Transient, marked, unexplained elevation of serum alkaline phosphatase

Area of Science:

• Pediatric Endocrinology
• Biochemistry
• Clinical Diagnostics

Background:

• Elevated serum alkaline phosphatase (SAP) in children can indicate various underlying conditions, necessitating careful diagnosis.
• Distinguishing benign from pathological causes of SAP elevation is crucial for appropriate patient management.

Observation:

• Five young children (16-38 months) presented with SAP levels 7-30 times the upper limit of normal.
• Skeletal origin was suggested for the elevated enzyme, with no other clinical abnormalities identified.
• SAP levels spontaneously normalized in all observed cases.

Findings:

• A retrospective review of 74 children with lymphoblastic leukemia revealed only four instances of similar transient, isolated SAP elevation.
• This review encompassed 661 patient-years and 2,417 enzyme measurements, highlighting the rarity of this specific finding.
• Benign, transient hyperphosphatasemia is a rarely recognized clinical entity.

Implications:

• Recognition of benign, transient hyperphosphatasemia can prevent extensive and potentially unnecessary diagnostic workups.
• Increased awareness among clinicians can lead to more efficient patient evaluation for elevated SAP levels.
• This condition underscores the importance of considering benign, self-limiting causes of biochemical abnormalities in pediatric patients.