Procalcitonin is more likely to be released by the fetus rather than placental tissue during chorioamnionitis

Development and Validation of a Multivariable Predictive Model for the Risk of Histologic Chorioamnionitis in Patients with Premature Rupture of Membranes in the Late Preterm and Term

Background

This study aimed to develop and validate a model to predict histologic chorioamnionitis (HCA) risk in late preterm and term premature rupture of membranes (PROM) patients using clinical and laboratory parameters.

Methods

We conducted a retrospective study on 116 late preterm and term PROM cases, divided into a training (n=81) and a validation set (n=35). A multivariable logistic regression model was developed using the training set. Performance was assessed via the area under the receiver operating characteristic curve (AUC) and net reclassification index (NRI). Decision curve analysis (DCA) evaluated the model's clinical utility. Additionally, nomograms and a web version of the model were developed.

Results

In the training set, the combined model constructed using maternal BMI, gravidity, amniotic fluid characteristics, and prenatal white blood cell (WBC) count showed significantly higher AUC than WBC alone (0.859 vs 0.710, P=0.010), with improved accuracy and sensitivity. In the validation set, the AUC of the combined model remained higher than that of WBC, but the difference was not statistically significant (0.728 vs 0.584, P=0.173). NRI analysis indicated that the combined model improved the correct classification of HCA by 25.0% (P=0.012) compared to that of WBC alone. DCA demonstrated that the combined model had a higher net benefit than WBC in most cases. The nomograms and web version of the model provided convenient tools for clinicians to predict the risk of HCA.

Conclusion

This study successfully developed and validated a clinically feasible multivariable model to predict the risk of HCA in women with late preterm and term PROM.

Procalcitonin levels in pregnancy: A systematic review and meta-analysis of observational studies

BACKGROUND

The utility of procalcitonin to identify obstetric sepsis is unknown.

OBJECTIVE

To calculate the mean (range) procalcitonin in pregnancy among healthy women not in labor (group 1), healthy women in labor (group 2), and women with preterm prelabor rupture of membranes (PPROM) without clinical chorioamnionitis (group 3).

SEARCH STRATEGY

NLM PubMed, Elsevier Embase, and Wiley Cochrane Central Register of Controlled Trials from inception to February 21, 2022.

SELECTION CRITERIA

Ten or more pregnant women with procalcitonin reported at more than 20 weeks of pregnancy, with information on labor, PPROM, and infection. Exclusions were major medical comorbidities.

DATA COLLECTION AND ANALYSIS

Each abstract and full-text review was independently reviewed by the same two authors. Quality was reviewed using the Newcastle-Ottawa Scale. A meta-analysis was performed using a random effects model.

MAIN RESULTS

The systematic review included 25 studies: 10 (40%) of good quality and 15 (60%) of poor quality. The meta-analysis included 21 studies. Mean procalcitonin in group 1 was 0.092 ng/mL (range 0.036-0.049 ng/mL), in group 2 it was 0.130 ng/mL (range 0.049-0.259 ng/mL), and in group 3 it was 0.345 ng/mL (range 0.005-1.292 ng/mL).

CONCLUSIONS

Among healthy pregnant women not in labor, procalcitonin levels are comparable to those in non-pregnant adults and may be useful in identifying infection. Procalcitonin levels in other groups overlap abnormal values of procalcitonin in non-pregnant adults, and may not discriminate infection among women in labor or with obstetric comorbidities.

PROSPERO

CRD42020157376, registered 4/28/2020.

Procalcitonin in preterm rupture of membranes: a systematic review and meta-analysis

PURPOSE

Early detection of infection is of supreme importance in obstetrics; however, during pregnancy it is not reliably predicted by standard laboratory tests. We aimed to determine if procalcitonin (PCT) is a reliable predictor of chorioamnionitis (CA) in women with premature rupture of membranes (PPROM).

METHODS

An electronic search of Scopus, ISI, Medline, Embase, ClinicalTrials.gov and the Cochrane Library databases was performed using specified key words. We examined all English and French reports on PCT measurement after admission for PPROM and considered: human studies published between 1990 and 2019; observational studies; and randomized controlled trials. A protocol was determined previously, registered at PROSPERO as CRD42019145464. The eligibility was independently assessed by two researchers and literature search yielded 590 studies; after revision of the titles and abstracts, 46 articles were identified as potentially eligible; eight studies were included in the meta-analysis. Primary data synthesis was performed in Review Manager Version 5.3 and average sensitivity and specificity was calculated using Midas, Stata.

