Interleukin-8 in cord sera: a sensitive and specific marker for the detection of preterm chorioamnionitis

Oxidative and Inflammatory Markers Are Higher in Full-Term Newborns Suffering Funisitis, and Higher Oxidative Markers Are Associated with Admission

The aim of this study was to assess whether oxidative and inflammatory mediators in the cord blood of newborns with funisitis and chorioamnionitis can serve as indicators of their inflammatory status, and whether there is a positive association between higher mediator levels and an increased risk of admission to the neonatal intensive care unit (NICU). This study was conducted prospectively in a neonatology department of a university hospital. In total, 52 full-term newborns were evaluated, including 17 funisitis cases, 13 chorioamnionitis cases, and 22 control newborns without funisitis or chorioamnionitis. Cord blood samples were measured for oxidative stress and inflammatory status markers. The oxidative stress markers included the total nitric oxide (NO), total hydroperoxide (TH), biological antioxidant potential (BAP), and TH/BAP ratio, comprising the oxidative stress index (OSI). Inflammatory markers included interleukin (IL)-1b, IL-6, IL-8, IL-10, tumor necrosis factor alpha (TNFα), interferon γ (IFNγ), and complement component C5a. TH, OSI, IL-1b, IL-6, and IL-8 concentrations were higher in the funisitis group than in the chorioamnionitis and control groups. C5a was higher in the funisitis and chorioamnionitis groups than in the control group. Among all enrolled newborns, 14 were admitted to the NICU. Multiple logistic regression analysis showed that elevated umbilical cord blood levels of OSI and TH were associated with a higher risk of admission to the NICU (OSI: R = 2.3, 95% CI 1.26–4.29, p = 0.007 and TH: R = 1.02, 95%CI = 1.004–1.040, p = 0.015). In conclusion, OSI and TH in cord blood from full-term newborns can provide an index of inflammatory status, and higher levels are associated with the risk of admission to the NICU and, therefore, could serve as an early indicator of inflammatory conditions in newborns.

Re-evaluation of Urinary Trypsin Inhibitor on Pregnancy Course in Patients with Threatened Preterm Delivery: A Single-Center Retrospective Study

Background

We evaluated the necessity of urinary trypsin inhibitor for patients with threatened premature labor.

Methods

We enrolled 146 women with singleton pregnancies who were treated for threatened premature labor as inpatients. The uterine cervical length of each patient was ≤ 25 mm at 22-35 weeks of gestation on transvaginal ultrasonography. The patients were divided into two groups: the urinary trypsin inhibitor group (91 patients treated with urinary trypsin inhibitor daily) or non-urinary trypsin inhibitor group (55 patients not treated with urinary trypsin inhibitor). The childbirth outcomes were retrospectively assessed.

Results

The median cervical length measured on the day of admission was almost similar between the urinary trypsin inhibitor and non-urinary trypsin inhibitor groups. Depending on the symptoms of uterine contractions, we determined whether ritodrine hydrochloride and/or magnesium sulfate would be appropriate for treatment. The median gestational week at birth was 38 weeks in the urinary trypsin inhibitor group, and no obvious differences were observed when compared with the non-urinary trypsin inhibitor group. With regard to birth weight, no significant difference was found between the two groups (urinary trypsin inhibitor group, 2776 g; non-urinary trypsin inhibitor group, 2800 g).

Conclusion

Our data showed no significant beneficial effects of urinary trypsin inhibitor in the maternal course and delivery outcomes.

Differential expression of CXC chemokines CXCL10 and CXCL12 in term and pre-term neonates and their mothers

BACKGROUND AND AIM

Pre-term delivery is a mostly unknown frequent disorder worldwide. This project aimed to investigate the circulating levels of CXCL12 (SDF-1) and CXCL10 (IP-10) in cord blood of term and pre-term delivered fetuses and their corresponding mothers.

MATERIAL AND METHODS

Cord and peripheral blood samples were collected from 50 pre-term and 50 term infants and their mothers. Serum levels of CXCL12 and CXCL10 were measured by ELISA.

RESULTS

The findings of this study indicated that the circulating levels of CXCL10 were elevated in mothers bearing pre-term infants, while CXCL12 was only increased in pre-term infants.

CONCLUSION

The results suggested that the pathophysiological status of both mother and infant are involved in prematurity. Moreover, these findings suggest an inflammatory response in pre-term labor, which probably is controlled by inducible chemokines such as CXCL10.

