[Evaluation of CD3+/TCR-alpha-beta and CD3+/TCR-gamma-delta lymphocytes in umbilical cord blood].

The neonate's immune system is immunocompetent, but because of the "virgin" status, the immune system do react differently to antigens and is less efficient. The aim of the study was to determine the relative and absolute numbers of CD3+/TCR alpha beta and CD3+/TCR gamma delta lymphocytes in the umbilical blood. The examinations comprised 26 full term neonates and 41 preterm ones. The immunophenotyping analysis was performed using an FACScan flow cytometer and anti- TCR alpha beta, anti- TCR gamma delta monoclonal antibodies (Becton Dickinson). The mode of delivery did not influence significantly the value of CD3+/TCR alpha beta lymphocytes. The elective cesarean section influenced significantly on the decrease of relative and absolute number of CD3+/TCR gamma delta lymphocytes in neonates. Low absolute number of CD3+/TCR gamma delta lymphocytes was observed in the preterm infants born after preterm placenta separation and preterm rupture of membranes. The immune system of the newborn infant is immature and hyporesponsive when compared with adults. Neonates are more susceptible to infection than adults, and exhibit more severe or prolonged symptoms when infected.