RESULTS

From the eight studies included, 335 participants with PPROM were enrolled. Our meta-analysis disclosed that PCT has a poor sensitivity (0.50; 95% CI 0.28-0.73) and a modest specificity (0.72; 95% CI 0.51-0.87) in diagnosing CA. C-reactive protein (CRP) not only has better sensitivity (0.71; 95% CI 0.53-0.84), but also better specificity (0.75; 95% CI 0.55-0.88), compared with the other inflammatory parameters analyzed. Procalcitonin does not seems to be better than CRP in preterm rupture of membranes for chorioamnionitis diagnosis.

Association of Histological and Clinical Chorioamnionitis With Neonatal Sepsis Among Preterm Infants: A Systematic Review, Meta-Analysis, and Meta-Regression

Chorioamnionitis (CA) is considered a key risk factor for very preterm birth and for developing early onset sepsis (EOS) in preterm infants, but recent data suggest that CA might be protective against late onset sepsis (LOS). We performed a systematic review and meta-analysis of studies exploring the association between CA and sepsis. A comprehensive literature search was performed in PubMed/MEDLINE and EMBASE, from their inception to December 1, 2018. A random-effects model was used to calculate odds ratios (OR) and 95% confidence intervals (CI). Sources of heterogeneity were analyzed by subgroup and meta-regression analyses. The following categories of sepsis were analyzed: EOS, LOS, unspecified onset sepsis (UOS), culture-proven, and clinical sepsis. CA was subdivided into clinical and histological chorioamnionitis. Funisitis was also analyzed. We found 3,768 potentially relevant studies, of which 107 met the inclusion criteria (387,321 infants; 44,414 cases of CA). Meta-analysis showed an association between any CA and any EOS (OR 4.29, CI 3.63-5.06), any LOS (OR 1.29, CI 1.11-1.54), and any UOS (OR 1.59, CI 1.11-1.54). Subgroup analysis showed that CA was associated with culture-proven EOS (OR 4.69, CI 3.91-5.56), clinical EOS (OR 3.58, CI 1.90-6.76), and culture-proven LOS (OR 1.31, CI 1.12-1.53), but not with clinical LOS (OR 1.52, CI 0.78-2.96). The presence of funisitis did not increase the risk of either EOS or LOS when compared with CA without funisitis. CA-exposed infants had lower gestational age (-1.11 weeks, CI -1.37 to -0.84) than the infants not exposed to CA. Meta-regression analysis showed that the lower gestational age of the CA group correlated with the association between CA and LOS but not with the association between CA and EOS. In conclusion, our data suggest that the positive association between chorioamnionitis and LOS may be modulated by the effect of chorioamnionitis on gestational age.

Maternal and umbilical cord procalcitonin, high-sensitivity C-reactive protein, and interleukin-6 levels in preeclamptic and normotensive patients: A cross-sectional study

OBJECTIVES

To report maternal and umbilical vein levels of procalcitonin (PCT) in patients with preeclampsia (PE) compared to controls. As secondary aims, we measured high-sensitivity C-reactive protein (hs-CRP), and interleukin-6 (IL-6). Moreover, correlation analyses were performed between the inflammatory biomarkers and mean arterial pressure (MAP).

STUDY DESIGN

This was a single center, cross-sectional study.

MAIN OUTCOME MEASURES

After Institutional Review Board approval and written informed consent, patients with or without PE were enrolled. PCT, hs-CRP, and IL-6 levels were compared between groups using multiple linear regression models. We calculated the adjusted ratios of geometric means (aRGM) for the comparison of patients with and without PE. Correlation analysis between the inflammatory biomarkers and MAP was performed using Spearman's method.

