Circulating levels of neutrophil gelatinase-associated lipocalin (NGAL) correlate with the presence and severity of preeclampsia

Pre-eclampsia and maternal health through the prism of low-income countries

Hypertensive syndrome in pregnancy complicates up to 15% of pregnancies, and preeclampsia (PE) occurs in about 3-10% of pregnant women. Inadequate prenatal care is associated with higher mortality from PE, possibly due to reduced monitoring, detection, and missed opportunities for early intervention. The imperative of the clinician's work is to monitor the symptoms and clinical signs of PE, and stratification of patients in relation to the risk of PE is essential. PE represents a multisystem inflammatory response, and the consequences can be expected in all organs. The question of the effect of PE on long-term maternal health is raised. The aim of the paper is to present the effect of PE on the patient's health through the prism of low-income countries.

Neutrophil Gelatinase-Associated Lipocalin and Hypertensive Disorders of Pregnancy: A Cohort Study in Twin Pregnancies

Hypertensive disorders complicate more than 10% of twin pregnancies. Several studies showed increased neutrophil gelatinase-associated lipocalin (NGAL) values in women with singleton pregnancies and preeclampsia. This study aimed to assess NGAL values in twin pregnancies complicated by hypertensive disorders. We conducted a study of 242 consecutive twin pregnancies at the Medical University of Vienna. Serum NGAL was evaluated twice during pregnancy and once in the postpartum period. Furthermore, serum NGAL values were compared between women who developed hypertensive disorders and those who had normal blood pressure. In all twin pregnancies, mean NGAL values increased significantly from the first to the second visit (p = 0.004) and, further, after delivery (p < 0.001). NGAL was significantly higher in pregnancies that developed pregnancy hypertension or preeclampsia when compared to the control group at the first visit (109.2 ± 48.9 ng/mL vs. 91.9 ± 29.4 ng/mL, p = 0.04, respectively). The predictive power of first visit NGAL values for development of pregnancy hypertension or preeclampsia was evaluated. When using a cut-off value of 115 ng/mL, we obtained a sensitivity of 45% with a specificity of 77%. We conclude that women with twin pregnancies who develop hypertensive disorders of pregnancy showed increased NGAL values at 11−16 weeks.

Trimester-specific reference intervals for cystatin C and neutrophil gelatinase-associated lipocalin during pregnancy

BACKGROUND

During normal pregnancy, the glomerular filtration rate (GFR) increases dramatically. Failure to obtain this physiological increase is an important risk factor for morbidity and mortality for both mother and child. The estimated GFR (eGFR) using serum creatinine levels is unsuitable for accurate measurement of renal function during pregnancy. Therefore, new biomarkers have been proposed. Elevated levels of Cystatin C (CysC) and Neutrophil Gelatinase-Associated Lipocalin (NGAL) are associated with renal failure and preeclampsia (PE). In this study, we determined reference intervals for CysC and NGAL during pregnancy.

METHODS

Healthy pregnant women were recruited and blood samples were collected at 9-13 weeks (T1), 27-29 weeks (T2), and 36-39 weeks (T3) of gestation and at 4-13 weeks postpartum (PP). The samples from women with uncomplicated pregnancy were analyzed to determine median values and upper reference limits (URLs, 97.5 percentiles) of creatinine, CysC, and NGAL.

RESULTS

A total of 175 women were included. Longitudinal changes and median values of creatinine, CysC, and NGAL were determined using only complete data sets (n=59). URLs were determined using all available data. The URL at T1, T2, T3, and PP were 60, 63, 74, 93 μmol/L for creatinine; 0.93, 1.04, 1.61, 1.23 mg/L for CysC; and 87, 84, 88, 95 ng/mL for NGAL.

CONCLUSIONS

CysC concentrations are highly dynamic and increase during pregnancy. NGAL concentrations are less dynamic, but well below the URL specified by the manufacturer for non-pregnant women. It is therefore recommended to use trimester-specific reference values for both CysC and NGAL.

