Fig 1.
Expression levels of 507 inflammatory and immunoregulatory proteins in amniotic fluid (AF) from women with preterm premature rupture of membranes (PPROM), comparing the imminent spontaneous preterm delivery (iSPTD) and non-imminent SPTD groups.
The pooled AF samples in each group (15 women with iSPTD, 15 gestational age-matched women without iSPTD) were assayed using a human antibody array kit (AAH-BLM-1B-2; RayBiotech, Norcross, GA). Using cut-off values of fold change of ≥ 1.5 or ≤ 0.66 for upregulated or downregulated proteins, 4 differentially regulated proteins in AF samples from women with iSPTD relative to women without iSPTD are indicated in rectangles. Number 1 shows the positive controls.
Fig 2.
List of 4 proteins with significantly differential expression between the amniotic fluid (AF) from women with preterm premature rupture of membranes (PPROM), who had subsequent spontaneous preterm delivery (SPTD) within 14 days of sampling and AF from PPROM women delivering after 14 days, using the criteria of a ≥ 1.5-fold change or a ≤ 0.66-fold change in signal intensity.
iSPTD, imminent spontaneous preterm delivery.
Table 1.
Characteristics of the study population grouped by spontaneous preterm delivery within 14 days of sampling in the total cohort.
Fig 3.
(A) Receiver operating characteristic (ROC) curves of amniotic fluid (AF) lipocalin-2 and S100 A8/A9 at predicting spontaneous preterm delivery (SPTD) within 14 days (AF lipocalin-2: area under the curve [AUC] = 0.725, SE = 0.054; and AF S100 A8/A9: AUC = 0.714, SE = 0.055). (B) ROC curves of AF matrix metalloproteinase-9 (MMP-9) and interleukin-8 (IL-8) at predicting SPTD within 14 days (AF MMP-9: AUC = 0.755, SE = 0.053; and AF IL-8: AUC = 0.717, SE = 0.055). Differences among the AUCs of AF lipocalin-2, S100 A8/A9, MMP-9, and IL-8 were not significant (all variables: P = 0.25–0.92). S100 A8/A9, S100 calcium binding protein A8/A9 complex.
Table 2.
Multivariable logistic regression model showing the unadjusted and adjusted odds ratios of association between potential amniotic fluid proteins and spontaneous preterm delivery within 14 days in women with preterm premature rupture of membranes in the total cohort (n = 88).
Table 3.
Diagnostic indices of lipocalin-2, MMP-9, S100 A8/A9, and interleukin-8 in amniotic fluid to predict spontaneous preterm delivery within 14 days of sampling in women with preterm premature rupture of membranes in the total cohort (n = 88).
Table 4.
The unadjusted and adjusted odds ratios of spontaneous preterm delivery within 14 days of sampling according to quartiles of potential amniotic fluid protein expression in women with preterm premature rupture of membranes in the total cohort (n = 88).
Fig 4.
Kaplan-Meier survival estimates of the sampling-to-delivery interval for (A) AF lipocalin-2 of ≥0.36 or <0.36 μg/mL (median, 7.00 days [95% CI, 4.23–9.78] vs. 36.00 days [95% CI, 27.23–44.78]; P < 0.001), (B) AF MMP-9 of ≥ 4.27 or < 4.27 ng/mL (median, 8.00 days [95% CI, 4.84–11.16] vs. 36.00 days [95% CI, 27.21–44.79]; P < 0.001), and (C) AF S100 A8/A9 of ≥10.99 or <10.99 μg/mL (median, 5.00 days [95% CI, 3.29–6.70] vs. 21.00 days [95% CI, 14.16–27.84]; P = 0.004). AF, amniotic fluid; CI, confidence interval; MMP-9, matrix metalloproteinase-9; S100 A8/A9, S100 calcium binding protein A8/A9 complex.