Complement component C4A and apolipoprotein A-I in plasmas as biomarkers of the severe, early-onset preeclampsia

Preeclampsia is a common pregnancy complication that is associated with maternal perinatal morbidity and mortality. Because of its early onset (before 34 weeks) and the potential for serious outcomes, severe, early-onset preeclampsia (sePE) should be regarded as a different form of preeclampsia. It is an important cause of preterm birth and fetal growth restriction and adverse maternal and neonatal outcomes. As there is no diagnostic test yet available for this disease, we used a proteomic approach to identify novel plasma biomarkers for developing severe, early-onset preeclampsia. We conducted case-control studies comparing nulliparous women with severe preeclampsia requiring delivery prior to 34 weeks of gestation with healthy nulliparous women matched by gestational age at sampling. Plasma was depleted of albumin and IgG and analyzed by two-dimensional gel electrophoresis (2DE). Seven specific plasma proteins for early-onset preeclampsia were detected by mass spectrometry had statistically significant expression differences when compared to controls. The expression of complement component C4A and apolipoprotein A-I were validated by immunoblotting. The complement component C4A in the plasmas of sePE women is lower than the severe, late-onset PE (slPE) women [mean ± SD; 3.05 ± 0.14 times reference level (normal/sePE) in sePE women vs. 2.73 ± 0.10 times reference level (normal/slPE) in slPE women, P < 0.05]. Apolipoprotein A-I is higher in sePE women than slPE women [mean ± SD; 1.58 ± 0.14 times reference level (sePE/normal) in sePE women vs. 1.04 ± 0.16 times reference level (slPE/normal) in slPE women, P < 0.05]. Furthermore, C4A can accurately distinguish severe PE (sePE and slPE) from mild PE (mePE and mlPE) and was proved by the results of ELISA. Further studies have been done to determine the relation between PE and hypoxia. JAR cells were cultured under hypoxia for 72 h. Total cellular proteins were gathered and lysed. Lower C4A and higher apolipoprotein A-I had been observed in JAR of hypoxia conditions than normoxia conditions through western blotting. The result proved that PE is correlated with hypoxia. In summary, C4A and apolipoprotein A-I are able to function as markers to distinguish ePE women from lPE women, and severe PE from mild PE, or perhaps even as disease predictors that might become relevant for diagnostics.

Effects of 4-hydroxy-2-nonenal, a major lipid peroxidation-derived aldehyde, and N-acetylcysteine on the cyclooxygenase-2 expression in human uterine myometrium

BACKGROUND

Chorioamnionitis is one of the important causes of preterm labor. Preterm labor with chorioamnionitis is associated with oxidative stress. We reported that 4-hydroxy-2-nonenal (4-HNE), a major end product of oxidative fatty acid metabolism, is accumulated in the placenta with chorioamnionitis. The aim of this study was to confirm the effect of 4-HNE on cyclooxygenase-2 (COX-2) and prostaglandin (PG) induction in the uterine myometrial tissues. We also examined the effect of N-acetylcysteine (NAC) on 4-HNE-induced COX-2 expression.

METHODS

Uterine myometrial tissues were obtained from 5 patients. One of them underwent elective cesarean section without labor, and 4 of them underwent hysterectomy because of placental previa or atonic bleeding. We stimulated the uterine myometrial tissues with 4-HNE. In addition, the tissues were pretreated with NAC before 4-HNE treatment. The expression of COX-2 mRNA was observed by real-time PCR. PGE2 and prostacyclin release into the supernatants of the tissue cultures was measured by ELISA.

RESULTS

4-HNE induced the COX-2 mRNA expression and PGE2 production in the uterine myometrial tissue culture in a dose-dependent and time-dependent manner. NAC inhibited 4-HNE-induced COX-2 expression.

CONCLUSION

4-HNE may play an important role in preterm labor. NAC might be protective against preterm labor under oxidative stress.

Interleukin 8 (IL-8) - a universal biomarker?

Many clinical conditions including various types of cancers are complex and generally require invasive, laborious, expensive and time-consuming investigations for their diagnosis, treatment and follow-up. There is therefore a general need for exploring non-invasive markers in clinical medicine. Interleukin 8 (IL-8) is currently being applied in various subspecialties of medicine either for the purpose of rapid diagnosis or as a predictor of prognosis. Nevertheless, there is need for large-scale studies to substantiate accuracy and outcome. This article will summarize current evidence suggesting that Interleukin 8 (IL-8) may serve as a useful biomarker.

Blood cytokines during the perinatal period in very preterm infants: relationship of inflammatory response and bronchopulmonary dysplasia

OBJECTIVE

To evaluate the influence of chorioamnionitis (CA) on plasma cytokines and the cytokine-associated risk of bronchopulmonary dysplasia (BPD) during the perinatal period.

STUDY DESIGN

Eleven cytokines from 128 very low gestational age infants were analyzed from cord blood and from plasma at ages 1 day and 7 days after birth. The diagnosis of CA was based on histology of the placenta, fetal membranes, and umbilical cord. Neonatal risk factors were recorded.

RESULTS

In the 48 infants born with CA, high concentrations of inflammatory cytokines in cord blood decreased during the first postnatal day. Inflammatory cytokines in cord blood was associated with the severity of CA. At 1 day after birth, the concentration of interleukin (IL)-8 predicted the risk of BPD. For the 75 infants born without CA, cytokine concentrations increased after birth. For the 128 infants born with or without CA, at 1 day after birth, the concentrations of IL-8, granulocyte colony-stimulating factor, and anti-inflammatory IL-10 were associated with the risk of BPD, after adjustment for the duration of gestation and severity of respiratory distress during the first day.

