Urinary congophilia in women with hypertensive disorders of pregnancy and preexisting proteinuria or hypertension

Validation of urinary Congo Red preeclampsia detection point-of-care devise

OBJECTIVES

To evaluate a commercial a Congo Red urine devise for assessing preeclampsia risk.

STUDY DESIGN

Prospective non-intervention study among women presenting with clinical suspicion of preeclampsia. The devise was used at the time of enrolment and, depending on gestation, on 1-3 later occasions.

OUTCOME MEASURES

Abnormal diffusion patterns classified as positive or negative, in relation to subsequent confirmation of preeclampsia (detection and false-positive rates, and predictive value) and the probability of diagnosis within a fixed time period (rule-in and rule-out).

RESULTS

600 women were enrolled in the study and follow-up information was available on 538, of whom 95 had preeclampsia at delivery and 443 did not. At enrolment the detection rate was 18 % and the false-positive rate 3.2 %; positive predictive value - probability of positive result being associated with preeclampsia - was 55 % and negative predictive value - probability of negative result not being preeclampsia - was 85 %. A positive test ruled-in delivery with preeclampsia within 28 days among 35 % and ruled-out preeclampsia with 7 days among 98 %. Repeat testing after enrolment yielded similar results to the initial sample.

CONCLUSION

The test has screening potential although published studies differ in the observed detection rate. Using the test to rule-out preeclampsia within 7 days can provide a significant management advantage especially for triaging patients and selecting those who can be managed at the peripheral centres.

Overexpression of long noncoding RNA DUXAP8 inhibits ER-phagy through activating AKT/mTOR signaling and contributes to preeclampsia

Preeclampsia (PE) is a life-threatening pregnancy-specific complication with controversial mechanisms and no effective treatment except delivery is available. Currently, increasing researchers suggested that PE shares pathophysiologic features with protein misfolding/aggregation disorders, such as Alzheimer disease (AD). Evidences have proposed defective autophagy as a potential source of protein aggregation in PE. Endoplasmic reticulum-selective autophagy (ER-phagy) plays a critical role in clearing misfolded proteins and maintaining ER homeostasis. However, its roles in the molecular pathology of PE remain unclear. We found that lncRNA DUXAP8 was upregulated in preeclamptic placentae and significantly correlated with clinical indicators. DUXAP8 specifically binds to PCBP2 and inhibits its ubiquitination-mediated degradation, and decreased levels of PCBP2 reversed the activation effect of DUXAP8 overexpression on AKT/mTOR signaling pathway. Function experiments showed that DUXAP8 overexpression inhibited trophoblastic proliferation, migration, and invasion of HTR-8/SVneo and JAR cells. Moreover, pathological accumulation of swollen and lytic ER (endoplasmic reticulum) was observed in DUXAP8-overexpressed HTR8/SVneo cells and PE placental villus trophoblast cells, which suggesting that ER clearance ability is impaired. Further studies found that DUXAP8 overexpression impaired ER-phagy and caused protein aggregation medicated by reduced FAM134B and LC3II expression (key proteins involved in ER-phagy) via activating AKT/mTOR signaling pathway. The increased level of FAM134B significantly reversed the inhibitory effect of DUXAP8 overexpression on the proliferation, migration, and invasion of trophoblasts. In vivo, DUXAP8 overexpression through tail vein injection of adenovirus induced PE-like phenotypes in pregnant rats accompanied with activated AKT/mTOR signaling, decreased expression of FAM134B and LC3-II proteins and increased protein aggregation in placental tissues. Our study reveals the important role of lncRNA DUXAP8 in regulating trophoblast biological behaviors through FAM134B-mediated ER-phagy, providing a new theoretical basis for understanding the pathogenesis of PE.

Aβ1-42 stimulates an increase in autophagic activity through tunicamycin-induced endoplasmic reticulum stress in HTR-8/SVneo cells and late-onset pre-eclampsia

Environmental changes can trigger endoplasmic reticulum (ER) stress and misfolded protein accumulation, potentially leading to pre-eclampsia (PE). Amyloid-β (Aβ) is a crucial misfolded protein that can overactivate autophagy. Our study assessed the expression of Aβ1-42 and autophagic activity in PE placental tissues and trophoblasts under ER stress. Placental tissues were surgically collected from normal pregnant women (NP) and pregnant women with late-onset PE (LOPE) delivering through cesarean section. The expression levels of Aβ1-42 were detected in both PE and NP placental tissues, as well as in tunicamycin (TM)-induced HTR-8/SVneo cells. Autophagy-related proteins, such as Beclin-1, the ratio of LC3-II to LC3-I, ATG5, and SQSTM1/p62 in the placental tissues and HTR-8/SVneo cells were measured by Western blot. The number and morphology of autophagosomes were observed using transmission electron microscopy (TEM). Potential targets associated with the unfolded protein response (UPR) in the placental tissues of NP and PE cases were screened using PCR Arrays. The misfolded protein was significantly upregulated in the PE group. In both PE placental tissues and TM-induced HTR-8/SVneo cells, not only was Aβ1-42 upregulated, but also Beclin-1, ATG5, and LC3BII/I were significantly increased, accompanied by an increase in autophagosome count, while SQSTM1/P62 was downregulated. A total of 17 differentially expressed genes (DEGs) associated with the UPR were identified, among which elevated calnexin (CANX) was validated in the placenta from both PE and TM-induced HTR-8/SVneo cells. Autophagy is significantly upregulated in PE cases due to ER stress-induced Aβ1-42 accumulation, likely mediated by autophagy-related proteins involved in the UPR.

