Cytochemical leukocyte reactions in normal children

Area of Science:

• Hematology
• Clinical Chemistry
• Pediatrics

Background:

• Cytochemical reactions are vital for diagnosing various pediatric conditions.
• Understanding age-related variations in these reactions is crucial for accurate interpretation.
• Established reference ranges for adults and older children exist, but pediatric data, especially for infants, requires further elucidation.

Purpose of the Study:

• To evaluate the age-specific performance of five common cytochemical reactions (MPO, PAS, LAP, SB, EST) in children.
• To compare cytochemical reaction values in different pediatric age groups (infants, toddlers, young children) and with adult values.
• To identify significant variations in cytochemical profiles between newborns and older children.

Main Methods:

• The study analyzed five cytochemical reactions: Myeloperoxidase (MPO), Periodic Acid-Schiff (PAS), Leukocyte Alkaline Phosphatase (LAP), Sudan Black (SB), and Esterase (EST).
• A cohort of 180 children aged 1 month to 6 years was divided into three age groups: <12 months, 1-3 years, and 3-6 years.
• Cytochemical reaction values were compared across these pediatric age groups and with established adult reference ranges.

Main Results:

• No significant differences were observed in the mean values of MPO, PAS, LAP, SB, and EST between the pediatric age groups (1 month to 6 years) and adults.
• Newborn children demonstrated notable differences compared to older children and adults, including a significant decrease in LAP activity.
• Conversely, newborn neutrophils showed increased SB, EST, and PAS positivity, indicating distinct developmental changes in these enzymatic and cytochemical markers.

Conclusions:

• The studied cytochemical reactions (MPO, PAS, LAP, SB, EST) exhibit relatively stable profiles in children from 1 month to 6 years, mirroring adult values.
• Significant variations in LAP, SB, EST, and PAS are characteristic of the newborn period, highlighting developmental hematopoiesis.
• These cytochemical tests are valuable diagnostic tools for investigating inborn metabolic errors, chromosomal anomalies, hematological diseases, and immune system defects in children.