Dynamic trend in alkaline phosphatase activity in infants aged 0-12 months revealed by an indirect approach

Area of Science:

• Biochemistry
• Pediatrics
• Clinical Diagnostics

Background:

• Alkaline phosphatase (ALP) is vital for diagnosing childhood diseases, particularly metabolic bone disorders in rapidly growing infants.
• Infant ALP activity shows significant monthly variations, yet authoritative reference standards are lacking.
• Accurate ALP activity standards are needed for reliable infant disease diagnosis.

Purpose of the Study:

• To establish month-wise percentile curves for alkaline phosphatase (ALP) activity in infants aged 0-12 months.
• To provide a reliable reference standard for diagnosing diseases associated with abnormal ALP levels in infants.
• To address the lack of established ALP activity standards for infant populations.

Main Methods:

• Analysis of 24,618 infant blood samples (0-12 months) from three medical centers in Chongqing, China.
• Exclusion of infants with conditions known to affect ALP activity.
• Construction of percentile curves using MATLAB and the skewness-median-coefficient of variation method for curve fitting.

Main Results:

• Infant ALP activity peaked between 1-2 months and gradually declined thereafter, with the lowest levels at 11-12 months.
• A distinct pattern of ALP activity was observed in male and female infants.
• Chinese infants showed later peak ALP activity and a greater subsequent decline compared to German infants.

Conclusions:

• A comprehensive percentile curve for month-wise ALP activity in male and female infants was successfully constructed.
• This established curve serves as a valuable reference for diagnosing infant diseases related to abnormal ALP levels.
• The findings highlight ethnic variations in infant ALP activity, necessitating population-specific reference ranges.