Preterm prelabour rupture of membranes (PPROM) complicated by intra-amniotic inflammation (IAI) represents a substantial proportion of preterm birth cases. Currently, IAI is frequently defined as amniotic fluid IL-6 concentration above 2,600 pg/mL. However, the amniotic fluid IL-6 concentration was never correlated with the global response of other proinflammatory proteins to the ongoing IAI. In this cross-sectional study, protein quantification was performed using mass spectrometry (MS) analysis followed by target quantification of selected proinflammatory proteins. Levels of amniotic fluid proteins determined by MS were put into the correlation with IL-6 concentration determined by electrochemiluminescence immunoassay method (ECLIA). In total, 925 proteins were efficiently quantified and differential expression analysis revealed 378 proteins upregulated towards IL-6 concentration above 10,000 pg/mL. Four proteins (LCN2, MMP8, MPO, and S100A12) were selected to verify the achieved results and IL-6 concentration of 10,000 pg/mL was determined as the cut-off value for global IAI response.

• MeSH
• Biomarkers metabolism   MeSH
• Chorioamnionitis * metabolism   MeSH
• Adult MeSH
• Interleukin-6 metabolism   MeSH
• Humans MeSH
• Amniotic Fluid * metabolism   MeSH
• Fetal Membranes, Premature Rupture * metabolism   pathology   MeSH
• S100A12 Protein metabolism   MeSH
• Cross-Sectional Studies MeSH
• Pregnancy MeSH
• Inflammation * metabolism   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Pregnancy MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Biomarkers MeSH
• IL6 protein, human MeSH Browser
• Interleukin-6 MeSH
• S100A12 Protein MeSH

Preterm prelabour rupture of membranes beyond the 34th week of gestation (late PPROM) is frequently associated with the risk of the microbial invasion of the amniotic fluid (MIAC) and histological chorioamnionitis (HCA). Hence, we employed a Tandem Mass Tag-based approach to uncover amniotic fluid proteome response to the presence of MIAC and HCA in late PPROM. Protein dysregulation was associated with only five cases in the group of 15 women with confirmed MIAC and HCA. Altogether, 138 amniotic fluid proteins were changed in these five cases exclusively. These proteins were particularly associated with excessive neutrophil responses to infection, such as neutrophil degranulation and extracellular trap formation. We believe that the quantification of these proteins in amniotic fluid may assist in revealing women with the highest risk of excessive inflammatory response in late PPROM.

• MeSH
• Chorioamnionitis metabolism   microbiology   MeSH
• Adult MeSH
• Pregnancy Complications, Infectious metabolism   MeSH
• Cohort Studies MeSH
• Humans MeSH
• Infant, Newborn MeSH
• Fetal Membranes, Premature Rupture metabolism   MeSH
• Proteomics methods   MeSH
• Pregnancy MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Infant, Newborn MeSH
• Pregnancy MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

BACKGROUND: Amniotic fluid is clinically accessible via amniocentesis and its protein composition may correspond to birth timing. Early changes in the amniotic fluid proteome could therefore be associated with the subsequent development of spontaneous preterm delivery. OBJECTIVE: The main objective of this study was to perform unbiased proteomics analysis of the association between mid-trimester amniotic fluid proteome and spontaneous preterm delivery and gestational duration, respectively. A secondary objective was to validate and replicate the findings by enzyme-linked immunosorbent assay using a second independent cohort. METHODS: Women undergoing a mid-trimester genetic amniocentesis at Sahlgrenska University Hospital/Östra between September 2008 and September 2011 were enrolled in this study, designed in three analytical stages; 1) an unbiased proteomic discovery phase using LC-MS analysis of 22 women with subsequent spontaneous preterm delivery (cases) and 37 women who delivered at term (controls), 2) a validation phase of proteins of interest identified in stage 1, and 3) a replication phase of the proteins that passed validation using a second independent cohort consisting of 20 cases and 40 matched controls. RESULTS: Nine proteins were nominally significantly associated with both spontaneous preterm delivery and gestational duration, after adjustment for gestational age at sampling, but none of the proteins were significant after correction for multiple testing. Several of these proteins have previously been described as being associated with spontaneous PTD etiology and six of them were thus validated using enzyme linked immunosorbent assay. Two of the proteins passed validation; Neutrophil gelatinase-associated lipocalin and plasminogen activator inhibitor 1, but the results could not be replicated in a second cohort. CONCLUSIONS: Neutrophil gelatinase-associated lipocalin and Plasminogen activator inhibitor 1 are potential biomarkers of spontaneous preterm delivery and gestational duration but the findings could not be replicated. The negative findings are supported by the fact that none of the nine proteins from the exploratory phase were significant after correction for multiple testing.

