Endotoxin-specific chromogenic assay for plasma in pregnant women, umbilical cords, neonates and children

A risk score for early predicting bloodstream infections in febrile obstetric patients: a pilot study

PURPOSE

Early prediction of bloodstream infections (BSI) among obstetric patients remains to be a challenge for clinicians. The objective of this study was to develop a risk score and assess its discriminative ability in febrile obstetric patients in a maternal intensive care unit (ICU).

METHODS

Between May 2015 and August 2020, a total of 497 febrile obstetric patients were categorized into BSI group (n = 276) and Non-BSI group (n = 221) based on the result of blood cultures. White blood cell count, C-reactive protein (CRP), procalcitonin (PCT), time of interval from amniorrhea to fever (IFAF) and maximum body temperature (T_max) were compared between the two groups. All patients were divided into training set (n = 298) and validation set (n = 199). The risk score was established using univariate and multivariate logistic regression from patients in the training set, and its discriminative ability was tested among patients in the validation set.

RESULTS

The levels of neutrophil, CRP, PCT, IFAF and T_max were significantly higher in BSI group than those in Non-BSI group. PROM, T_max, neutrophil and CRP acted as independent predictive factors for BSI in the training set. The area under the receiver operating characteristic curve of risk score for early prediction of BSI in the training, validation set and the whole population was 0.829 (95% CI 0.783-0.876), 0.848 (95% CI 0.792-0.903) and 0.838 (95% CI 0.803-0.873), respectively.

CONCLUSION

The risk score has a feasible discriminatory ability in early prediction of BSI in febrile obstetric patients.

Maternal blood endotoxin activity in pregnancies complicated by preterm premature rupture of membranes

Objective: To compare maternal blood endotoxin activity (EA) in women with preterm premature rupture of membranes (PPROM) with gestational age (GA) matched controls; to evaluate serial EA till birth in PPROM and its correlation with latency to delivery. Methods: We followed singleton preterm pregnancies from admission with PPROM until birth. Uncomplicated, GA-matched pregnancies served as controls. Demographics, birth and neonatal outcomes were collected. EA (EAA™) was assessed serially in PPROM and at study entry in controls. EA was compared using Mann Whitney and Wilcoxon tests, p value <.05 was considered significant. Results: We recruited 20 cases of PPROM and 20 controls. Demographics were similar between groups. Mean GA of PPROM was 29.0 ± 2.2 weeks and median latency was 7.5 (IQR 14.1) weeks. Median EA at admission following PPROM was significantly elevated over controls (0.43 (0.18) versus 0.36 (0.2); p < .02). Overall there was no difference in median EA at admission and in labor (0.43 (0.18) versus 0.33 (0.21); p = .2) following PPROM. However, on comparing cases with latency to delivery ≤7 days (n = 10) versus >7 days (n = 10), there was a significant drop in EA in the latter group (0.44 (0.2) versus 0.34 (0.2); p < .004). Conclusions: EA in PPROM represents a promising biomarker in predicting the clinical evolution of preterm birth.

Lipopolysaccharide and soluble CD14 in cord blood plasma are associated with prematurity and chorioamnionitis

BACKGROUND

Lipopolysaccharide (LPS), an endotoxin of Gram-negative bacteria, causes preterm birth in animals and has been implicated as a factor triggering preterm labor and systemic complications in humans. Little is known regarding LPS in the cord blood (CB) of term and preterm infants and its association with maternal and fetal characteristics.

METHODS

CB was obtained from term (n = 15) and preterm infants (n = 76) after delivery. Plasma levels of LPS, C-reactive protein (CRP), and soluble CD14 (sCD14) were measured using commercially available kits (limulus amebocyte lysate and enzyme-linked immunosorbent assay). Four linear regression models were created in order to identify independent variables that predict plasma LPS levels.

RESULTS

The analyte levels were significantly higher in preterm vs. term infant CB: LPS (24.48 vs. 1 pg/ml; P = 0.0009), CRP (87.9 vs. 47 ng/ml; P = 0.01), and sCD14 (0.32 vs.0.35 µg/ml; P = 0.013). There was a (significant) positive correlation between CB LPS levels and gestational age, birth weight, CRP levels, sCD14 levels, and association with both clinical and histological chorioamnionitis.

CONCLUSION

Our data suggest that LPS is associated with preterm labor and inflammation (CRP elevation and chorioamnionitis). These findings may be relevant to the understanding of the role of LPS in prematurity and its role in preterm morbidities.

Stimulation of human fetal astrocyte proliferation by bacterial lipopolysaccharides and lipid A

This report concerns the effect of bacterial endotoxin [lipopolysaccharide(LPS) and lipid A] on cultured human fetal astrocytes. Exposure to 1 micrograms/ml LPS or lipid A caused a striking stimulation of the rate of proliferation of the cells. The effect was most pronounced with exponentially growing cultures. Stimulation was associated with enhance DNA synthesis as ascertained by [3H]thymidine incorporation. These findings at the cellular level may be of relevance in the elucidation of the effects of bacterial endotoxins on the developing human brain.