Cervicovaginal Fluid Protein Microarray for Detection of Microbial Invasion of the Amniotic Cavity in Preterm Labor

Measurements of Interleukin-8 and Matrix Metalloproteinases-9 in Cervicovaginal Fluid in Women with Preterm Labor: A Direct Comparison with Amniotic Fluid

OBJECTIVE

  We aimed to evaluate the correlation and agreement of interleukin (IL)-8 and matrix metalloproteinases (MMP-9) levels between cervicovaginal (CVF) and amniotic fluids (AF) in women with preterm labor (PTL) and to determine the clinical values of these proteins in CVF compared with those in AF.

STUDY DESIGN

 We designed a retrospective cohort study of 85 singleton pregnant women with PTL at 23 to 34 weeks, who underwent amniocentesis. The AF was cultured, and CVF samples were collected at the time of amniocentesis. Paired AF and CVF samples were assayed for IL-8 and MMP-9 by enzyme-linked immunoassay (ELISA) in duplicate on a single plate, using similar dilution ratios.

RESULTS

 A significant but weak correlation was found for IL-8 levels between AF and CVF (r = 0.333), while no correlation was found for MMP-9 levels between AF and CVF (r = -0.039). Intra-class correlation coefficient for the agreement of IL-8 levels between CVF and AF was 0.4335 and -0.279 for MMP-9, indicating a poor-to-fair level of agreement between the two measured values, respectively. IL-8 and MMP-9 levels in CVF were not associated with the risk of either microbial invasion of the amniotic cavity (MIAC) or spontaneous preterm delivery (SPTD) within 7 days, whereas those in AF provided good-to-excellent predictive values for these two outcomes (area under the curve [AUCs]: 0.82-0.95). AUCs for IL-8 and MMP-9 were significantly larger using AF rather than using CVF for the prediction of MIAC and SPTD.

CONCLUSION

 In women with PTL, IL-8 and MMP-9 levels in CVF do not precisely reflect the levels of the corresponding proteins in AF. IL-8 and MMP-9 levels in CVF had poor predictive values for the risk of MIAC and SPTD and were significantly inferior to those in AF.

KEY POINTS

· IL-8 and MMP-9 levels in CVF do not precisely reflect levels of the corresponding proteins in AF.. · Diagnostic accuracy of IL-8 and MMP-9 in CVF alone is not sufficient to predict MIAC and SPTD.. · IL-8 and MMP-9 levels in AF provide good-to-excellent predictive values for these two outcomes..

Complement Activation Fragments in Cervicovaginal Fluid Are Associated with Intra-Amniotic Infection/Inflammation and Spontaneous Preterm Birth in Women with Preterm Premature Rupture of Membranes

OBJECTIVE

 We sought to determine whether the levels of complement and other inflammatory and angiogenic mediators in cervicovaginal fluid (CVF) are independently associated with intra-amniotic infection and/or inflammation (IAI) and imminent spontaneous preterm birth (SPTB, £48 hours of sampling) in women with preterm premature rupture of membranes (PPROM).

STUDY DESIGN

 This was a retrospective study consisting of 85 singleton pregnant women with PPROM at 200/7 to 336/7 weeks. Amniotic fluid (AF) obtained via amniocentesis was cultured and assayed for interleukin-6. CVF samples collected at the time of amniocentesis were assayed for complement C3a, C4a, and C5a, HSP70 (heat shock protein 70), M-CSF (macrophage colony-stimulating factor), M-CSF-R (macrophage colony-stimulating factor-receptor), S100 A8, S100 A9, thrombospondin-2, VEGF (vascular endothelial growth factor-receptor), and VEGFR-1 (vascular endothelial growth factor-receptor 1) by enzyme-linked immunosorbent assay.

