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Published on: August 7, 2017
Determination of iFGF23 Upper Reference Limits (URL) in healthy pediatric population, for its better correct use
Vincenzo Brescia1, Antonietta Fontana1, Roberto Lovero1
1Clinical Pathology Unit, Azienda Ospedaliero-Universitaria (AOU) Policlinico Consorziale di Bari - Ospedale Giovanni XXIII, Bari, Italy.
Insights
This study establishes upper reference limits for intact Fibroblast Growth Factor 23 (iFGF23) in healthy children. These pediatric reference values aid in diagnosing and managing phosphate metabolism disorders.
Area of Science:
- Pediatric Endocrinology
- Clinical Chemistry
- Biochemistry
Background:
- Fibroblast Growth Factor 23 (FGF23) measurement is crucial for diagnosing and managing phosphate metabolism abnormalities in patients with or without chronic kidney disease (CKD).
- Existing FGF-23 assays vary significantly in the molecule measured (intact iFGF23 vs. C-terminal cFGF23), analytical performance, and reference ranges.
- Establishing reliable reference ranges, particularly for pediatric populations, is essential for accurate clinical interpretation.
Purpose of the Study:
- To determine the Upper Reference Limits (URL) for intact FGF23 (iFGF23) in apparently healthy pediatric individuals.
- To provide validated iFGF23 reference values for the DiaSorin Liaison XL automated immunochemiluminescent assay.
- To facilitate improved clinical diagnosis and monitoring of phosphate-related disorders in children.
Main Methods:
- Plasma iFGF23 levels were measured in 115 apparently healthy pediatric subjects (median age 10 years, range 1-18) using an automated immunochemiluminescent sandwich assay (DiaSorin Liaison XL).
- Statistical analysis included calculation of the 95% reference interval and right-sided upper reference limits according to CLSI C28-A3 guidelines.
- Covariables including age and sex were verified for their influence on iFGF23 concentrations.
Main Results:
- The Upper Reference Limit (URL) for iFGF23 in the studied pediatric population was determined to be 61.21 pg/mL (90% CI: 58.63 to 63.71).
- No statistically significant differences in median iFGF23 concentrations were observed when stratified by sex.
- Similarly, no significant differences were found based on age groups within the pediatric cohort.
Conclusions:
- The established iFGF23 Upper Reference Limits (URL) for the Liaison test in healthy children provide essential pediatric reference values.
- Accurate iFGF23 measurement is vital for the differential diagnosis of various rickets forms and for monitoring treatment efficacy.
- Availability of these pediatric reference values will enhance the clinical utility of iFGF23 testing in pediatric care.
Background:
The measurement of Fibroblast growth factor 23 (FGF23) may be useful in the diagnosis and management of abnormal phosphate metabolism in both patients with preserved renal function or with chronic kidney disease (CKD). FGF-23 tests differ considerably by molecule assayed (iFGF23 or cFGF23), analytical performance and reference ranges. We establish iFGF23 Upper Reference Limits (URL) in apparently healthy pediatric individuals using automated immunochemiluminescent assay.
Methods:
We measured the levels of plasma iFGF23 from 115 samples from apparently healthy pediatric subjects [59 (51.3%) individuals were male; median age 10 years (range 1-18)] included in an observational study conducted at Policlinico University Hospital of Bari. The method used for the iFGF23 assay was immunochemiluminescent sandwich assay developed by DiaSorin on the Liaison XL platform. Statistical calculation of 95% reference interval, right-sided (CLSI C28-A3) and verification of age and sex covariables was performed for the calculation of the URL.
Results:
The URL concentration of iFGF23 was 61.21 pg/mL (58.63 to 63.71, 90% CI). No significant differences were found between the median concentrations of iFGF23 differentiated by sex and age.
Conclusions:
The dosage of iFGF23 is important both for the differential diagnosis of the various forms of rickets, and for the subsequent monitoring of the effectiveness of drug treatment. We have established the URL for the iFGF23 Liaison test in apparently healthy pediatric subjects. The availability of iFGF23 pediatric reference values will allow a better clinical use of the test.
