Establishment of Reference Intervals for 41 Serum Biochemical Analytes in Healthy Chinese Children

Owing to the absence of appropriate pediatric reference intervals (RIs), this study attempted to establish age-specific RIs for serum biochemical analytes in healthy Chinese children. A total of 2627 residual serum samples were collected from 28 days to 17 years at Shenzhen Baoan Women's and Children's Hospital. Forty-one analytes, including enzymes, proteins, lipids, electrolytes, and others, were measured using the Mindray BS-2800M analyzer. Outlier removal and RIs establishment were performed according to Clinical and Laboratory Standards Institute (CLSI) EP28 guideline. Age-dependent trajectories were visualized, and RIs were compared with multicenter studies. Additionally, the pediatric patterns of estimated glomerular filtration rate (eGFR) were also evaluated by equations. Twenty-one analytes showed distinct age-dependent dynamics, including liver enzymes, prealbumin, bilirubin, immunoglobulins, renal biomarkers, cardiac enzymes, ferritin, and anti-streptolysin O. Meanwhile, electrolytes, proteins, glucose, and other anemia markers remained stable across ages. RIs for thirty-six analytes were largely consistent with comparative studies, although quantitative discrepancies were noted for triglyceride and anti-streptolysin O. In 806 children, eGFR increased rapidly during the first two years of life, with inter-formula variability. The European Kidney Function Consortium equation produced distributions pattern closest to measured ranges from comparative study. This study established comprehensive pediatric biochemical RIs for forty-one serum analytes, with twenty-one exhibiting distinct age-dependent dynamics. Comparisons with landmark studies showed good agreement for thirty-six analytes. The eGFR equation selection requires caution, particularly in young children. These RIs provide reliable evidence to support cross-regional harmonization and help reduce inappropriate use of references in children.