The application of serum cystatin C in estimating the renal function in women with severe preeclamptic toxemia

Abstract Introduction Preeclampsia is a medical condition where hypertension arises in association with significant amount of proteinuria. It appears likely that there are substances from the placenta that can cause endothelial dysfunction in the maternal blood vessels of susceptible women. Preeclampsia usually develops from 20 weeks and it is the most common of the dangerous pregnancy complications; it may affect both the mother and the fetus so the ability to predict the appearance of preeclampsia later in pregnancy would be of great value, although the only known treatment for eclampsia or advancing preeclampsia is delivery. Early prediction of the complication will allow close monitoring and early intervention. Aim The present study aimed at evaluating the role of cystatin C in the evaluation of renal function in the severe preeclampsia. Subjects Twenty normal primigravidae with singleton pregnancy and another 40 with severe preeclampsia recruited from preeclamptic unit of El-Shatby Maternity University Hospital, Egypt in the third trimester of gestation with exclusion of any medical disease. Methods They are selected and subject to full history taking, complete clinical examination, laboratory investigation with special emphasis on serum uric acid, creatinine and serum cystatin C, obstetric abdominal ultrasound and Doppler. Results of the study were tabulated and statistically analyzed. Results The difference in the mean serum uric acid level (3.55 ± 0.58 versus 6.76 ± 1.06 mg/dl) was significantly higher in the preeclampsia ( p  = 0.001), the specificity was 100% and sensitivity of the test was 97.5%, the difference in the mean serum concentration of creatinine (1.55 ± 0.89 versus 0.66 ± 0.12) was significantly higher in preeclampsia ( p  = 0.001), the specificity of the test was 100% and the sensitivity was 60%. Serum cystatin C level has a mean (0.98 ± 0.29 versus 0.70 ± 0.06) which was significantly higher in preeclampsia ( p  = 0.001) with a specificity 100% and sensitivity 72.5%. We found a positive significant correlation between serum concentration of cystatin, and PI of umbilical artery Doppler ( p  = 0.05). Also, a significant correlation was found between serum concentration of cystatin and both PI and RI of middle cerebral artery Doppler ( p  = 0.05); this indicates the relation of serum cystatin C level with the severity of preeclampsia. Therefore, the past results demonstrate that the serum cystatin C and uric acid are having a good diagnostic accuracy for renal function of preeclampsia when compared to creatinine. Conclusion This indicates that cystatin C serum levels may have a significant role as a marker of preeclampsia and alternative marker of renal function in preeclampsia even more so when used in combination with uric acid levels which is still the most accurate predictor of preeclampsia and most accurate indicator of renal function of preeclampsia.