Acute Kidney Injury in Severe Preeclamptic Patients Admitted to Intensive Care Unit: Epidemiology and Role of Serum Neutrophil Gelatinase-associated Lipocalcin

Background

Patients with preeclampsia admitted to the intensive care unit (ICU) may have risk factors for acute kidney injury (AKI). Although the use of neutrophil gelatinase-associated lipocalcin (NGAL) to predict AKI is previously validated, we could locate only scanty data regarding the epidemiology of AKI and role of NGAL in preeclamptic patients admitted to ICU.

Methods

Patients with preeclampsia admitted to our ICU were included. The incidence and severity of AKI during the entire ICU stay were assessed using kidney disease improving global outcomes criteria, while the a priori risk factors and serum NGAL were also evaluated.

Results

A total of 52 preeclamptic patients admitted to ICU were included, among whom the majority had eclampsia (75%). AKI developed in 25 (48.1%) patients with stages 1, 2, and 3 in 56, 36, and 8%, respectively. The incidence of sepsis (16 vs 0%), shock (40 vs 7.4%), and anemia (84 vs 59.3%) was significantly greater in patients with AKI (p < 0.05). ICU mortality (28 vs 3.7%), duration of ICU, and hospital stay were significantly higher in patients who developed AKI (p < 0.05). There was no association of serum NGAL [274 (240–335) ng/mL] with AKI or the mortality (p = 0.725, 0.861); there was, however, a significant discriminatory value for eclampsia [p = 0.019; area under curve = 0.736 (95% confidence interval: 0.569–0.904)].

Conclusions

Although AKI is common among patients with preeclampsia admitted to ICU, serum NGAL does not predict its occurrence.

How to cite this article

Tyagi A, Yadav P, Salhotra R, Das S, Singh PK, Garg D. Acute Kidney Injury in Severe Preeclamptic Patients Admitted to Intensive Care Unit: Epidemiology and Role of Serum Neutrophil Gelatinase-associated Lipocalcin. Indian J Crit Care Med 2021;25(9):1013–1019.

The value of Neutrophil gelatinase-associated lipocalin and Neutrophil / Lymphocyte Ratio in the diagnosis of preeclampsia and its severity

Many hypotheses underlie the pathogenesis of preeclampsia. This study aims to evaluate Neutrophil gelatinase-associated lipocalin (a marker of immune hypothesis) and Neutrophil / Lymphocyte ratio (a marker of inflammation) in the diagnosis of preeclampsia and its severity and to determine the correlation between them.Study design : This randomized case-control study involved 132 pregnant women ; 88 were diagnosed with PE (divided into non-severe and severe groups), and 44 healthy pregnant women as a control group. Results : The mean serum level of NGL was significantly higher in PE (535.37 ± 158.61 ng / ml for severe PE, 522.5 ± 106.3 ng / ml for non-severe PE, and 161.96 ± 17.48 ng / ml for the control group). The ROC Curve NGL criteria of more than 204.4 ng / ml showed 100% sensitivity and specificity in both severe and non-severe cases versus control. The N / L ratio showed a significant difference (5.81 ± 5.24 for severe PE, 4.1 ± 3.41 for non-severe PE, and 3.89 ± 1.79 for the control group), but the ROC curve criterion was not significant. Both showed a non-significant positive correlation. Conclusion : NGL is an excellent diagnostic factor, whereas N / L might have lower diagnostic performance compared with NGL. Both are related independently to the pathophysiology of PE. J. Med. Invest. 68 : 321-325, August, 2021.

NGAL for Preeclampsia: How Sure are We?

How to cite this article: Gupta S, Tomar DS. NGAL for Preeclampsia: How Sure are We? Indian J Crit Care Med 2021;25(9):972-973.

A retrospective review of clinical and non-clinical factors associated with unscheduled cesarean deliveries at one urban medical center

OBJECTIVE

To investigate factors associated with unscheduled cesarean delivery at one urban tertiary medical center.