A point-of-care urine test to predict adverse maternal and neonatal outcomes in Asian women with suspected preeclampsia

OBJECTIVES

To assess clinical utility of the urine Congo red dot test (CRDT) in predicting composite adverse maternal and neonatal outcomes in women with suspected preeclampsia (PE).

METHODS

CRDT result and pregnancy outcomes were prospectively documented in women with new onset or pre-existing hypertension, new or pre-existing proteinuria, PE symptoms and suspected PE-related fetal growth restriction or abnormal Doppler presenting from 20 weeks' gestation between January 2020 and December 2022. Participants and clinicians were blinded to the CRDT result and managed according to internally agreed protocols. Composite maternal outcome was defined as PE, postpartum hemorrhage, intensive care unit admission, and maternal death. Composite neonatal outcome was defined as small for gestational age, preterm birth, 5-min Apgar score < 7, neonatal intensive care unit admission, and neonatal death.

RESULTS

Two hundred and forty-four women out of two hundred and fifty-one (97.2%) had a negative CRDT. All seven women with positive CRDT had both adverse maternal and neonatal outcomes, giving positive predictive values (PPV) of 100%. Rates of composite adverse maternal and neonatal outcomes in CDRT negative women were 103/244 [42.2%, 95% confidence interval (CI) 36.2%-48.5%] and 170/244 (69.7%, 95% CI 63.6%-75.1%), respectively. CRDT negative predictive values (NPV) for adverse maternal and neonatal outcomes were, respectively, 141/244 (57.8%, 95% CI 48.6%-68.2%) and 74/244 (30.3%, 95% CI 23.8%-38.1%).

CONCLUSION

CRDT had low NPV but high PPV for adverse maternal and neonatal outcomes in women with suspected PE. Its role in clinical management and triage of women with suspected PE is limited as it cannot identify those at low risk of developing adverse outcomes.

Exploiting sweet relief for preeclampsia by targeting autophagy-lysosomal machinery and proteinopathy

The etiology of preeclampsia (PE), a severe complication of pregnancy with several clinical manifestations and a high incidence of maternal and fetal morbidity and mortality, remains unclear. This issue is a major hurdle for effective treatment strategies. We recently demonstrated that PE exhibits an Alzheimer-like etiology of impaired autophagy and proteinopathy in the placenta. Targeting of these pathological pathways may be a novel therapeutic strategy for PE. Stimulation of autophagy with the natural disaccharide trehalose and its lacto analog lactotrehalose in hypoxia-exposed primary human trophoblasts restored autophagy, inhibited the accumulation of toxic protein aggregates, and restored the ultrastructural features of autophagosomes and autolysosomes. Importantly, trehalose and lactotrehalose inhibited the onset of PE-like features in a humanized mouse model by normalizing autophagy and inhibiting protein aggregation in the placenta. These disaccharides restored the autophagy-lysosomal biogenesis machinery by increasing nuclear translocation of the master transcriptional regulator TFEB. RNA-seq analysis of the placentas of mice with PE indicated the normalization of the PE-associated transcriptome profile in response to trehalose and lactotrehalose. In summary, our results provide a novel molecular rationale for impaired autophagy and proteinopathy in patients with PE and identify treatment with trehalose and its lacto analog as promising therapeutic options for this severe pregnancy complication.

Comparing urine point-of-care tests to screen preeclampsia: Congo-red dot paper test versus dipstick urinalysis

To compare the urine Congo-red dot paper test (CRD) with dipstick urinalysis to screen preeclampsia (PE). A total of 409 paired spot urine samples were obtained prospectively from women with suspected pre-eclampsia attending for routine hospital visits. Congo-red dot paper test and dipstick urinalysis were examined and compared to screen pre-eclampsia. The agreement between the two urinary test is modest (kappa coefficient = 0.28, 95% CI 0.14-0.42). The specificity of CRD was higher than urinalysis (97.4% vs. 90.4%, p < .001). Urinalysis performed better in sensitivity (77.3% vs. 40.9%, p = .04) and the area under the receiver operating characteristic curves (AUC) (0.84 [95% CI 0.74-0.94] vs. 0.69 [95% CI 0.55-0.83], p = .04) than CRD, respectively. The sensitivity, specificity, AUC of the parallel test of them is 86.4% (64.0%-96.4%), 89.1% (85.5%-92.0%), and 0.88 (95% CI 0.79-0.96). And the serial test is 31.8% (14.7%-54.9%), 98.7% (96.8%-99.5%), 0.65 (95% CI 0.51-0.79), accordingly. The urinalysis is a better diagnosing test for preeclampsia. CRD could aid in the diagnosis of patients with preeclampsia. Combined the two tests in suspected patients may further improve the performance in the diagnosis of preeclampsia. Further study need to be made for its potential clinical practice.

Protein Misfolding in Pregnancy: Current Insights, Potential Mechanisms, and Implications for the Pathogenesis of Preeclampsia

Protein misfolding disorders are a group of diseases characterized by supra-physiologic accumulation and aggregation of pathogenic proteoforms resulting from improper protein folding and/or insufficiency in clearance mechanisms. Although these processes have been historically linked to neurodegenerative disorders, such as Alzheimer's disease, evidence linking protein misfolding to other pathologies continues to emerge. Indeed, the deposition of toxic protein aggregates in the form of oligomers or large amyloid fibrils has been linked to type 2 diabetes, various types of cancer, and, in more recent years, to preeclampsia, a life-threatening pregnancy-specific disorder. While extensive physiological mechanisms are in place to maintain proteostasis, processes, such as aging, genetic factors, or environmental stress in the form of hypoxia, nutrient deprivation or xenobiotic exposures can induce failure in these systems. As such, pregnancy, a natural physical state that already places the maternal body under significant physiological stress, creates an environment with a lower threshold for aberrant aggregation. In this review, we set out to discuss current evidence of protein misfolding in pregnancy and potential mechanisms supporting a key role for this process in preeclampsia pathogenesis. Improving our understanding of this emerging pathophysiological process in preeclampsia can lead to vital discoveries that can be harnessed to create better diagnoses and treatment modalities for the disorder.

