B, T and null lymphocytes in newborn infants and their mothers.

Estimation of B, T and null cells were performed on 29 newborn healthy babies and 16 mothers. The lymphocytes were isolated from peripheral venous blood, which is considered to be more representative of the immune state in the newborn than the cord blood. B lymphocytes were estimated by cytofluorometric measurements, T lymphocytes by sheep red blood cell rosette technique, (SRBC-R). Combined immunofluorescence and SRBC-R technique revealed the null cells. In the newborn babies the amount of B and T cells were found to be diminished. In the mothers the amount of B lymphocytes were low compared with normal adults. The rather high null cell percentage found in the babies might represent immature precursor cells. Mothers seem to be immuno-depressed as reflected in the low amount of B cells.