All issues > Volume 38(11); 1995

Original Article

J Korean Pediatr Soc. 1995;38(11):1476-1485. Published online November 15, 1995.

Concentrations and Placenta Transferability of Subclasses of IgG in Newborn Infants with Gestational Age

Gyung Hee GH Kim¹

¹Department of Pediatrics, Ewha Woman`s University, College of Medicine, Seoul, Korea

Abstract

Purpose
: The object of this study was to investigate concentration and placental transfer of IgG subclasses in greater detail and examine the effect of gestational age.
Methods
: The concentration of IgGl. IgGz. IgG3 and IgG4 were estimated in 119 pairs of maternal and cord sera from pregnancies of various gestation ranging from 32 to 43 weeks using the method of E.I.A.
Results
: 1) All subclasses of IgG crossed the human placenta fully. 2) Levels of subclasses of IgG exceed maternal levels in all pregnancies. 3) The transferability of each IgG subclasses is IgG1≥IgG3>IgG4>IgGz. 4) This was significant rise in IgGl concentration with gestational age and birth weight. 5) The transferability of IgG4 is a significant rise with gestational age and birth weight. 6) The sex did not effect the concentrations of IgG subclasses.
Conclusion
: This study suggests that each subclasses of IgG passes from mother to fetus via the placenta by an active transport passes and fetal concentration of IgG subclasses approximate to maternal concentration beyond 32 weeks of gestation. All IgG subclasses were sufficiently transferred from mother to fetus after 32 weeks of gestation, which is so enough as to provide passive immunity to wide range of potential pathogens in newborns. We have to investigate the subclasses of IgG in the extremly preterm baby and high risk pregnancies.

Keywords :IgG subclasses, Placenta transferability, Gestational age