Elevated C-reactive protein levels in histological chorioamnionitis at term: impact of funisitis on term neonates

Interleukin-6 pathobiology in equine placental infection

PROBLEM

Ascending placentitis is the leading cause of abortion in the horse. Interleukin (IL)-6 is considered predictive of placental infection in other species, but little is understood regarding its role in the pathophysiology of ascending placentitis.

METHOD OF STUDY

Sub-acute ascending placentitis was induced via trans-cervical inoculation of S zooepidemicus, and various fluids/serum/tissues collected 8 days later. Concentrations of IL-6 were detected within fetal fluids and serum in inoculated (n = 6) and control (n = 6) mares. RNASeq was performed on the placenta (endometrium and chorioallantois) to assess transcripts relating to IL-6 pathways. IHC was performed for immunolocalization of IL-6 receptor (IL-6R) in the placenta.

RESULTS

IL-6 concentrations increased in allantoic fluid following inoculation, with a trend toward an increase in amniotic fluid. Maternal serum IL-6 was increased in inoculated animals, while no changes were noted in fetal serum. mRNA expression of IL-6-related transcripts within the chorioallantois indicates that IL-6 is activating the classical JAK/STAT pathway, thereby acting as anti-inflammatory, anti-apoptotic, and pro-survival. The IL-6R was expressed within the chorioallantois, indicating a paracrine signaling pathway of maternal IL-6 to fetal IL-6R.

CONCLUSION

IL-6 plays a crucial role in the placental response to induction of sub-acute equine ascending placentitis, and this could be noted in amniotic fluid, allantoic fluid, and maternal serum. Additionally, IL-6 is acting as anti-inflammatory in this disease, potentially altering disease progression, impeding abortion signals, and assisting with the production of a viable neonate.

Impact of additional risk factors on the incidence of preterm delivery among pregnant women diagnosed with short cervix

OBJECTIVE

Additional risk factors for preterm delivery in pregnant women with cervical shortening are not fully understood; however, mid-trimester cervical shortening is accepted as a risk factor for preterm delivery. This study aimed to identify risk factors associated with subsequent preterm delivery among patients with short cervix detected after late mid-trimester.

MATERIALS AND METHODS

This was a retrospective study of medical data from a single perinatal tertiary facility. We identified 134 asymptomatic women with singleton pregnancies where cervical shortening (≤25 mm) was detected during routine universal screening at 22-33 weeks. Statistical analyses were conducted to identify causal relationships between the incidence of preterm delivery and known risk factors for preterm delivery.

RESULTS

Incidence of preterm delivery was 27.6% (37/134) and preterm premature rupture of membrane was preceded in 46.0% (17/37) of the women with preterm delivery. Using logistic regression analysis, we identified uterine contractions [aOR 4.25, 95% confidence intervals (CI):1.68-12.1] and increased C-reactive protein (CRP) and increased white blood cell (WBC) in blood test (CRP: aOR 3.45, 95% CI:1.50-9.71; WBC: aOR 1.28, 95% CI: 1.08-1.55) as risk factors which significantly increased the risk of preterm delivery among women diagnosed with short cervix. Preterm delivery occurred in 91% of women positive for both uterine contractions and CRP >0.5 mg/dl.

CONCLUSIONS

Uterine contraction and elevated CRP were additional risk factors for preterm delivery among women with short cervix. These results might be clinically useful to evaluate subsequent risk for preterm delivery in asymptomatic pregnant women presenting with short cervix in mid-pregnancy.

Evaluation of leucine-rich alpha-2 glycoprotein as a biomarker of fetal infection

This study aimed to determine the association between umbilical cord leucine-rich alpha-2 glycoprotein (LRG) and fetal infection and investigate the underlying mechanism of LRG elevation in fetuses. We retrospectively reviewed the medical records of patients who delivered at Osaka University Hospital between 2012 and 2017 and selected those with histologically confirmed chorioamnionitis (CAM), which is a common pregnancy complication that may cause neonatal infection. The participants were divided into two groups: CAM with fetal infection (CAM-f[+] group, n = 14) and CAM without fetal infection (CAM-f[−] group, n = 31). Fetal infection was defined by the histological evidence of funisitis. We also selected 50 cases without clinical signs of CAM to serve as the control. LRG concentrations in sera obtained from the umbilical cord were unaffected by gestational age at delivery, neonatal birth weight, nor the presence of noninfectious obstetric complications (all, p > 0.05). Meanwhile, the LRG levels (median, Interquartile range [IQR]) were significantly higher in the CAM-f(+) group (10.37 [5.21–13.7] μg/ml) than in the CAM-f(−) (3.61 [2.71–4.65] μg/ml) or control group (3.39 [2.81–3.93] μg/ml; p < 0.01). The area under the receiver operating characteristic (ROC) curve of LRG for recognizing fetal infection was 0.92 (optimal cutoff, 5.08 μg/ml; sensitivity, 86%; specificity, 88%). In a mouse CAM model established by lipopolysaccharide administration, the fetal LRG protein in sera and LRG mRNA in the liver were significantly higher than those in phosphate-buffered saline (PBS)-administered control mice (p < 0.01). In vitro experiments using a fetal liver-derived cell line (WRL68) showed that the expression of LRG mRNA was significantly increased after interleukin (IL)-6, IL-1β, and tumor necrosis factor- alpha (TNF-α) stimulation (p < 0.01); the induction was considerably stronger following IL-6 and TNF-α stimulation (p < 0.01). In conclusion, LRG is an effective biomarker of fetal infection, and fetal hepatocytes stimulated with inflammatory cytokines may be the primary source of LRG production in utero.