Salivary uric acid as a predictive test of preeclampsia, pregnancy-induced hypertension and preterm delivery: A pilot study

Vaginal host immune-microbiome-metabolite interactions associated with spontaneous preterm birth in a predominantly white cohort

In order to improve spontaneous preterm birth (sPTB) risk stratification in a predominantly white cohort of non-labouring pregnant women, we analysed their vaginal microbiota, metabolite, cytokine and foetal fibronectin (FFN) concentrations at two gestational time points (GTPs): GTP1 (20+0-22+6 weeks, preterm = 17; term = 32); and GTP2 (26+0-28+6 weeks, preterm = 14; term = 31). At GTP1, the preterm-delivered women showed abundant G. vaginalis (AUC = 0.77) over L. crispatus and L. iners, and upregulation of 10 metabolites. At GTP2, the same women had more lactobacilli- and mixed anaerobes-dominated microbiota, upregulation of five metabolites, and decreased TNFR1, distinguishing them from their term counterparts (AUC = 0.88). From GTP1 to GTP2, sPTB was associated with increased microbiota α-diversity, and upregulation of pantothenate and urate. CXCL10 declined in the term-delivered women by ~3-fold, but increased in the preterm-delivered women (AUC = 0.68), enhanced by FFN (AUC = 0.74). Characterising the complex dynamic interactions between cervicovaginal microbial metabolites and host immune responses could enhance sPTB risk stratification.

Analysis of uric acid and high-density lipoprotein levels in refractory posner-schlossman syndrome patients: a matched case-control study by the propensity score

BACKGROUND

Recent studies have indicated that oxidative stress is a crucial pathophysiological process in glaucoma. We hypothesized that Posner-Schlossman syndrome (PSS) is a vascular inflammation in the ciliary body due to oxidative stress and endothelial dysfunction. Thus, we investigated serum uric acid (UA) and lipid levels in patients with refractory PSS with the aim of providing basic evidence for the mechanism of PSS.

METHODS

This is a retrospective, case-control study. A total of 81 refractory PSS and 409 control participants were included in this study. Clinical and laboratory characteristics were reviewed using an electronic medical system. Propensity score-matched (PSM) analysis was performed to reduce demographic differences. The t-test, Mann-Whitney U test, and χ2 test were used to assess the differences between the PSS and control groups. Logistic regression analysis was used to identify the predictors of PSS.

RESULTS

The higher serum UA (364.14 ± 98.72µmol/L vs. 322.38 ± 72.09µmol/L), higher low-density lipoprotein (LDL) / High-density lipoprotein (HDL) ratio (2.50 ± 0.97 vs. 1.95 ± 0.72) and lower HDL (1.29 ± 0.32 mmol/L vs. 1.59 ± 0.38 mmol/L) can be noticed in refractory PSS than control group. Logistics regression identified UA > 420 µmol/L (OR = 4.461) and the HDL < 1.03 mmol/L (OR = 3.896) were the independent risk factors for refractory PSS.

CONCLUSIONS

Increasing serum UA and decreasing HDL levels were positively correlated with the incidence risk of refractory PSS. Further prospective longitudinal studies and animal models are needed.

The clinical efficacy of a novel smartphone-based salivary self-test for the prediction of pre-eclampsia, pregnancy-induced hypertension and intrauterine growth restriction: a prospective cohort study

Introduction

This study investigated the efficacy of a digital health solution utilizing smartphone images of colorimetric test-strips for home-based salivary uric acid (sUA) measurement to predict pre-eclampsia (PE), pregnancy-induced hypertension (PIH), and intrauterine growth restriction (IUGR).

Methods

495 pregnant women were included prospectively at Zealand University Hospital, Denmark. They performed weekly self-tests from mid-pregnancy until delivery and referred these for analysis by a smartphone-app. Baseline characteristics were obtained at recruitment and pregnancy outcomes from the journals. The mean compliance rate of self-testing was assessed. For the statistical analyses, standard color analyses deduced the images into the red-green-blue (RGB) color model value, to observe the individual, longitudinal pattern throughout the pregnancy for each outcome. Extended color analyses were applied, deducing the images into 72 individual color variables that reflected the four dominant color models. The individual discriminatory ability was assessed by calculating the area under the curve for the outcome of PE, and the outcome of hypertensive pregnancy disorders solely or combined with IUGR at 25 weeks of gestation and for the weekly color change between 20 and 25 weeks of gestation.

Results

Thirty-four women (6.9%) developed PE, 17 (3.4%) PIH, and 10 (2.0%) IUGR. The overall mean compliance rate was 67%, increasing to 77% after updating the smartphone-app halfway through the study. The longitudinal pattern of the RGB value showed a wide within-person variability, and discrimination was not achieved. However, it was noted that all women with IUGR repeatedly had RGB values below 110, contrasting women with non-IUGR. Significant discriminatory ability was achieved for 8.2% of the analyses of individual color variables, of which 27.4% summarized the Hue color variable. However, the analyses lacked consistency regarding outcome group and gestational age.