CONCLUSIONS

In infants exposed to CA, insufficient inhibition of high fetal inflammatory cytokine response shortly after birth may increase the risk of BPD.

Identification of proteomic biomarkers of preeclampsia in amniotic fluid using SELDI-TOF mass spectrometry

OBJECTIVE

To identify proteomic biomarkers in amniotic fluid (AF) that can distinguish preeclampsia (PE) from chronic hypertension (CHTN) and normotensive controls (CTR).

METHODS

AF from women with PE, CHTN, and CTR were subjected to proteomic analysis by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry.

RESULTS

Proteomic profiling of AF identified 2 biomarkers: peak X (17399.11 Da), which distinguished PE from CTR, and peak Y (28023.34 Da), which distinguished PE and CHTN from CTR. High performance liquid chromatography fractions containing the biomarkers were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and in-gel tryptic digestion. The biomarkers were matched to proapolipoprotein A-I (peak Y) and a functionally obscure peptide, SBBI42 (peak X). Western blot analysis confirmed that AF from PE and CHTN had higher proapolipoprotein A-I levels than CTR.

CONCLUSION

Proteomic analysis of AF can distinguish PE from CHTN and CTR. The discriminatory proteins were identified as proapolipoprotein A-I and SBBI42.

Population cohort associating chorioamnionitis, cord inflammatory cytokines and neurologic outcome in very preterm, extremely low birth weight infants

Intrauterine inflammation may relate to neurologic disability among preterm children. We investigated the relationship between chorioamnionitis, cord serum cytokines, and neurologic outcome. Sixty-one consecutively born very preterm extremely low birth weight (ELBW) infants were prospectively enrolled. Histologic inflammation in placenta and umbilical cord and vascular pathology were evaluated. Cord sera were analyzed for five proinflammatory cytokines. Serial brain ultrasound and magnetic resonance imaging were performed for evaluation of intraventricular hemorrhage (IVH grade I-III) and white matter damage (WMD: cystic periventricular leukomalacia or IVH grade IV). Neurologic and neurocognitive outcomes were assessed at the corrected age of 2 y. The incidences of HCA, WMD, and abnormal neurologic outcome were 48%, 13% and 19%, respectively. HCA or high IL-6 in cord serum predicted spontaneous preterm labor with high accuracy. HCA increased the risk of IVH grade II-III. In HCA, without either clinical chorioamnionitis or histologic placental perfusion defect, the children had a low risk of WMD (0%) and a low risk of abnormal neurologic outcome (6%). In HCA, the concentration of IL-6 in cord serum was lower in children with abnormal neurologic outcome than in children with normal neurologic outcome. In HCA and placental perfusion defect (compound defect) the risk of abnormal neurologic outcome was high. Compound placental defect and WMD additively predicted abnormal neurologic outcome. We propose that HCA together with other insults (placental perfusion defect or maternal systemic infection) increases the risk of poor neurologic outcome in very preterm ELBW infants.

Establishment of a prediction method for premature rupture of membranes in term pregnancy using active ceruloplasmin in cervicovaginal secretion as a clinical marker

AIM

Term pregnancy complicated by premature rupture of membranes (PROM) is thought to be associated in part with subclinical infection, and places mothers and neonates at an increased risk for several complications. Therefore, perinatal care would be greatly helped if a reliable clinical measure were available for predicting the incidence of PROM.

METHODS

One hundred and ninety-six pregnant women who consented to enter this study were screened using a method developed to assess active ceruloplasmin in cervicovaginal secretion as a clinical marker for predicting the incidence of PROM. Cervicovaginal secretions were obtained from the cervical canal at about 36 weeks of pregnancy. The active ceruloplasmin level in the cervicovaginal secretion was measured using an original enzyme-linked immunoabsorbent assay.

RESULTS

Of 196 women, 27 women (13.8%) developed PROM and 169 women (86.2%) did not develop PROM. Active ceruloplasmin in the cervicovaginal secretion was significantly higher in the PROM group than in the non-PROM group (P < 0.001). Analysis using receiver-operating characteristic curves showed that the active ceruloplasmin level (1420.0 ng/mL) proved to be the proper cut-off value to best predict the incidence of PROM.

CONCLUSION

Active ceruloplasmin in the cervicovaginal secretion might be a reliable clinical marker for term PROM.

IL-8 concentrations in maternal serum, amniotic fluid and cord blood in relation to different pathogens within the amniotic cavity

OBJECTIVE

The association between elevated interleukin (IL)-8 concentrations in amniotic fluid and preterm delivery is well described. Little consideration has been given to the impact of different groups of microorganisms within the amniotic cavity on IL-8 concentration.

METHODS

We collected amniotic fluid, placental tissue and amniotic membranes during preterm cesarean sections for bacterial culture. In addition, we determined IL-8 concentrations in maternal serum, amniotic fluid and cord blood and correlated them with the various intra-amniotic pathogens isolated by bacterial culture.

