Cystatin C as a novel predictor of preterm labor in severe preeclampsia

The model of screening for preeclampsia in the second and third trimesters of gestation

<b>Purpose:</b> Preeclampsia (PE) is a specific syndrome of multiple organ insufficiency in case of pregnancy, which is included in the panel of major obstetric syndromes and is among the main causes of maternal morbidity and mortality in the whole world.<br /> <b>Material and methods</b>: We conducted a prospective cohort study of 91 pregnant women to evaluate the effectiveness of integrated use of maternal risk factors (2019 International Federation of Gynecology and Obstetrics recommendations), placenta location (ultrasound at 18-20 weeks of gestation), and serum cystatin C (at 18-36 weeks of gestation) in screening for pe in the second and third trimesters of gestation.<br /> <b>Results: </b>In the subgroup of pregnant women with cystatin C levels greater than 1.0 mg/L (27 women), PE developed in 26 women, which is 96.29% in percentage terms. When calculating GFR for cystatin C in a group with PE there was a significant violation of the renal filtration system -52.46±2.08 (95% CI, 48.39-56.54), while in healthy group the indicator is within normal limits -97.6±1.64 (95% CI, 94.38-100.82). In the analysis of the ratio of cystatin C levels more than 1.0 mg / l and the development of PE, a sensitivity of 98.46%, specificity of 100% and accuracy of 98.9%, p&lt;0.001.<br /> <b>Conclusions: </b>The data show that the combined model of maternal factors, ultrasound of the placenta and serum cystatin C, is prognostically effective in pregnant women in the second and third trimesters of gestation and is a reliable marker for the development of pe.

Incidence and predictors of acute kidney injury among women with severe pre-eclampsia at Mbarara Regional Referral Hospital

BACKGROUND

The presence of acute kidney injury (AKI) in pre-eclampsia complicates treatment including; increasing length of hospital stay and a need to access services like dialysis which are largely expensive in resource-limited settings. We aimed to determine incidence and predictors of acute kidney injury among women with severe pre-eclampsia at Mbarara Regional Referral Hospital in southwestern Uganda.

METHODS

We carried out a hospital-based prospective cohort study from 16 November  2018 to 18 April 2019, among pregnant women with severe pre-eclampsia followed up in the hospital. We enrolled 70 mothers with severe pre-eclampsia and eclampsia; we excluded patients with a history of chronic kidney disease, chronic hypertension, and gestational hypertension. Data on socio-demographics, laboratory parameters, health system, obstetric and medical factors were collected. Baseline serum creatinine, complete blood count, and CD4 T-cell count were all done at admission (0-hour). A second serum creatinine was done at 48-hours to determine the presence of AKI and AKI was defined as a relative change of serum creatinine value at least 1.5 times the baseline (i.e., at admission) within 48 h. The proportion of women diagnosed with acute kidney injury among the total number of women with severe pre-eclampsia was reported as incidence proportion. Univariate and multivariate logistic regression was used to establish the association between acute kidney injury and severe pre-eclampsia.

RESULTS

Incidence of acute kidney injury was high (42.86%) among women with severe pre-eclampsia. Antenatal care attendance was protective with an odds ratio of 0.14 (0.03, 0.73), p-value 0.020 at bivariate analysis but had no statistical significance at multivariate analysis. Eclampsia was an independent risk factor for acute kidney injury. (aOR 5.89 (1.51, 38.88), p-value 0.014.

CONCLUSION

The incidence of acute kidney injury in patients with severe pre-eclampsia is high. Eclampsia is an independent risk factor of acute kidney injury. The findings of this study highlight the urgent need for more research and better perinatal care for these women.

Association of Maternal Serum Uric Acid and Cystatin C Levels in Late Pregnancy with Adverse Birth Outcomes: An Observational Cohort Study in China

Objective

To investigate the associations between serum uric acid (UA) and cystatin C (CysC) levels in late pregnancy with major unfavorable birth outcomes.

Methods

We retrospectively analyzed the maternal UA and CysC levels during late pregnancy and their relationship with unfavorable birth outcomes in a Chinese population (n = 11,580).

Results

Women with the highest quartile of UA had higher risks of low birth weight (LBW) and small for gestational age (SGA) babies and a lower risk of preterm birth (PTB) compared to women with the lowest quartile [for LBW, adjusted-odds ratio (OR) = 2.63, 95% CI: 1.76, 3.95; for SGA, adjusted-OR = 2.11, 95% CI: 1.73, 2.57; for PTB, adjusted-OR = 0.55, 95% CI: 0.45, 0.69; all P for trend <0.001]. Compared to women in the lowest quartile of CysC, higher risks of macrosomia and large for gestational age (LGA) and lower risks of PTB and SGA were observed for those in the highest quartile (for macrosomia, adjusted-OR = 2.01, 95% CI: 1.60, 2.51; for LGA, adjusted-OR = 1.97, 95% CI: 1.67, 2.32; for PTB, adjusted-OR = 0.32, 95% CI: 0.26, 0.41; all P for trend <0.001; for SGA, adjusted-OR = 0.78, 95% CI: 0.64, 0.96; P for trend <0.05).

