Infant Reference Intervals-Steps Towards Improving the Supportive Data for Result Interpretation

Area of Science:

• Pediatric Laboratory Medicine
• Clinical Chemistry
• Biomarker Analysis

Background:

• Accurate interpretation of blood test results requires comparative data, with reference intervals being a key concept.
• Infant biomarker levels change rapidly due to development and growth, necessitating age-specific reference data.
• Conventional methods for establishing reference intervals have limitations, including extensive blood sampling requirements.

Purpose of the Study:

• To summarize the current state of reference intervals, with a specific focus on infant populations.
• To highlight the limitations of existing reference interval methodologies in pediatrics.
• To explore emerging approaches and recent data for establishing infant reference intervals.

Main Methods:

• A literature review of reference percentiles for infants (birth to 12 months) published from 1950 to 2024.
• Searched for terms including pediatric, infant, and neonatal reference intervals.
• Investigated current clinical reference interval data by examining three routine biomarkers on seven Nordic laboratory websites.

Main Results:

• Infant biomarker levels exhibit rapid changes during development and growth.
• New methods using trimmed laboratory data are emerging, but require verification to avoid modeling pathological data.
• Recently published Nordic reference interval data, based on healthy infants at specified time points, show promise.

Conclusions:

• Infant reference interval methodology demands careful consideration due to developmental changes.
• Heterogeneity in current infant reference interval practices necessitates further methodological research.
• Harmonization activities and software development are crucial for improving infant reference interval concepts.