Journal of Clinical Immunology

, Volume 13, Issue 2, pp 145–151

Half-life of the maternal IgG1 allotype in infants

  • H. Sarvas
  • I. Seppälä
  • S. Kurikka
  • Rita Siegberg
  • O. Mäkelä
Original Articles

DOI: 10.1007/BF00919271

Cite this article as:
Sarvas, H., Seppälä, I., Kurikka, S. et al. J Clin Immunol (1993) 13: 145. doi:10.1007/BF00919271

Abstract

The residence time of maternal IgG1 in the circulation of infants was measured by monitoring f-allotypic IgG1 or f-positive tetanus toxoid antibody in geneticallyG1mf-negative infants.G1ma-positive maternal tetanus toxoid antibody was similarly monitored in genetically a-negative infants. Blood samples were taken from infants at the age of 1–3 days, ca. 4 months, and ca. 6 months. An exponential decay at the same rate took place from age 1–3 days to 4 months and for the 2 subsequent months. The average concentration of the maternal IgG1 had dropped to ca. 10% of the 1- to 3-day value in 4 months and to ca. 3% in 6 months. The drop was due mainly to clearance but partly also to the weight increase of the child (doubling in 6 months). By correcting for the weight increase, we calculated that ca. 17 and 7% of the original maternal IgG1 was still present at ages 4 and 6 months, respectively. The average half-life of the maternal IgG1 was thus 48.4 days. The concentration of endogenous IgG1 in the cord blood was determined by studying a separate series of mother-newborn pairs. Assuming that cross-reactions of antiallotype reagents had no effect, the highest measured concentration of f-positive IgG1 in infants of f-negative mothers was 10 mg/L, half a percent of adult heterozygote values. Crossreaction may have played a role, however, and the value must be considered the upper limit of the true concentration.

Key words

Half-lifeIgGGm allotypes

Copyright information

© Plenum Publishing Corporation 1993

Authors and Affiliations

  • H. Sarvas
    • 1
  • I. Seppälä
    • 1
  • S. Kurikka
    • 2
  • Rita Siegberg
    • 3
  • O. Mäkelä
    • 1
  1. 1.Department of Bacteriology and ImmunologyUniversity of HelsinkiHelsinkiFinland
  2. 2.National Public Health InstituteHelsinkiFinland
  3. 3.Department I of Obstetrics and GynecologyHelsinki University Central HospitalHelsinkiFinland