Conclusion

This study reports the associations of maternal UA and CysC with adverse birth outcomes, and suggests that routine determination of maternal UA and CysC in late pregnancy is beneficial for assessing the risks of these outcomes.

Maternal plasma pro-atrial and C-type natriuretic peptide levels and their associations with cardiovascular and renal function in the second half of normal pregnancy: a longitudinal study

BACKGROUND

Physiological adaptation in pregnancy is characterized by remodeling of endocrine, cardiovascular and renal functions leading to fluid retention, volume expansion, altered cardiac loading conditions and hyperdynamic circulation. Natriuretic peptides have been used as biomarkers of cardiovascular function, but their associations with gestational age-related changes in maternal cardiac, endothelial and renal function have not been elucidated. The aim of this study was to establish longitudinal reference values for maternal plasma atrial natriuretic peptide (proANP) and C-type natriuretic peptide (CNP) and investigate their temporal association with cardiovascular and renal function in the second half of pregnancy.

METHODS

This study was a prospective longitudinal study of 53 low-risk pregnancies. Women were examined every 3-5 weeks during 22-40 weeks of gestation (252 observations). Fasting maternal blood samples were obtained to measure proANP, CNP, creatinine, cystatin C, uric acid, and fibrinogen levels. Cardiac function and systemic hemodynamics were assessed noninvasively by impedance cardiography (ICG) and vascular endothelial function by flow-mediated vasodilation of brachial artery (FMD).

RESULTS

The plasma proANP (R²adj = 0.79; P = 0.007), CNP (R2adj = 0.54; P = 0.005) decreased between 22 and 40 weeks. The creatinine (R²adj = 0.90; P < 0.001), cystatin C (R²adj = 0.93; P = < 0.001) and uric acid (R²adj = 0.83; P < 0.001) increased significantly, whereas the estimated glomerular filtration rate (R²adj = 0.93; P < 0.001) decreased with gestational age. The FMD did not change significantly but fibrinogen (R²adj = 0.79; P < 0.001) increased with advancing gestation. The maternal systemic vascular resistance index (R²adj = 0.50; P < 0.001) increased, stroke index (R²adj = 0.62; P < 0.001) decreased, whereas the cardiac index (R²adj = 0.62; P = 0.438) and thoracic fluid content (R²adj = 0.72; P = 0.132) did not change significantly with gestation. The proANP was associated with thoracic fluid content (R²adj = 0.74; P < 0.001) and fibrinogen (R²adj = 0.78; P = 0.034) but not with other variables of systemic hemodynamics, endothelial function, or renal function. The CNP was not associated significantly with parameters of cardiovascular or renal function.

CONCLUSION

Longitudinal reference values for maternal plasma proANP and CNP were established. These natriuretic peptides decreased slightly with advancing gestation, but they did not reflect the temporal physiological changes in maternal systemic hemodynamics, vascular endothelial function and renal function during the second half of pregnancy. The proANP correlated with the thoracic fluid content reflecting volume load in pregnancy.

Acute kidney injury in patients operated on for type A acute aortic dissection: incidence, risk factors and short-term outcomes

OBJECTIVES

Acute kidney injury (AKI) is a relatively common complication after an operation for type A acute aortic dissection and is indicative of a poor prognosis. We examined the risk factors for and the outcomes of developing AKI in patients being operated on for thoracic aortic diseases.

METHODS

We retrospectively analysed 712 patients with acute type A dissection who had deep hypothermic circulatory operations from January 2014 to December 2018, emphasizing those who developed AKI. Logistic regression models were used to identify predisposing factors for the postoperative development of AKI.

RESULTS

Among all enrolled patients, 359 (50.4%) had AKI; of these, 133 were diagnosed as stage 1 (18.7%), 126 were stage 2 (17.7%) and 100 were stage 3 (14.0%). Postoperative haemodialysis was required in 111 patients (15.9%). The development of AKI after aortic surgery contributed to the higher mortality rate within 30 days after surgery (P < 0.001), longer stay in the intensive care unit (P = 0.01) and longer hospital stay (P < 0.001). Binary logistic regression analysis showed that preoperative cystatin C levels [odds ratio (OR) 2.615, 95% confidence interval (CI) 1.139-6.002; P = 0.023] and postoperative ventilation time (OR 1.019, 95% CI 1.005-1.034; P = 0.009) were independent risk factors for developing AKI. Multiple ordinal logistic regression analyses showed that the preoperative cystatin C level (OR 2.921, 95% CI 1.542-5.540; P = 0.001) was an independent risk factor associated with the severity of AKI.

CONCLUSIONS

Our data suggested that the development of AKI after surgery for type A acute aortic dissection was common and associated with an increased short-term mortality rate. The preoperative cystatin C level was identified as an indicator for the occurrence and severity of AKI postoperatively. Furthermore, we discovered that longer postoperative ventilation time was also associated with the development of AKI.