METHODS

A retrospective chart review was performed on 11 162 deliveries between 2009 and 2019. The dependent variable was unscheduled cesarean delivery. Covariates examined included time of delivery, as well as several maternal and pregnancy-related factors.

RESULTS

There were a total of 7037 (63.1%) vaginal, 1133 (10.1%) elective cesarean, and 2992 (26.8%) unscheduled cesarean deliveries. Independent factors associated with increased odds for unscheduled cesarean delivery included daytime delivery (odds ratio [OR] 1.29, 95% confidence interval [CI] 1.18-1.42, P < 0.001); advanced maternal age (OR 1.40, 95% CI 1.26-1.56, P < 0.001); obesity (OR 1.04, 95% CI 1.03-1.05, P < 0.001); history of previous cesarean delivery (OR 2.77, 95% CI 1.91-4.01, P < 0.001); hypertension (OR 1.72, 95% CI 1.27-2.32, P < 0.001); multiparity (OR 3.99, 95% CI 2.82-5.64, P < 0.001); pre-eclampsia (OR 1.96, 95% CI 1.33-2.89, P = 0.001); and HELLP (hemolysis, elevated liver enzymes and low platelet count) syndrome (OR 5.45, 95% CI 1.13-26.28, P = 0.035).

CONCLUSION

Factors associated with unscheduled cesarean delivery in this study cohort included daytime delivery, advanced maternal age, obesity, hypertension, previous cesarean delivery, multiparity, preterm labor, pre-eclampsia, and HELLP syndrome.

Cardiac dysfunction after preeclampsia; an overview of pro- and anti-fibrotic circulating effector molecules

Preeclampsia (PE) is strongly associated with heart failure (HF) later in life. The aberrant cardiac remodelling is likely initiated or amplified during preeclamptic pregnancy. Aberrant remodelling often persists after delivery and is known to relate strongly to cardiac fibrosis. This review provides an overview of pro- and anti- fibrotic circulating effector molecules that are involved in cardiac fibrosis and their association with PE. Women with PE complicated pregnancies show increased ANG-II sensitivity and elevated levels of the pro-fibrotic factors IL-6, TNF-α, TGs and FFAs compared to uncomplicated pregnancies. In the postpartum period, PE pregnancies compared to uncomplicated pregnancies have increased ANG-II sensitivity, elevated levels of the pro-fibrotic factors IL-6, TNF-α, LDL cholesterol and leptin, as well as decreased levels of the anti-fibrotic factor adiponectin. The review revealed several profibrotic molecules that associate to cardiac fibrosis during and after PE. The role that these fibrotic factors have on the heart during and after PE may improve the understanding of the link between PE and HF. Furthermore they may provide insight into the pathways in which the relation between both diseases can be understood as potential mechanisms which interfere in the process of cardiovascular disease (CVD). Unravelling the molecular mechanism and pathways involved might bring the diagnostic and therapeutic abilities of those factors a step closer.

Restrictive versus Liberal Fluid Therapy for Post-Cesarean Acute Kidney Injury in Severe Preeclampsia: a Pilot Randomized Clinical Trial

OBJECTIVES

The aim of this study was to determine whether a restrictive compared to a liberal fluid therapy will increase postoperative acute kidney injury (AKI) in patients with severe preeclampsia.

METHODS

A total of 46 patients (mean age, 32 years; standard deviation, 6.8 years) with severe preeclampsia were randomized to liberal (1500 ml of lactated Ringer's, n=23) or restrictive (250 ml of lactated Ringer's, n=23) intravenous fluid regimen during cesarean section. The primary outcome was the development of a postoperative renal dysfunction defined by AKI Network stage ≥1. Serum cystatin C and neutrophil gelatinase-associated lipocalin (NGAL) were evaluated at postoperative days 1 and 2. ClinicalTrials.gov: NCT02214186.

