The calcium binding protein, S100B, is increased in the amniotic fluid of women with intra-amniotic infection/inflammation and preterm labor with intact or ruptured membranes

Perinatal S100B Protein Assessment in Human Unconventional Biological Fluids: A Minireview and New Perspectives

Growing evidence is now available on the use of S100B protein as a valuable marker of brain damage and its role as a neurotrophic factor. Bearing in mind, among different S100B protein properties that are still being investigated, the possibility of measuring this protein in different biological fluids renders it suitable for use in several disciplines. This is the case with perinatal medicine where even more noninvasive techniques are particularly desirable in order to ensure the minimal handling diagnostic and therapeutic strategies. In this setting, the present minireview reports data on the presence and the usefulness of S100B protein as brain damage marker and as a neurotrophic factor in the so-called unconventional biological fluids such as saliva and human milk, respectively. Results offer new possibilities for the use of S100B in perinatal medicine as a key-protein for the investigations focusing on central nervous system development and damage.

Detection of ureaplasmas by the polymerase chain reaction in the amniotic fluid of patients with cervical insufficiency

AIMS

The purpose of this study was to determine the clinical significance of detecting microbial footprints of ureaplasmas in amniotic fluid (AF) using specific primers for the polymerase chain reaction (PCR) in patients presenting with cervical insufficiency.

METHODS

Amniocentesis was performed in 58 patients with acute cervical insufficiency (cervical dilatation, > or =1.5 cm) and intact membranes, and without regular contractions (gestational age, 16-29 weeks). AF was cultured for aerobic and anaerobic bacteria as well as genital mycoplasmas. Ureaplasmas (Ureaplasma urealyticum and Ureaplasma parvum) were detected by PCR using specific primers. Patients were divided into three groups according to the results of AF culture and PCR for ureaplasmas: those with a negative AF culture and a negative PCR (n=44), those with a negative AF culture and a positive PCR (n=10), and those with a positive AF culture regardless of PCR result (n=4).

RESULTS

1) Ureaplasmas were detected by PCR in 19.0% (11/58) of patients, by culture in 5.2% (3/58), and by culture and/or PCR in 22.4% (13/58); 2) Among the 11 patients with a positive PCR for ureaplasmas, the AF culture was negative in 91% (10/11); 3) Patients with a negative AF culture and a positive PCR for ureaplasmas had a significantly higher median AF matrix metalloproteinase-8 (MMP-8) concentration and white blood cell (WBC) count than those with a negative AF culture and a negative PCR (P<0.001 and P<0.05, respectively); 4) Patients with a positive PCR for ureaplasmas but a negative AF culture had a higher rate of spontaneous preterm birth within two weeks of amniocentesis than those with a negative AF culture and a negative PCR (P<0.05 after adjusting for gestational age at amnio-centesis); 5) Of the patients who delivered within two weeks of amniocentesis, those with a positive PCR for ureaplasmas and a negative AF culture had higher rates of histologic amnionitis and funisitis than those with a negative AF culture and a negative PCR (P<0.05 after adjusting for gestational age at amniocentesis, for each); 6) However, no significant differences in the intensity of the intra-amniotic inflammatory response and perinatal outcome were found between patients with a positive AF culture and those with a negative AF culture and a positive PCR.

CONCLUSIONS

1) Cultivation techniques for ureaplasmas did not detect most cases of intra-amniotic infection caused by these microorganisms (91% of cases with cervical insufficiency and microbial footprints for ureaplasmas in the amniotic cavity had a negative AF culture); 2) Patients with a negative AF culture and a positive PCR assay were at risk for intra-amniotic and fetal inflammation as well as spontaneous preterm birth.

Pentraxin 3 in amniotic fluid: a novel association with intra-amniotic infection and inflammation

OBJECTIVE

Pentraxin 3 (PTX3) is a soluble pattern recognition receptor (PRR) that has an important role in immunoregulation and vascular integrity. The aim of this study was to determine if PTX3 is present in amniotic fluid (AF) and whether its concentration changes with gestational age (GA), in the presence of preterm or term labor, and in cases of intra-amniotic infection/inflammation (IAI) associated with spontaneous preterm labor (PTL) or preterm prelabor rupture of membranes (PROM).

