Value of vaginal fluid proinflammatory cytokines for the prediction of early-onset neonatal infection in preterm premature rupture of the membranes

Diagnosis of Neonatal Sepsis: The Role of Inflammatory Markers

This is a narrative review on the role of biomarkers in the diagnosis of neonatal sepsis. We describe the difficulties to obtain standardized definitions in neonatal sepsis and discuss the limitations of published evidence of cut-off values and their sensitivities and specificities. Maternal risk factors influence the results of inflammatory markers as do gestational age, the time of sampling, the use of either cord blood or neonatal peripheral blood, and some non-infectious causes. Current evidence suggests that the use of promising diagnostic markers such as CD11b, CD64, IL-6, IL-8, PCT, and CRP, either alone or in combination, might enable clinicians discontinuing antibiotics confidently within 24-48 h. However, none of the current diagnostic markers is sensitive and specific enough to support the decision of withholding antibiotic treatment without considering clinical findings. It therefore seems to be justified that antibiotics are often initiated in ill term and especially preterm infants. Early markers like IL-6 and later markers like CRP are helpful in the diagnosis of neonatal sepsis considering the clinical aspect of the neonate, the gestational age, maternal risk factors and the time (age of the neonate regarding early-onset sepsis) of blood sampling.

Predictive value of vaginal IL-6 and TNFα bedside tests repeated until delivery for the prediction of maternal-fetal infection in cases of premature rupture of membranes

OBJECTIVE

Examine the predictive value for maternal-fetal infection of routine bedside tests detecting the proinflammatory cytokines, TNFα and IL-6, in the vaginal secretions of women with premature rupture of the membranes (PROM).

STUDY DESIGN

This prospective two-center cohort study included all women hospitalized for PROM over a 2-year period. A bedside test assessed IL-6 and TNFα in vaginal secretions. Both centers routinely tested CRP and leukocytes, assaying both in maternal serum, and analyzed vaginal bacterial flora; all samples were repeated twice weekly until delivery.

RESULTS

The study included 689 women. In cases of preterm PROM (PPROM) before 37 weeks (n=184), a vaginal sample positive for one or more bacteria was the only marker associated with early neonatal infection (OR 5.6, 95%CI; 2.0-15.7). Its sensitivity was 82% (95%CI; 62-94) and its specificity 56% (95%CI; 47-65). All positive markers of infection were associated with the occurrence of chorioamnionitis. In cases of PROM from 37 weeks onward (n=505), only CRP >5mg/dL was associated with early neonatal infection (OR=8.3, 95%CI; 1.1-65.4) or clinical chorioamnionitis (OR=6.8, 95%CI; 1.5-30.0). The sensitivity of CRP >5mg/dL was 91% (95%CI; 59-100) and its specificity 45% (95%CI; 40-51) for predicting early neonatal infection, and 89% (95%CI; 65-99) and 46% (95%CI; 41-51), respectively, for predicting clinical chorioamnionitis.

CONCLUSION

The association of vaginal cytokines with maternal-fetal infection is weak and thus prevents their use as a good predictor of maternal-fetal infection. CRP and vaginal samples may be useful for identifying a group of women at low risk of infection.

Do the levels of tumor makers or proinflammatory cytokines in mid-trimester cervical fluid predict early-stage cervical shortening?

AIM

In the present study, we aimed to assess the biomarkers in mid-trimester cervical fluid that can predict early stage cervical shortening.

MATERIAL AND METHODS

We obtained cervical swab specimens from 96 gravidas, after which the cervical length was measured, at approximately 20 weeks of gestation. Cervical length was measured again at 4 weeks after the initial examination. Cervical shortening was noted in 20 women between 20 and 24 weeks of gestation (group A), whereas no cervical shortening was noted in 76 women (group B). We evaluated the use of the levels of tumor markers, proinflammatory cytokines, and matrix metalloproteinase-8 (MMP-8) as candidate biomarkers. CA-125 and carcinoembryonic antigen levels were determined by using an automatic immunoassay system in both groups. Furthermore, IL-1β, IL-8, tumor necrosis factor-α, and MMP-8 levels were measured using an enzyme-linked immunosorbent assay.

RESULTS

The levels of inflammatory cytokines and MMP-8 did not differ between the two groups, and were not correlated with cervical length or the change in cervical length. Although CA-125 and carcinoembryonic antigen levels were higher in group A, they were not statistically significant (P = 0.304 and 0.092, respectively).

CONCLUSION

Early stage cervical shortening in mid-trimester was not associated with an increase in the levels of tumor markers or proinflammatory cytokines in cervical fluid.

Investigation of the maternal and cord plasma levels of IL-1 beta, TNF-alpha and VEGF in early membrane rupture

OBJECTIVE

Recent studies indicate a relationship between early membrane rupture (EMR) and proinflammatory cytokines like tumor necrosis factor (TNF) and interleukin (IL) and angiogenic factors like vascular endothelial growth factor (VEGF). In this study, we aimed to investigate the relationship between EMR and maternal and cord blood plasma levels of TNF-alpha, IL-1 beta and VEGF.

