Preeclamptic nephropathy

Evaluation of the predictive values of elevated serum L-homoarginine and dimethylarginines in preeclampsia

L-homoarginine (hARG) is involved in nitric oxide biosynthesis, but its role and concentration in preeclampsia (PE) have not been fully revealed. The purpose of this study was to develop and validate a feasible clinical assay to quantify serum hARG, arginine (ARG), asymmetric (ADMA) and symmetric dimethylarginines (SDMA) levels by LC-MS/MS and investigate their differences at different stages of pregnancy with or without preeclampsia. Serum samples were collected from 84 pregnant women without complications (controls), 84 with mild preeclampsia (MPE), and 81 with severe preeclampsia (SPE) at various gestation stages (before the 20th week, during the 20th-28th week or after the 28th week of gestation). No significant difference in ARG levels was observed between PE and controls at any stage (P > 0.05). The serum hARG levels and hARG/ADMA ratios of MPE before the 20th week were higher than those of controls (P < 0.001). ADMA levels of MPE were higher than those of controls during the 20th-28th week (P < 0.01). SDMA levels of SPE were higher than those of MPE (P < 0.01) and controls (P < 0.05) after the 28th week. Elevated serum hARG before the 20th week was identified as an independent predictor for PE (OR = 1.478, 95% CI 1.120-1.950). ROC curve analysis showed serum hARG before the 20th week had a good potential to predict MPE (AUC = 0.875, 95% CI 0.759-0.948). In conclusion, our study indicated that elevated serum hARG and dimethylarginine levels detected by LC-MS/MS might serve as potential biomarkers for the early prediction of PE.

Role of GRK2 in Trophoblast Necroptosis and Spiral Artery Remodeling: Implications for Preeclampsia Pathogenesis

Impaired invasion of extravillous trophoblasts and severe oxidative stress manifest the poor placentation in preeclampsia, which is life-threatening and more than a hypertensive disease of pregnancy. Previous studies have reported that G protein-coupled receptor kinases (GRKs) play a key role in initiating hypertension and hypertensive renal damage, yet little evidence so far suggests a link between GRKs and preeclampsia-related hypertension. Here, we demonstrate GRK2 expression is significantly downregulated (P < 0.0001) in preeclamptic placentae compared to normotensive controls. Knockdown or inhibition of GRK2 in placentae caused insufficient arterial remodeling and elevated trophoblast necroptosis in vivo. These further induced preeclampsia-like phenotype in mice: hypertension, proteinuria, and elevated pro-angiogenic cytokines. By human extra-villous invasive trophoblast cell line (HTR8/SVneo cells), we revealed the knockdown or inhibition of GRK2 triggered excessive death with typical necroptotic characteristics: nuclear envelope rupture and the activation of RIPK1, RIPK3, and MLKL. Necrostatin-1, an inhibitor of RIPK1, is able to restore the survival of trophoblasts. Together, our findings demonstrated that insufficient GRK2 activity compromises spiral artery remodeling and initiates necrotic events in placentae, thereby leading to preeclampsia. These findings advance our understanding of GRK2 in the pathogenesis of preeclampsia and could shed light on a potential treatment for preeclampsia.

Multiple Gestations and Hypertensive Disorders of Pregnancy: What Do We Know?

PURPOSE OF REVIEW

The occurrence of hypertensive disorders of pregnancy (HDP) including gestational hypertension, chronic hypertension, preeclampsia, and eclampsia is proportional to the number of fetuses: singletons 6.5%, twins 12.7%, and triplets 20.0%. Literature on HDP in multifetal gestation is sparse compared with singletons. We aim to summarize the current evidence on HDP, specifically in twins.

RECENT FINDINGS

HDP occurs more frequently, at an earlier gestational age, and can present more severely and atypically in twin pregnancies. HDP in twins carries a higher risk of maternal/fetal morbidity and mortality including renal failure, stroke, cardiac arrest, pulmonary edema, placental abruption, cesarean delivery, fetal growth restriction, and iatrogenic preterm delivery. Low-dose aspirin (60-150 mg) should be initiated in all multifetal pregnancies to reduce the risk of preeclampsia. To improve outcomes and reduce inherent risks associated with multiple gestations, twins should be managed as high-risk pregnancies, and different from singletons.

Epidemiology and maternal prognosis of hypertension disorders of pregnancy in French Guiana

BACKGROUND

Hypertensive disorders of pregnancy (HDP) are responsible for high maternal mortality and morbidity worldwide.

OBJECTIVE

Our primary objective was to report the epidemiological and clinical features of HDP in Cayenne General Hospital. Our secondary objectives were to search for factors associated to preeclampsia (PE) and to severe PE in patients with HDP.