STUDY DESIGN

This cross-sectional study included the following groups: 1) mid-trimester (n=45); 2) uncomplicated pregnancies at term with (n=48) and without (n=40) spontaneous labor; 3) women with PTL and intact membranes who: a) delivered at term (n=44); b) delivered preterm without IAI (n=40); or c) delivered preterm with IAI (n=62); 4) women with preterm PROM with (n=63) and without (n=36) IAI. PTX3 concentration in AF was determined by ELISA. Non-parametric statistics were used for analyses.

RESULTS

1) Among women with PTL and intact membranes, the median AF PTX3 concentration was significantly higher in women with IAI than in those without IAI (7.95 ng/mL vs. 0.38 ng/mL; P<0.001) and than in those who delivered at term (0.55 ng/mL; P<0.001); 2) women with preterm PROM and IAI had a higher median AF PTX3 concentration than those without IAI (9.12 ng/mL vs. 0.76 ng/mL; P<0.001); 3) the median AF PTX3 concentration did not change with GA (mid-trimester: 0.79 ng/mL vs. term not in labor: 0.58 ng/mL; P=0.09); and 4) labor at term was not associated with a significant change of AF PTX 3 concentration (in labor: 0.54 ng/mL vs. not in labor: 0.58 ng/mL, P=0.9).

CONCLUSIONS

PTX3 is a physiologic constituent of the AF, and its median concentration is elevated in the presence of IAI, suggesting that PTX3 may play a role in the innate immune response against IAI.

Soluble receptor for advanced glycation end products (sRAGE) and endogenous secretory RAGE (esRAGE) in amniotic fluid: modulation by infection and inflammation

OBJECTIVE

The receptor for advanced glycation end products (RAGE) has been proposed to participate in the innate and adaptive immune responses. RAGE can induce production of pro-inflammatory cytokines and chemokines, as well as neutrophil chemotaxis in a manner that may be suppressed or stimulated by soluble, truncated forms of RAGE including the soluble form of RAGE (sRAGE) and endogenous secretory RAGE (esRAGE). The objective of this study was to determine whether intra-amniotic infection/inflammation (IAI) is associated with changes in the amniotic fluid concentration of sRAGE and esRAGE.

STUDY DESIGN

Amniotic fluid (AF) was retrieved from patients in the following groups: 1) mid-trimester (14-18 weeks of gestation; n=68); 2) term not in labor (n=24); 3) term in labor (n=51); 4) preterm labor and intact membranes (n=124); and 5) preterm PROM (n=80). Intra-amniotic infection and inflammation were defined as the presence of a positive amniotic fluid culture for microorganisms and an AF interleukin-6 concentration >or=2.6 ng/mL, respectively. The AF concentration of sRAGE and esRAGE were determined using specific and sensitive ELISAs which measured total immunoreactive sRAGE and esRAGE, respectively. Patients were matched for gestational age at amniocentesis to compare the AF concentration of sRAGE and esRAGE in patients with and without IAI. Non-parametric statistics were used for analysis and a P<0.05 was considered significant.

RESULTS

1) Patients at term not in labor had higher median AF concentrations of sRAGE and esRAGE than those in the mid-trimester (P<0.001 for both comparisons) and those at term in labor (P=0.03 and P=0.04, respectively); 2) patients with preterm labor and intact membranes with intra-amniotic infection/inflammation (IAI) had higher median AF concentrations of sRAGE and esRAGE than those without IAI (P=0.02 and P=0.005, respectively); 3) similarly, patients with preterm PROM with IAI had higher median AF concentrations of sRAGE and esRAGE than those without IAI (P=0.03 and P=0.02, respectively).

CONCLUSION

Intra-amniotic infection/inflammation is associated with increased amniotic fluid concentrations of sRAGE and esRAGE. Changes in the amniotic fluid concentration of sRAGE and esRAGE may represent part of the immune response to intra-amniotic infection/inflammation.