Diagnostics of preeclampsia based on Congo red binding to urinary components: Rationales and limitations

Preeclampsia is a disorder that can occur during pregnancy and is one of the leading causes of death among pregnant women. This disorder occurs after the 20th week of pregnancy and is characterized by arterial hypertension, proteinuria, fetoplacental, and multiple organ dysfunctions. Despite the long history of studying preeclampsia, its etiology and pathogenesis remain poorly understood, and therapy is symptomatic. One of the factors of the disorder is believed to be misfolded proteins that are prone to form amyloid aggregates. The CRD tests, utilizing the binding of the amyloid-specific dye Congo red to urine components, demonstrate high efficiency in diagnosing preeclampsia. However, these tests have also been found to be positive in other disorders with proteinuria, presumably associated with concomitant amyloidosis. To assess the limitations of the CRD tests, we examined urine congophilia and protein components mediating Congo red positivity in patients with proteinuria, including preeclampsia, amyloid and non-amyloid nephropathies. We stained the urine samples and calculated congophilia levels. We also assessed the contribution of large protein aggregates to congophilia values using ultracentrifugation and determined the molecular weights of congophilic urinary proteins using centrifugal concentrators. All proteinuric groups demonstrate positive results in the CRD tests and congophilia levels were more than two times higher compared with the control non-proteinuric groups (p <0.01). There was a strong correlation between urine protein excretion and congophilia in amyloid nephropathy (rs = 0.76), non-amyloid nephropathies (rs = 0.90), and preeclampsia (rs = 0.90). Removal of large aggregates from urine did not affect the congophilia levels. Separation of urine protein fractions revealed congophilic components in the range of 30-100 kDa, including monomeric serum albumin. Our results indicate limitations of CRD tests in preeclampsia diagnostics in women with renal disorders and underscore the need for further research on the mechanisms of Congo red binding with urine components.

Urinary congophilia in pregnancy: a marker of kidney injury rather than preeclampsia

BACKGROUND

The differentiation between preeclampsia and similarly presenting kidney disease in pregnancy is a diagnostic challenge. Although some laboratory tests have been utilized, globally validated tools are yet needed, particularly in resource-limited settings. Congophilic proteins are abundantly detected in the urine of pregnant women who develop preeclampsia that is thought to be a marker of disease process. The present study aimed to assess the diagnostic and predictive utility of urinary congophilia in pregnant women with hypertensive disorders of pregnancy as well as kidney diseases.

METHODS

This cohort study included 157 pregnant women, classified as healthy controls ( n  = 38), preeclampsia/eclampsia ( n  = 45), gestational hypertension ( n  = 9), chronic hypertension ( n  = 8), chronic kidney disease (CKD) ( n  = 27), and pregnancy-related acute kidney injury (PR-AKI) ( n  = 30). Urinary congophilia was assessed by Congo Red Dot Blot assay.

RESULTS

Congo red retention (CRR) values were significantly higher in women with preeclampsia/eclampsia ( P  ≤ 0.001), chronic hypertension ( P  = 0.029), gestational hypertension ( P  = 0.017), CKD ( P  ≤ 0.001), PR-AKI secondary to preeclampsia ( P  ≤ 0.001), and PR-AKI secondary to other causes ( P  = 0.001), compared with healthy controls. Women with preeclampsia, CKD, and PR-AKI (non-preeclampsia related) exhibited the highest levels of CRR. CRR positively correlated to proteinuria ( P  = 0.006) and serum creatinine ( P  = 0.027). CRR did not significantly vary between women who presented antepartum and those presented postpartum after removal of the placenta ( P  = 0.707). CRR at a cut-off point of at least 1.272 had 91% specificity and 61.1% sensitivity in predicting renal recovery in PR-AKI patients. CRR had a poor specificity in discriminating preeclampsia from the other clinical presentations.

CONCLUSION

Urinary congophilia could not discriminate preeclampsia from similarly presenting kidney diseases in pregnancy. Further studies are needed to improve differentiation of these conditions.

A point-of care urine test to predict preeclampsia development in Asian women with suspected preeclampsia

OBJECTIVES

To evaluate the diagnostic performance and clinical utility of the urine Congo red dot test (CRDT) in predicting preeclampsia (PE) within 7 days, 14 days and 28 days of assessment.

STUDY DESIGN

A prospective single center double blind non-intervention study conducted from January 2020 to March 2022. Urine congophilia has been proposed as a point-of-care test for the prediction and rapid identification of PE. In our study, urine CRDT and pregnancy outcomes were assessed in women presenting with clinical features of suspected PE after 20 weeks of gestation.

RESULTS

Among the 216 women analyzed, 78 (36.1 %) women developed PE, in which only 7 (9.0 %) of them had a positive urine CRDT test. The median (IQR) interval between the initial test and the diagnosis of PE was significantly shorter for women with a positive urine CRDT compared with women with a negative urine CRDT (1 day (0-5 days) vs 8 days (1-19 days), P = 0.027). The negative predictive value of a negative urine CRDT test for PE within 7 days, 14 days and 28 days of assessment were 83.73 % (95 %CI 81.75 %- 85.54 %), 78.92 % (95 % confidence interval [CI] 77.07 %- 80.71 %) and 71.77 % (95 %CI 70.06 %- 73.42 %) respectively. The sensitivity of the urine CRDT in ruling in PE within 7 days, 14 days and 28 days of assessment were 17.07 % (95 %CI 7.15 %- 32.06 %), 13.73 % (95 %CI 5.70 %- 26.26 %) and 10.61 % (95 %CI 4.37 %- 20.64 %), respectively.