METHODS

Our study was observational and non-interventional. It was conducted over 4-month period (January to April 2019) in the Obstetrics and Gynaecology Unit of the Cayenne General Hospital. We included all pregnant women after 20 weeks of gestation (WG), who gave birth and who presented HDP and/or PE.

RESULTS

During the study period 1243 patients gave birth in our unit. Among them, 156 were diagnosed with HDP (12.6%). The median age was 33 years (IQR 28 - 38 years). The most frequent medical histories were diabetes (27.5%) and chronic hypertension (23.5%). The socioeconomic status was low in 31% of patients. Ninety-four patients (61.4%) developed PE with a severe form in 80.9% of cases. HELLP syndrome was diagnosed in 6.5% and nephropathy in 3.3% of cases. Delivery was by cesarean in 49.7% of cases. The median gestational age at delivery was 37 WG (IQR: 35-39). Multivariate analysis showed no independent factors associated with the occurrence of PE or severe PE in patients with HDP.

CONCLUSION

Our study shows a high prevalence of PE in patients with HDP. Hospitalization and repeated clinical evaluation are needed to screen for women exposed to develop PE or severe PE.

ACOG Practice Bulletin No. 202: Gestational Hypertension and Preeclampsia

Hypertensive disorders of pregnancy constitute one of the leading causes of maternal and perinatal mortality worldwide. It has been estimated that preeclampsia complicates 2-8% of pregnancies globally (). In Latin America and the Caribbean, hypertensive disorders are responsible for almost 26% of maternal deaths, whereas in Africa and Asia they contribute to 9% of deaths. Although maternal mortality is much lower in high-income countries than in developing countries, 16% of maternal deaths can be attributed to hypertensive disorders (). In the United States, the rate of preeclampsia increased by 25% between 1987 and 2004 (). Moreover, in comparison with women giving birth in 1980, those giving birth in 2003 were at 6.7-fold increased risk of severe preeclampsia (). This complication is costly: one study reported that in 2012 in the United States, the estimated cost of preeclampsia within the first 12 months of delivery was $2.18 billion ($1.03 billion for women and $1.15 billion for infants), which was disproportionately borne by premature births (). This Practice Bulletin will provide guidelines for the diagnosis and management of gestational hypertension and preeclampsia.

Assessment of the diagnostic value of a urinary adipsin rapid strip test for pre-eclampsia: A prospective multicenter study

AIM

The purpose of the present study was to evaluate the clinical value of the rapid strip test of urinary adipsin for the quick diagnosis of pre-eclampsia.

METHODS

In a multicenter diagnostic test study, we studied the diagnostic accuracy of the rapid strip test of urinary adipsin in women presenting with pre-eclampsia. A total of 204 pre-eclampsia patients and 254 healthy pregnant women were recruited for this study, respectively. The rapid strip test of urinary adipsin was used to detect the adipsin in the urine of each patient.

RESULTS

The diagnostic value of the rapid strip test of urinary adipsin for pre-eclampsia was demonstrated by its high sensitivity and specificity (95.10% and 97.64%, respectively). The diagnostic accuracy was 96.51%. The consistency analysis showed that the kappa value was 0.93 compared with the gold standard diagnosis of pre-eclampsia.

CONCLUSION

The rapid strip test of urinary adipsin is a non-invasive test for the diagnosis of pre-eclampsia with high sensitivity and specificity. It could help the quick diagnosis of pre-eclampsia in clinical practice greatly.

Impact of pre-eclampsia in extremely premature infants: Population-based study

BACKGROUND

The relationship between chorioamnionitis (CAM) and neonatal mortality has been extensively investigated, but that of maternal pre-eclampsia and neonatal mortality is unclear. We investigated neonatal mortality and morbidity of maternal pre-eclampsia and clinical CAM in extremely premature infants using data from a population-based cohort study.

METHODS

We retrospectively analyzed data obtained from the Neonatal Research Network in Japan, a population-based cohort study (n = 18 900) conducted to clarify the clinical characteristics and morbidity of very low-birthweight infants. Patients were divided into four diagnosis-based groups for comparative analysis: sole pre-eclampsia; sole clinical CAM; concurrent pre-eclampsia and clinical CAM; and non-diagnosis (of pre-eclampsia and clinical CAM).

RESULTS

Mortality was higher in the pre-eclampsia groups compared with the groups without (18.3%, 84/459 vs 14.0%, 567/4059; OR, 1.38; 95%CI: 1.07-1.78). In contrast, mortality was not affected by presence of clinical CAM (with, 13.7% 182/1328 vs without, 15.0% 469/3190; OR, 0.92; 95%CI: 0.77-1.11). With regard to small for gestational age, the mortality rate increased by two-three-fold as gestational week decreased. The complication survival rate in the whole group was 35% (1135/3218).

