Decreased proportion of peripheral blood vascular endothelial growth factor-expressing T and natural killer cells in preeclampsia

OBJECTIVE: The purpose of this study was to determine the proportion of circulating T and natural killer (NK) cells that express intracellular vascular endothelial growth factor (VEGF) in women with preeclampsia compared to those with a normal pregnancy. STUDY DESIGN: In all, 24 preeclamptic patients and 30 healthy pregnant women were involved in this case-control study. Intracellular VEGF expression of unstimulated lymphocytes was determined with flow cytometric examination. RESULTS: In healthy pregnant women, the majority of both T and NK cells expressed VEGF in their cytoplasma (median, 79.9%; 25-75 percentile, 73.7-87.0 and median, 78.3%; 25-75 percentile, 64.1-85.3, respectively). Furthermore, CD4(+) helper and CD8(+) cytotoxic T cells showed a similar pattern of VEGF expression in normal pregnancy. However, the proportion of VEGF-expressing peripheral blood T (both helper and cytotoxic) and NK cells was markedly decreased in preeclampsia (for T cells: median, 51.6%; 25-75 percentile, 40.1-60.0; P < .001; for NK cells: median, 45.2%; 25-75 percentile, 27.4-64.0; P < .001). CONCLUSION: Our results suggest decreased production of VEGF by circulating T and NK cells in preeclampsia, which might contribute to the development of the generalized endothelial dysfunction characteristic of the maternal syndrome of the disease.