CONCLUSIONS

Urine CRDT alone has high specificity yet low sensitivity in the short-term prediction of PE in women with suspected PE. Further studies are required to evaluate its clinical utility.

The effectiveness of the Congo Red Dot paper test in hypertensive disorders of pregnancy: A systematic review and meta-analysis

Background

Congo Red Dot Paper Test (CRDPT) appears to be a simple, cost-effective, non-invasive diagnostic tool for hypertensive disorders of pregnancy (HDP). The main objective of the study is to assess the effectiveness of CRDPT in detecting HDP.

Methods

This is a systemic review and meta-analysis of published studies on the effectiveness of CRDPT in the detection of HDP. The study was conducted in line with the PRISMA-DTA guidelines. The PICOS framework was used to search for relevant articles using Medline, PubMed, Google Scholar, Web of Science, and the Cochrane Library databases. The articles were screened against a set of inclusion and exclusion criteria and analysed using the Review Manager 5.4 software.

Results

A title, abstract and full article screening was conducted on 18,153 potential articles based on the inclusion and exclusion criteria. The screening yielded five articles for meta-analysis. The total number of normotensive pregnant women (n = 3,380) in the included studies was five times higher than the total number of women with pre-eclampsia (n = 535). A difference between the HDP and normotensive group was noted. This is indicated by a significantly decreased in the effectiveness of CRDPT in detecting HDP as compared to normotensive group [Risk Ratio (RR) = 6.32 (2.17, 18.43) p < 0.00001]. The included studies had a high nature of heterogeneity (I ² = 98%, p < 0.00001) partially due to different study designs included in the analysis and different regions where studies were conducted given that none of these studies were conducted in African countries where HDP is prominent.

Conclusions

According to results generated from 5 studies in this meta-analysis, it was found that CRDPT might not be effective in the detection of hypertensive disorder of pregnancy. Moreover, more research, especially in African women where hypertensive disorders of pregnancy are prevalent, are re-quired to ascertain these findings.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021283679, identifier: CRD42021283679.

Evidence From Human Placenta, Endoplasmic Reticulum-Stressed Trophoblasts, and Transgenic Mice Links Transthyretin Proteinopathy to Preeclampsia

BACKGROUND

We have demonstrated that protein aggregation plays a pivotal role in the pathophysiology of preeclampsia and identified several aggregated proteins in the circulation of preeclampsia patients, the most prominent of which is the serum protein TTR (transthyretin). However, the mechanisms that underlie protein aggregation remain poorly addressed.

METHODS

We examined TTR aggregates in hypoxia/reoxygenation-exposed primary human trophoblasts (PHTs) and the preeclampsia placenta using complementary approaches, including a novel protein aggregate detection assay. Mechanistic analysis was performed in hypoxia/reoxygenation-exposed PHTs and Ttr transgenic mice overexpressing transgene-encoded wild-type human TTR or Ttr^-/- mice. High-resolution ultrasound analysis was used to measure placental blood flow in pregnant mice.

RESULTS

TTR aggregation was inducible in PHTs and the TCL-1 trophoblast cell line by endoplasmic reticulum stress inducers or autophagy-lysosomal disruptors. PHTs exposed to hypoxia/reoxygenation showed increased intracellular BiP (binding immunoglobulin protein), phosphorylated IRE1α (inositol-requiring enzyme-1α), PDI (protein disulfide isomerase), and Ero-1, all markers of the unfolded protein response, and the apoptosis mediator caspase-3. Blockade of IRE1α inhibited hypoxia/reoxygenation-induced upregulation of Ero-1 in PHTs. Excessive unfolded protein response activation was observed in the early-onset preeclampsia placenta. Importantly, pregnant human TTR mice displayed aggregated TTR in the junctional zone of the placenta and severe preeclampsia-like features. High-resolution ultrasound analysis revealed low blood flow in uterine and umbilical arteries in human TTR mice compared with control mice. However, Ttr^-/- mice did not show any pregnancy-associated abnormalities.

CONCLUSIONS

These observations in the preeclampsia placenta, cultured trophoblasts, and Ttr transgenic mice indicate that TTR aggregation is an important causal contributor to preeclampsia pathophysiology.

Urinary Congophilia Confirmed With the CapCord Test Is Associated With Pregnancy Outcomes in Women With Early-Onset Pre-eclampsia

Background: The association between misfolded proteins presented in the urine of pregnant women and pregnancy outcomes associated with early-onset pre-eclampsia (PE) remains unclear. This study aimed to investigate this association to examine the predictive value of urinary congophilia in the prognostication of pregnancy outcomes in this patient group in the Chinese population.

Materials and Methods: This study included 1,397 patients, of which 46, 147, and 8 patients had gestational hypertension, PE, and chronic hypertension, respectively, and 1,196 were healthy controls undergoing the CapCord test for urinary congophilia. Patients with PE were divided into early- and late-onset groups. Patients with early-onset PE were further divided into iatrogenic prematurity and full-term delivery groups, the rates of urinary congophilia were compared between the groups; additionally, this patient group was divided into positive and negative urinary congophilia groups, clinical characteristics and pregnancy outcomes were compared between the groups. Univariate and multivariate logistic regression analyses were performed.