RESULTS

 Multivariate logistic regression analyses revealed that elevated CVF concentrations of complement C3a, 4a, and 5a were significantly associated with an increased risk of IAI and imminent SPTB, whereas those of M-CSF were associated with IAI, but not imminent SPTB (p = 0.063), after adjustment for baseline covariates (e.g., gestational age at sampling). However, univariate, and multivariate analyses showed that the CVF concentrations of angiogenic (thrombospondin-2, VEGF, and VEGFR-1) and inflammatory (HSP70, M-CSF-R, S100 A8, and S100 A9) proteins were not associated with either IAI or imminent SPTB.

CONCLUSION

 In women with PPROM, elevated CVF concentrations of complement C3a, C4a, and C5a are independently related to an increased risk of IAI and imminent SPTB. These findings suggest that complement activation in CVF is significantly involved in mechanisms underlying preterm birth and in the host response to IAI in the context of PPROM.

KEY POINTS

· Elevated CVF levels of C3a, 4a and 5a are associated with IAI and SPTB.. · CVF C3a, 4a and 5a have better predictability for SPTB, compared to AF WBC.. · Elevated CVF levels of M-CSF were associated with IAI, but not SPTB..

Protein microarray analysis of amniotic fluid proteins associated with spontaneous preterm birth in women with preterm labor

PROBLEM

To identify proteins present in the amniotic fluid (AF) that could be associated with spontaneous preterm birth (SPTB; delivery < 7 days) in women with preterm labor (PTL).

METHOD OF STUDY

First, the AF proteome of 20 women with PTL and SPTB was compared with that of 20 matched women with term deliveries using an antibody microarray. Next, nine identified candidate biomarkers of SPTB were further validated in 267 singleton pregnant women with PTL who underwent amniocentesis at 26-33 weeks of gestation using ELISA, and whether the degree of expression of these proteins was associated with the risk severity for subsequent SPTB was retrospectively assessed.

RESULTS

Of the 507 proteins evaluated in the microarray analysis, 27 displayed significant intergroup differences. In particular, ELISA quantification confirmed that the expression of EN-RAGE, IL-6, IL-8, IP-10, lipocalin-2, MMP-8, MMP-9, S100 A8/A9, and TNFR2 were all increased in the AF of women spontaneously delivering within 7 days of sampling compared with those delivering after 7 days. Moreover, the odds of SPTB within 7 days, even upon adjusting for confounders, tended to significantly increase with each increasing quartile of baseline AF levels of each protein (P-value for trend < .05).

CONCLUSION

Nine AF proteins were found to be independently associated with higher risk of subsequent SPTB in women with PTL, all of which were immune-, inflammation-, and extracellular matrix-related proteins. Moreover, risk severity for this subsequent SPTB is closely related to the degree of expression of each of these proteins.

Self-reported pain scores as a predictor of preterm birth in symptomatic twin pregnancy: a retrospective study

Background

To evaluate the self-reported pain scores as a predictor of preterm birth (PTB) in symptomatic twin pregnancy and to develop a nomogram for the prediction model.

Methods

We conducted a retrospective study of 148 cases of symptomatic twin pregnancies before 34 weeks of gestation visited at Seoul national university hospital from 2013 to 2018. With other clinical factors, self-reported pain score was evaluated by the numerical rating scale (NRS) pain scores for pain intensity. By multivariate analyses and logistic regression, we developed a prediction model for PTB within 7 days. Using the Cox proportional hazards model, the curves were plotted to show the predictability of the PTB according to NRS pain score, while adjusting the other covariates.

Results

Twenty-three patients (15.5 %) delivered preterm within 7 days. By a logistic regression analysis, higher NRS pain score (OR 1.558, 95 % CI 1.093–2.221, P < 0.05), shorter cervical length (OR 3.164, 95 % CI 1.262–7.936, P < 0.05) and positive fibronectin results (OR 8.799, 95 % CI 1.101–70.330, P < 0.05) affect PTB within 7 days. Using the variables, the area under the receiver operating characteristic curve (AUROC) of the prediction model was 0.917. In addition, we developed a nomogram for the prediction of PTB within 7 days.

Conclusions

Self-reported pain scores combined with cervical length and fetal fibronectin are useful in predicting impending PTB in symptomatic twin pregnancy.