56 Impairment of CD163 receptor are associated with increased levels of TNF-α and IL-1β in plasma from pregnant women with preeclampsia: Immune and inflammatory mechanisms

Introduction Preeclampsia (PE) is a pregnancy-specific syndrome characterized by a systemic inflammatory response that polarizes peripheral blood monocytes to the M1 phenotype. CD163 is a scavenger receptor expressed by monocytes/macrophages which may shed from their cell membrane after proteolytic cleavage producing soluble CD163 molecule (sCD163) that plays a role in the modulation of inflammatory response. Objectives This study aimed at evaluate expression of CD163 on monocytes and the levels of sCD163 as well as pro- and anti-inflammatory cytokines in plasma of pregnant women with the severe and mild forms of PE. Methods Fifty-six women with preeclampsia, 28 normotensive pregnant women matched for gestational age and 20 healthy non-pregnant women were included. Preeclamptic women were classified according to the disease severity as mild ( n  = 28) or severe ( n  = 28) PE. Plasma levels of sCD163, tumor necrosis factor-alpha (TNF- α ), Interleukin-1 beta (IL-1 β ), IL-10 and transforming growth factor beta (TGF- β 1) were determined by enzyme-linked immunosorbent assay, and CD163 expression by monocytes was assessed by flow cytometry. Differences between groups were compared by parametric analysis of variance with significance level set at 5%. Results Monocytes from preeclamptic women showed lower expression of CD163 receptor compared with normotensive pregnant and non-pregnant women. Plasma levels of sCD163 were also significantly lower in pregnant women with severe or mild PE than in normotensive pregnant women. No significant differences were detected between both groups of PE in relation to this parameter. A positive correlation was observed between sCD163 and IL-10 concentration in plasma from normotensive pregnant women ( r  = 0.5829; p  = 0.0111). The values of IL-1 β , TGF- β 1 and TNF- α were higher in severe PE than in mild PE and normotensive pregnant women. Both groups of preeclamptic women showed decreased plasma levels of IL-10. A negative correlation was observed between concentrations of sCD163 and IL-1 β ( r  = −0.4251; p  = 0.0341) and between sCD163 and TNF- α ( r  = −0.5075; p  = 0.0096) in the group of severe PE. Conclusions The results showed that decreased plasma levels of sCD163 could possibly be explained by the lower expression of CD163 by monocytes from preeclamptic women. The association between the pro-inflammatory cytokine profile and the lower concentration of sCD163 and IL-10 in plasma from pregnant women with severe PE suggests an impairment in the modulation of the inflammatory response in this preeclamptic group. Financial support – FAPESP 2013/12260-7.