RESULTS

The rate of postoperative AKI was 43.5% in the liberal fluid group and 43.5% in the restrictive fluid group (p=1.0). Intraoperative urine output was higher in the liberal (116 ml/h, IQR 69-191) than in the restrictive fluid group (80 ml/h, IQR 37-110, p<0.05). In both groups, serum cystatin C did not change from postoperative day 1 compared to the preoperative period and significantly decreased on postoperative day 2 compared to postoperative day 1 (p<0.05). In the restrictive fluid group, NGAL levels increased on postoperative day 1 compared to the preoperative period (p<0.05) and decreased on postoperative day 2 compared to postoperative day 1 (p<0.05).

CONCLUSION

Among patients with severe preeclampsia, a restrictive fluid regimen during cesarean section was not associated with increased postoperative AKI.

Prediction of Preeclampsia in Nulliparous Women according to First Trimester Maternal Factors and Serum Markers

OBJECTIVE

To evaluate the performance of maternal risk factors (BMI and mean arterial pressure [MAP]) and first-trimester maternal serum markers in the early prediction of preeclampsia (PE) in nulliparous women.

MATERIAL AND METHODS

This was a case-cohort study based on a cohort of 14,207 nulliparous women. A total of 213 cases with term PE (from 37 weeks + 0 days) and 55 cases with preterm PE (before 37 weeks + 0 days) were identified and validated. Randomly, 449 controls were selected. Serum samples previously collected for the double test (pregnancy-associated plasma protein A [PAPP-A] and free β human chorionic gonadotrophin [hCGβ]) as part of the first-trimester screening program were retrieved and analyzed for placental growth factor (PlGF), soluble fms-like tyrosine kinase 1 (sFlt-1), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and neutrophil gelatinase-associated lipocalin (NGAL). Concentrations were transformed to multiples of the median (MoM). Multivariate regression analysis was used for prediction models. Receiver-operating characteristics (ROC) curves were used for evaluation of the screening performance.

RESULTS

In preterm PE, the PlGF (0.79 MoM), sFlt-1 (0.86 MoM), NGAL (1.15 MoM), and PAPP-A (0.89 MoM) medians were significantly altered. In term PE, PlGF (0.90 MoM) and NT-proBNP (0.86 MoM) medians were significantly reduced. The combination of MAP and PlGF yielded a 39% detection rate of preterm PE for a 10% false-positive rate. The combination of MAP, BMI, and PlGF yielded a 33% detection rate of term PE with a 10% false-positive rate.

CONCLUSION

First-trimester MAP, maternal serum PlGF, and NGAL are markers of preterm PE. Maternal serum sFlt-1 is a significant marker of preterm PE, but only early in the first trimester. First-trimester maternal serum NT-proBNP is not a predictor of PE. Screening performance for PE with these markers individually or in combination is modest.

Neutrophil Gelatinase-associated Lipocalin: As a Predictor of Early Diabetic Nephropathy in Type 2 Diabetes Mellitus

This study was carried out to look for diagnostic and prognostic role of neutrophil gelatinase-associated lipocalin (NGAL) in early diabetic nephropathy (DN) in type 2 diabetes individuals. NGAL was measured in both urinary and serum sample of 144 type 2 diabetes individuals stratified into three categories based on urinary albumin-creatinine ratio and 54 control populations with estimated glomerular filtration rate >60 mL/min/1.73 m² and serum creatinine <1.2 mg/dl. The serum NGAL (sNGAL), urine NGAL (uNGAL), and uNGAL/urine creatinine were significantly higher in diabetic individuals than in the control populations with significant difference in between the groups (P < 0.05). Difference of above values between control value and normoalbuminuria was also statistically significant (P < 0.05). Again, sNGAL and uNGAL correlate positively with albuminuria (P < 0.05). Tubular injury may precede glomerular injury in diabetic individuals, and NGAL can be used as a biomarker to diagnose DN even earlier to incipient nephropathy. Both sNGAL and uNGAL can predict albuminuria and be used as a noninvasive tool for diagnosis, staging, and progression of DN.

