Functional changes of human peripheral B-lymphocytes in pre-eclampsia

The aim of our study was to investigate the functional changes of human peripheral B-lymphocytes in healthy and pre-eclamptic pregnancies.

Twenty patients with pre-eclampsia and 15 healthy third-trimester pregnant women were recruited in this study. Peripheral blood mononuclear cells (PBMCs) were isolated and directly stained with fluorescein isothiocyanate (FITC)-labeled anti-CD27 monoclonal antibody (mAb) and phycoerythrin (PE)-labeled anti-CD38 mAb. The percentages of the individual B-cell subsets were estimated out of total lymphocytes by flow cytometric analysis. Additionally, the enriched PBMCs were cultured with or without the stimulation of pokeweed mitogen (PWM) for 5 days. Then morphologic observation of plasma cells was analysed by Wright-Giemsa stain, and antibody-producing cells were detected by enzyme-linked immunospot assay.

The percentage of CD27(-)CD38(-) naïve B-cells and CD27(-)CD38(+) plasma cells did not differ between study groups (P > 0.05). The percentage of CD27(+)CD38(-) memory B-cells and CD27(+)CD38(+) plasma cell precursors increased in pre-eclamptic women compared with the controls (P < 0.05). Irrespective of whether the PBMCs were stimulated with or w/o PWM in vitro, the mean percentages of generated plasma cells were significantly higher in pre-eclamptic group than in the controls (P < 0.05). There were more antibody-producing cells in pre-eclamptic women following the activation of PWM than those in the controls (P < 0.01).

Our findings implicate that the functional changes of human circulating B-cells might contribute to the etiology of pre-eclampsia.