Increased tissue factor and thrombomodulin expression and histopathological changes in placentas of pregnancies with preeclampsia

INTRODUCTION

Preeclampsia has a global frequency of 2-8% and a frequency of 10% in developing countries. In Colombia, preeclampsia causes 42% of maternal mortality. Alterations in placental homeostasis have been proposed to be involved in its pathophysiology. The aim of this study was to compare mRNA and protein levels of tissue factor (F3) and thrombomodulin (THBD) and the histopathological findings of placentas.

MATERIALS AND METHODS

We studied 16 placentas from patients with preeclampsia and 19 term placentas with uncomplicated pregnancy. An expert pathologist, who was masked to the group assignment, conducted an evaluation to determine specific histological changes. Assessments of mRNA and protein levels of F3 and THBD were performed using real-time PCR and ELISA, respectively.

RESULTS

Cases and controls differed in the frequency of decidual arteriopathy (p = 0.027), acute infarction (p = 0.001) and hyperplasia of the syncytiotrophoblast (p = 0.0017). Cases had increased levels of F3 mRNA (p = 0.0124) and protein (p <  0.0001) and THBD mRNA (p <  0.0001) and protein (p <  0.0001).

CONCLUSION

In placenta of patients with preeclampsia, we detected abnormal expression of F3 and THBD with increased protein and mRNA levels. The role of these molecules in the pathogenesis of this disease and in alterations of hemostatic and histopathological aspects of placentas need further studying.

Pulse oximetry reference values at high altitude

Pulse oximetry is becoming popular for measuring oxygen saturation of haemoglobin in paediatric patients. There are no reference values for children living at high altitudes, and the aim of this study was to determine the values of oxygen saturation of haemoglobin in healthy children in Bogota (2640 m above sea level). The saturation was determined in 189 children aged 5 days to 24 months with a Nellcor N10 oximeter. Mean values and 95% confidence intervals (CI) were calculated. Analysis of variance was used for assessing the differences in saturation with age and physiological status. The values were normally distributed with a mean (SD) of 93.3 (2.05)% and 95% CI of 93.0% to 93.6%. There were no clinically important differences in the oxygen saturation of haemoglobin in the range of ages included. The mean saturation in sleeping children was significantly lower than that during other physiological states (91.1% v 93.3%) but the difference was not clinically important. As expected, the values for the oxygen saturation of haemoglobin in the children studied were lower than those reported from children living at sea level. These estimates can be used for interpreting results of the oxygen saturation in haemoglobin in children from Bogota and other cities located at a similar altitude.