Analytical Performance of a Novel, Fully Automated Multiplexed Microarray Immunoassay Prototype for the Simultaneous Detection of Fifteen Autoantibodies Associated with Connective Tissue Diseases

Abstract

Background: There is currently a limited offer of automated multi-analyte tests for autoantibody testing in autoimmune connective tissue diseases (CTD). We assessed the analytical performance of a novel, single-use, multiplexed microarray immunoassay prototype (MosaiQ AiPlex CTDplus), used with the fully automated MosaiQⓇ system, for the simultaneous detection of fifteen autoantibodies associated with CTD, compared with selected CE-marked devices. Methods: Banked human serum samples, characterized as reactive to ≥ 1 autoantibody or non-reactive were included. Reactive samples were characterized with FIDIS™ Connective Profile (Theradiag) for CENP B, Jo-1, Ribosomal P, Scl-70, Sm, Sm/RNP, SS-A 60, TRIM21 (SS-A 52), SS-B and U1RNP; EliA CCP (Phadia) for CCP2, QUANTA LiteⓇ Chromatin (Werfen) for Chromatin, QUANTA FlashⓇ DFS70* (Werfen) for DFS70, Anti-dsDNA-IgG-ELISA (DRG) for dsDNA, and Immunodot (Euroimmun) for RNA polymerase III (RNAP III). For CCP2, only reactive samples were included. For the remaining analytes, non-reactive samples were characterized using immunofluorescence (ANA-Ro IgG FLUORESCENT HEp-2000Ⓡ; Immuno Concepts, Germany) and ANAscreen ELISA (ORGENTEC-Diagnostika-GmbH, Germany). Each individual non-reactive sample was tested with the investigational device once; reactive samples were tested in duplicates. Positive percentage agreement (PPA) and negative percentage agreement (NPA) for individual analytes were calculated. For CCP2 only PPA is presented as no negative samples were included. Results: Compared with relevant devices, the investigational prototype showed PPA ranging from 75% for chromatin to 99% for SS-A 60 and TRIM21. NPA ranged from 95% for chromatin, RNAP III, Scl-70 and Sm to 100% for DFS70, SS-A 60 and TRIM21. Performance details are shown in the Table. Conclusions: The investigational prototype demonstrated substantial agreement with the compared CE-marked devices. Further studies will allow for expanded performance assessment of the investigational device. This fully-automated multiplexed platform has the potential to contribute to optimizing CTD evaluation by simplifying complex testing pathways and analyzing large number of samples per day.