Results: A total of 113 (76.9%) of 147 patients in the PE group had urinary congophilia; this rate was higher than that observed in the other three groups (χ² = 780.892, p < 0.001). Gestational age in the early-onset PE group at both onset and delivery was lower than that in the late-onset PE group (p < 0.001). The rates of iatrogenic prematurity and hemolysis, elevated liver enzymes, and low platelet count syndrome were both higher in the early-onset PE group than in the late-onset PE group (p < 0.001, p < 0.05). In addition, the rate of urinary congophilia in the early-onset PE group was higher than that in the late-onset PE group (χ² = 13.297, p < 0.001). Urinary congophilia was an independent risk factor for iatrogenic prematurity among patients with early-onset PE in both univariate [odds ratio (OR) 17.143, 95% confidence interval (CI): 4.719–62.271; p < 0.001] and multivariate (OR 18.174; 95% CI: 4.460–74.063; p < 0.001) analyses. Patients with early-onset PE and urinary congophilia were more likely than their counterparts without urinary congophilia to deliver at a lower gestational age, present with iatrogenic prematurity, and have a shorter latency period between onset and delivery.

Conclusion: Urinary congophilia confirmed with the CapCord test may help predict pregnancy outcomes in patients with early-onset PE.

Congo red dot test in the early prediction and diagnosis of pre-eclampsia in a tertiary health care centre in India

OBJECTIVES

To demonstrate the use of urine congophilia quantification in the prediction and diagnosis of pre-eclampsia using Congo red dot test.

STUDY DESIGN

A prospective cohort study in 378 consecutive pregnant women was conducted. All eligible, consenting women of gestational age between 10 and 34 weeks were enrolled in the study. The presence of urinary misfolded proteins was screened by a simple dot test technique on unsupported nitrocellulose membrane using Congo red dye.

RESULTS

The urinary congophilia was increased in urine from women with pre eclampsia compared to healthy pregnant controls. The mean CRR value of pre eclamptic pregnant women (35.2 ± 9.4%) was five times higher than that of mean CRR value of normotensive pregnant women (6.9 ± 4.7%). The mean gestational age at which Congo red test showed positive was 26.95 ± 2.90 weeks and the time taken from CRD positive to development of PE was 4.92 ± 2.54 weeks of gestation.

CONCLUSIONS

In our study, the CRD test was not only effective in predicting pre-eclampsia but was also useful in differentiating between pre-eclampsia and other forms of hypertension, as well as early onset and late onset pre-eclampsia, with positive predictive value of 80.36% and negative predictive value of 92.86.

Cell death mechanisms and their roles in pregnancy related disorders

Autophagy and apoptosis are catabolic pathways essential for homeostasis. They play a crucial role for normal placental and fetal development. These cell death mechanisms are exaggerated in placental disorders such as preeclampsia, intrauterine growth restriction (IUGR) and gestational diabetes mellitus (GDM). Apoptosis is widely studied, highly controlled and regulated whereas; autophagy is an orderly degradation and recycling of the cellular components. Cellular senescence may be initiated by a variety of stimuli, including hypoxia, oxidative stress, reduction in survival signals and nutrition deprivation. Apoptosis is regulated by two types of pathways intrinsic and extrinsic. Extrinsic pathway is initiated by apoptosis inducing cells such as macrophages, natural killer cells whereas; intrinsic pathway is initiated in response to DNA damage, cell injury and lack of oxygen. In autophagy, the cell or organelles undergo lysosomal degradation. Placental apoptosis increases as the gestation progresses while autophagy plays a role in trophoblast differentiation and invasion. In pregnancy disorders like preeclampsia and IUGR, proapoptotic markers such as caspase 3, 8, BAX are higher and antiapoptotic markers like Bcl-2 are lower. In GDM, apoptotic markers are reduced resulting in increased placental mass and fetal macrosomia. Apoptosis in the pathological pregnancies is also influenced by the reduced levels of micronutrients and long chain polyunsaturated fatty acids resulting in disturbed placental biology. This chapter describes the role of various key molecular events involved in cellular senescence and the various factors influencing them. This will help identify future therapeutic strategies for better management of these processes.

Congo red test for identification of preeclampsia: Results of a prospective diagnostic case-control study in Bangladesh and Mexico

BACKGROUND

Misfolded proteins in the urine of women with preeclampsia bind to Congo Red dye (urine congophilia). We evaluated a beta prototype of a point-of-care test for the identification of urine congophilia in preeclamptic women.

METHODS

Prospective diagnostic case-control study conducted in 409 pregnant women (n = 204 preeclampsia; n = 205 uncomplicated pregnancies) presenting for delivery in two tertiary level hospitals located in Bangladesh and Mexico. The GV-005, a beta prototype of a point-of-care test for detecting congophilia, was performed on fresh and refrigerated urine samples. The primary outcome was the prevalence of urine congophilia in each of the two groups. Secondary outcome was the likelihood of the GV-005 (index test) to confirm and rule-out preeclampsia based on an adjudicated diagnosis (reference standard).

FINDINGS

The GV-005 was positive in 85% of clinical cases (83/98) and negative in 81% of clinical controls (79/98) in the Bangladesh cohort. In the Mexico cohort, the GV-005 test was positive in 48% of clinical cases (51/106) and negative in 77% of clinical controls (82/107). Adjudication confirmed preeclampsia in 92% of Bangladesh clinical cases (90/98) and 61% of Mexico clinical cases (65/106). The odds ratio of a urine congophilia in adjudicated cases versus controls in the Bangladesh cohort was 34^.5 (14^.7 - 81^.1) (p<0^.001) compared to 4^.2 (2^.1 - 8^.4; p<0^.001) in the Mexico cohort.

