The application of serum cystatin C in estimating the renal function in women with preeclampsia.

Objective: Serum cystatin C (Cys-C) is known to reflect the glomerular filtration rate (GFR) more precisely in native kidney diseases and renal dysfunctions secondary to other diseases. This study investigated the serum Cys-C in estimating the renal function in preeclamptic women.

Methods: A total of 96 patients with normal pregnancy (controls) and 48 cases of severe preeclampsia were recruited in this study. We measured the 24-hour creatinine clearance (CrCl), serum creatinine, Cys-C, uric acid (UA), and beta trace protein (BTP) concentrations on all the pregnant women in the second trimester and third trimester and in the postpartum of the patients with severe preeclampsia. Multiple comparisons and correlation analysis were used to analyze the indexes estimating the GFR.

Results: In the normal pregnancies, the concentrations of serum creatinine, UA, and BTP were significantly higher in the third trimester compared to the second trimester, however with no significant differences in the serum Cys-C levels. Comparison between the second and third trimester in patients with severe preeclampsia indicated that significant difference existed in the serum Cys-C, with higher concentration in third trimester. Correlation analyses demonstrated that significant negative correlations could be detected between Cys-C and 24-hour CrCl in the second trimester and third trimester of all the 144 pregnant women and in the postpartum of the patients with severe preeclampsia, and better correlations in normal participants than in participants with preeclampsia.

Conclusions: Serum Cys-C seems to reflect the GFR precisely in women with severe preeclampsia and can be a good marker to monitor the renal function from antepartum to postpartum.