Placental protein 14 as a potential biomarker for diagnosis of preterm premature rupture of membranes

The abundances of LTF and SOD2 in amniotic fluid are potential biomarkers of gestational age and preterm birth

Neonates who are born preterm (PT) are usually characterized by immature physiological development, and preterm birth (PTB) is the leading cause of neonatal morbidity and mortality if intensive medical care is not available to PTB neonates. Early prediction of a PTB enables medical personnel to make preparations in advance, protecting the neonate from the subsequent health risks. Therefore, many studies have worked on identifying invasive or noninvasive PT biomarkers. In this study, we collected amniocentesis-derived (at the second trimester of gestation) amniotic fluid (AF) samples. At delivery, AF samples were classified into PTB or full-term birth (FTB). We first applied protein mass spectrometry technology to globally screen AF proteins, followed by specific protein validation with ELISA. We identified four protein biomarkers of PTB, including lactotransferrin (LTF), glutathione-disulfide reductase (GSR), myeloperoxidase (MPO) and superoxide dismutase 2 (SOD2). Further analyses demonstrated that their abundances were negatively correlated with neonatal weight and gestational age. In addition, by mimicking survival rate analysis widely used in tumor biology, we found that LTF and SOD2 were prognostic factors of gestational age, with higher levels denoting shorter gestational age. Finally, using the abundances of the four protein biomarkers, we developed a prediction model of PTB with an auROC value of 0.935 (sensitivity = 0.94, specificity = 0.89, p value = 0.0001). This study demonstrated that the abundances of specific proteins in amniotic fluid were not only the prognostic factors of gestational age but also the predictive biomarkers of PTB. These four AF proteins enable identification of PTB early in the second trimester of gestation, facilitating medical intervention to be applied in advance.

Vaginal fluid urea and creatinine, an untapped diagnostic tool for premature rupture of membranes

PURPOSE

The diagnosis of premature rupture of membranes (PROM) can be difficult in equivocal cases. This study was designed to test the validity of vaginal fluid urea and creatinine in the diagnosis of PROM against the gold standard, the Amnisure ROM test™ METHODS: The study was a prospective observational study. All consenting eligible pregnant women between gestational ages of 28 weeks to 41 weeks + 6 days were recruited from the obstetrics emergency and antenatal clinic of the Federal medical centre, Keffi. Patients with history of drainage of liquor were recruited as the case group, and controls who match for age, parity and gestational age were recruited from the antenatal clinic to constitute the control group. Vaginal fluid aspirated was assessed in the laboratory for urea and creatinine levels and an Amnisure ROM test™ done. The sensitivity, specificity, negative and positive predictive values of vaginal fluid urea and creatinine were assessed in the diagnosis of PROM.

RESULTS

Vaginal fluid urea and creatinine had sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), respectively, of 94%, 82%, 93.18% and 83.93%, and 98%, 90%, 97.82% and 90.74%. The cutoff values for vaginal fluid urea and creatinine were 1.25 mg/dl and 0.23 mg/dl, respectively.

CONCLUSIONS

This study has found that vaginal fluid urea and creatinine are very effective tests in diagnosis of PROM. It is a cheaper and more readily available alternative to the Amnisure test. It is especially useful in our environment, especially in cases of equivocal PROM, as a cost-effective means to confirm the diagnosis.

TRIAL REGISTRATION NUMBER (NIGERIA CLINICAL TRIAL REGISTRY)

72961653, retrospectively registered on the 2020-07-09.

Keratin 8 Is an Inflammation-Induced and Prognosis-Related Marker for Pancreatic Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the highest-grade malignancies in the world. More effective biomarkers and treatment plans are necessary to improve the diagnosis rate and clinical outcome. The oncogenesis of PDAC is influenced by several factors, including chronic pancreatitis (CP). Keratin 8 (KRT8) is an important member of the keratin protein family and plays a role in regulating the cellular response to stress stimuli and mediating inflammatory reactions. However, the role of KRT8 in pancreatitis and PDAC is still poorly understood. Here we assessed the differentially expressed genes (DEGs) by bioinformatic methods with expression profiles available online for a caerulein-induced mouse model and human PDAC tissue. The prognostic value was evaluated by Kaplan–Meier analysis and Cox regression analysis. The diagnostic value was evaluated by Receiver Operating Characteristic analysis (ROC). The function of the genes was predicted by protein-protein interaction analysis, correlation analysis, and GO analysis. The conclusion was further validated in rat pancreatitis model, human tissue, and PDAC cell lines, including immunohistochemical staining (IHC), CCK-8 assay, wound healing assay, and flow cytometry. KRT8 was found to be upregulated in murine pancreatitis tissue, human CP tissue, and human PDAC tissue. High expression of KRT8 had a negative impact on the prognosis of PDAC patients. KRT8 was predicted to be involved in the regulation of the migration and viability of PDAC cells, which was validated in PDAC cell lines. Knockdown of KRT8 impaired the migration and proliferation and induced apoptosis in PDAC cell lines. In conclusion, keratin 8 is an inflammation-induced molecule and could serve as a diagnostic and prognostic marker for PDAC patients. More studies are needed for further validation from the perspective of precision and individualized medicine.

