IMMUNOGLOBULIN DEVELOPMENT DURING FIRST YEAR OF LIFE - A LONGITUDINAL STUDY

In 33 infants repeated blood samples were taken during the first year of life for determination of the different immunoglobulins. The infants were divided into groups according to their histories of infection. These groups were compared with each other and, as also was the series as a whole, with a series of children investigated previously from a Baby Welfare Centre (BWC). A distinct relationship was found between the infants' histories of infection and their immunoglobulin development. The history of infection appeared to be reflected predominantly in the serum concentrations of IgA and IgM, and to a lesser extent in their IgG levels. The initial IgG concentration appeared to be of little importance for the IgG development after the first weeks of life. The infants who had the highest IgG levels at birth showed a significantly more rapid decrease in their IgG concentrations during the first 6 weeks of life than those with the lowest initial IgG levels. This finding may possibly indicate a later start of their own synthesis of IgG in infants who have a high serum concentration of maternal IgG at birth. The infants exhibited a very early capacity for IgM synthesis and the mean IgM curve rose steeply during the first two weeks of life, subsequently becoming flatter. The infants with recurrent infections of different kinds showed, on the average, twice as high IgM concentrations at the age of 1 year as the children in the previously reported BWC series. The IgA development took place considerably more slowly than that of IgM, but at the age of 1 year the infants with recurrent infections had, however, on the average, more than twice as high IgA concentrations as the children in the BWC series. On comparing this longitudinally studied series of infants in its entirety with the previous BWC series, which can be regarded as selected from the point of view of infection, the former series was found to show a more rapid development of the IgG, IgA and IgM levels during the first year of life. Copyright © 1969, Wiley Blackwell. All rights reserved