Plasma levels of inflammatory markers neopterin, sialic acid, and C-reactive protein in pregnancy and preeclampsia

Abstract

Background: To determine whether the cellular inflammatory marker of activated macrophages and monocytes, neopterin (NEO), and the acute-phase inflammatory markers sialic acid (SA) and C-reactive protein (CRP) are elevated in pregnancy and further elevated in the pregnancy syndrome preeclampsia.

Methods: Maternal plasma concentrations of NEO, SA, and CRP were measured by high-sensitivity enzyme-linked immunosorbent assay (ELISA) or high-performance liquid chromatography in 20 nonpregnant women, 40 women with uncomplicated pregnancies, 50 women with transient hypertension of pregnancy alone, 49 women with small for gestational age (SGA) infants without preeclampsia, and 47 women with preeclampsia.

Results: The mean concentration of plasma NEO, SA, and CRP were all significantly elevated in all groups of pregnant women compared to nonpregnant women (P < 0.001 for all). In addition, maternal plasma NEO concentrations were further elevated in women with preeclampsia compared to the other groups of pregnant women (P < 0.01). As expected, the acute-phase inflammatory markers CRP and SA correlated positively with each other. However, CRP was also correlated with the activated macrophage and monocyte marker NEO in women with transient hypertension of pregnancy and with preeclampsia (P < 0.05).

Conclusions: The inflammatory markers NEO, SA, and CRP are all elevated during pregnancy. However, only NEO, a marker of macrophage and monocyte activation, was further elevated in women with preeclampsia. These data suggest that there is a striking increase in inflammation during pregnancy, and cellular immune activation is further elevated during preeclampsia.

Figure

Maternal plasma neopterin is elevated in pregnancy and further elevated in preeclampsia. Box and whisker plots of maternal plasma neopterin; the filled black circles are the median, the horizontal line within the box is the mean, the open circles are the 90th and 10th percentiles, and the top and bottom lines of the box are the 75^th and 25^th percentiles of the data for each group. (#: p<0.005 vs. non-pregnant; **: p<0.005 vs. uncomplicated pregnancy, and *: p<0.01 vs. uncomplicated pregnancy)