High-throughput analysis of amniotic fluid proteins associated with histological chorioamnionitis in preterm premature rupture of membranes using an antibody-based microarray

Association Analysis Between Maternal Neutrophil Ratio and the Risk of Histological Chorioamnionitis in Pregnant Women with Premature Rupture of Membranes in Late Pregnancy

Background

We aimed to investigate the association between maternal neutrophil ratio and histological chorioamnionitis (HCA) risk in pregnant women with premature rupture of membranes (PROM) in late pregnancy.

Methods

A retrospective analysis was conducted on 95 cases of women with PROM in their late pregnancy between March 2018 and August 2021. These women were divided into two groups based on the presence of HCA. General clinical data and laboratory indicators were compared between the two groups. A generalized additive model was used for curve fitting, and a segmented regression model was used to explain further the non-linear relationship between neutrophil ratio and HCA risk.

Results

After adjusting for confounding factors, the curve fitting showed a "U"-shaped curve relationship between the neutrophil ratio and the risk of HCA. When the neutrophil ratio was <76.3%, the risk of HCA exhibited a decreasing trend, but the difference was not statistically significant (adjusted OR = 0.884, 95% CI: 0.781-1.001, P = 0.053). However, when the neutrophil ratio was >76.3%, the HCA risk was significantly increased (adjusted OR = 1.339, 95% CI: 1.067-1.680, P = 0.012). Furthermore, we equally divided the neutrophil ratio into three groups. The risk of HCA was significantly increased in the low-ratio group (OR = 4.292, 95% CI: 1.247-14.706, P = 0.021) compared with the middle-ratio group, which was used as the reference group. Similarly, the HCA risk of the high-ratio group (OR = 13.145, 95% CI: 1.796-96.233, P = 0.011) was also significantly enhanced. However, there was no significant difference in HCA risk between the high-ratio and low-ratio groups (OR = 1.182, 95% CI: 0.357-3.909, P = 0.784).

Conclusion

There was a significant "U"-shaped relationship between maternal neutrophil ratio and HCA risk in women with PROM in late pregnancy.

Potential of plasma inflammatory and angiogenic mediators for predicting spontaneous preterm delivery, intraamniotic infection/inflammation, and composite neonatal morbidity/mortality in women with early preterm premature rupture of membranes

PROBLEM

To assess the potential of five inflammatory and six angiogenic/antiangiogenic plasma proteins for predicting imminent spontaneous preterm delivery (SPTD; ≤14 days of sampling), microbial invasion of the amniotic cavity and/or intraamniotic inflammation (MIAC/IAI), and composite neonatal morbidity and mortality (CNMM) in women with early preterm premature rupture of membranes (PPROM).

METHODS OF STUDY

This retrospective cohort study included 76 singleton pregnant women with early PPROM (23-30 weeks). Amniotic fluid obtained via amniocentesis was cultured for microorganism detection and assayed for interleukin-6 to define IAI (≥2.6 ng/mL). Plasma C4a, endoglin, endostatin, IGFBP-1, IGFBP-2, MMP-9, PlGF, S100A8, S100A9, S100 A8/A9, and VEGFR-1 levels were determined using ELISA.

RESULTS

Multivariate logistic regression analyses revealed significant associations between (i) high levels of plasma S100A8/A9, SPTD ≤14 days after sampling, and shorter sampling-to-delivery intervals; (ii) elevated plasma MMP-9, S100A9, and S100A8/A9 levels and MIAC/IAI, and (iii) decreased plasma endoglin levels and increased CNMM risk, while adjusting for gestational age at sampling (or delivery) and tocolytic use. The area under the curves of the aforementioned proteins ranged from 0.655 to 0.731 for each outcome. Notably, the SPTD risk increased significantly with increasing plasma S100A8/A9 levels (P for trend < .05).

CONCLUSIONS

Plasma S100A8/A9, MMP-9, S100A9, and endoglin may represent valuable biomarkers associated with SPTD, MIAC/IAI, and CNMM in women with early PPROM. Owing to their less invasive nature, repeatability, and fair-to-moderate diagnostic accuracy, these biomarkers may contribute to risk stratification of PPROM-related complications in the clinical setting.

Inflammatory biomarkers in the cervicovaginal fluid to identify histologic chorioamnionitis and funisitis in women with preterm labor

OBJECTIVE

We investigated the association between altered levels of inflammatory proteins in the cervicovaginal fluid (CVF) and acute histologic chorioamnionitis (HCA) and funisitis in women with preterm labor (PTL).

METHODS

In this study, a total of 134 consecutive singleton pregnant women with PTL (at 23+0-34+0 weeks) who delivered preterm (at  < 37 weeks) and from whom CVF samples were collected at admission were retrospectively enrolled. The CVF levels of haptoglobin, interleukin-6/8, kallistatin, lipocalin-2, matrix metalloproteinase (MMP)-8, resistin, S100 calcium-binding protein A8, and serpin A1 were determined using enzyme-linked immunosorbent assay. The placentas were histologically analyzed after delivery.

RESULTS

Multiple logistic regression analyses showed significant associations between elevated CVF interleukin-8 and resistin levels and acute HCA after adjusting for baseline covariates (e.g., gestational age at sampling). CVF haptoglobin, interleukin-6/8, kallistatin, MMP-8, and resistin levels were significantly higher in women with funisitis than in those without, whereas the baseline covariates were similar between the two groups (P > 0.1). The area under the receiver operating characteristic curves of the aforementioned biomarkers ranged from 0.61 to 0.77 regarding each outcome. Notably, HCA risk significantly increased with increasing CVF levels of interleukin-8 and resistin (P for trend  < 0.05).

CONCLUSIONS

Haptoglobin, interleukin-6/8, kallistatin, MMP-8, and resistin were identified as potential inflammatory CVF biomarkers predictive of acute HCA and funisitis in women with PTL. Moreover, the risk severity of acute HCA may be associated with the degree of the inflammatory response in the CVF (particularly based on interleukin-8 levels).