Conclusion

This study is the first proof-of-concept that digital self-tests utilizing colorimetric sUA measurement for the prediction of PE, PIH, and IUGR is acceptable to pregnant women. The discriminatory ability was not found be sufficient to have clinical value. However, being the first study that compares individual color variables of the four dominant color models, this study adds important methodological insights into the expanding field of smartphone-assisted colorimetric test-strips.

Is salivary uric acid, a putative biomarker of pre-eclampsia, of maternal, placental, or fetal origin?

OBJECTIVES

Increased salivary uric acid (sUA) represents a potential biomarker predictive of pre-eclampsia (PE), but its origin is unclear. The study explores whether sUA levels reflect maternal or feto-placental physiological stress and whether sUA levels in these cases correlate with amniotic fluid (fetal origin), maternal blood (maternal origin), or cord blood (fetal vs placental origin).

STUDY DESIGN

Pregnant women (n = 39) undergoing amniotomy or caesarean section after 34 gestational weeks were designated into three groups of either maternal, feto-placental, or no signs of physiological stress: women (n = 15) in the established first phase of active labour and without any signs of fetal growth restriction (FGR) or PE were assigned to the maternal stress group, women (n = 6) with an ultrasound-based diagnosis of FGR, with or without PE, were assigned to the feto-placental stress group, and women (n = 18) not yet in active labour and without any signs of FGR or PE, were assigned to the control group. Uric acid levels in corresponding samples of amniotic fluid, saliva, maternal blood, and cord blood were compared between groups and between body compartments within each group.

RESULTS

The feto-placental stress group showed increased UA levels in saliva (median, interquartile range [IQR]: 0.47 [0.38] mmol/L, P = 0.023) and maternal blood (0.42 [0.13] mmol/L, P = 0.032), but no differences in amniotic fluid or cord blood compared with the other groups. Within the control and maternal stress group, sUA levels were lower compared with maternal blood (0.20 [0.08] vs 0.25 [0.08] mmol/L, Pcontrol = 0.018; 0.20 [0.06] vs 0.26 [0.08] mmol/L, Pmaternal = 0.001) and highest in amniotic fluid (control group (0.49 [0.18] mmol/L): Pmaternal,blood = 0.001, Pumbilical,artery = <0.001, Pumbilical,vein = <0.001, Psaliva = <0.001) (maternal stress group (0.56 [0.23] mmol/L): Pmaternal,blood = 0.021, Pumbilical,artery = 0.006, Pumbilical,vein = 0.004, Psaliva = 0.003). Levels did not differ between compartments in the feto-placental stress group.

CONCLUSIONS

Salivary and maternal blood UA levels were increased in the feto-placental stress group with salivary levels increasing more than blood levels compared with the maternal stress and control groups, whilst UA in amniotic fluid were not different between the groups, suggesting a placental origin and potential use of sUA as a biomarker of placental dysfunction, including FGR and severe PE.

Effects of information-knowledge-attitude-practice health education combined with cluster-based care in patients with gestational hypertension

To analyze the impact of information-knowledge-attitude-practice (IKAP) health education incorporated with cluster-based care on blood pressure control, pregnancy outcome and life quality in those who have gestational hypertension, and to provide methodological backing for the care of patients. A total of 80 patients with pregnancy-induced hypertension were selected as the research objects and randomly divided into control and experimental groups, with 40 cases in each group. The control group received routine cluster care, which included providing individual and group health information through the distribution of health education manuals to hypertensive patients during pregnancy and their families. The experimental group received additional IKAP health education, including data collection, health knowledge imparted, concept change and behavior generation process. Blood pressure control status was measured and recorded. Adverse pregnancy outcomes include placenta previa, cesarean section, hyperamniotic fluid, fetal distress, and postpartum hemorrhage. Postpartum quality of life conditions, including physical activity, emotional awareness, physical discomfort, mental health, sleep quality, postpartum anxiety or depression, and general health were evaluated. Age, prepregnancy BMI, and educational level did not significantly vary between the 2 groups(P > .05). In comparison to the control group, the experimental group demonstrated healthier behavior. Blood pressure and weight control during pregnancy were better than control group. The frequency of adverse pregnancy was inferior to control group. The number of adverse neonatal conditions was inferior to control group. The postpartum quality of life score was higher in the experimental group compared to the control group. The combination of IKAP health education and cluster based care has a better effect on blood pressure control compared to the sole use of cluster based care. This approach can reduce the likelihood of experiencing adverse pregnancy outcomes and help improve the quality of life for patients after delivery.

