Performance assessment of a fully automated electro-chemiluminescence immunoassay system for serum S100B protein

The altered expression levels of S100 proteins can lead to four different categories of diseases: diseases of the heart and of the central nervous system, inflammatory disorders and cancer. Various studies have shown the lack of harmonization of the results obtained with different methods, mainly due to different performances and measurements of S100B. The purpose of this work was to compare quantitatively the fully automated Elecsys® immunoassay with the reference immunoenzimatic method CanAg® EIA for serum S100B protein. In the study serum samples were analyzed of 161 patients: 85 females (aged 22-83 years) and 76 males (aged 16-90 years), affected by oncological and non-oncological pathologies. Passing–Bablok regression was used to analyze the comparison between the assays; it showed a strong interassay correlation: r = 0.9350 (95% CI =0.9122 – 0.9520), with an intercept of 0.02063 (95% CI=- 0.02850 – 0.01400) and a slope of 1.1125 (95% CI=1.0200 – 1.2417). Elecsys® S100 assay should be preferred to CanAg® S100 for better standardization, good reliability and precision but also with the aim to reduce costs and obtain results in a shorter time.