Kyo Hoon Park

Objective: To determine whether plasma acute phase‐, adhesion‐related, and multifunctional proteins, alone or in combination with ultrasound and traditional blood tests, can predict the microbial invasion of the amniotic cavity and/or intra‐amniotic inflammation (MIAC/IAI) and spontaneous preterm birth (SPTB) in women with preterm labor (PTL). Study Design: A retrospective cohort study was performed on 249 singleton pregnant women with PTL (at 23+0 to 34+0 weeks) who underwent transabdominal amniocentesis. Plasma samples were obtained at amniocentesis. MIAC/IAI was characterized by a positive amniotic fluid (AF) culture and/or an elevated interleukin (IL)‐6 level (≥2.6 ng/mL) in the AF. Plasma levels of hepcidin, mannose‐binding lectin (MBL), retinol‐binding protein 4 (RBP4), serum amyloid A1 (SAA1), E‐selectin, P‐selectin, progranulin, transforming growth factor β1, and vitamin d‐binding protein levels were measured using enzyme‐linked immunosorbent assay. C‐reactive protein levels, white blood cell (WBC) counts, neutrophil‐to‐lymphocyte ratio, and sonographic cervical lengths (CLs) were measured. Results: After adjusting for baseline covariates, multivariable logistic regression analyses showed significant associations between (i) decreased RBP4 and E‐selectin levels and elevated SAA1 levels in the plasma and MIAC/IAI; and (ii) decreased RBP4 and progranulin levels and elevated SAA1 levels in the plasma and SPTB ≤7 days of sampling. Using stepwise regression analyses, noninvasive prediction models for MIAC/IAI and SPTB ≤7 days were developed, comprising plasma RBP4, SAA1, MBL, and E‐selectin levels; CL; and WBC counts, with area under the curve values of 0.86 and 0.89, respectively. Conclusions: SAA1, RBP4, E‐selectin, and progranulin may represent valuable plasma biomarkers for predicting MIAC/IAI and imminent SPTB in women with PTL. Particularly, the combination of these plasma biomarkers with ultrasound and traditional inflammatory blood markers can significantly support the diagnosis of MIAC/IAI and imminent SPTB.

Background: To determine whether (i) altered levels of acute-phase response (APR)-, inflammation-, and extracellular matrix (ECM)-related proteins in the amniotic fluid (AF) were associated with spontaneous preterm delivery (SPTD) in asymptomatic women with midtrimester short cervix (SCX) and (ii) if SPTD risk severity was related to the expression levels of inflammation-related proteins in the AF. Methods: This retrospective cohort study included 70 singleton pregnant women diagnosed with a SCX (i.e., h epcidin, kallistatin, MBL, pentraxin-2, RBP4 , and serpin A1) , inflammatory ( i.e., IL-6, IL-8, and resistin) , and ECM-related ( i.e., lumican, MMP-8, TGFBI, and uPA) molecules were assayed in the AF by ELISA. The primary outcome measure was SPTD at inflammatory mediator were divided into quartiles to assess the correlation between their AF expression profiles and SPTD risk severity. Results: Multivariable Firth logistic regression analyses revealed that elevated AF levels of IL-6, IL-8, kallistatin, pentraxin-2, resistin, and serpin A1, and IAI presence were independently associated with SPTD at Conclusions: APR (kallistatin, pentraxin-2, and serpin A1)- and inflammation (IL-6/8 and resistin)-, but not ECM-related mediators in the AF are involved in SPTD development in asymptomatic women with a midtrimester SCX. In particular, SPTD risk (especially risk severity) is associated with the degree of the inflammatory response in the AF, as categorized by inflammatory protein expression profiles, as well as IAI presence.

