Hyaluronan and CD44 in maternal serum from pre-eclampsia

Background: Pre-eclampsia is associated with serum factors which can activate blood vessel endothelial cells. Hyaluronan (HYA) and its specific receptor CD44 play a central role in cell activation processes. Our study focussed on the behavior of serum concentrations of HYA and the soluble standard form of CD44 (sCD44std) in the maternal serum from normotensive and pre-eclamptic pregnancies. Patients and methods: Serum was collected from normotensive pregnant woman (n = 10) and from pregnant women with a severe pre-eclampsia (n = 10). HYA-serum concentrations were measured with a radioimmunoassay while sCD44std were measured with an ELISA. Results: The pre-eclampsia group shows a significant (p < 0.001, Mann and Whitney u-test) increased HYA serum concentration (median 79 ng/ml, range 53-165 ng/ml) when compared to the normotensive group (n = 10, median 32 ng/ml, range 19-59 ng/ml). sCD44std-serum-concentration in the pre-eclampsia group (328.3 +/- 68.3 ng/ml) was weakly higher but not statistically significant (p > 0.05) when compared to the normotensive group (292.9 +/- 74.0 ng/ml). There exist no correlations between the HYA and sCD44std serum concentrations in both preeclamptic and normotensive groups. Conclusion: The increased HYA-serum-concentration may indicate a pathophysiological role of the HYA/CD44-signal transduction system in pre-eclampsia. The existing overlap of HYA serum levels in the pre-eclampsia group with HYA serum levels in the normotensive control group limits the diagnostic precision of HYA serum concentration as a diagnostic parameter in pre-eclampsia. According CD44 it is not excluded that serum concentration of other soluble CD44-isoforms is increased in pre-eclampsia.