RESULTS

IL-8 concentrations were determined in amniotic fluid in 107 cases, in cord blood in 185 cases and in maternal blood in 158 cases. Women with intra-amniotic Ureaplasma urealyticum infection had significantly higher amniotic fluid concentrations of IL-8 than those without (P< 0.001). In cord blood, we found significantly elevated IL-8 concentrations due to intra-amniotic infection with U. urealyticum (P=0.045) and other pathogens (P=0.04). In maternal sera, we found no significant elevation of maternal IL-8 in any of the groups.

CONCLUSION

Intrauterine infection with U. urealyticum seems to play a profound role in the cascade of inflammation and increases IL-8 concentrations in amniotic fluid and cord blood.

The pulmonary paradox in premature infants: in-utero infected lungs do better than those with accelerated maturation

AIMS

To document, and explain, the pulmonary paradox whereby despite relative lung immaturity, preterm infants exposed to amniotic infection (AI) have better postnatal pulmonary function than those exposed to preeclampsia (PE).

METHODS

Lung maturation was characterized in 65 preterm perinatal deaths [AI (n=40) and PE (n=25)] and postnatal respiratory function in 100 preterm survivors [AI (n=50) and PE (n=50)].

RESULTS

At autopsy, lung architecture was in advance of gestational age in 5% of AI infants versus 40% of PE infants (P<0.001). In survivors, the groups were similar in age and Apgar scores. At birth, 40% of the AI group required continuous positive airway pressure or mechanical ventilation versus 24% of the PE group (NS). However, 24 hours later, only 1 AI infant had deteriorated compared to 40% of PE infants (P<0.05).

CONCLUSIONS

Accelerated morphologic lung maturation in preterm PE infants does not translate into improved postnatal respiratory function. Most likely, this is due to a relative lack of surfactant, ascribable to low stimulant cytokine and high TNF-alpha levels. An intrauterine history supplemented by an antenatal cytokine profile could identify an increased exogeneous surfactant need in preterm infants exposed to PE.

Antenatal corticosteroids for fetal maturation in women at risk for preterm delivery

The available data unambiguously support the beneficial, short-term fetal effects of antenatal corticosteroids in women at risk for preterm delivery. There are still several incompletely addressed questions, including the use of corticosteroids in women with preterm premature rupture of membranes, the optimal corticosteroid preparation to be used, and the impact of repeated dosing. These issues are discussed in this review from the perspective of recent scientific evidence on the mechanisms responsible for positive short-term effects on survival and possible harmful long-term effects.

Role of cytokines (interleukin-1beta, 6, 8, tumour necrosis factor-alpha, and soluble receptor of interleukin-2) and C-reactive protein in the diagnosis of neonatal sepsis

AIM

To investigate whether the serum levels of interleukin-1beta, 6, 8, tumour necrosis factor-alpha and the soluble receptor of IL-2 are useful in the diagnosis of neonatal sepsis, and whether their diagnostic power is increased when in combination with classical markers such as C-reactive protein and white blood cell count.

METHODS

Blood samples were collected at admission from 40 neonates with suspected infection. Patients were included in different groups according to the bacteriological and laboratory results: Group I consisted of 20 newborns with positive blood cultures and other biological tests suggestive of infection. Group II included 20 neonates with negative blood cultures and biological tests not suggestive of infection. The control group included 20 healthy neonates with no clinical or biological data of infection.

RESULTS

Mean values of C-reactive protein were significantly higher in Group I. No differences were found between the groups for white blood cell count, with the exception of the presence of leucocytosis in Group II. Levels of interleukin-1beta, 6, 8, tumour necrosis factor-alpha, soluble receptor of interleukin-2, and C-reactive protein were significantly higher in infected neonates than in the control groups. Detection sensitivity and specificity were 80 and 92% for C-reactive protein, 60 and 87% for interleukin-1beta, 61 and 80% for interleukin-6, 62 and 96% for interleukin-8, 54 and 92% for tumour necrosis factor-alpha and 63 and 94% for soluble receptor of interleukin-2. The discriminant analysis showed that the best combination for sepsis diagnosis was C-reactive protein + interleukin-8 + soluble receptor of interleukin-2, with a sensitivity of 85% and a specificity of 97.1%.

CONCLUSION

Our study suggests that no individual test can on its own identify infected neonates, and that although the combination of C-reactive protein, interleukin-8 and the soluble receptor of interleukin-2 exhibits a high specificity, its sensitivity is limited.

High levels of intrauterine corticotropin-releasing hormone, urocortin, tryptase, and interleukin-8 in spontaneous abortions