METHODS

This prospective, cross-sectional study was conducted with 85 pregnant women. The patients were divided into four groups as Group I (term EMR group, n = 21), Group II (preterm EMR group, n = 23), Group III (preterm non-EMR group, n = 19) and Group IV (term non-EMR group, n = 22). Plasma levels were assayed with ELISA method.

RESULTS

IL-1 beta levels were significantly lower, but TNF-alpha levels were significantly higher in maternal and cord plasma of EMR participants compared to non-EMR participants. There was no significant difference for VEGF levels. Cord plasma TNF-alpha levels were significantly higher than maternal plasma levels in EMR participants and cord plasma. VEGF levels were significantly higher than maternal levels in all participants.

CONCLUSIONS

Higher TNF-alpha levels in our EMR participants indicate an inflammatory process during EMR. Higher cord plasma VEGF levels may point out placental or fetal production. Further studies conducted with expanded populations are needed to discuss our results.

Inflammatory markers in cord blood or maternal serum for early detection of neonatal sepsis-a systemic review and meta-analysis

OBJECTIVE

To perform a quantitative review of the evidence on the diagnostic value of inflammatory markers in maternal serum or umbilical cord blood for the diagnosis of early-onset neonatal sepsis (EONS).

STUDY DESIGN

We searched multiple databases for studies published through March 2013 that evaluated the diagnostic performance of procalcitonin (PCT), C-reactive protein (CRP) and interleukin-6 (IL-6), and leukocyte count (white blood cell, WBC) in either umbilical cord blood or maternal serum for diagnosis of EONS. We summarized test performance characteristics with the use of forest plots, hierarchical summary receiver operating characteristic curves and bivariate random effects models.

RESULT

Our search identified 3874 citations, of which 15 studies evaluating 2178 episodes of suspected neonatal infection were included for analysis. IL-6 in cord blood with a pooled-positive likelihood ratio (LR+) of 9.47 (95% confidence interval: 3.86 to 23.3), PCT in cord blood with a LR+ of 5.72 (1.56 to 21.0) and IL-6 in maternal serum with a LR+ of 5.47 (2.10 to 14.2) can be qualified as a valid rule-in test. IL-6 in cord blood with a LR- of 0.10 (0.05 to 0.21) and PCT in cord blood with a LR- of 0.20 (0.12-0.37) can be qualified as a useful rule-out test. Either CRP or WBC was inadequate for diagnosis of EONS.

CONCLUSION

For cord blood sample, IL-6 or PCT can be used as reliable rule-in and rule-out tool. For maternal serum, only IL-6 appeared to be sufficient for rule-in diagnosis. An interventional study may be needed to answer whether the addition of these tests will improve the outcome of patients with EONS.

Rapid evaluation of the absence of inflammation after rupture of membranes

OBJECTIVES

The aim of this study was to validate the results of an immunochromatographic bedside test to detect IL6 and IL8 in vaginal secretions after rupture of membranes (ROM) with results obtained by ELISA tests.

METHODS

A prospective cohort of 60 women with ROM or preterm ROM (PROM) was recruited. An immunochromatographic bedside test was performed with vaginal secretions samplings at admission, every 48 hrs until labor and during labor. Remaining samples were frozen for ELISA analysis. The results of bedside tests were compared to those from ELISA analysis for 114 samples.

RESULTS

With all samples combined, the positive predictive values were 50% for IL6 and 86.8% for IL8 and the negative predictive values were 97.4% for IL6 and 53.3% for IL8. Kappa coefficients were 0.54 for IL6 and 0.41 for IL8.

CONCLUSION

Our findings show that a bedside test can detect the absence of IL6 in vaginal secretions. This result suggests that bedside test could be used for expectant management after premature PROM to inform the attending physician of the absence of inflammation in vaginal secretions.

Human trophoblast responses to Porphyromonas gingivalis infection

Porphyromonas gingivalis is a periodontal pathogen that is also associated with preterm low-birthweight delivery. We investigated the transcriptional responses of human extravillous trophoblasts (HTR-8) to infection with P. gingivalis. Over 2000 genes were differentially regulated in HTR-8 cells by P. gingivalis. In ontology analyses of regulated genes, overpopulated biological pathways included mitogen-activated protein (MAP) kinase signaling and cytokine production. Immunoblots confirmed overexpression of the MAP kinase pathway components MEK3, p38 and Max. Furthermore, P. gingivalis infection induced phosphorylation and activation of MEK3 and p38. Increased production of interleukin (IL)-1beta and IL-8 by HTR-8 cells was demonstrated phenotypically by enzyme-linked immunosorbent assay of HTR-8 cell lysates and culture supernatants. Hence, infection of trophoblasts by P. gingivalis can impact signal transduction pathways and modulate cytokine expression, outcomes that could disrupt the maintenance of pregnancy.