Dynamic biological changes in metabolic disease biomarkers in childhood and adolescence: A CALIPER study of healthy community children.

Background: Understanding age- and sex-specific biological changes in metabolic disease biomarkers is essential for their appropriate utilization in management of children with inborn errors of metabolism (IEM). The CALIPER program aimed to establish pediatric reference values in healthy community children for common metabolic biomarkers and determine the effects of key covariates including age and sex across the pediatric age.

Methods: A cohort of 500 healthy children and adolescents from birth to 19years were initially recruited to establish pediatric reference intervals according to the CLSI C28-A3 guidelines.

Pediatric reference value distributions for vitamins A and E in the CALIPER cohort and establishment of age-stratified reference intervals.

Objectives: Vitamin A (retinol) and vitamin E (α-tocopherol) are fat soluble micronutrients most commonly measured in the pediatric population to monitor deficiencies due to malabsorption secondary to gastrointestinal (GI) disorders. One of the major challenges of vitamin A and E testing is the lack of reliable pediatric reference intervals which limits accurate interpretation of results. Here we report new pediatric reference intervals (RI) for both vitamins as part of the Canadian Laboratory Initiative for Pediatric Reference Intervals (CALIPER).

Analytical measurement of serum 25-OH-vitamin D₃, 25-OH-vitamin D₂ and their C3-epimers by LC-MS/MS in infant and pediatric specimens.

Objectives: To develop a simple and sensitive LC-MS/MS procedure for quantification of serum 25-OH-vitamin D₃ (25-OH-D₃), 25-OH-vitamin D₂ (25-OH-D₂), and their C3-epimers.

Methods: Serum 25-OH-vitamin D metabolites were extracted with MTBE and quantified by LC-MS/MS. Commercially available calibrators and QC materials were employed.

Analytical performance and workflow evaluation of the Roche E170 modular immunoassay analyzer in a pediatric setting.

Objectives: To evaluate the analytical performance of the Roche E170 modular analytics immunoassay analyzer and assess its impact on workflow efficiency and ability to consolidate workstations in a pediatric setting.

Design And Methods: Analytical performance of eleven common immunoassays was assessed. Total imprecision was determined using Roche PreciControl Universal controls, Bio-Rad Lyphochek Immuno Plus, Anemia controls, and a human serum pool.