Affiliation:
1. CALIPER Program, Department of Pediatric Laboratory Medicine, Hospital for Sick Children, and
2. Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
3. Abbott Diagnostics, Abbott Park, Chicago, IL
Abstract
BACKGROUND
Reference intervals are indispensable in evaluating laboratory test results; however, appropriately partitioned pediatric reference values are not readily available. The Canadian Laboratory Initiative for Pediatric Reference Intervals (CALIPER) program is aimed at establishing the influence of age, sex, ethnicity, and body mass index on biochemical markers and developing a comprehensive database of pediatric reference intervals using an a posteriori approach.
METHODS
A total of 1482 samples were collected from ethnically diverse healthy children ages 2 days to 18 years and analyzed on the Abbott ARCHITECT i2000. Following the CLSI C28-A3 guidelines, age- and sex-specific partitioning was determined for each analyte. Nonparametric and robust methods were used to establish the 2.5th and 97.5th percentiles for the reference intervals as well as the 90% CIs.
RESULTS
New pediatric reference intervals were generated for 14 biomarkers, including α-fetoprotein, cobalamin (vitamin B12), folate, homocysteine, ferritin, cortisol, troponin I, 25(OH)-vitamin D [25(OH)D], intact parathyroid hormone (iPTH), thyroid-stimulating hormone, total thyroxine (TT4), total triiodothyronine (TT3), free thyroxine (FT4), and free triiodothyronine. The influence of ethnicity on reference values was also examined, and statistically significant differences were found between ethnic groups for FT4, TT3, TT4, cobalamin, ferritin, iPTH, and 25(OH)D.
CONCLUSIONS
This study establishes comprehensive pediatric reference intervals for several common endocrine and immunochemical biomarkers obtained in a large cohort of healthy children. The new database will be of global benefit, ensuring appropriate interpretation of pediatric disease biomarkers, but will need further validation for specific immunoassay platforms and in local populations as recommended by the CLSI.
Publisher
Oxford University Press (OUP)
Subject
Biochemistry, medical,Clinical Biochemistry
Reference40 articles.
1. IMMULITE 2000 age and sex-specific reference intervals for alpha fetoprotein, homocysteine, insulin, insulin-like growth factor-1, insulin-like growth factor binding protein-3, C-peptide, immunoglobulin E and intact parathyroid hormone;Soldin;Clin Biochem,2008
2. Comparison of FT4 with log TSH on the Abbott Architect ci8200: pediatric reference intervals for free thyroxine and thyroid-stimulating hormone;Soldin;Clin Chim Acta,2010
3. Pediatric reference ranges for creatine kinase, CKMB, Troponin I, iron, and cortisol;Soldin;Clin Biochem,1999
4. Closing the gaps in pediatric laboratory reference intervals: a CALIPER database of 40 biochemical markers in a healthy and multiethnic population of children;Colantonio;Clin Chem,2012
5. R Core Team. R: a language and environment for statistical computing. http://www.R-project.org/ (Accessed January 2013).