INTERPRETATION

The GV-005, a beta prototype of a point-of-care test for detection of urine congophilia, is a promising tool for rapid identification of preeclampsia.

FUNDING

Saving Lives at Birth.

Differential Diagnosis of Preeclampsia Based on Urine Peptidome Features Revealed by High Resolution Mass Spectrometry

Preeclampsia (PE) is a severe pregnancy complication, which may be considered as a systemic response in the second half of pregnancy to physiological failures in the first trimester, and can lead to very serious consequences for the health of the mother and fetus. Since PE is often associated with proteinuria, urine proteomic assays may represent a powerful tool for timely diagnostics and appropriate management. High resolution mass spectrometry was applied for peptidome analysis of 127 urine samples of pregnant women with various hypertensive complications: normotensive controls (n = 17), chronic hypertension (n = 16), gestational hypertension (n = 15), mild PE (n = 25), severe PE (n = 25), and 29 patients with complicated diagnoses. Analysis revealed 3869 peptides, which mostly belong to 116 groups with overlapping sequences. A panel of 22 marker peptide groups reliably differentiating PE was created by multivariate statistics, and included 15 collagen groups (from COL1A1, COL3A1, COL2A1, COL4A4, COL5A1, and COL8A1), and single loci from alpha-1-antitrypsin, fibrinogen, membrane-associated progesterone receptor component 1, insulin, EMI domain-containing protein 1, lysine-specific demethylase 6B, and alpha-2-HS-glycoprotein each. ROC analysis of the created model resulted in 88% sensitivity, 96.8% specificity, and receiver operating characteristic curve (AUC) = 0.947. Obtained results confirm the high diagnostic potential of urinary peptidome profiling for pregnancy hypertensive disorders diagnostics.

Evidence for lysosomal biogenesis proteome defect and impaired autophagy in preeclampsia

The etiology of preeclampsia (PE), a serious pregnancy complication, remains an enigma. We have demonstrated that proteinopathy, a pathologic feature of neurodegenerative diseases, is a key observation in the placenta and serum from PE patients. We hypothesize that the macroautophagy/autophagy machinery that mediates degradation of aggregated proteins and damaged organelles is impaired in PE. Here, we show that TFEB (transcription factor EB), a master transcriptional regulator of lysosomal biogenesis, and its regulated proteins, LAMP1, LAMP2, and CTSD (cathepsin D), were dysregulated in the placenta from early and late onset PE deliveries. Primary human trophoblasts and immortalized extravillous trophoblasts (EVTs) showed reduced TFEB expression and nuclear translocation as well as lysosomal protein content in response to hypoxia. Hypoxia-exposed trophoblasts also showed decreased PPP3/calcineurin phosphatase activity and increased XPO1/CRM1 (exportin 1), events that inhibit TFEB nuclear translocation. These proteins were also dysregulated in the PE placenta. These results are supported by observed lysosomal ultrastructural defects with decreased number of autolysosomes in hypoxia-treated primary human trophoblasts. Autophagy-deficient human EVTs exhibited poor TFEB nuclear translocation, reduced lysosomal protein expression and function, and increased MTORC1 activity. Sera from PE patients induced these features and protein aggregation in EVTs. Importantly, trophoblast-specific conditional atg7 knockout mice exhibited reduced TFEB expression with increased deposition of protein aggregates in the placenta. These results provide compelling evidence for a regulatory link between accumulation of protein aggregates and TFEB-mediated impaired lysosomal biogenesis and autophagy in the placenta of PE patients. Abbreviation:atg7: autophagy related 7; CTSD: cathepsin D; ER: endoplasmic reticulum; EVTs: extravillous trophoblasts; KRT7: keratin 7; LAMP1: lysosomal associated membrane protein 1; LAMP2: lysosomal associated membrane protein 2; mSt: mStrawberry; MTORC1: mechanistic target of rapamycin complex 1; NP: normal pregnancy; NPS: normal pregnancy serum; PE: preeclampsia; PES: preeclampsia serum; p-RPS6KB: phosphorylated ribosomal protein S6 kinase B1; SQSTM1/p62: sequestosome 1; TEM: transmission electron microscopy; TFEB: transcription factor EB; XPO1/CRM1: exportin 1.

Placental extracellular vesicles and pre-eclampsia

Pre-eclampsia is a hypertensive disease of pregnancy characterized by new-onset hypertension, with either proteinuria and/or organ dysfunction. Pre-eclampsia is a leading cause of maternal morbidity and mortality; however, the underlying cellular and molecular mechanisms are not well understood. There is consensus that the underlying mechanism(s) resulting in pre-eclampsia is centered around abnormal placentation, inadequate spiral-artery remodeling, and deficiency in trophoblast invasion, resulting in impaired maternal blood flow to the placenta and a release of signals and/or inflammatory mediators into maternal circulation triggering the systemic manifestations of pre-eclampsia. ER stress, resulting in impaired autophagy and placental release of aggregated proteins, may also confer systemic stress to maternal organs in pre-eclampsia. Extracellular vesicles (EVs), lipid-bilayer enclosed structures containing macromolecules including proteins, miRNA, and other important nucleotides, have been suggested to play an important role in this maternal-fetal communication. Circulating EVs are present in greater quantity in the plasma of pre-eclampsia subjects compared to normal pregnancy, and the placental derived EVs have been shown to have altered protein and RNA cargo. In this review, we will focus on EVs and their role in pre-eclampsia, specifically their role in immune responses, inflammation, altered angiogenesis, and endothelial dysfunction.

