PP069. The expressions of B7-H1 and B7-H4 co-stimulatory molecules on myeloid and lymphoid dendritic cells in pre-eclampsia and normal pregnancy. The expressions of B7-H1 and B7-H4 co-stimulatory moleculeson myeloid and lymphoid dendritic cells in pre-eclampsia and normal pregnancy.

INTRODUCTION: Pre-eclampsia (PE) is a common obstetric syndrome affecting about 5-10% of pregnant women. The syndrome is a leading cause of maternal and fetal morbidity and mortality, even in developed world. The etiology and pathogenesis of this syndrome are not fully understood. There are many studies describing alterations in the innate and adaptive immune system which may have an influence on the onset of this disorder. It was suggested that activation of cell-mediated immunity may play the key role in the etiology of pre-eclampsia. OBJECTIVES: The purpose of our study was to estimate the expressions of B7-H1 and B7-H4 costimulatory molecules on myeloid and lymphoid DCs (CD1c(+), BDCA-2(+)) in the peripheral blood of patients with pre-eclampsia and normal pregnant women in the third trimesters of physiological pregnancy. METHODS: Thirty three patients with pre-eclampsia and 26 normal pregnant women were included in the study. Dendritic cells were isolated from peripheral blood, stained with monoclonal antibodies against blood dendritic cell antigens and B7-H1 and B7-H4 molecules and estimated using flow cytometry. RESULTS: The expressions of B7-H1 molecule on CD1c(+) myeloid DCs and B7-H4 molecule on BDCA-2(+) lymphoid DCs did not differ in pre-eclampsia and healthy third trimester pregnant women. The expressions of B7-H4 molecule on CD1c(+) myeloid DCs and B7-H1 molecule on BDCA-2(+) lymphoid DCs were significantly higher in peripheral blood of patients with pre-eclampsia in comparison with the control group. CONCLUSION: It seems possible that higher expressions of B7-H4 molecule on CD1c(+) myeloid DCs and B7-H1 molecule on lymphoid BDCA-2(+) DCs in pre-eclampsia may be the tolerogenic mechanism secondary to the pro-inflammatory response which is observed in this syndrome.

The expression of B7-H1 and B7-H4 molecules on immature myeloid and lymphoid dendritic cells in cord blood of healthy neonates.

The aim of our study was to estimate both B7-H1 and B7-H4 molecules on immature myeloid and lymphoid dendritic cells in umbilical cord blood of healthy neonates in comparison with peripheral blood of healthy adults. Thirty nine healthy full-term neonates from physiological single pregnancies and 27 healthy adults were included in the study. The expression of B7-H1 and B7-H4 was revealed using the immunofluorescence method. Statistical analysis was performed using a non-parametric test (Mann-Whitney U-Test). The percentages of BDCA-1+ dendritic cells with B7-H1 and B7-H4 expressions were significantly higher in peripheral blood of healthy adults (p<0.00003). It was either observed that the percentage of BDCA-2+ dendritic cells with the expression of B7-H4 molecules was significantly higher in peripheral blood of healthy adults in comparison with umbilical cord blood (p<0.02). Decreased percentages of dendritic cells and co-stimulatory molecules indicate that neonates have immature immune system. Depletion of co-stimulatory B7-H1 and B7-H4 molecules enable appropriate development of immune response.