Potential Serum Biomarkers Associated with Premature Rupture of Fetal Membranes in the First Trimester

Premature rupture of the fetal membranes (PROM) is a common and important obstetric complication with increased risk of adverse consequences for both mothers and fetuses. An accurate and timely method to predict the occurrence of PROM is needed for ensuring maternal and fetal safety. Untargeted metabolomics was applied to characterize metabolite profiles related to PROM in early pregnancy. 41 serum samples from pregnant women who developed PROM later in gestation and 106 from healthy pregnant women as a control group, were analyzed. Logistic regression analysis was adjusted to analyze a PROM prediction model in the first trimester. A WISH amniotic cell viability assay was applied to explore the underlying mechanisms involved in PROM, mediated by C8-dihydroceramide used to mimic a potential biomarker (Cer 40:0; O2). Compared with healthy controls, 13 serum metabolites were identified. The prediction model comprising four compounds (Cer 40:0; O2, sphingosine, isohexanal and PC O-38:4) had moderate accuracy to predict PROM events with the maximum area under the curve of a receiver operating characteristics curve of approximately 0.70. Of these four compounds, Cer 40:0; O2 with an 1.81-fold change between PROM and healthy control serum samples was defined as a potential biomarker and inhibited the viability of WISH cells. This study sheds light on predicting PROM in early pregnancy and on understanding the underlying mechanism of PROM.

Trial Registration: This study protocol has been registered at www.ClinicalTrials.gov, CT03651934, on 29 August 2018 (prior to recruitment).

Applications of Tandem Mass Spectrometry (MS/MS) in Protein Analysis for Biomedical Research

Mass Spectrometry (MS) allows the analysis of proteins and peptides through a variety of methods, such as Electrospray Ionization-Mass Spectrometry (ESI-MS) or Matrix-Assisted Laser Desorption Ionization-Mass Spectrometry (MALDI-MS). These methods allow identification of the mass of a protein or a peptide as intact molecules or the identification of a protein through peptide-mass fingerprinting generated upon enzymatic digestion. Tandem mass spectrometry (MS/MS) allows the fragmentation of proteins and peptides to determine the amino acid sequence of proteins (top-down and middle-down proteomics) and peptides (bottom-up proteomics). Furthermore, tandem mass spectrometry also allows the identification of post-translational modifications (PTMs) of proteins and peptides. Here, we discuss the application of MS/MS in biomedical research, indicating specific examples for the identification of proteins or peptides and their PTMs as relevant biomarkers for diagnostic and therapy.

Current and Emerging Strategies for Prediction and Diagnosis of Prelabour Rupture of the Membranes: A Narrative Review

Prelabour rupture of membranes (PROM) refers to the disruption of foetal membranes before the onset of labour, resulting in the leakage of amniotic fluid. PROM complicates 3% and 8% of preterm and term pregnancies, respectively. Accurate and timely diagnosis is crucial for effective management to prevent adverse maternal- and foetal-outcomes. The diagnosis of equivocal PROM cases with traditional methods often becomes challenging in current obstetrics practice; therefore, various novel biochemical markers have emerged as promising diagnostic tools. This narrative review is sought to review the published data to understand the current and emerging trends in diagnostic modalities in term and preterm pregnancies complicated with PROM and the potential role of various markers for predicting preterm PROM (pPROM) and chorioamnionitis in women with pPROM.

IgGFc-binding protein in pregnancies complicated by spontaneous preterm delivery: a retrospective cohort study

To determine the IgGFc-binding protein (FcgammaBP) concentration in amniotic and cervical fluids in preterm prelabor rupture of membranes (PPROM) and preterm labor with intact membranes (PTL) and to assess the diagnostic indices of FcgammaBP to predict intra-amniotic infection (the presence of both microbial invasion of the amniotic cavity and intra-amniotic inflammation). In this study, we included 170 and 79 women with PPROM and PTL, respectively. Paired cervical and amniotic fluid samples were obtained using a Dacron polyester swab and transabdominal amniocentesis, respectively. The FcgammaBP concentrations in the samples were assessed using an enzyme-linked immunosorbent assay. The presence of intra-amniotic infection was associated with elevated FcgammaBP concentrations in pregnancies with PPROM and PTL [PPROM—presence: 86 ng/mL vs. absence: 13 ng/mL, p < 0.0001, area under receiver operating characteristic curve (AUC) = 0.94; PTL—presence: 140 ng/mL vs. absence: 22 ng/mL, p < 0.0001, AUC = 0.86]. In cervical fluid, the concentrations of FcgammaBP were elevated in the presence of intra-amniotic infection in pregnancies with PPROM only (presence: 345 ng/mL vs. absence: 60 ng/mL, p < 0.0001, AUC = 0.93). FcgammaBP in amniotic fluid might be a marker of intra-amniotic infection in women with both PPROM and PTL However, in cervical fluid, it is only observed in women with PPROM.