Normal Pregnancy is Associated with Peripheral Leukocyte Activation

PROBLEM: Normal pregnancy has been described as both a pro-inflammatory condition and a T helper (Th)2-dominated state. Deviations in the percentage of different subpopulations of circulating leukocytes have been detected, although with conflicting results. This study was designed to analyse further the phenotype of subpopulations of peripheral blood leukocytes in normal pregnant women. METHOD OF STUDY: Whole-blood flow cytometry was used to differentiate subsets of leukocytes using directly labeled monoclonal antibodies to specific cell surface antigens and to a panel of activation-associated markers in 33 normal pregnant women in their third trimester and in 26 non-pregnant controls. RESULTS: We found a significant increase in the proportion of granulocytes and of CD8+ T lymphocytes during pregnancy. Up-regulation of the expression of adhesion molecules was observed on granulocytes, monocytes and T lymphocytes. CONCLUSIONS: Pregnancy alters the representation of leukocyte subpopulations in the maternal circulation and is associated with systemic activation of leukocytes.