Problem: To determine whether altered cervicovaginal fluid (CVF) levels of acute‐phase proteins (APPs) and resistin, alone or in combination with conventional clinical and blood‐based markers, could predict microbial invasion of the amniotic cavity (MIAC) and/or intra‐amniotic inflammation (IAI) and acute histologic chorioamnionitis (HCA) in women with preterm premature rupture of membranes (PPROM).Methods of study: Women with singleton pregnancies with PPROM at 20 + 0–34 + 0 weeks (n = 82) were retrospectively evaluated. Amniotic fluid (AF) obtained via amniocentesis was cultured to diagnose MIAC, and interleukin‐6 levels (≥ 2.6 ng/mL) were used to diagnose IAI. Haptoglobin, MBL, pentraxin‐2, RBP4, serpin A1, and resistin levels in CVF samples, collected during amniocentesis, were determined by ELISA. Neutrophil‐to‐lymphocyte ratio (NLR) and C‐reactive protein levels were measured.Results: The prevalence of MIAC and/or IAI and acute HCA was 53.6% (44/82) and 49.3% (38/77), respectively. Multivariate logistic regression analyses revealed that (i) elevated CVF haptoglobin (adjusted odds ratio [aOR], 5.857; 95% confidence interval [CI], 1.263–27.173), pentraxin‐2 (aOR, 1.024; 95% CI, 1.005–1.043), and resistin (aOR, 1.009; 95% CI, 1.003–1.015) levels were independently associated with MIAC/IAI, and (ii) elevated CVF resistin levels (aOR, 1.009; 95% CI, 1.003–1.015) were independently associated with acute HCA after adjusting for baseline covariates. Using stepwise regression analysis, a noninvasive prediction model comprising CVF, resistin, and pentraxin‐2 levels, NLR, and gestational age at sampling was developed, which provided a good prediction of MIAC/IAI (area under the curve [AUC], 0.87; 95% CI, 0.78–0.95), with greater predictive potential than any single covariate included in the model (resistin: AUC, 0.72; 95% CI, 0.60‐0.83; pentraxin‐2: AUC, 0.64; 95% CI, 0.52‐0.76; NLR: AUC, 0.74; 95% CI, 0.62‐0.85; gestational age: AUC, 0.71; 95% CI, 0.60–0.82) (p < 0.05 for each).Conclusions: Haptoglobin, pentraxin‐2, and resistin levels in the CVF may be valuable to evaluate the risk of MIAC, IAI, and acute HCA in women with PPROM. In particular, the combination of these acute‐phase and inflammatory CVF biomarkers with conventional clinical and blood‐based markers can significantly support MIAC/IAI diagnosis.

Background: We aimed to investigate the potential of altered levels of various acute phase proteins (APPs) in the plasma, either used alone or in combination with ultrasound-, clinical-, and conventional blood-based tests, for predicting the risk of intra-amniotic inflammation (IAI), microbial invasion of the amniotic cavity (MIAC), histologic chorioamnionitis (HCA), and funisitis in women with preterm premature rupture of membranes (PPROM). Methods: A total of 195 consecutive pregnancies involving singleton women with PPROM (at 23 + 0–34 + 0 weeks) who underwent amniocentesis and from whom plasma samples were obtained at amniocentesis were retrospectively included in this study. Amniotic fluid (AF) was cultured to assess the MIAC and analyzed for interleukin (IL)-6 levels to define IAI (AF IL-6 level of ≥2.6 ng/mL). The plasma concentrations of hepcidin, mannose-binding lectin (MBL), pentraxin-2, retinol-binding protein 4 (RBP4), serum amyloid A1 (SAA1), and serpin A1 were determined using ELISA. Ultrasonographic cervical length (CL), neutrophil-to-lymphocyte ratio (NLR), and C-reactive protein levels were measured. IAI/MIAC was defined as IAI, MIAC, or both. Results: Multivariate logistic regression analyses showed the following: (1) elevated plasma levels of hepcidin and SAA1 and decreased levels of RBP4 in the plasma were independently associated with IAI/MIAC and (2) decreased plasma RBP4 levels were independently associated with funisitis; however, (3) none of the plasma APPs investigated were associated with acute HCA when adjusted for baseline covariates. Using stepwise regression analysis, noninvasive prediction models comprising plasma RBP4 levels, CL, NLR, and gestational age at sampling were proposed, which provided a good prediction of IAI/MIAC and funisitis (area under the curve: 0.80 and 0.72, respectively). Conclusions: Hepcidin, RBP4, and SAA1 were identified as potential APP biomarkers in the plasma predictive of IAI/MIAC or funisitis in patients with PPROM. In particular, combination of these APP biomarkers with ultrasound-, clinical-, and conventional blood-based markers can significantly support the diagnosis of IAI/MIAC and funisitis.

