Serum Cystatin C in Pregnancies With Normal and Restricted Fetal Growth

Elevated levels of renal function tests conferred increased risks of developing various pregnancy complications and adverse perinatal outcomes: insights from a population-based cohort study

OBJECTIVES

Physiological changes during pregnancy can affect the results of renal function tests (RFTs). In this population-based cohort study, we aimed to establish trimester-specific reference intervals (RIs) of RFTs in singleton and twin pregnancies and systematically investigate the relationship between RFTs and adverse pregnancy outcomes.

METHODS

The laboratory results of the first- and third-trimester RFTs, including blood urea nitrogen (BUN), serum uric acid (UA), creatinine (Crea) and cystatin C (Cys C), and the relevant medical records, were retrieved from 29,328 singleton and 840 twin pregnant women who underwent antenatal examinations from November 20, 2017 to January 31, 2021. The trimester-specific RIs of RFTs were estimated with both of the direct observational and the indirect Hoffmann methods. The associations between RTFs and pregnancy complications as well as perinatal outcomes were assessed by logistic regression analysis.

RESULTS

Maternal RFTs showed no significant difference between the direct RIs established with healthy pregnant women and the calculated RIs derived from the Hoffmann method. In addition, elevated levels of RFTs were associated with increased risks of developing various pregnancy complications and adverse perinatal outcomes. Notably, elevated third-trimester RFTs posed strong risks of preterm birth (PTB) and fetal growth restriction (FGR).

CONCLUSIONS

We established the trimester-specific RIs of RFTs in both singleton and twin pregnancies. Our risk analysis findings underscored the importance of RFTs in identifying women at high risks of developing adverse complications or outcomes during pregnancy.

The role of cystatin C, neutrophil-lymphocyte ratio and platelet-lymphocyte ratio in the evaluation of kidney function in women with preeclampsia

OBJECTIVE

We aimed to compare the diagnostic efficiency of cystatin C with traditional kidney markers in preeclampsia and to evaluate the relationship of these markers with neutrophil-lymphocyte and thrombocyte-lymphocyte ratios.

MATERIALS AND METHODS

14 severe preeclampsia, 48 mild preeclampsia and 79 patients with healthy pregnancy who presented to our obstetrics and gynecology clinic within one year were compared. These three groups were compared in terms of demographic characteristics, physical findings, serum urea, creatinine, cystatin C levels, and neutrophil-lymphocyte and platelet-lymphocyte ratios.

RESULTS

The mean serum cystatin C, creatinine and uric acid levels were higher in the severe preeclampsia group compared with the mild preeclamptic and healthy pregnancies (p < 0.001). While cystatin C values increased as the week of gestation increased in the mild preeclampsia group, there was no relation with the gestational week in the control group and the severe preeclampsia group. However, the highest cystatin C values were in the severe preeclampsia group, regardless of the week (p < 0.05). The area under the ROC curve was statistically significant for cystatin C, uric acid and creatinine, but of these three values, cystatin C had the highest sensitivity and specificity. Neutrophil-lymphocyte ratio (NLR) was significantly higher in the severe preeclampsia group than healthy pregnancies, but the level was not significant compared to mild preeclampsia. There was no difference between the groups in terms of platelet-lymphocyte ratio.

CONCLUSION

It can be suggested that cystatin C level reflects renal functions better than uric acid and creatinine in preeclampsia. Cystatin C can be used as a prognostic marker in preeclamptic pregnancies, and rising levels may be valuable for predicting severe preeclampsia. Especially with advancing gestational week, the increase in cystatin C level may indicate an association with the development of preeclampsia. NLR levels may be a parameter correlating with severity in severe preeclampsia.

Serum cystatin C levels in preterm newborns in our setting: Correlation with serum creatinine and preterm pathologies

BACKGROUND

Cystatin C (CysC) is a renal function marker that is not as influenced as creatinine (Cr) by endogenous or exogenous agents, so it is therefore proposed as a marker in preterm infants.

OBJECTIVES

To determine serum CysC values in preterm infants during the first week of life, compared to Cr. To analyze alterations caused by prematurity diseases.

METHOD

The design involved a longitudinal, observational study of prospective cohorts. Groups were based on gestational age (GA): Group A (24-27 weeks), Group B (28-33 weeks), Group C (34-36 weeks). Blood samples were collected at birth, within 48-72hours and after 7 days of life.

STATISTICS

SPSS v.20 software was used. The statistical methods applied included chi-squared test and ANOVA.

RESULTS

A total of 109 preterm infants were included in the study. CysC levels were: 1.54mg/L (±0.28) at birth; 1.38mg/L (±0.36) within 48-72hours of life; 1.50mg/L (±0.31) after 7 days (p<0.05). Cr levels were: 0.64mg/dL (±0.17) at birth; 0.64mg/dL (±0.28) within 48-72hours; 0.56mg/dL (±0.19) after 7 days (P<.05). CysC values were lower in hypotensive patients and those with a respiratory disease (P<.05), and no alterations associated with other diseases were observed. There were no differences in Cr levels associated with any disease. Creatinine levels were higher in patients ≤1.500g (P<.05).

CONCLUSIONS

Serum CysC decreased within 48-72hours of life, and this decline showed significance (P<.05). The levels increased after 7 days in all 3 GA groups, and there was no difference in CysC levels among the groups. More studies in preterm infants with hypotension and respiratory disease are required. CysC is a better glomerular filtration (GF) marker in ≤1.500g preterm infants.

Serum cystatin C during 30 postnatal days is dependent on the postconceptional age in neonates

BACKGROUND

Cystatin C (CysC) is a promising endogenous marker for renal function. However, the reference serum CysC level is not sufficiently studied in neonates. This study was conducted to investigate the reference level of serum CysC for neonates, including very low birth weight infants according to the postconceptional age (PCA).

METHODS

Serum CysC levels were measured in 883 blood samples (246 neonates including 127 premature infants). Infants with symptoms or signs of acute kidney injury, systemic illness, congenital anomaly, or renal pathology were excluded. CysC levels were analyzed for association between subgroups dichotomized by postnatal age and PCA.

RESULTS

Reference ranges of serum CysC were determined and a decreasing trend of CysC levels was observed as PCA increased, except for the first 3 postnatal days. CysC levels were negatively correlated with gestational age at birth, and PCA (P < 0.001), while positively correlated with postnatal age and serum creatinine (P < 0.001).

CONCLUSION

The reference level of serum CysC was determined according to postnatal age and PCA. As the reference CysC level was dependent on gestational age and PCA, consideration of these parameters is warranted when assessing CysC levels in neonates.

Cystatins in Health and Diseases

The Cystatins constitute a large group of evolutionary related proteins with diverse biological activities. They have been recently realized as instrumental in myriad of pathophysiological conditions. They have been implicated in various pathological conditions. The degree of malignancy of various types of cancer cells has been found to be inversely associated with the expression of cystatins. Cystatins have been found to have various antimicrobial, antiviral and immunomodulatory properties. Keeping in view as their being prospective drug targets and anti-disease options this review explores the role of cytoplasmic and cell secreted cystatins in various human diseases.