[Expression and significance of soluble fms-like tyrosine kinase 1 in preeclampsia placenta]

OBJECTIVE: To investigate the expression and significance of serum soluble fms-like tyrosine kinase 1 (sFlt-1) in preeclampsia placenta.

METHODS: Immunohistochemistry and semi-quantitative RT-PCR were used to investigate the expression of sFlt-1 and sFlt-1 mRNA in placenta of 30 women with preeclampsia (including mild and moderate preeclampsia 11 cases, severe preeclampsia 19 cases) and 45 normal pregnant women (including first trimester pregnancy 18 cases, 2nd trimester pregnancy 12 cases, and 3rd trimester pregnancy 15 cases). The levels of vascular endothelial growth factor (VEGF) and sFlt-1 in serum were detected by enzyme linked immunosorbent assay.

RESULTS: (1) The expression of sFlt-1 mRNA was significantly higher in preeclampsia group (0.90 +/- 0.11) compared with the third trimester group (0.80 +/- 0.06; P < 0.01), and was higher in the severe preeclampsia group (0.93 +/- 0.12) than that in the mild group (0.85 +/- 0.05; P < 0.05). (2) The mean density of sFlt-1 in preeclampsia placenta (0.156 +/- 0.008) was significantly higher than that in the third trimester group (0.143 +/- 0.009, P < 0.01), and was higher in the severe group (0.159 +/- 0.008) than in the mild group (0.151 +/- 0.005; P < 0.05). (3) The level of VEGF in serum of the preeclampsia group (19.3 +/- 2.9) ng/L was significantly lower than that of the third trimester group [(30.2 +/- 3.1) ng/L, P < 0.01]. The level of sFlt-1 in serum of the preeclampsia group (30.2 +/- 13.7) microg/L was significantly higher than that of the third trimester group [(7.4 +/- 3.1) microg/L, P < 0.01]. (4) There was significant correlation between the serum level of sFlt-1 and the expression of sFlt-1 mRNA or sFlt-1 in placenta of normal pregnancy group (r = 0.314, P < 0.05; r = 0.439, P < 0.01) and preeclampsia groups (r = 0.372, r = 0.383; P < 0.05).

CONCLUSION: Upregulation of sFlt-1mRNA and excess expression of sFlt-1 in placenta may induce higher level of sFlt-1 in serum, which may be involved in the pathophysiological processes of preeclampsia.