RESULTS

A total of 156 participants were enrolled, yielding 156 venous blood samples and umbilical venous blood samples. Seventy-six patients were in the PE group, and 80 patients were in the control group. Maternal plasma and serum concentrations of PCT (aRGM 3.35 (95% confidence interval [CI]: 2.26, 4.95; p < 0.001)), hs-CRP (aRGM 1.85 (95% CI: 1.30, 2.63; p = 0.003)), and IL-6 (aRGM 1.49 (95% CI: 1.08, 2.04; p = 0.045)) were higher in the PE group. In umbilical venous samples, the concentrations of PCT (aRGM 2.54 (95% CI: 1.46, 4.44; p = 0.003)) and hs-CRP (aRGM 1.45 (95% CI: 1.13, 1.87; p = 0.012)) in the PE group were higher than the controls. No difference in umbilical venous IL-6 concentrations were detected between PE vs. control groups (aRGM 1.46; 95% CI: 1.07, 1.98; p = 0.051). There was positive correlation for both PCT and hs-CRP with MAP in maternal and umbilical venous samples. However, there was no correlation between IL and 6 and MAP in maternal or umbilical venous samples.

CONCLUSIONS

PCT levels were elevated in maternal and umbilical venous samples of patients with PE, and correlated with disease severity.

Establishment of reference intervals for maternal blood and umbilical cord blood procalcitonin in healthy Chinese women in late pregnancy

AIM

To establish reference intervals (RIs) for maternal blood and umbilical cord blood procalcitonin (PCT) in healthy Chinese women in late pregnancy.

METHODS

One hundred and twenty-seven healthy Chinese women in late pregnancy, including 70 vaginal deliveries and 57 cesarean section deliveries, were retrospectively analyzed. These pregnant women gave birth to 58 male infants and 69 female infants. Another 127 age-matched healthy women who were not pregnant were enrolled as the control group. PCT levels in maternal blood, umbilical cord blood and control blood were determined using electrochemiluminescence immunoassay. The RIs of PCT were defined using an intermediate 95% interval.

RESULTS

The RIs for maternal blood and umbilical cord blood PCT were 0.020-0.075 ng/mL and 0.020-0.159 ng/mL, respectively. The cord blood PCT level was not significantly different between different delivery methods (P > 0.05). In contrast, the umbilical cord blood PCT in female newborns was higher than that in male newborns (0.088 ± 0.046 ng/mL vs 0.072 ± 0.030 ng/mL, P < 0.05).

CONCLUSION

Maternal blood and umbilical cord blood PCT of Chinese women in late pregnancy have different RIs, and umbilical cord blood PCT level is affected by the gender of newborns.

Overview of procalcitonin in pregnancy and in pre-eclampsia

Procalcitonin (PCT), a precursor for calcitonin, is a prohormone involved in the inflammatory processes, which has been poorly studied in the context of pregnancy. During severe inflammation, PCT derives from almost all cell types, including monocytes and parenchymal tissues, making it a good predictive and diagnostic marker of an inflammatory state with rapidly increased serum levels in inflammation or sepsis. In normal pregnancy, PCT is basally expressed at very low level by decidual cells, even if decidual macrophages, which in normal pregnancy are skewed to M2 macrophages, are resistant to lipopolysaccharide (LPS)-induced production of PCT. As PCT increase is associated with an inflammatory state, several research groups investigated whether PCT can be considered a marker of pre-eclampsia, a pregnancy disease characterized by systemic inflammation. The first aim of this review is to summarize what is already known about the tissues synthesizing PCT, about the stimuli that cause the increase of circulating PCT levels and how PCT acts as a proinflammatory stimulus by itself. Secondly, we will describe the role of this prohormone in normal pregnancy and in pregnancies complicated by pre-eclampsia, highlighting the involvement of the decidual macrophages and the proinflammatory cytokine tumor necrosis factor-α in the modulation of PCT expression in the decidual microenvironment.

Gestational diabetes mellitus increases the baseline level of procalcitonin in maternal blood but not in umbilical cord blood in late pregnancy: A retrospective case-controlled study

To study the effects of gestational diabetes mellitus (GDM) on the level of procalcitonin (PCT) in maternal blood and umbilical cord blood in late-pregnant women.We retrospectively analyzed 37 pregnant women in late pregnancy who had GDM and compared with those of 97 age-matched normal glucose-tolerant (NGT) pregnant women. The PCT level was converted to a value with normal distribution (LG-PCT) by taking the logarithm of each value to the base 10 (log10).The body mass index (BMI) before delivery, family history of diabetes mellitus (DM), and postpartum blood loss within 24 hours were markedly higher in GDM group than in NGT group, while the gestational age was smaller in GDM group than in NGT group. The maternal blood LG-PCT was significantly higher in GDM group than in NGT group, while the umbilical cord blood LG-PCT was not significantly different between the 2 groups. Multivariate analysis showed that family history of DM, gestational age, and maternal blood LG-PCT were independent risk factors of GDM after adjusting for BMI and postpartum blood loss within 24 hours.GDM increases the baseline level of maternal blood PCT but has little effect on umbilical cord blood PCT.