Stress induces CRH secretion that activates hypothalamic-pituitary-adrenal axis and is also abortogenic. In addition to hypothalamus, CRH and its analog urocortin (Ucn) are also secreted locally outside the brain where they activate mast cells leading to inflammation; however, the level of CRH and Ucn or mast cell mediators has not been examined in products of conception (POC). CRH and Ucn were measured by enzyme immunoassay, tryptase by fluoroenzyme immunoassay, and IL-8 by ELISA in POC of 7-9 wk gestation from Caucasian women; they were divided into group I with elective abortions (n = 4), group II with one spontaneous abortion (n = 12), and group III with at least two spontaneous abortions (n = 7). CRH, Ucn, tryptase, and IL-8 levels were higher (P < 0.05) in group III (8683 +/- 1201 pg/g, 7961 +/- 1499 pg/g, 1553 +/- 572 ng/g, and 8317 +/- 1874 pg/g, respectively) than group II (2561 +/- 314 pg/g, 2349 +/- 394 pg/g, 403 +/- 97 ng/g, and 3199 +/- 449 pg/g, respectively) and group I (163 +/- 162 pg/g, 328 +/- 327 pg/g, 72 +/- 31 ng/g, and 3681 +/- 931 pg/g, respectively). Immunostaining of POC showed significantly more tryptase in group III women. High POC levels of CRH and Ucn under stress in habitual spontaneous abortions may activate uterine mast cells to secrete abortogenic tryptase and IL-8.

Cervical Lactobacillus and leukocyte infiltration in preterm premature rupture of membranes

OBJECTIVES

To evaluate the possible association between microorganisms present in the cervical secretions and amniotic fluid of pregnant women with preterm premature rupture of membranes (PPROM), and histologic chorioamnionitis.

METHODS

Thirty-seven pregnant women with PPROM and 21 healthy pregnant women were studied. Secretions from the cervical canal and amniotic fluid were collected to isolate microorganisms present in the genital tract. Cervical smears were Gram stained and evaluated microscopically. At delivery, chorioamniotic membranes were collected for histopathologic analysis.

RESULTS

Microscopic examination of the cervical secretion smears obtained from the PPROM group showed a low rate of Lactobacillus species, large numbers of leukocytes, and a wide diversity of microorganisms compared with the control group. The PPROM group presented an 80% rate of chorioamnionitis. Staphylococcus aureus isolation in cervical secretion was associated with intense inflammatory infiltrate in the membranes and might play a role in the pathogenesis of PPROM.

CONCLUSIONS

The low colonization of cervical flora by Lactobacillus species associated with an intense leukocyte infiltrate detected in Gram-stained cervical smears can be considered a rapid method of detecting chorioamnionitis in pregnant women with PPROM.

Antenatal factors and the development of bronchopulmonary dysplasia

The lung of the preterm fetus is often exposed to antenatal glucocorticoids, and histologic chorioamnionitis is frequent. Clinically and experimentally, antenatal glucocorticoids and/or chorioamnionitis are associated with early lung maturation, but in experimental models, both glucocorticoids and intra-uterine inflammation decrease alveolarization. Experimental chorioamnionitis also can amplify the inflammatory response of the preterm lung to mechanical ventilation. In this article, the hypothesis developed is that bronchopulmonary dysplasia occurs because of repetitive adverse lung exposures, or hits, and that the initial hits may be antenatal glucocorticoid exposure and/or antenatal inflammation.

Elevations of group II phospholipase A2 concentrations in serum and amniotic fluid in association with preterm labor

OBJECTIVE

The purpose of this study was to determine whether the elevation of secretory group II phospholipase A(2) concentration in the serum and amniotic fluid in preterm labor is associated with intrauterine inflammation.

STUDY DESIGN

Serum and amniotic fluid were collected from women with preterm delivery (<37 weeks' gestation; n = 38) and term delivery (n = 20). Phospholipase activity was measured with a highly sensitive system that was based on reverse-phase high-performance liquid chromatographic separation of 9-anthracenylmethyl derivatives of fatty acids released by phospholipase A(2). The concentrations of immunoreactive isozymes (group I or II) of secretory phospholipase A(2) were assayed with a radioimmunoassay kit with a monoclonal antibody against human pancreatic phospholipase A(2) and splenic IIA phospholipase A(2). Localization of immunoreactive group II phospholipase A(2) in the amniotic membrane was determined by immunostaining visualized with the Vectastain ABC (Vector Laboratories, Inc, Burlingame, Calif) method.

RESULTS

Enzymatic activities of phospholipase A(2) in the serum and amniotic fluid specimens obtained from patients in preterm labor with chorioamnionitis were significantly higher than those in specimens from patients in term labor. Significant elevations of phospholipase A(2) activities were observed in patients with preterm labor without histologically evident chorioamnionitis. The activity of phospholipase A(2) was clearly correlated with the concentration of the immunoreactive group II phospholipase A(2). Group II phospholipase A(2) was localized in amniotic cells obtained from patients with a pathologically determined diagnosis of chorioamnionitis. The predictive value for chorioamnionitis of the group II phospholipase A(2) concentration was relatively higher than the predictive values of the concentrations of C-reactive protein and interleukins 6 and 8.

CONCLUSION

Significant elevations of group II phospholipase A(2) concentrations were detected in the serum and amniotic fluid of women with preterm labor. Group II phospholipase A(2) concentration may be a useful indicator for preterm labor, and phospholipid metabolism is certainly activated both in preterm labor and in apparent inflammatory diseases.

Fetal distress increases interleukin-6 and interleukin-8 and decreases tumour necrosis factor-alpha cord blood levels in noninfected full-term neonates

OBJECTIVE

To assess the influence of fetal distress on interleukin-1beta, interleukin-6, interleukin-8 and on tumour necrosis factor-alpha blood levels in noninfected full-term neonates.

