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To compare a new ready-to-use monotest immunoassay, CHORUS Promonitor, for the quantification of serum biological drug levels and anti-drug antibodies of anti-TNF agents, against the reference batch-based ELISA test, Promonitor.Blood samples were collected from patients treated with anti-TNF agents, infliximab (IFX) or adalimumab (ADL). IFX and ADL levels, as well as anti-IFX and anti-ADL antibodies were quantified and compared between the standard ELISA reference test, Promonitor, and the automated monotest ELISA assay, CHORUS Promonitor. Data analysis included both qualitative and quantitative comparison between both tests. For the qualitative comparison, overall percent agreement (OPA) was calculated. For the quantitative comparison, Passing-Bablok regression analysis and Bland–Altman analysis were used.For IFX and ADL levels, the qualitative overall agreement between methods was 100 % (Cohen’s coefficient=1). For anti-IFX and anti-ADL antibodies, OPA was 98.8 % and 97.3 %, respectively. Quantitative comparison indicated a very strong correlation between both assays: IFX (r=0.97, n=74), ADL (r=0.95, n=54), anti-IFX (r=0.93, n=72), and anti-ADL (r=0.97, n=61). The regression analysis determined an excellent comparability of drug levels between methods. Bland–Altman analysis showed a bias difference between assays of 6 % for IFX, 0 % for ADL, 24 % for anti-IFX, and 14 % for anti-ADL.Monotest CHORUS Promonitor was a reliable assay to quantify IFX, ADL, anti-IFX and anti-ADL in samples with comparable results to those obtained with the reference batch-based ELISA technique. [ABSTRACT FROM AUTHOR]

Purpose: Alpha-1-antitrypsin deficiency (AATD) is a rare hereditary condition resulting from the mutations in the SERPINA1 (serine protease inhibitor) gene and is characterized by low circulating levels of the alpha-1 antitrypsin (AAT) protein. The traditional algorithm for laboratory testing of AATD involves the analysis of AAT concentrations (nephelometry), phenotyping (isoelectric focusing, IEF), and genotyping (polymerase chain reaction, PCR); in selected cases, full sequencing of the SERPINA1 gene can be undertaken. New technologies arise that may make diagnosis easier and faster., Methods: We developed and evaluated a new diagnostic algorithm based on Luminex xMAP (multi-analyte profiling) technology using Progenika A1AT Genotyping Test. In an initial learning phase, 1979 samples from individuals suspected of having AATD were examined by both, a traditional and a "new" algorithm. In a second phase, 1133 samples were analyzed with the Luminex xMAP only., Results: By introducing a Luminex xMAP based algorithm, we were able to simultaneously identify 14 mutations in SERPINA1 gene (instead of two- S and Z-by using our old algorithm). Although the quantity of IEF assays remained unchanged, the nephelometric measurements and sequencing were reduced by 79% and 63.4%, respectively., Conclusion: The new method is convenient, fast and user-friendly. The application of the Luminex xMAP technology can simplify and shorten the diagnostic workup of patients with suspected AATD., Competing Interests: Martina Veith reports grants from Grifols, during the conduct of the study; grants from Grifols, outside the submitted work. Iker Anton, Rachid El Hamss, and Noelia Rapun are employees of Progenika Biopharma-Grifols. Viktor Kotke reports grants from Grifols, outside the submitted work. Dr. Robert Bals reports grants, personal fees from CSL Behring and Grifols, grants from Boehinger Ingelheim and Novartis, during the conduct of the study. Claus Franz Vogelmeier reports grants, personal fees from AstraZeneca, GlaxoSmithKline, Grifols, Novartis, and Boehringer Ingelheim, personal fees from CSL Behring, Menarini, Mundipharma, Teva, Cipla, Nuvaira, and Chiesi, grants from Bayer Schering Pharma AG, MSD, and Pfizer, outside the submitted work. Timm Greulich reports grants from Grifols, during the conduct of the study; personal fees from AstraZeneca, Berlin-Chemie, Boehringer-Ingelheim, Chiesi, CSL-Behring, Grifols, GSK, and Novartis, outside the submitted work. The authors report no other conflicts of interest in this work., (© 2019 Veith et al.)