1 The Department of Pediatrics, College of Medicine, State University of Iowa, Iowa City, Iowa.
2 The Department of Biochemistry, College of Medicine, State University of Iowa, Iowa City, Iowa.
Electrophoretic studies of plasma proteins have been made for 54 healthy children ranging in age from birth to 17 years. Mean values for most plasma protein fractions agreed well with previously published results for normal adults and children, but changes in the relative concentration of some of the components with age were noted.
Although the percentage of albumin decreased from infancy to midchildhood and appeared to be lowest in children 5 to 11 years old, figures for absolute concentration of albumin in gm./100 ml. showed no significant decrease in albumin for this age group.
The percentage and the absolute concentration of
2-globulin were highest in infancy and decreased gradually with increasing age.
Both the percentage and the absolute concentration of
-globulin decreased from unusually high values in the newborn infant to unusually low values in infancy, then gradually increased with age to reach the normal adult level in midchildhood, 5 to 11 years of age. These changes are believed to be related to the loss of passive immunity received by the infant from its mother and the accumulation of antibodies and the development of active immunity in the child.