STUDY DESIGN

In a multicentre prospective study, cord blood samples were obtained at time of delivery from 234 noninfected full-term neonates for the purposes of measuring serum levels of interleukin-1beta, interleukin-6, interleukin-8 and tumour necrosis factor-alpha using immunoassays. Women were classified into four groups according to the mode of delivery (vaginal delivery or caesarean section) and the presence or absence of fetal distress. The role of labour was also investigated.

RESULTS

No significant relationship was found between cytokine cord blood levels and the mode of delivery. Fetal distress was associated with an increase in interleukin-6 (P = 0.01) and interleukin-8 (P < 0.001) levels, and a decrease in tumour necrosis factor-alpha (P < 0.001). Labour was also associated with a significant increase in interleukin-6 and interleukin-8 cord blood levels (P = 0.01 and P < 0.001, respectively).

CONCLUSION

Fetal distress and labour were each associated with elevated interleukin-6 and interleukin-8 cord blood levels in noninfected full term neonates while only fetal distress was associated with decreased tumour necrosis factor-alpha levels.

Interleukin-8 release from human gestational tissue explants: effects of gestation, labor, and chorioamnionitis

Interleukin-8 (IL-8) is a chemotactic cytokine that has been implicated in the process of human parturition, including the processes of cervical ripening and rupture of fetal membranes. In this study, the in vitro release of IL-8 from human amnion, choriodecidua, and placenta tissues obtained before and after spontaneous labor onset both at term and preterm, was assessed. The effect of chorioamnionitis on IL-8 release was also established. All tissue explants examined released IL-8; however, IL-8 release from choriodecidual explants was significantly (p < 0.02) greater than that observed from amnion and placenta. Furthermore, choriodecidual IL-8 release was significantly (p < 0.001) greater from term tissues (850 +/- 134.4 ng/mg DNA, n = 18) than from preterm tissues (458 +/- 68.8 ng/mg DNA, n = 17). Spontaneous onset of labor, irrespective of the eventual mode of delivery, was not associated with any significant changes in IL-8 release from human gestational tissues compared to not-in-labor tissues, both at term and preterm. IL-8 release from gestational tissues was not significantly different in the absence or presence of chorioamnionitis. These data are in contrast to the previously reported stimulatory effects of bacterial endotoxin on IL-8 release from human gestational tissues. The data are consistent, however, with the suggestion that IL-8 release is an early event in chorioamnionitis that precedes the appearance of clinically overt symptoms.

Human placental cells show enhanced production of interleukin (IL)-8 in response to lipopolysaccharide (LPS), IL-1 and tumour necrosis factor (TNF)-alpha, but not to IL-6

Interleukin-8 (IL-8) is a chemotactic and activating factor for neutrophils which play important roles in host defence mechanisms. The human placenta constitutively produces IL-8 during pregnancy and enhances its production in chorioamnionitis. The present study was designed to investigate in vitro the regulatory mechanism for IL-8 production in the placentas in normal and inflammatory states. Placental cells produced IL-8 in a dose-dependent fashion when stimulated with lipopolysaccharide (LPS). The purified trophoblasts showed significantly higher IL-8 production than untreated placental cells. The expression of IL-8 gene in the trophoblasts in the third trimester was observed by reverse transcription-polymerase chain reaction (RT-PCR). The placental cells also release IL-8 in a dose-dependent manner, in response to r-(recombinant) IL-1alpha and tumour necrosis factor (TNF)-alpha, but not rIL-6. Moreover, LPS-activated placental cells spontaneously produced a much larger amount of IL-8 and showed increased responses to rIL-1alpha and TNF-alpha. It may, therefore, be proposed that placental cells with multiple endocrine functions exert immunological functions by constitutive production of IL-1 and TNF-alpha, which stimulate placental IL-8 release. This cytokine cascade in the placenta may be augmented by LPS in chorioamnionitis, thereby potentiating the feto-maternal defence mechanisms against infection.

Increased serum concentrations of soluble tumor necrosis factor receptors p55 and p75 in early onset neonatal sepsis

Sepsis and pneumonia are major causes of morbidity and mortality in the neonatal period. The symptoms are variable and unspecific. So far, no reliable diagnostic test for neonatal infection has been found. In this study we measured serum levels of soluble tumor necrosis factor receptors (sTNFR) p55 and p75 in non-infected and infected neonates, and evaluated the diagnostic value of these mediators as tests for early detection of neonates with sepsis or pneumonia. Blood was collected on admission and after 3-4 days from 161 neonates consecutively admitted to the Neonatal Intensive Care Unit (NICU) during the first week of life. Twenty two neonates suffered from infection and 127 were classified as non-infected (controls). Samples were analyzed for p55 and p75, C-reactive protein (CRP) and white blood cell count with differential. Both preterm and term infected neonates had initially higher concentrations of p55 (both p <0.01) and p75 (p = 0.01 and p = 0.05, respectively) than controls. In non-infected neonates p55 levels decreased in the perinatal period, whereas p75 levels remained stable. Levels of both p55 and p75 decreased in neonates with infection during the perinatal period. CRP was a more specific parameter than p55 and p75 (CRP: 97%, p55: 65% and p75: 75%) whereas the sensitivity of all three parameters was at similar levels (CRP: 59%, p55: 70% and p75: 67%). We conclude that assessment of sTNFR may not improve accuracy in the diagnosis of early onset neonatal sepsis compared to the use of CRP.

