[Phenotyping of peripheral lymphocytes with monoclonal antibodies in newborn infants and adults]

The authors investigated and compared lymphocyte subsets natural killer in 33 newborns and in 33 healthy adults. From 5 ml of heparinized venous blood were separated mononuclear cells on density-gradient Ficoll-Hypaque. The vitality was determined with immunofluorescent method (orange acridine and ethiobromide). It was positive if resulted at least 95%. Lymphocyte phenotype was also examined after incubation with monoclonal antiserum Becton-Dickinson conjugated with FITC and PE for 45' at 4 degrees C. Two hundred cells were counted on each slide with fluorescent microscopy. Total number of T-lymphocyte (Leu-4) was increased in newborns; total B-cells (Leu-12) were similar in newborns and healthy adults; T-helper/T-suppressor (Leu-3a/Leu-2a) ratio was above the normal range for increase T-helper. The percentage of subsets with double marker Leu-2a+/Leu-3a+ was always about 15-20%. NK cells with phenotype HNK-1 (Leu-7) were a little number in newborns while the percentage of NK-cells-Leu-11a was similar among adults and newborns.