CONCLUSIONS

Maternal pre-eclampsia is associated with poor prognosis in extremely premature infants. We also need to deliberate on the trade-off between the advantages of early rescue from pre-eclampsia and risk of prematurity.

Expression of nephrin in the human placenta and fetal membranes

Nephrin is the signature molecule in the podocyte of the glomerulus that forms the renal slit diaphragm, the main functional unit of the glomerulus. The present study focused on the expression of nephrin in the human placenta, which may also have a role in filtration and the maintenance of homeostasis in the kidneys. A total of nine placentas from normal healthy pregnant females at full term were investigated. Reverse transcription-quantitative polymerase chain reaction, western blotting and immunofluorescence were performed. The expression of nephrin mRNA was relatively increased in the chorion compared with that in the villi and the amnion. The nephrin gene was detected in the villous cytotrophoblast cells and the endothelium of the intravillous vessels. It was also present in the chorionic and amniotic membranous lining, with its distribution being particularly dense in the amniocytes. The identification of nephrin in the human placenta, particularly at the maternal‑fetal interface, provides a novel insight into the molecular basis of the selective permeability of the placental barrier, which requires further elucidation.

Hypothesis: Pentoxifylline explores new horizons in treatment of preeclampsia

Preeclampsia, the leading cause of maternal morbidity and perinatal mortality, initiates as inappropriate immune response to trophoblastic invasion impairs placentation and placental circulation. A poorly perfused placenta generates superoxide anions as well as anti-angiogenic factors and this series of events result in impairment of endothelial function, followed by maternal morbidities such as hypertension, kidney injury and proteinuria. Renal loss of anti-coagulant proteins and subsequent hyper-coagulable state along with endothelial dysfunction accelerates progression of the disease toward eclampsia. Since Pentoxifylline, a methyl-xanthine derivative known for enhancement of vascular endothelial function, down-regulation of many inflammatory cytokines increased during preeclampsia, improvement of placental circulation, reduction of ischemia-reperfusion injury, enhancement of vasodilatation and endothelial function, ameliorating proteinuria, inhibition of platelet aggregation and decreasing risk of preterm labor, which are all amongst morbidities of preeclampsia, here it is hypothesized that Pentoxifylline prevents development of preeclampsia and/or decelerate progression of the disease.

Urinary lysosomal enzyme excretion in pregnant women with hypertensive disorders

BACKGROUND

The authors assessed proximal renal tubular dysfunction and/or damage in pregnant women with various types of hypertension by measuring the three urinary lysosomal enzyme levels: N-acetyl-β-d-glucosaminidase (NAG), arylsulfatase A and β-glucuronidase.

METHODS

The study consisted of 120 pregnant women divided into four groups: 41 women in 20th week of gestation or more, with pregnancy-induced hypertension (PIH group), 28 pregnant women after 20 weeks of pregnancy with pre-eclampsia (PE group), 21 pregnant women with chronic hypertension, identified before 20th week of pregnancy (CH group) and 30 healthy, pregnant women (healthy controls (HC) group).

RESULTS

Statistical analysis showed significantly higher levels of all the three of lysosomal enzymes in the urine of patients with PE compared with the healthy pregnant women, pregnant women with PIH and the ones with chronic hypertension. Additionally, significantly higher values of NAG were found in the group of pregnant women with PIH compared with healthy pregnancies. No correlation was found between the concentration of enzymes in urine and values of blood pressure in any of the analyzed groups of pregnant women.

CONCLUSIONS

The authors conclude that higher values of all the studied enzymes in PE group, in the comparison with the other groups, indicate proximal tubular damage at the cellular level. The lack of correlation between the concentration of lysosomal enzymes and blood pressure suggests that the damage to these parts of kidney is complex. In addition, mechanisms other than hypertension realizing intracellular enzymes may be involved in this process.

From preeclampsia to renal disease: a role of angiogenic factors and the renin-angiotensin aldosterone system?

Complicating up to 8% of pregnancies, preeclampsia is the most common glomerular disease worldwide and remains a leading cause of infant and maternal morbidity and mortality. Although the exact pathogenesis of this syndrome of hypertension and proteinuria is still incomplete, a consistent line of evidence has identified an imbalance of proangiogenic and anti-angiogenic proteins as a key factor in the development of preeclampsia. Furthermore, more attention has been recently addressed to the renin-angiotensin aldosterone system (RAAS), to provide understanding on the hypertension of preeclampsia. The imbalance of the RAAS and the imbalance between angiogenic and anti-angiogenic factors, which may be both common to preeclampsia and chronic kidney disease (CKD), might explain why a history of preeclampsia predisposes women to develop CKD. In this review, we briefly describe the characteristics of preeclampsia with a focus on the mechanisms of angiogenesis and the RAAS and its role in the pathogenesis of preeclampsia. Our main focus will be on the intriguing association between preeclampsia and the subsequent increased risk of developing CKD and on the potential mechanisms by which the risk of CKD is elevated in women with a history of preeclampsia.