Late pregnancy screening for preeclampsia with a urinary point-of-care test for misfolded proteins

The aim was to describe and assess a new late pregnancy point-of-care urinary preeclampsia screening test. Urine samples were collected from a consecutive series of 1,532 pregnant women hospitalized at 20-41 weeks gestation in a Chinese single obstetric unit. A simple disposable Congo red based device was newly developed and employed to prospectively test misfolded proteins in pregnant women's urine. A total of 140 preeclampsia cases were clinically diagnosed, 101 severe and 87 pre-term. Detection and false positive rates were similar in the training and validation subsets with combined 74% and 3.0%. The detection rate was 83% in severe, 86% in pre-term, 49% and 50% in mild and term cases (P<0.0001) respectively. In conclusion, a simple point-of-care urinary test for misfolded proteins can be used to screen for preeclampsia in late pregnancy with very high screening performance. To the best of our knowledge, this is the first study to screen for preeclampsia using Congo red based device in Chinese pregnant population.

The high-resolution mass spectrometry study of the protein composition of amyloid-like urine aggregates associated with preeclampsia

The study of protein misfolding and post-translational processing abnormalities is a promising diagnostic approach for socially significant pathologies associated with the accumulation of abnormal forms of proteins. Recently, it was shown that amyloid-like aggregates can be observed in the urine of pregnant women with preeclampsia, which is the most severe hypertensive complication that can lead to fateful outcomes. The protein composition of urine aggregates may clarify the molecular mechanisms underlying the pathology and has not yet been studied in detail. Using a proteomic approach based on high-resolution mass spectrometry, we studied the protein composition of amyloid-like structures that aggregate in the presence of Congo red azo-dye in the urine of pregnant women with preeclampsia. Fragments of β-sheets of α-1-antitrypsin, complement 3, haptoglobin, ceruloplasmin, and trypstatin were identified as most likely targets for Congo red binding.

Current Understanding of Autophagy in Pregnancy

Autophagy is an evolutionarily conserved process in eukaryotes to maintain cellular homeostasis under environmental stress. Intracellular control is exerted to produce energy or maintain intracellular protein quality controls. Autophagy plays an important role in embryogenesis, implantation, and maintenance of pregnancy. This role includes supporting extravillous trophoblasts (EVTs) that invade the decidua (endometrium) until the first third of uterine myometrium and migrate along the lumina of spiral arterioles under hypoxic and low-nutrient conditions in early pregnancy. In addition, autophagy inhibition has been linked to poor placentation—a feature of preeclamptic placentas—in a placenta-specific autophagy knockout mouse model. Studies of autophagy in human placentas have revealed controversial results, especially with regard to preeclampsia and gestational diabetes mellitus (GDM). Without precise estimation of autophagy flux, wrong interpretation would lead to fixed tissues. This paper presents a review of the role of autophagy in pregnancy and elaborates on the interpretation of autophagy in human placental tissues.

Urinary protein carbonyl levels and its correlation with protein misfolding in preeclampsia

OBJECTIVE

To evaluate the association of protein carbonylation with preeclampsia and its correlation with urinary protein misfolding.

METHOD

Protein carbonyl and misfolded protein levels were measured in the midstream urine sample (58 preeclamptic and 44 normotensive pregnancy) by ELISA and Congo Red Dot assay respectively.

RESULTS

Significant difference was observed in the levels of protein carbonyls (P = 0.002) and misfolded proteins (P = 0.001). Correlation between protein carbonyl and misfolded proteins levels was significant but weak (r = 0.3; P = 0.018).

CONCLUSION

Urinary protein carbonyl level is elevated in preeclampsia but plays a minor role in proteins misfolding.

Congo Red Dot Paper Test for Antenatal Triage and Rapid Identification of Preeclampsia

BACKGROUND

Proteins in the urine of women with preeclampsia (PE) bind Congo Red dye (urine congophilia). We sought to determine the diagnostic performance of a paper-based point-of-care test detecting urine congophilia for rapid triage and diagnosis of PE.

METHODS

Prospective cohort study conducted in 346 consecutive pregnant women evaluated for PE in the Labour and Delivery triage unit at our institution. The Congo Red Dot (CRD) Paper Test (index test) was performed on fresh urine samples. The CRD Paper Test results were compared to an expert adjudicated diagnosis in each case. The accuracy of the CRD Paper Test was also compared to urine and serum analytes (placental growth factor and soluble fms-like tyrosine kinase-1) previously proposed as diagnostic aids for PE.

FINDINGS

During the first triage visit, 32% (112/346) of women received a clinical diagnosis of PE. Yet, 63% (217/346) were admitted for in-patient diagnostic work-up or delivery. The CRD Paper Test was positive in 25% (86/346) of the cases. Adjudication confirmed PE in 28% (96/346) of all cases. The CRD Paper Test outperformed measured serum and urine markers (80·2% sensitivity, 89·2% specificity, 92·1% negative predictive value, 86·7% accuracy). The pre-test, positive and negative post-test probabilities were 27·7%, 74·0%, and 8·0%, respectively. Of women who were discharged undelivered, 38% (133/346) had at least one additional triage visit and the interval between the last negative and first positive CRD Paper Test was 12 (interquartile range, [5-34]) days.

INTERPRETATION

The CRD Paper Test is a simple, non-invasive, "sample-in/answer-out" point-of-care clinical tool for rapid identification of PE.

FUNDING

Saving Lives at Birth Program and NICHD.