• MeSH
• Amniocentesis MeSH
• Adult MeSH
• Pregnancy Trimester, Second metabolism   MeSH
• Gestational Age * MeSH
• Cohort Studies MeSH
• Humans MeSH
• Amniotic Fluid chemistry   metabolism   MeSH
• Premature Birth metabolism   MeSH
• Proteome analysis   MeSH
• Pregnancy MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Male MeSH
• Pregnancy MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Research Support, N.I.H., Extramural MeSH
• Names of Substances
• Proteome MeSH

OBJECTIVE: The main aim of this study was to determine the relationship between the maternal white blood cell (WBC) count at the time of hospital admission in pregnancies complicated by preterm prelabor rupture of membranes (PPROM) and the presence of microbial invasion of the amniotic cavity (MIAC) and/or intra-amniotic inflammation (IAI). The second aim was to test WBC diagnostic indices with respect to the presence of MIAC and/or IAI. METHODS: Four hundred and seventy-nine women with singleton pregnancies complicated by PPROM, between February 2012 and June 2017, were included in this study. Maternal blood and amniotic fluid samples were collected at the time of admission. Maternal WBC count was assessed. Amniotic fluid interleukin-6 (IL-6) concentration was measured using a point-of-care test, and IAI was characterized by an IL-6 concentration of ≥ 745 pg/mL. MIAC was diagnosed based on a positive polymerase chain reaction result for the Ureaplasma species, Mycoplasma hominis, and/or Chlamydia trachomatis and/or for the 16S rRNA gene. RESULTS: Women with MIAC or IAI had higher WBC counts than those without (with MIAC: median, 12.8 × 109/L vs. without MIAC: median, 11.9 × 109/L; p = 0.0006; with IAI: median, 13.7 × 109/L vs. without IAI: median, 11.9 × 109/L; p < 0.0001). When the women were divided into four subgroups based on the presence of MIAC and/or IAI, the women with both MIAC and IAI had a higher WBC count than those with either IAI or MIAC alone, and those without MIAC and IAI [both MIAC and IAI: median, 14.0 × 109/L; IAI alone: 12.1 × 109/L (p = 0.03); MIAC alone: 12.1 × 109/L (p = 0.0001); and without MIAC and IAI: median, 11.8 × 109/L (p < 0.0001)]. No differences in the WBC counts were found among the women with IAI alone, MIAC alone, and without MIAC and IAI. CONCLUSION: The women with both MIAC and IAI had a higher maternal WBC count at the time of hospital admission than the remaining women with PPROM. The maternal WBC count at the time of admission showed poor diagnostic indices for the identification of the presence of both MIAC and IAI. Maternal WBC count at the time of admission cannot serve as a non-invasive screening tool for identifying these complications in women with PPROM.

• MeSH
• Chorioamnionitis diagnosis   MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Amniotic Fluid microbiology   MeSH
• Leukocyte Count * MeSH
• Fetal Membranes, Premature Rupture * MeSH
• Pregnancy MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Pregnancy MeSH
• Female MeSH
• Publication type
• Journal Article MeSH