Serum cytokine levels and T lymphocyte subsets in pregnant women with eclampsia

Abstract

Background: Eclampsia, defined as the occurrence during pregnancy of hypertension, oedema, proteinuria and/or other neurologic abnormalities, causes substantial morbidity and mortality for both mother and foetus. However, its aetiology is largely unknown. Genetic and immune factors may play a role including a reduced maternal response to paternal antigen and an altered adaptation of the maternal immune system to the foetus. Methods: Participants consisted of pregnant women with and without a diagnosis of eclampsia (N = 20, each group), and normal healthy nonpregnant controls (N = 18). Women with smear positive malaria or clinical infections were excluded. Serum levels of TNFα and IL-10 were assayed by ELISA. T lymphocyte subsets of pregnant patients with and without eclampsia were also studied by direct immunofluorescence using monoclonal antibodies and compared with the control group of 18 normal healthy nonpregnant women (NHC). Results: Eclampsia was associated with significantly lower mean serum IL-10 levels compared to normal pregnant and nonpregnant controls. Levels of the pro-inflammatory cytokine TNFα were higher in pregnant women with and without eclampsia, compared to control nonpregnant women. Further differences on serum cytokine levels were observed in the significantly increasing ratio of IL-10 to TNFα from nonpregnant controls to normal pregnant women and to pregnant women with eclampsia. The mean values of CD3+ and CD4+ positive lymphocytes was significantly decreased in patients with eclampsia (p < 0.05) in this study compared to pregnant controls. Similarly, CD3+ and CD4+ T cells were further decreased in eclampsia and pregnant controls compared to nonpregnant controls (p < 0.05). A decreasing CD4/CD8 ratio was observed from non-pregnant to pregnant controls and to patients with eclampsia buttressing an increase in CD8+ cells in eclampsia and pregnancy compared to controls. Conclusions: While a pro-inflammatory immune milieu during pregnancy complicated with eclampsia was demonstrated, the presence of eclampsia was not associated with further cytokine differences.