve (ROC-curve) analysis with 79 % (60.28 to 92.01 %, 95 % CI) sensitivity, 99 % (88.06 to 100.0 %, 95 % CI) specificity, and a positive likelihood ratio of 23. The area under the curve was 0.9298 (p < 0.0001). The apparent affinity of anti-ADA antibodies from pediatric patients' sera was measured, analyzing the interaction of anti-drug antibodies using whole sera, enriched IgG fractions, and isolated anti-ADA antibodies. The immobilized drug ADA interacted with purified antibodies at low affinities (10(-6) M > K D > 10(-9) M). Graphical Abstract Adalimumab immobilized on the biosensor chip surface detects specific anti-drug antibodies in treated patients' sera.

Label-Free Quantification of Anti-TNF-α in Patients Treated with Adalimumab Using an Optical Biosensor

“…The p -value (<0.0001) confirmed statistically significant differences between study groups. Our results agreed with that reported in the literature stating that plasma and serum samples produce instrumental background noise [ 75 ]. However, using a reference channel in SPR-based assays helps in correcting non-specific adsorptions and compensating for refraction index differences [ 76 ].…”

“…Studies for evaluating adalimumab by Bian et al, showed plasma concentrations ranging from 19 to 0.3 µg/mL (SPR) [ 75 ] agreeing with results of the same magnitude reported in other studies which had been determined by evaluating three types of commercial ELISA, values ranging from 20 to 0.5 µg/mL [ 39 , 77 , 78 ]. Our results for patients’ samples agreed with the previously reported magnitude.…”

“…The above was demonstrated by the good linearity and sensitivity obtained in the anti-TNF-α mAb calibration curve (R 2 > 0.90). Another study has reported identifying anti-adalimumab antibodies and characterisation kinetics based on amine route immobilisation, but using an indirect bridging strategy with ELISA [ 75 ].…”

A Surface Plasmon Resonance-based assay to measure serum concentrations of therapeutic antibodies and anti-drug antibodies

“…In comparison to ELISA and the other techniques proposed so far (RIA 39 , HMSA 43 , electrochemiluminescence assays 47 ) SPR has obvious advantages in that it does not require labelled compounds and avoids long incubation/separation/detection steps, reducing the complexity and associated variability. Some reports have already appeared where SPR was used to measure IFX 48,49 or anti-drug antibodies 50–52 , but this is the first study addressing the simultaneous analysis of both. Most importantly, we demonstrate the advantages of SPR through rigorous characterisation and validation of the assay performances, to fulfil the requirements for reliable analysis of clinical samples.…”

Modeling interaction between gp120 HIV protein and CCR5 receptor

“…The Nt peptide was tested at the concentrations 20, 15, 10, and 5 μg/ml. Kinetic experiments were conducted following the previously described SPR protocol with optimization of the dissociation phase times and regeneration solutions for the present study . Diluted samples were injected in duplicate over each immobilized peptide for 120 seconds at a flow rate of 5 μl/minute.…”