A-107 Sample Matrix Matters: A Precision Study of BioRad, TechnoPath, and Patient Pooled Samples Across 20 High Volume Chemistries and Immunoassays

Abstract

Background BioRad is a major provider of QC materials in the US with robust peer data, and Technopath has emerged as a recent competitor, especially on cost. While many factors are considered when selecting QC materials, primary considerations include commutability, matrix effects, decision levels, and acceptability limits. A couple studies comparing BioRad and Technopath QC performance were published in recent years. However, none have compared performance to patient-pooled samples. We undertook a comparison of BioRad/Technopath QC performance, with the addition of patient-pooled samples in order to assess potential matrix effects. Methods We compared precision for 20 high-volume chemistry/immunoassay tests (Table 1) across two levels of BioRad and Technopath QC and a patient pooled sample over 7 days on 2 Abbott Alinity-i and 4 Alinity-C instruments. Each immunoassay control level was run 5 times/day across 10 tests and 7 days per instrument, (i.e., 700 results/level), and the same for chemistry controls (1,400 results/level). Lithium-heparin plasma patient-pool was prepared by obtaining sufficient volume and preparing daily frozen aliquots (i.e., 1400 immunoassay and 2800 chemistry results). Results BioRad and Technopath Chemistry QCs were highly comparable with all levels demonstrating <1% CV difference. Notably, CO2, B12, FT4 pooled-patient CVs were >2% lower than the best performing high control. Additionally, greater differences in performance were observed across immunoassay controls with high BioRad QC performing better for 7 tests. Conclusions Chemistry QC for Technopath and BioRad are largely comparable (i.e., CV differences <1%). Overall, BioRad immunoassay control performance was slightly to somewhat better (i.e., B12, CA125, and CA15-3). B12 and CO2 were particularly unstable (as reflected by patient-pool CVs). That said, differences in performance were not untenable and could be handled based on a tailored approach of extending QC limits if assay/instrument performance allows, and/or changing control material or reagents on a tighter schedule.