Phenotypic characterization of mononuclear blood cells from pregnant Gabonese and their newborns.

OBJECTIVES

As many studies have analysed the immunological phenotype of either neonatal cord or maternal blood during pregnancy, but few have compared paired maternal and neonatal samples, we designed and conducted such a study in a Central African setting.

METHODS

We used flow cytometric analyses with blood samples from pairs of Gabonese mothers and their newborns to determine the cellular composition of mononuclear cells as well as the activation status of T and B lymphocytes and antigen-presenting cells.

RESULTS

The results indicate higher activation levels of neonatal cells involved in the first-line defence against pathogens such as natural killer cells, while the neonatal T- and B-cell compartment as well as the neonatal monocyte subpopulations shows a less mature phenotype.

CONCLUSIONS

Our findings likely reflect a specific neonatal defence mechanism that compensates for otherwise poorly developed immune responses at birth, especially important in an area with a high burden of infectious agents such as Gabon. The data contribute to the establishment of reference values for the mother-neonate relationship in African regions that have similar environmental characteristics.