Changes of serum gamma globulin levels with age are described in a group of 140 normal infants from birth to 2 years of age.
The mean cord blood level of gamma globulin is significantly higher than the level in the mother's blood. This relation is, however, by no means constant in the individual pairs, as one-third of the 28 pairs showed the opposite relationship.
The gamma globulin level drops soon after birth, reaching about one-third of the birth value at 1 month of age. After very little change between 1 and 3 months, the levels start to rise and adult values are closely approximated by 2 years of age.
Breast-fed newborns show as rapid a decrease in gamma globulin levels as do artificially fed newborns. Colostrum does not, therefore, seem to contribute significantly to the serum gamma globulin levels in humans.
The above described changes in serum gamma globulin levels with age appear to be different in direction, timing, and extent, from changes observed in the other serum protein fractions.
The decrease of serum gamma globulin in the first month of life has the characteristics of a simple exponential decay. Comparison of this decay curve with that of passively acquired antibodies, and consideration of available data on gamma globulin turnover rates, warrant the hypothesis that there is practically no gamma globulin formation in the first month of life.
- Received February 17, 1955.
- Accepted May 5, 1955.
- Copyright © 1955 by the American Academy of Pediatrics