Expression changes of proteins associated with the development of preeclampsia in maternal plasma: A case-control study

Defective deep placentation, involving abnormal transformation of the spiral arteries in the junctional zone of the myometrium, is known to cause significant obstetric complications, such as preeclampsia (PE), fetal growth restriction, and placental infarction leading to fetal death. Serological biomarkers to predict and diagnose PE would help antenatal care and reduce obstetric complications. To discover candidate PE biomarkers, we first performed global proteomic profiling of three pairs of plasma samples obtained from pregnant women in the early second trimester, who subsequently developed PE, and controls to identify candidate proteins that were abundant in the patients. We further evaluated the changes in the expression of PE-representing proteins in stored plasma samples of a cohort that subsequently developed PE and their matched controls by MRM-MS analysis. We identified that both complement C1s subcomponent (C1S) and protein AMBP were elevated in the plasma samples of the PE cohort before the manifestation of clinical disease. We propose that these proteins may be involved in the remodeling process of the spiral arteries even before PE manifestation. These proteins can serve as potential plasma biomarkers to predict the pregnant women having an increased risk of developing PE.

A Dormant Microbial Component in the Development of Preeclampsia

Preeclampsia (PE) is a complex, multisystem disorder that remains a leading cause of morbidity and mortality in pregnancy. Four main classes of dysregulation accompany PE and are widely considered to contribute to its severity. These are abnormal trophoblast invasion of the placenta, anti-angiogenic responses, oxidative stress, and inflammation. What is lacking, however, is an explanation of how these themselves are caused. We here develop the unifying idea, and the considerable evidence for it, that the originating cause of PE (and of the four classes of dysregulation) is, in fact, microbial infection, that most such microbes are dormant and hence resist detection by conventional (replication-dependent) microbiology, and that by occasional resuscitation and growth it is they that are responsible for all the observable sequelae, including the continuing, chronic inflammation. In particular, bacterial products such as lipopolysaccharide (LPS), also known as endotoxin, are well known as highly inflammagenic and stimulate an innate (and possibly trained) immune response that exacerbates the inflammation further. The known need of microbes for free iron can explain the iron dysregulation that accompanies PE. We describe the main routes of infection (gut, oral, and urinary tract infection) and the regularly observed presence of microbes in placental and other tissues in PE. Every known proteomic biomarker of "preeclampsia" that we assessed has, in fact, also been shown to be raised in response to infection. An infectious component to PE fulfills the Bradford Hill criteria for ascribing a disease to an environmental cause and suggests a number of treatments, some of which have, in fact, been shown to be successful. PE was classically referred to as endotoxemia or toxemia of pregnancy, and it is ironic that it seems that LPS and other microbial endotoxins really are involved. Overall, the recognition of an infectious component in the etiology of PE mirrors that for ulcers and other diseases that were previously considered to lack one.

Prognostic role of maternal neutrophil gelatinase-associated lipocalin in women with severe early-onset preeclampsia

INTRODUCTION

The association between maternal plasma levels of neutrophil gelatinase-associated lipocalin (NGAL) and maternal complications in women admitted with severe early-onset preeclampsia was evaluated.

MATERIAL AND METHODS

Plasma levels of NGAL were measured at admission in patients with severe early-onset (presenting before 34 weeks) preeclampsia. The maternal outcome of women with elevated plasma levels was compared with those with normal levels. Maternal complications included eclampsia, HELLP syndrome, acute renal failure, subcapsular hepatic hematoma, pulmonary edema and disseminated intravascular disease.

RESULTS

Sixty-seven patients were included. The median NGAL plasma levels in the group of women who subsequently had a complication were significantly higher than in those uncomplicated cases (114.8 vs. 84.2 ng/ml; Mann-Whitney U test p = 0.03). Maternal complications were more common in the elevated (>100 ng/ml) NGAL group (58.3 vs. 25.6%; χ(2) test p = 0.008), with an OR of 4.1 (95% CI 1.4-11.8). After adjustment by gestational age at onset, the association between elevated NGAL plasma levels and maternal complications remained significant (OR 4.2; 95% CI 1.4-12.4).

DISCUSSION

Women with severe early-onset preeclampsia are at higher risk of maternal complications if plasma levels of NGAL are elevated.