Reference ranges for serum alpha 1 antitrypsin

Area of Science:

• Biochemistry
• Pediatric Medicine
• Clinical Chemistry

Background:

• Alpha 1 antitrypsin (AAT) is a crucial serum protein.
• Establishing age-specific reference ranges for AAT is vital for accurate clinical interpretation.
• Previous data on AAT levels across different age groups, particularly infancy and early childhood, may be incomplete or lack standardization.

Purpose of the Study:

• To construct reliable reference ranges for serum alpha 1 antitrypsin (AAT) across various age groups.
• To compare AAT concentrations in cord blood and infancy with adult values.
• To define normative AAT levels during early school age.

Main Methods:

• Serum samples were analyzed for alpha 1 antitrypsin concentrations.
• Reference ranges were constructed using specific protein calibration material (SPS-01).
• Median values and 5th-95th centile ranges were calculated for different age cohorts, including cord blood, infancy (0-12 months), and early school age.

Main Results:

• Serum alpha 1 antitrypsin levels in cord blood were found to be equivalent to adult levels.
• A notable decrease in median AAT concentration was observed during the first six months of life.
• AAT levels returned to adult values by 12 months of age, with concentrations in early school-aged children exceeding those of normal adults.

Conclusions:

• The study provides age-specific reference ranges for serum alpha 1 antitrypsin, aiding in accurate diagnosis.
• Infant AAT levels exhibit a distinct pattern, with a transient dip in the first six months.
• Higher AAT concentrations in early school-aged children compared to adults warrant further investigation into developmental changes.