The diagnostic utility of procalcitonin, interleukin-6 and interleukin-8, and hyaluronic acid in the Norwegian consensus definition for early-onset neonatal sepsis (EONS)

Introduction

A key challenge in identifying serious bacterial infection in new born infants is the nonspecific clinical presentation of early-onset neonatal sepsis (EONS). Routinely used C-reactive protein, white blood cell count, and platelets are nonspecific. We assessed the diagnostic utility of single biomarkers or combinations of procalcitonin (PCT), interleukin (IL)-6, IL-8, and hyaluronic acid (HA) in newborn infant with EONS, and in human umbilical cord blood (HUCB) from deliveries with chorioamnionitis.

Materials and methods

Blood was collected from term infants with strictly defined EONS (group 1, n=15), healthy term infants (group 2, n=15), and the umbilical vein from pregnancies with suspected chorioamnionitis (group 3, n=8), and from healthy pregnancies with no signs of infection (group 4, n=15).

Results

Neonatal plasma PCT and IL-8 showed good predictive value (90% and 83%) for EONS, and the combination of IL-6 or HA with PCT increased the predictability to 87% and 90%, respectively. PCT, IL-6, IL-8, and HA were 8.4-, 4.5-, 3.6-, and 1.9-fold higher when compared with plasma levels in noninfected neonates. PCT, IL-6, and IL-8 in HUCB predicted chorioamnionitis and fever in the delivering mother (89%, 83%, and 72%, respectively). HA was a poor predictor (59%), but its predictability increased in combination with PCT, IL-8, or IL-6. In HUCB from chorioamnionitic deliveries, IL-6, IL-8, and PCT were 23-, 14-, and 2.4-fold higher, respectively, when compared with HUCB from healthy deliveries. There was no correlation between C-reactive protein, white blood cell, and platelet count with PCT, IL-6, IL-8, or HA.

Conclusion

In neonates that fulfilled the Norwegian consensus definition of neonatal sepsis, PCT, IL-6, and IL-8, but not HA, have the potential to improve our management of neonates at risk. Except for PCT and IL-8, both with a predictability of >80% in neonatal plasma, combinations of biomarkers increased the predictability for EONS and chorioamnionitis.

Prediction of histological chorioamnionitis and neonatal and infantile outcomes using procalcitonin in the umbilical cord blood and amniotic fluid at birth

Aim

We aimed to clarify the usefulness of procalcitonin (PCT) in the evaluation of histological chorioamnionitis (CAM) and in the prediction of neonatal and infantile outcomes as a reference of interleukin‐6 (IL‐6).

Methods

Subjects were 36 singleton pregnant women delivered at 22–37 weeks’ gestation due to threatened premature delivery and/or preterm premature rupture of membranes. Cases were classified into the CAM and non‐CAM groups, according to Blanc's criteria. Comparisons were made on umbilical venous and amniotic fluid PCT levels among the groups. The relations between umbilical venous PCT and IL‐6 levels and neonatal and infantile outcomes were also analyzed.

Results

The umbilical venous PCT level in the CAM group (240.2 pg/mL, 125.4–350.3 pg/mL: median, first quartile–third quartile) was higher than that in the non‐CAM group (105.1, 50.2–137.5 pg/mL; P = 0.0006). There were no differences in the amniotic fluid PCT levels between the groups. There was a strong correlation between umbilical venous PCT and IL‐6 levels (correlation coefficient: 0.793). Among 10 cases with an umbilical venous PCT level of ≥170.0 pg/mL and six cases with IL‐6 ≥ 11.0 pg/mL, six (60.0%) and five cases (83.3%), respectively, had adverse neonatal and infantile outcomes. Among seven cases with adverse neonatal and infantile outcomes, six (85.7%) and five (71.4%) cases showed umbilical venous PCT levels of ≥170.0 pg/mL and IL‐6 levels of ≥11.0 pg/mL, respectively.

Conclusion

Similar to IL‐6, the umbilical venous PCT level is a promising parameter for predicting histological CAM and adverse neonatal and infantile outcomes related to in utero inflammatory status.