Validation Study of a New Random-Access Chemiluminescence Immunoassay Analyzer i-TRACK10 to Monitor Infliximab and Adalimumab Serum trough Levels and Anti-Drug Antibodies.

. Monitoring of biological TNF inhibitors is a very important tool to guide clinical decisions using specialized algorithms, especially in gastroenterology. A new chemiluminescent instrument (i-TRACK from Theradiag) could replace ELISA techniques to calculate the dosage of drugs and anti-drug antibodies. In this bi-centric study, we explored the analytical performances of i-TRACK using manual or automated (DS2) ELISA Lisa-Tracker assays, and compared the results. . Intra- and inter-run performances were evaluated with i-TRACK in two different laboratories and for two different ranges of values for infliximab, adalimumab, and their respective antibodies. Patients' samples were used in the labs to compare the results obtained between the new instrument and either the manual Lisa-Tracker or the automated DS2. . Intra- and inter-run performances were satisfactory, with values between 1.8% and 16.1% (for inter-run imprecision at low/medium values of infliximab). Results were generally comparable between assays. with the lowest value of correlation at 0.59 (anti-adalimumab dosage between i-TRACK and manual ELISA). Most often, values of drugs and anti-drug antibodies were higher with i-TRACK than with manual ELISA assay, and correlation values were better with automated ELISA. Agreements were globally acceptable, and the lowest coefficients of 0.7 was obtained for adalimumab values between i-TRACK and the two ELISA methods, and for anti-adalimumab values between i-TRACK and manual ELISA. The type of assay can potentially induce a change in the class of patients and lead to divergent therapeutic decisions. . The new random-access instrument i-TRACK presents many advantages in a routine laboratory: rapidity, the possibility of standardization, usability, and expansion of the measurement range. Despite the relatively good agreement of results, it is preferable to use the same assay in longitudinal follow-up of a patient, because quantitative results were not completely equivalent especially for anti-drug antibodies.