The potential role of the gingival crevicular fluid biomarkers in the prediction of pregnancy complications

Early and minimally invasive methods are required to predict the risk of multiple adverse pregnancy outcomes. A potential technique with growing interest utilizes the gingival crevicular fluid (GCF), a physiological serum exudate found in the healthy gingival sulcus and in the periodontal pocket in inflammatory conditions. Analysis of biomarkers in the GCF is a minimally invasive method that can be feasible and cost-effective. The potential use of GCF biomarkers along with other clinical indicators in early pregnancy may provide reliable predictors of several adverse pregnancy outcomes, therefore, reducing both maternal and fetal morbidities. Various studies have reported that increased or decreased concentrations of different biomarkers in GCF are associated with a high risk of developing pregnancy complications. In particular, such associations have been commonly demonstrated with gestational diabetes, pre-eclampsia, and pre-term birth. However, limited evidence is available regarding other pregnancy complications such as preterm premature rupture of membranes, recurrent miscarriage, small for gestational age, and hyperemesis gravidarum. In this review, we discuss the reported association between individual GCF biomarkers and common pregnancy complications. Future research is required to provide more solid evidence of the predictive value of those biomarkers in estimating women's risk for each disorder.

Characterizing and Evaluating Diurnal Salivary Uric Acid Across Pregnancy Among Healthy Women

Uric acid levels during pregnancy have been examined as a potential indicator of risk for gestational diabetes mellites, hypertension, and related adverse birth outcomes. However, evidence supporting the utility of serum uric acid levels in predicting poor maternal and fetal health has been mixed. The lack of consistent findings may be due to limitations inherent in serum-based biomeasure evaluations, such as minimal repeated assessments and variability in the timing of these assessments. To address these gaps, we examined repeated measurements of diurnal salivary uric acid (sUA) levels in a sample of 44 healthy women across early-mid and late pregnancy. We assessed potential covariates and confounds of sUA levels and diurnal trajectories, as well as associations between maternal weight gain and blood pressure during pregnancy and sUA concentrations. Using multilevel linear models, we found sUA increased across pregnancy and displayed a robust diurnal pattern with the highest concentrations at waking, a steep decline in the early morning, and decreasing levels across the day. Maternal pre-pregnancy BMI, age, prior-night sleep duration, and fetal sex were associated with sUA levels and/or diurnal slopes. Maternal blood pressure and gestational weight gain also showed significant associations with sUA levels across pregnancy. Our results expand upon those found with serum UA measurements. Further, they demonstrate the feasibility of using at-home, minimally-invasive saliva sampling procedures to track UA levels across pregnancy with potential applications for the long-term monitoring of maternal cardiometabolic risk.

Rational design of allosterically regulated toehold mediated strand displacement circuits for sensitive and on-site detection of small molecule metabolites

Development of small molecule biosensors enables rapid and de-centralized small molecule detection that meets the demands of routine health monitoring and rapid diagnosis. Among them, allosteric transcription factor (aTF)-based biosensors have shown potential in modular design of small molecule detection platforms due to their ligand-regulated DNA binding activity. Here, we expand the capabilities of a biosensor that leverages the aTF-based regulation of toehold-mediated strand displacement (TMSD) circuits for uric acid (UA) detection in non-invasive salivary samples by utilizing the UA-responsive aTF HucR. The impact of the low ligand affinity of the native HucR was addressed by engineering a two-pass TMSD circuit with in silico rational design. This combined strategy achieved enrichment of the output signal and overcame the negative impact of the matrix effect on the sensitivity and overall response of the biosensor when using real samples, which enabled semi-quantitative detection in the normal salivary UA levels. As well, enhancements provided by the two-pass design halved the turnaround time to less than 15 minutes. To sum up, the two-cycle DNA circuit design enabled aTF-based simple, rapid and one-step non-invasive salivary UA detection, showing its potential in metabolite detection for health monitoring.

Salivary Uric Acid: A Noninvasive Wonder for Clinicians?

This review is a summary of the modern-day approach and recent trend in the determination of uric acid in the saliva of humans and its use in diagnosis by clinicians. Uric acid, which is the end product obtained from the breakdown of purine nucleotides, is an important biomarker associated with various conditions. Uric acid is found in various body fluids, such as serum, plasma, and urine. It can be used as an important tool for various diseases, such as gout and hyperuricemia, or conditions that are associated with increased oxidative stress. Recently, there has been an emergence of studies that have utilized uric acid concentrations measured in the saliva and studied its association with various diseases. Salivary uric acid can prove to be a noninvasive method to provide a diagnosis of serious illness. A raised uric acid level in the saliva can be associated with cancer, human immunodeficiency virus (HIV) infection, gout, and hypertension. A reduced level of salivary uric acid on the other hand can be a marker for Alzheimer's disease, progression of multiple sclerosis, and impairment of cognition. Online search databases, including Google Scholar, Scopus, PubMed, and Web of Science, were searched, and articles that were published before September 2021 based on salivary uric acid analysis were analyzed for this review. Uric acid is an essential biomarker that has antioxidant properties. Assessment of salivary uric acid levels was found to be essential in conditions such as cancer, metabolic syndrome, neurological conditions, psychiatric conditions, human immunodeficiency virus, and gout and in monitoring treatment of hyperuricemia. Although having importance in diagnosis and therapeutic monitoring, salivary uric acid analysis has not gained enough popularity due to limitations such as saliva collection and sample processing issues. With proper education and standardization, salivary uric acid analysis can be used as a cost-effective and noninvasive tool for getting a clue about antioxidant biomarker concentration in saliva and hence various diseases associated with oxidative stress.