Selective transfer of maternal antibodies in preterm and fullterm children

Area of Science:

• Immunology
• Neonatal Medicine
• Maternal-Fetal Health

Background:

• Preterm newborns face higher infectious disease risks compared to full-term infants.
• The reasons for this vulnerability, whether due to compromised immune development, remain unclear.
• Understanding maternal-fetal antibody transfer is crucial for neonatal immunity.

Purpose of the Study:

• To investigate differences in maternal-fetal antibody transfer profiles between preterm and full-term infants.
• To assess the quantity and functional quality of specific antibodies from birth through 12 weeks.
• To elucidate placental transfer mechanisms and their impact on neonatal immunity.

Main Methods:

• Assessed 24 vaccine-, pathogen-, and antigen-specific antibodies in 11 preterm and 12 full-term maternal:infant pairs.
• Measured antibody levels and functional quality (Fc-receptor binding) from birth to 12 weeks.
• Analyzed temporal transfer patterns and identified specific antibody types transferred early.

Main Results:

• Full-term newborns had higher total IgG levels for several key antigens (influenza, pneumococcus, measles, rubella, EBV, RSV).
• Preterm newborns showed selective transfer of Fc-receptor binding antibodies.
• Despite quantitative differences, antibody-effector functions were comparable between preterm and full-term infants.
• Early transfer of FcRn, FcγR2, and FcγR3 binding antibodies indicated differential placental sieving.

Conclusions:

• Placental transfer mechanisms are selective based on gestational age.
• This selectivity ensures robust humoral immunity in infants, even those born preterm.
• The functional quality of transferred antibodies, not just quantity, is critical for neonatal defense.