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Depletion of Specific Cell Populations by Complement Depletion
06:17

Depletion of Specific Cell Populations by Complement Depletion

Published on: February 5, 2010

The complement system of the newborn infant

J H Drew, C M Arroyave

    Biology of the Neonate
    |January 1, 1980
    PubMed

    Insights

    Newborn infants have lower complement levels than adults, with preterm infants showing the lowest. Complement activation, indicated by C3 split products, is present in 54% of infected infants, aiding diagnosis.

    Area of Science:

    • Immunology
    • Neonatal Medicine
    • Biochemistry

    Background:

    • The complement system is crucial for innate immunity.
    • Complement levels in newborns are not well-established compared to adults.
    • Developmental factors influence complement component levels in neonates.

    Purpose of the Study:

    • To compare complement activity and component levels in infected and non-infected newborns.
    • To investigate the impact of prematurity and intrauterine growth retardation on complement.
    • To assess the diagnostic utility of complement activation markers in neonatal infections.

    Main Methods:

    • Measured whole complement activity (CH50) and levels of classical (C1q, C4, C3) and alternative (factor B, properdin) pathway components.
    • Analyzed complement levels in 55 non-infected and 11 infected newborn infants.
    • Detected C3 split products to differentiate developmental deficiencies from complement activation.

    Main Results:

    • Newborns exhibited lower complement levels than adults; preterm infants had significantly lower levels than term infants.
    • Complement levels were not affected by intrauterine growth retardation.
    • Absence of C3 split products suggested developmental deficiencies, while their presence in 54% of infected infants indicated complement activation.

    Conclusions:

    • Neonatal complement levels are developmentally lower than adult levels.
    • Complement activation, evidenced by C3 split products, is common in infected newborns.
    • Assessing C3 split products may improve the diagnosis of infection in neonates.

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