Influence of age and sex on serum complement components in children

Area of Science:

• Immunology
• Pediatric Medicine
• Biochemistry

Background:

• The complement system is crucial for innate and adaptive immunity.
• Establishing normative data for complement components in children is essential for accurate diagnosis and monitoring.
• Previous studies have not comprehensively analyzed age- and sex-specific complement component concentrations in a large pediatric cohort.

Purpose of the Study:

• To determine the concentrations of eight key complement components in healthy children.
• To investigate the correlation between complement component concentrations and age in pediatric populations.
• To identify potential sex-specific differences in these correlations.

Main Methods:

• Sera from 419 healthy children (198 boys, 221 girls) aged 1–19 years were analyzed.
• Concentrations of eight complement components (C1q, C1s, C4, C3, C5, factor B, properdin, and C1 inhibitor) were measured.
• Statistical analyses were performed to assess correlations with age and sex.

Main Results:

• Significant correlations between complement component concentrations and age were observed in girls for all eight components.
• In boys, significant age-related correlations were found for C1q, C4, C3, C5, and properdin.
• These results indicate age-dependent variations in complement component levels in children, with some sex-specific patterns.

Conclusions:

• Age is a significant factor influencing serum complement component concentrations in children.
• Normal reference ranges for complement components in pediatric populations should account for age and potentially sex.
• These findings contribute to a better understanding of pediatric immune system development and provide a basis for improved clinical interpretation.