Adrenal steroids reference ranges in infancy determined by LC-MS/MS

Area of Science:

• Endocrinology
• Pediatric Medicine
• Mass Spectrometry

Background:

• Interpreting steroid hormone measurements in early infancy is challenging.
• Disorders of steroidogenesis require accurate diagnostic tools.
• Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a powerful method for steroid analysis.

Purpose of the Study:

• To develop normative data for 14 steroids and four adrenal enzyme activity indices in infants from 3 days to 6 months of age.
• To utilize LC-MS/MS for precise steroid profiling in early life.
• To establish reference ranges for accurate diagnosis of steroidogenesis disorders.

Main Methods:

• Collected plasma steroid concentrations from 324 healthy neonates and infants (151 female).
• Calculated age- and sex-specific percentile curves for steroid concentrations.
• Evaluated steroid ratios as biomarkers for adrenal enzyme activities and tested diagnostic efficiency in patients with deficiencies.

Main Results:

• Nine steroids exhibited age-specific variations, with no sex specificity observed.
• Progestin and androgen concentrations peaked at 7-14 days, decreasing significantly after the first month.
• Adrenal enzyme activities shifted towards increased cortisol production over the first six months; patients showed distinct profiles compared to healthy infants.

Conclusions:

• Most adrenal steroids display age-related changes during the neonatal period and early infancy.
• The developed normative data enable precise interpretation of steroid measurements for diagnosing disorders of steroidogenesis.
• LC-MS/MS-based reference ranges are essential for differentiating physiological changes from pathological defects in infants.