Plasma levels and gene expression of granulocyte colony-stimulating factor, tumor necrosis factor-alpha, interleukin (IL)-1beta, IL-6, IL-8, and soluble intercellular adhesion molecule-1 in neonatal early onset sepsis

Bacterial sepsis is still a leading cause of neonatal morbidity and mortality. Early onset sepsis in particular, presents with a different clinical course and involves other pathogens than sepsis later in life. In this study, plasma concentrations and mRNA expression of granulocyte colony-stimulating factor (G-CSF), tumor necrosis factor-alpha (TNF-alpha), IL-1beta, IL-6, IL-8, and soluble intercellular adhesion molecule-1 (sICAM-1) of neonates with early onset sepsis were evaluated in cord blood and during the first days of life. Irrespective of prematurity, plasma levels of G-CSF, TNF-alpha, IL-1beta, IL-6, and IL-8, but not sICAM-1, were excessively elevated in septic neonates when compared with both healthy infants and infants with clinically suspected but not confirmed sepsis. Compared with the corresponding maternal levels, neonatal cytokine cord plasma levels were likewise highly elevated, indicating the endogenous cytokine production by the neonate. With the exception of TNF-alpha, mRNA expression in blood cells from septic infants was, however, not more frequently detectable than in those from nonseptic patients. Cytokine levels decreased significantly within the first days of life, whereas levels of sICAM-1 and C-reactive protein increased during the same time period. In summary, in contrast to C-reactive protein and sICAM-1, cord blood plasma levels, but not the presence of mRNA, of G-CSF, TNF-alpha, IL-1beta, IL-6, and IL-8 can predict neonatal early onset sepsis with a high sensitivity and specificity. Cell types other than blood cells are likely to contribute considerably to the high cytokine production in septic newborns.

Early increase in endothelin-1 in tracheal aspirates of preterm infants: correlation with bronchopulmonary dysplasia

OBJECTIVES

To determine whether endothelin-1 (ET-1) in tracheal aspirates (TA) is a specific marker for acute lung injury in preterm infants with respiratory distress syndrome (RDS) who progress to bronchopulmonary dysplasia (BPD); and to investigate the relationship between TA ET-1 and the proinflammatory cytokines, interleukin-6 (IL-6) and IL-8, as early mediators of BPD.

STUDY DESIGN

We measured TA ET-1, IL-6, and IL-8 levels in preterm infants whose lungs were mechanically ventilated for RDS, categorized into two groups, BPD or non-BPD, on the basis of oxygen requirement at 36 weeks' postconceptional age.

RESULTS

A total of 106 TA samples were obtained from 34 infants with gestational ages ranging from 24 to 28 weeks on days 1, 3, 5, and 7 of life. There was a wide range of ET-1 concentration. TA ET-1 levels were significantly elevated on days 1, 3, and 7 in infants in whom BPD developed, in comparison with the non-BPD group (Mann-Whitney U test: p < 0.01). TA IL-8 levels were elevated on days 1, 3, 5, and 7 in the BPD group (p < 0.01); TA IL-6 levels were elevated (p < 0.05) only on day 5. There was a similarity in pattern of increase of TA ET-1 and TA IL-8 levels in the BPD group, with both being elevated in the first 24 hours of life and through the first week. There was no correlation between ET-1 and IL-8 values.

CONCLUSION

Early significant increase in the TA ET-1 and IL-8 concentrations in preterm infants with acute lung injury correlates with subsequent progression to BPD.

Amniotic fluid granulocyte colony stimulating factor levels: a rapid marker for diagnosing chorioamnionitis

PROBLEM

To assess the usefulness of amniotic fluid (AF) granulocyte colony stimulating factor (G-CSF) levels as a rapid marker for diagnosing chorioamnionitis.

METHOD OF STUDY

AF levels were obtained from term and preterm patients with and without chorioamnionitis (CAM). Patients with urinary tract, respiratory tract, and other infections were excluded. Results obtained from the AF G-CSF assays were compared with those from other parameters used for diagnosing CAM: maternal fever, leukocytosis, tachycardia, fetal tachycardia, AF glucose levels, white blood cell count, Gram stain, and aerobic and anaerobic cultures. The sensitivity, specificity, and predictive values were calculated.

RESULTS

In the uninfected AF samples, G-CSF levels were present but low, ranging from 400 to 1600 pg/ml. Levels in the infected samples, however, were markedly increased, ranging from 1600 to 14,000 pg/ml; P < 0.05. When a cutoff of 2000 pg/ml was used as a clear marker for CAM, the sensitivity was 67%, the specificity was 100%, and the positive and negative predictive values were 100% and 86%, respectively. The comparison of the other AF G-CSF laboratory parameters also revealed high sensitivity, specificity, and predictive values for detecting CAM.

