Regulatory Τ-cell differentiation between maternal and cord blood samples in pregnancies with spontaneous vaginal delivery and with elective cesarian section.

PROBLEM: The immunological mechanisms preventing fetal antigenic rejection during normal pregnancy and the extent to which the type of delivery influences lymphocyte reactions are elusive.

METHOD OF STUDY: Maternal peripheral blood and neonatal umbilical cord blood (CB) was collected upon labor after vaginal delivery or cesarian section. Leukocytes were analyzed with flow cytometry, focusing on regulatory and γ/δ T-cells.

RESULTS

In CB from neonates delivered by vaginal delivery, natural killer cells were increased. On the other hand, in maternal blood, γ/δ T-cells were increased, and activated T-cells (cluster of differentiation [CD]4+/25(dim) /122+ cells) were decreased. Moreover, maternal blood presented increased levels of T regulatory cell subsets like CD4+/25(high) /45RO+, CD4+/25(high) /DR+, CD4+/25(high) /CD38+ and CD4+/25(high) /71+. In CB, CD19+, CD4+/25(high) /45RA+ and CD4+/25(high) /122+ cells were increased.

CONCLUSION

The effect of delivery type on lymphocyte immunophenotype was minimal. Mothers' and neonates' lymphocyte subsets differed significantly. Mothers' phenotype comprised significantly of lymphocytes involved in tolerance (memory and activated regulatory T-cells, γ/δ T-cells).