Immunologic findings in the newborn infant. II. Studies of humoral immunity, reference values of immunologic studies in the newborn infant

After dealing with cellular immune aspects in the first part of the paper the authors describe in the second part the state of humoral immunity in healthy full-term newborns aged one to three days. The number of complementreceptor lymphocytes was 17.0 +/- 8.9% or 0.75 +/- 0.51 (mean +/- S.D.) respectively, with the EAC-rosette method. The percentage value equalled that of adults but the absolute count is higher. Using the immunodiffusion method IgA was detectable in 4 out of 132 newborns only 8.86 +/- 2.52 g/l (mean +/- S.D.) was measured as an average IgG concentration. With regard to the IgM content the values often exceeded 0.30 g/l in newborns of mothers who had been suffering from pre-eclampsia. Their mean value of 0.35 +/- 0.21 g/l, too, was significantly higher than 0.13 +/- 0.08 in the resting infants. Raised IgM values frequently coincided with high spontaneous transformation activities in lymphocyte cultures. The possible causes are discussed. Complement C3-component was measured on average with 0.78 +/- 0.18 g/l and C4-component with 0.34 +/- 0.11 g/l. When calculating reference values for newborns the results of infants with maternal pre-eclampsia have been omitted.