B-056 Performance Characteristics of a New, Fully Automated Planar Microarray Immunoassay for the Detection of IgG Auto-Antibodies Against Centromere Protein B (CENP-B)

Abstract

Abstract Background Detection of auto-antibodies against Extractable Nuclear Antigens (ENA), including CENP-B, is key in identification of autoimmune (AI) diseases. Many current test methods are manual, slow, labor intensive or do not facilitate the simultaneous detection of several auto-antibodies, that could reduce time to provide comprehensive results to clinicians. We report the performance characteristics of MosaiQTM CENP-B (Quotient Suisse, Eysins, CH), a new planar microarray immunoassay designed for use with the fully automated, continuous random access, high throughput MosaiQ system for qualitative serological detection of CENP-B IgG auto-antibodies. CENP-B assay is one parameter of a multiplexed MosaiQ connective tissue disease panel in development. Methods MosaiQ CENP-B microarrays were prepared by printing CENP-B antigens onto epoxy-silane glass chips and assembled into magazines for processing on the MosaiQ 125 instrument (Fig. 1). Primary patient serum tubes and reagents are loaded on the instrument and automatically processed to generate immunoassay spot signals, interpreted by the instrument using a proprietary image analysis algorithm. Anonymized human serum samples (Hôpital Pitié Salpetrière, Paris, France), characterized as CENP-B auto-antibodies non-reactive or reactive with ≥1 CE-marked devices, were included in the study. Results After discordant analysis, MosaiQ system correctly identified 96/99 samples characterized as reactive by comparators and all 199 non-reactive samples: positive percent agreement 97.0% (95% CI, 91.4%, 99.4%), negative percent agreement 100% (95% CI, 98.2%, 100%), overall percent agreement 99% (95% CI, 97.1%, 99.8%). A reproducibility and repeatability evaluation showed, respectively, overall agreement of 99.7% and 100%. Conclusion MosaiQ CENP-B microarray provides a high level of clinical concordance with other CE-marked assays for detecting CENP-B auto-antibodies. The MosaiQ System has the potential to advance AI disease testing by increasing laboratory efficiency and productivity, with the ability to multiplex the detection of various auto-antibodies on a single microarray, and a capacity to automatically process thousands of samples per day.