Problem: To determine whether altered concentrations of various inflammation/immune‐, acute phase‐, extracellular matrix‐, adhesion‐, and serine protease‐related proteins in the amniotic fluid (AF) are independently associated with microbial invasion of the amniotic cavity and/or intra‐amniotic inflammation (MIAC/IAI), imminent spontaneous preterm delivery (SPTD; ≤7 days), and major neonatal morbidity/mortality (NMM) in women with early preterm prelabor rupture of membranes (PPROM).Method of Study: This was a retrospective cohort study involving 111 singleton pregnant women with PPROM (24–31 weeks) undergoing amniocentesis to diagnose MIAC/IAI. The following proteins were measured in stored AF samples by enzyme‐linked immunosorbent assay (ELISA): APRIL, DKK‐3, Gal‐3BP, IGFBP‐2, IL‐8, VDBP, lumican, MMP‐2, MMP‐8, SPARC, TGFBI, TGF‐β1, E‐selectin, ICAM‐5, P‐selectin, haptoglobin, hepcidin, SAA1, kallistatin, and uPA.Results: Multivariate logistic regression analyses revealed that (i) elevated APRIL, IL‐8, MMP‐8, and TGFBI levels in the AF, reduced lumican and SPARC levels in the AF, and high percentages of samples above the lower limit of quantification for AF TGF‐β1 and uPA were significantly associated with MIAC/IAI; (ii) elevated AF levels of IL‐8 and MMP‐8 were significantly associated with SPTD within 7 days; and (iii) elevated AF IL‐6 levels were significantly associated with increased risk for major NMM, when adjusted for baseline covariates.Conclusion: ECM (lumican, SPRAC, TGFBI, and TGF‐β1)‐ and serine protease (uPA)‐associated proteins in the AF are involved in the regulation of the host response to infection/inflammation in the amniotic cavity, whereas AF inflammation (IL‐8, MMP‐8, and IL‐6)‐associated mediators are implicated in the development of preterm parturition and major NMM in early PPROM.

Problem: To explore the clinical utility of nine inflammatory immune‐, adhesion‐, and extracellular matrix‐related mediators in the plasma for predicting intraamniotic inflammation and/or microbial invasion of the amniotic cavity (IAI/MIAC) and composite neonatal morbidity and/or mortality (CNMM) in women with preterm premature rupture of membranes (PPROM) when used alone or in combination with conventional blood‐, ultrasound‐, and clinical‐based factors.Methods of Study: This retrospective cohort comprised 173 singleton pregnant women with PPROM (24 + 0 – 33 + 6 weeks), who underwent amniocentesis. Amniotic fluid was cultured for microorganisms and assayed for IL‐6 levels. Plasma levels of AFP, CXCL14, E‐selectin, Gal‐3BP, kallistatin, progranulin, P‐selectin, TGFBI, and VDBP were determined by ELISA. Ultrasonographic cervical length (CL) and neutrophil‐to‐lymphocyte ratio (NLR) were measured.Results: Multivariate logistic regression analyses revealed significant associations between (i) decreased plasma kallistatin levels and IAI/MIAC and (ii) decreased plasma progranulin levels and increased CNMM risk after adjusting for baseline variables (e.g., gestational age at sampling [or delivery] and parity). Using stepwise regression analysis, noninvasive prediction models for IAI/MIAC and CNMM risks were developed, which included plasma progranulin levels, NLR, CL, and gestational age at sampling, and provided a good prediction of the corresponding endpoints (area under the curve: 0.79 and 0.87, respectively).Conclusions: Kallistatin and progranulin are potentially valuable plasma biomarkers for predicting IAI/MIAC and CNMM in women with PPROM. Particularly, the combination of these plasma biomarkers with conventional blood‐, ultrasound‐, and clinical‐based factors can significantly support the diagnosis of IAI/MIAC and CNMM.

