Plasma Thiol Status in Preeclampsia

In Brief Objective To measure plasma thiol levels in women with normal pregnancies, women with preeclampsia, and non-pregnant controls to define plasma thiol's effect on glutathione homeostasis and pathophysiology of preeclampsia. Methods Total plasma cysteine, γ-glutamylcysteine, homocysteine, cysteinylglycine, and glutathione levels were measured in ten nonpregnant women, ten women with normotensive pregnancies, and 20 women with preeclampsia at delivery. Results Median total plasma levels of all thiols in normotensive pregnant women were significantly lower than in nonpregnant women. Median total plasma cysteine and homocysteine levels in women with preeclampsia were significantly higher compared with pregnant controls (254 versus 190 μmol/L, P < .001; and 13.3 versus 8.4 μmol/L, P < .02, respectively), whereas glutathione levels were significantly lower in women with preeclampsia compared with those in pregnant controls (5.1 versus 6.3 μmol/L, P < .05). Conclusion In women with preeclampsia, homocysteine and cysteine levels, which are lowered in normotensive pregnancy, were comparable to levels in nonpregnant women, whereas glutathione levels were lower. Those results suggest that in women with preeclampsia, glutathione use is higher or its synthesis is disturbed. Therefore, glutathione might affect pathophysiology of preeclampsia. During pregnancy and especially in preeclampsia, plasma glutathione levels are lowered, suggesting higher use or decreased synthesis of glutathione.