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.

Evaluation of a next generation direct whole blood enzymatic assay for hemoglobin A1c on the ARCHITECT c8000 chemistry system.

Background: The utility of HbA1c for the diagnosis of type 2 diabetes requires an accurate, precise and robust test measurement system. Currently, immunoassay and HPLC are the most popular methods for HbA1c quantification, noting however the limitations associated with some platforms, such as imprecision or interference from common hemoglobin variants. Abbott Diagnostics has introduced a fully automated direct enzymatic method for the quantification of HbA1c from whole blood on the ARCHITECT chemistry system.

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).