[Immunological competence of newborns. Investigations into distribution of different lymphocyte populations and their-function in umbilical blood].

Lymphocyte populations were examined in the umbilical blood of 100 healthy newborns and the findings were compared with those obtained in 50 healthy adult subjects. It was established that there was a lower percentage of T-cells in the umbilical blood (20%) than in the peripheral blood of adults (40%). The proportion of B-cells in the umbilical blood (28%) was higher than in adult blood (15%). The absolute counts of both cell populations were higher in the newborns' blood than in that of the adults. This admits the conclusion that the infant organism is well prepared to counteract immunogenic stimuli in the environment effectively following birth. The results of stimulation of lymphocyte cultures from newborns with mitogens produced generally parallel behavior patterns both for the adult and for the newborn group. However, when the two test groups were compared with each other in respect of the mitogens PHA and ConA, the curve for the newborn group was shifted to the left, toward lower mitogen doses. When assayed with an optimal dose of PWM, the transformation rate in the newborn group was approx. twice as high as that in the adult group. Awareness of these conditions in healthy newborns permits early recognition and timely treatment of disorders of the immune system immediately after birth.