Extracellular vesicles: a novel window into kidney function and disease

PURPOSE OF REVIEW

There has been an increasing interest in extracellular vesicles as potential diagnostic, prognostic or therapeutic biomarkers for various kidney diseases, as extracellular vesicles mediate cell-cell or intercellular communication. This review explores the current state of knowledge regarding extracellular vesicles as a tool for examining kidney physiology and disease.

RECENT FINDINGS

Urinary extracellular vesicles may be useful as biomarkers to detect abnormal function in renal endothelial and tubular cells as well as podocytes. Recent studies suggest that urinary extracellular vesicles may facilitate early diagnosis and/or monitoring in acute kidney injury, glomerular disease, autosomal dominanat polycyst kidney disease and urinary tract malignancies. Circulating extracellular vesicles may serve as biomarkers to assess cardiovascular disease.

SUMMARY

Urinary and circulating extracellular vesicles have gained significant interest as potential biomarkers of renal diseases. Analysis of extracellular vesicles may serve as a logical diagnostic approach for nephrologists as well as provide information about disease pathophysiology.

Epigenetic age and pregnancy outcomes: GrimAge acceleration is associated with shorter gestational length and lower birthweight

BACKGROUND

Advanced biological aging, as measured by epigenetic aging indices, is associated with early mortality and morbidity. Associations between maternal epigenetic aging indices in pregnancy and pregnancy outcomes, namely gestational length and birthweight, have not been assessed. The purpose of this study was to examine whether epigenetic age during pregnancy was associated with gestational length and birthweight.

RESULTS

The sample consisted of 77 women from the Los Angeles, CA, area enrolled in the Healthy Babies Before Birth study. Whole blood samples for DNA methylation assay were obtained during the second trimester (15.6 ± 2.15 weeks gestation). Epigenetic age indices GrimAge acceleration (GrimAgeAccel), DNAm PAI-1, DNAm ADM, and DNAm cystatin C were calculated. Gestational length and birthweight were obtained from medical chart review. Covariates were maternal sociodemographic variables, gestational age at blood sample collection, and pre-pregnancy body mass index. In separate covariate-adjusted linear regression models, higher early second trimester GrimAgeAccel, b(SE) = - .171 (.056), p = .004; DNAm PAI-1, b(SE) = - 1.95 × 10-4 (8.5 × 10-5), p = .004; DNAm ADM, b(SE) = - .033 (.011), p = .003; and DNAm cystatin C, b(SE) = 2.10 × 10-5 (8.0 × 10-5), p = .012, were each associated with shorter gestational length. Higher GrimAgeAccel, b(SE) = - 75.2 (19.7), p < .001; DNAm PAI-1, b(SE) = - .079(.031), p = .013; DNAm ADM, b(SE) = - 13.8 (3.87), p = .001; and DNAm cystatin C, b(SE) = - .010 (.003), p = .001, were also associated with lower birthweight, independent of gestational length.

DISCUSSION

Higher maternal prenatal GrimAgeAccel, DNAm PAI-1, DNAm ADM, and DNAm cystatin C were associated with shorter gestational length and lower birthweight. These findings suggest that biological age, as measured by these epigenetic indices, could indicate risk for adverse pregnancy outcomes.

The Association Between GFR Evaluated by Serum Cystatin C and Proteinuria During Pregnancy

Introduction

Physiological changes in pregnancy result in increased cardiac output and renal blood flow, with a consequential increase in proteinuria. Data from studies of the relationship between proteinuria caused by isolated proteinuria and glomerular filtration rate (GFR) are still limited. The objective of this study was to investigate the effects of isolated proteinuria on the cystatin C–based GFR in the third trimester of pregnancy.

Methods

Data were collected from pregnant women in their third trimester whose serum creatinine levels were normal. The GFR of each participant was measured using serum cystatin C levels, and proteinuria was measured using urine protein–creatinine ratios. The participants were divided into 3 groups according to their level of proteinuria: normal (<150 mg/d), physiological (150–300 mg/d), and gestational (>300 mg/d). Changes in GFR were recorded for each group.

Results

The study included 89 participants, of whom 66.3% had levels of proteinuria that did not differ from that of the normal population (<150 mg/d). The incidence of physiological and gestational proteinuria was 21.4% and 12.4%, respectively. The results demonstrate that proteinuria >101.50 mg/d was significantly associated with declined estimated glomerular filtration rate (eGFR) (r = –0.34, P = 0.01). The analysis found that proteinuria >491.27 mg/d led to a risk of GFR <90 ml/min with an odds ratio of 12.69, P = 0.02 when adjusted for systolic blood pressure (SBP), diastolic blood pressure (DBP), and body mass index.

Conclusion

This study suggests that the term “physiological proteinuria” is a misnomer. When used in the traditional manner, creatinine level has inadequate sensitivity to estimate GFR in pregnant women. We found that there is a significant decline in GFR when urine protein > 101.5 mg/d, which could be an early biomarker for renal pathology rather than pregnancy physiology, suggesting that further workup and precaution is required.