Age-specific reference intervals for routine biochemical parameters in healthy neonates, infants, and young children...

Area of Science:

• Clinical Biochemistry
• Pediatric Laboratory Medicine
• Reference Interval Establishment

Background:

• Reference intervals (RIs) are crucial for interpreting laboratory results, especially in pediatric populations experiencing dynamic physiological changes.
• Limited data exists for key biomarkers in healthy neonates and infants, particularly within the Iranian population.
• Accurate RIs are essential for diagnosing and managing diseases in early life.

Purpose of the Study:

• To determine age-specific reference intervals for seven common biochemical parameters in Iranian neonates and infants.
• To address the critical gap in established RIs for pediatric populations.
• To improve the clinical interpretation of blood test results in young children.

Main Methods:

• A cross-sectional study involving 344 pediatric participants aged 3 days to 30 months.
• Serum levels of creatinine, urea, uric acid, calcium, phosphate, vitamin D, and high-sensitivity C-reactive protein (hs-CRP) were measured.
• Age-specific RIs were determined using CLSI guidelines (Ep28-A3 and C28-A3).

Main Results:

• No sex partitioning was required for any biomarker.
• Age partitioning was necessary for kidney function tests (urea, creatinine) and phosphate.
• Serum urea and creatinine increased with age; phosphate and uric acid decreased with age.
• Serum calcium, vitamin D, and hs-CRP showed no significant age-related changes.

Conclusions:

• Established age-specific RIs for 7 biochemical markers in Iranian children, from neonates to 30 months.
• These RIs reflect biochemical changes during growth and development, aiding clinical interpretation.
• The findings provide valuable data for clinical laboratories and disease management in pediatric populations.