Serum S100β protein reference values in a paediatric population

Abstract Introduction S100β protein has been proposed as a potential biomarker for both chronic and acute neurological disorders. Reference values of this protein are well defined in adults but not in children, in whom serum levels appear to vary with age. Reference values for serum S100β in children from 0 to 14 years are presented. Materials and methods A prospective study was conducted on 257 healthy children, who were divided into three age groups (under 12 months, 12–24 months and over 24 months). Results The study included 179 boys and 78 girls, with a mean age of 5.5 (3.75) years. The mean serum concentration of protein S100β was 0.156 (0.140–0.172) μg/L. In children under 12 months, serum S100β concentration was 0.350 (0.280–0.421) μg/L; 0.165 (0.139–0.190) μg/L in the group between 12 and 24 months and 0.121 (0.109–0.133) μg/L in children older than 24 months. An inverse relationship was observed between age and serum S100β, which declines as age increases. No differences were observed between sexes. Conclusions The concentration of S100β remains stable after two years of age, being possible to establish a baseline of S100β for over two years. During the first two years of life, S100β serum concentration is higher, the lower the age of the child. No differences in serum S100β levels between sexes are observed.