The podocyte's response to stress: the enigma of foot process effacement

Progressive loss of podocytes is the most frequent cause accounting for end-stage renal failure. Podocytes are complex, terminally differentiated cells incapable of replicating. Thus lost podocytes cannot be replaced by proliferation of neighboring undamaged cells. Moreover, podocytes occupy a unique position as epithelial cells, adhering to the glomerular basement membrane (GBM) only by their processes, whereas their cell bodies float within the filtrate in Bowman's space. This exposes podocytes to the danger of being lost by detachment as viable cells from the GBM. Indeed, podocytes are continually excreted as viable cells in the urine, and the rate of excretion dramatically increases in glomerular diseases. Given this situation, it is likely that evolution has developed particular mechanisms whereby podocytes resist cell detachment. Podocytes respond to stress and injury by undergoing tremendous changes in shape. Foot process effacement is the most prominent and, yet in some ways, the most enigmatic of those changes. This review summarizes the various structural responses of podocytes to injury, focusing on foot process effacement and detachment. We raise the hypothesis that foot process effacement represents a protective response of podocytes to escape detachment from the GBM.

HDAC inhibitors in experimental liver and kidney fibrosis

Histone deacetylase (HDAC) inhibitors have been extensively studied in experimental models of cancer, where their inhibition of deacetylation has been proven to regulate cell survival, proliferation, differentiation and apoptosis. This in turn has led to the use of a variety of HDAC inhibitors in clinical trials. In recent years the applicability of HDAC inhibitors in other areas of disease has been explored, including the treatment of fibrotic disorders. Impaired wound healing involves the continuous deposition and cross-linking of extracellular matrix governed by myofibroblasts leading to diseases such as liver and kidney fibrosis; both diseases have high unmet medical needs which are a burden on health budgets worldwide. We provide an overview of the potential use of HDAC inhibitors against liver and kidney fibrosis using the current understanding of these inhibitors in experimental animal models and in vitro models of fibrosis.

Diagnostic accuracy of spot urinary protein and albumin to creatinine ratios for detection of significant proteinuria or adverse pregnancy outcome in patients with suspected pre-eclampsia: systematic review and meta-analysis

OBJECTIVE

To determine the diagnostic accuracy of two "spot urine" tests for significant proteinuria or adverse pregnancy outcome in pregnant women with suspected pre-eclampsia.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Searches of electronic databases 1980 to January 2011, reference list checking, hand searching of journals, and contact with experts.

INCLUSION CRITERIA

Diagnostic studies, in pregnant women with hypertension, that compared the urinary spot protein to creatinine ratio or albumin to creatinine ratio with urinary protein excretion over 24 hours or adverse pregnancy outcome. Study characteristics, design, and methodological and reporting quality were objectively assessed.

DATA EXTRACTION

Study results relating to diagnostic accuracy were extracted and synthesised using multivariate random effects meta-analysis methods.

RESULTS

Twenty studies, testing 2978 women (pregnancies), were included. Thirteen studies examining protein to creatinine ratio for the detection of significant proteinuria were included in the multivariate analysis. Threshold values for protein to creatinine ratio ranged between 0.13 and 0.5, with estimates of sensitivity ranging from 0.65 to 0.89 and estimates of specificity from 0.63 to 0.87; the area under the summary receiver operating characteristics curve was 0.69. On average, across all studies, the optimum threshold (that optimises sensitivity and specificity combined) seems to be between 0.30 and 0.35 inclusive. However, no threshold gave a summary estimate above 80% for both sensitivity and specificity, and considerable heterogeneity existed in diagnostic accuracy across studies at most thresholds. No studies looked at protein to creatinine ratio and adverse pregnancy outcome. For albumin to creatinine ratio, meta-analysis was not possible. Results from a single study suggested that the most predictive result, for significant proteinuria, was with the DCA 2000 quantitative analyser (>2 mg/mmol) with a summary sensitivity of 0.94 (95% confidence interval 0.86 to 0.98) and a specificity of 0.94 (0.87 to 0.98). In a single study of adverse pregnancy outcome, results for perinatal death were a sensitivity of 0.82 (0.48 to 0.98) and a specificity of 0.59 (0.51 to 0.67).

CONCLUSION

The maternal "spot urine" estimate of protein to creatinine ratio shows promising diagnostic value for significant proteinuria in suspected pre-eclampsia. The existing evidence is not, however, sufficient to determine how protein to creatinine ratio should be used in clinical practice, owing to the heterogeneity in test accuracy and prevalence across studies. Insufficient evidence is available on the use of albumin to creatinine ratio in this area. Insufficient evidence exists for either test to predict adverse pregnancy outcome.