Healthy pediatric platelets are moderately hyporeactive in comparison with adults' platelets

Area of Science:

• Hematology
• Pediatric Medicine
• Biochemistry

Background:

• Platelet function studies in children are limited and yield conflicting results.
• Previous research has inconsistently reported pediatric platelets as either more or less active than adult platelets.

Purpose of the Study:

• To compare platelet function across various pediatric age groups and with adults.
• To determine the age at which pediatric platelet function reaches adult levels.

Main Methods:

• Evaluated platelet function using collagen-related peptide (CRP), PAR-1 activating peptide SFLLRN, PAR-4 activating peptide AYPGKF, and adenosine diphosphate (ADP).
• Measured parameters including forward (FSC) and side scatter (SSC), CD42b, CD61, CD62P, PAC-1, annexin V binding, and mepacrine release.
• Included 76 healthy children and 49 healthy adult volunteers.

Main Results:

• Resting pediatric platelets were similar to adults, with minor differences in FSC and dense granule volume in younger children.
• After CRP+SFLLRN stimulation, pediatric platelets exhibited lower alpha- and dense granule release (1.2-fold and 1.1-fold, respectively).
• Reduced granular release was observed in the youngest children for SFLLRN+AYPGKF+ADP stimulation, while ADP response was identical in all groups.

Conclusions:

• Pediatric platelets demonstrate diminished granular release compared to adult platelets.
• This functional difference in platelet granular release persists in children up to 18 years of age.
• The study provides clarity on age-related platelet function in children.