Preanalytical, analytical, gestational and pediatric aspects of the S100B immuno-assays.

BACKGROUND: Traumatic brain injury management is a tricky issue in children and pregnant women (due to adverse effects of computer tomography). To facilitate management, we report the main analytical performances and reference ranges for blood tests for the well-established S100B biomarker in under-16 children on a DiaSorin® Liaison XL analyzer and in pregnant women on DiaSorin® Liaison XL and Roche Diagnostics® Cobas e411 analyzers. METHODS: Serum S100B concentrations were determined by chemiluminescent immunoassay on a DiaSorin® analyzer in a population of 409 healthy children aged 0-16 years and on DiaSorin®/Roche Diagnostics® instruments in a population of 50 pregnant women (one blood sample for each trimester). The analytical performances of both instruments and the influence of blood cells and skin pigmentation on the assay were also studied. RESULTS: For children, four age-groups emerged, i.e. 0-3 months (mean: 0.97 µg/L; standard deviation (SD): 0.36; 95th percentile: 1.55), 4-9 months (mean: 0.58 µg/L; SD: 0.30; 95th: 1.18), 10-24 months (mean: 0.31 µg/L; SD: 0.12; 95th: 0.54) and 2-16 years (mean: 0.20 µg/L; SD: 0.07; 95th: 0.32). For pregnant women, serum S100B concentrations were similar to defined ranges for adults and not significantly different between trimesters on DiaSorin® (p=0.652)/Roche Diagnostics® (p=0.877) analyzers. We also found S100B expression (protein, total mRNA) in lymphocytes, an influence of skin pigmentation, and good analytical performances for both instruments. CONCLUSIONS: Data provided here is useful for interpreting serum S100B test results, in terms of preanalytical conditions, analytical performances, pediatric and pregnancy' environment.