This study aimed to identify plasma proteins that could serve as potential biomarkers for microbial invasion of the amniotic cavity (MIAC) or intra-amniotic inflammation (IAI) in women with preterm labor (PTL). A retrospective cohort comprised singleton pregnant women with PTL (24–34 weeks) who underwent amniocentesis. Pooled plasma samples were analyzed by label-free liquid chromatography-tandem mass spectrometry for proteome profiling in a nested case–control study (concomitant MIAC/IAI cases vs. non-MIAC/IAI controls [n = 10 per group]). Eight target proteins associated with MIAC/IAI were further verified by immunoassays in a large cohort (n = 230). Shotgun proteomic analysis revealed 133 differentially expressed proteins (fold change > 1.5, P < 0.05) in the plasma of MIAC/IAI cases. Further quantification confirmed that the levels of AFP were higher and those of kallistatin and TGFBI were lower in the plasma of women with MIAC and that the levels of kallistatin and TGFBI were lower in the plasma of women with IAI than in those without these conditions. The area under the curves of plasma AFP, kallistatin, and TGFBI ranged within 0.67–0.81 with respect to each endpoint. In summary, plasma AFP, kallistatin, and TGFBI may represent valuable non-invasive biomarkers for predicting MIAC or IAI in women with PTL.

Purpose To determine whether various inflammatory-, angiogenic/anti-angiogenic-, and extracellular matrix remodeling-associated proteins in plasma, alone or in combination with conventional blood-based markers, can predict intra-amniotic inflammation and/or microbial invasion of the amniotic cavity (IAI/MIAC) in women with spontaneous preterm labor (PTL). Methods A total of 193 singleton pregnant women with PTL (23–33 weeks) were included in this retrospective cohort study. Plasma samples were obtained at the time of amniocentesis. Amniotic fluid (AF) was cultured for microorganism detection and consequent MIAC diagnosis. IL-6 levels were determined in AF and used to identify IAI (AF IL-6 ≥ 2.6 ng/mL). Endostatin, haptoglobin, IGFBP-2/3, LBP, M-CSF, MMP-2/8, pentraxin 3, PlGF, S100A8/A9, and VEGFR-1 levels were assayed in plasma samples by ELISA. CRP levels and neutrophil-to-lymphocyte ratio (NLR) were measured. Results Plasma LBP, MMP-8, and S100A8/A9 levels, CRP levels, and NLR were significantly higher, and plasma IGFBP-2 and MMP-2 levels were significantly lower in women with IAI/MIAC than in those without this condition, whereas no baseline variables differed significantly between the two groups. Using a stepwise regression analysis, a noninvasive prediction model for IAI/MIAC was developed, which included plasma LBP, MMP-2, and MMP-8 levels (area under the curve [AUC], 0.785). The AUC for this prediction model was significantly or borderline greater than that of any single factor included in the model. Conclusions IGFBP-2, LBP, MMP-2, MMP-8, and S100A8/A9 may represent valuable plasma biomarkers for predicting IAI/MIAC in women with PTL. Combination of LBP, MMP-2, and MMP-8 expression data can significantly improve the predictive potential for IAI/MIAC.

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.

Park KH, et al. J Korean Med Sci. 2024 Oct;39(42):e310. https://doi.org/10.3346/jkms.2024.39.e310