Identification of Patients with Preeclampsia by Measuring Fluorescence of an Amyloid-Binding Aryl Cyano Amide in Human Urine Samples

Preeclampsia (PE) is a hypertensive disorder of pregnancy and one of the leading contributors to both maternal and perinatal morbidity and mortality. Reliable diagnostic parameters unique to the disorder that accurately define and diagnose PE are currently unavailable. Recent studies have revealed that PE is accompanied by the accumulation of amyloidogenic deposits in the placenta and the presence of congophilic amyloid-like protein aggregates in the urine. Here, we evaluate the capability of an amyloid-targeting aryl cyano amide (ARCAM-1) fluorophore to identify PE patients from analysis of urine samples. Our results reveal that this probe can distinguish patients with PE from gestationally healthy patients and patients suffering from non-PE hypertension, highlighting the potential for amyloid-targeting fluorophores to help identify PE patients during pregnancy.

Autophagy-Based Diagnosis of Pregnancy Hypertension and Pre-Eclampsia

This commentary highlights the article by Aoki et al that shows that Atg7 deficiency-mediated placental autophagy imbalance may contribute towards pre-eclampsia.

Prospective biomarkers in preterm preeclampsia: A review

Preterm pre-eclampsia (prior to 37 weeks' gestation) remains a major cause of maternal and fetal morbidity and mortality particularly in low to middle income countries. Much research has focused on first and second trimester predictors of pre-eclampsia with the aim of allowing stratification of antenatal care and trialling of potential preventative and therapeutic agents. However, none have been shown to be of benefit in randomised controlled trials. In this literature review we critically evaluate predictive and diagnostic tests for preterm pre-eclampsia and discuss their clinical use and potential value in the management of preterm pre-eclampsia. We defined preterm pre-eclampsia as pre-eclampsia occurring prior to 37 weeks' gestation. Substantial progress has been made in the development of predictive screening tests for preterm pre-eclampsia, but further research is needed prior to their introduction and integration into routine clinical practice. The performance of diagnostic tests mainly utilising angiogenic and anti-angiogenic factors for determining time to delivery in later pregnancy currently hold more promise than first trimester predictive tests, possible reflecting the heterogeneity of pre-eclampsia.

First-trimester screening for early and late preeclampsia using maternal characteristics, biomarkers, and estimated placental volume

BACKGROUND

Preeclampsia is a major cause of perinatal morbidity and mortality. First-trimester screening has been shown to be effective in selecting patients at an increased risk for preeclampsia in some studies.

OBJECTIVE

We sought to evaluate the feasibility of screening for preeclampsia in the first trimester based on maternal characteristics, medical history, biomarkers, and placental volume.

STUDY DESIGN

This is a prospective observational nonintervention cohort study in an unselected US population. Patients who presented for an ultrasound examination between 11-13+6 weeks' gestation were included. The following parameters were assessed and were used to calculate the risk of preeclampsia: maternal characteristics (demographic, anthropometric, and medical history), maternal biomarkers (mean arterial pressure, uterine artery pulsatility index, placental growth factor, pregnancy-associated plasma protein A, and maternal serum alpha-fetoprotein), and estimated placental volume. After delivery, medical records were searched for the diagnosis of preeclampsia. Detection rates for early-onset preeclampsia (<34 weeks' gestation) and later-onset preeclampsia (≥34 weeks' gestation) for 5% and 10% false-positive rates using various combinations of markers were calculated.

RESULTS

We screened 1288 patients of whom 1068 (82.99%) were available for analysis. In all, 46 (4.3%) developed preeclampsia, with 13 (1.22%) having early-onset preeclampsia and 33 (3.09%) having late-onset preeclampsia. Using maternal characteristics, serum biomarkers, and uterine artery pulsatility index, the detection rate of early-onset preeclampsia for either 5% or 10% false-positive rate was 85%. With the same protocol, the detection rates for preeclampsia with delivery <37 weeks were 52% and 60% for 5% and 10% false-positive rates, respectively. Based on maternal characteristics, the detection rates for late-onset preeclampsia were 15% and 48% for 5% and 10%, while for preeclampsia at ≥37 weeks' gestation the detection rates were 24% and 43%, respectively. The detection rates for late-onset preeclampsia and preeclampsia with delivery at >37 weeks' gestation were not improved by the addition of biomarkers.

CONCLUSION

Screening for preeclampsia at 11-13+6 weeks' gestation using maternal characteristics and biomarkers is associated with a high detection rate for a low false-positive rate. Screening for late-onset preeclampsia yields a much poorer performance. In this study the utility of estimated placental volume and mean arterial pressure was limited but larger studies are needed to ultimately determine the effectiveness of these markers.

Hypertension in Pregnancy: Defining Blood Pressure Goals and the Value of Biomarkers for Preeclampsia

Hypertensive disorders in pregnancy have been the cause of much clinical dilemma, affecting up to 10 % of all pregnancies. The precise blood pressure to achieve in a pregnant woman is usually a battle between minimizing end organ damage to the mother and providing adequate perfusion to the placenta and the fetus. This predicament is becoming more, not less, frequent as maternal ages increase in high resource nations. Biomarkers to predict preeclampsia, a subcategory of hypertension in pregnancy, have always been elusive. The discovery of angiogenic factors relevant to preeclampsia in the last decade, however, has propelled much needed research, both in the basic science and clinical arenas. In this review, we summarize the latest clinical studies and international guidelines on blood pressure goals in pregnancy, and discuss the most promising of biomarkers to predict or diagnose preeclampsia.

Hypertensive disorders in pregnancy

Renal injury or failure may occur in the context of pregnancy requiring special considerations with regard to fetal and maternal health. The condition of pregnancy itself may be a major factor in such injuries. In addition, for many young women previously known to be healthy, pregnancy may be the first presentation for routine urine and blood testing which may yield previously subclinical renal disease. As such, pregnancy may add complexity to considerations in the management of renal disease presenting coincidentally requiring knowledge of the physiologic changes and potential renal disorders that may be encountered during pregnancy.