CONCLUSION

(i) AF G-CSF levels are elevated in CAM. (ii) An AF G-CSF level > 2000 pg/ ml is a strong positive predictor of CAM. (iii) Elevated AF G-CSF levels appear to be more reliable in predicting CAM than any other single test currently used in clinical practice.

Interleukin-8 level in maternal serum as a marker for screening of histological chorioamnionitis at term

OBJECTIVE

To establish a clinical method for immediate diagnosis of histological chorioamnionitis, by maternal blood sampling at term.

METHOD

The sera of 22 mothers with chorioamnionitis and 81 mothers without chorioamnionitis at term delivery were collected. The serum levels of cytokines including interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and interleukin-8 (IL-8) were titered and other conventional markers such as white blood cell and CRP were measured simultaneously. Chorioamnionitis was histopathologically confirmed after delivery.

RESULT

The sera of mothers with histological chorioamnionitis showed a significant increase in IL-8 titer, but not in those of other cytokines or conventional markers, compared with those without chorioamnionitis. A positive correlation was observed between maternal and cord serum IL-8 levels. Maternal IL-8 showed the highest predictive value for diagnosis of histological chorioamnionitis.

CONCLUSION

Measurement of maternal IL-8 is useful for rapid prenatal screening of histological chorioamnionitis at term.

Interleukin 8 and granulocyte elastase alpha 1 proteinase inhibitor complex in the tracheobronchial aspirate of infants with chronic lung disease following respiratory distress syndrome

In order to elucidate the role of interleukin 8 (IL-8) on the development of chronic lung disease (CLD) in neonates following an episode of respiratory distress syndrome (RDS), serial and simultaneous measurements of the concentration of IL-8 and granulocyte elastase alpha 1 proteinase inhibitor complex (E-alpha 1 PI) in the tracheobronchial aspirate of very low birthweight infants with RDS were conducted. The concentration of IL-8 and E-alpha 1 PI in infants with CLD was low in the first 48 h of life, but dramatically increased after 48 h. The concentration of IL-8 between 48 h of life and day 5 was significantly correlated to the fraction of inspired oxygen concentration (FiO2) within 48 h of age, but not to the mean airway pressure. Interleukin 8 seemed to stimulate neutrophils to release granulocyte elastase which, in turn, caused lung tissue injury, resulting in the development of CLD. It is suggested that high FiO2 is an important factor causing IL-8 production in the lung.

Interleukin 8 and granulocyte elastase alpha 1 proteinase inhibitor complex in the tracheobronchial aspirate of infants with chronic lung disease following inter-uterine infection

In order to elucidate the role of interleukin 8 (IL-8) in the development of chronic lung disease (CLD) of neonates with intra-uterine infection, serial and simultaneous measurements of the concentration of IL-8 and granulocyte elastase alpha 1 proteinase inhibitor complex (E-alpha 1 PI) in the tracheobronchial aspirate of low birth weight infants were conducted. Infants with a high serum IgM level at birth, and who subsequently developed CLD, showed significantly high concentrations of IL-8 and E-alpha 1 PI in the first 48 h. It seemed that IL-8 stimulated neutrophils to release neutrophil enzymes which, in turn, caused the lung tissue injury, resulting in the development of CLD following intra-uterine infection.

Increase in interleukin-8 and soluble intercellular adhesion molecule-1 in bronchoalveolar lavage fluid from premature infants who develop chronic lung disease

Interleukin-8 (IL-8), soluble intercellular adhesion molecule-1 (sICAM), elastase and neutrophils were assessed in bronchoalveolar lavage fluid from nine infants who developed chronic lung disease (CLD) after respiratory distress syndrome (RDS), seven who had recovered from RDS, and in four control infants. IL-8, sICAM, elastase and neutrophils in bronchoalveolar lavage fluid were increased in the CLD group, the differences being most pronounced at 10 days of age. When babies with and without CLD were compared at 10 days of age, bronchoalveolar lavage fluid from the babies with CLD had significantly increased IL-8 (114.0 vs 12.7 ng/ml), sICAM (19.0 vs 1.1 micrograms/ml), elastase (6.9 vs 0.9 micrograms/ml) and neutrophils (1.9 vs 0.4 x 10(9)/l). In serum the increased concentration of IL-8 observed at birth in the CLD (247 pg/ml) and RDS (192 pg/ml) groups decreased over three weeks to the concentrations observed in the controls (< 70 pg/ml). Persistent inflammation could be a major contributory factor in the development of CLD.

Amniotic fluid interleukin-8 as a marker for intraamniotic infection

We measured the amniotic fluid Interleukin-8 (AF IL-8) levels of 80 women to see whether or not AF IL-8 levels were of value in the diagnosis of intraamniotic infection. Of twelve patients developing conventional signs of infection, 9 had an AF IL-8 concentration above 10,000 pg/ml serum. In two patients, whose baby had a serious neonatal infection, AF IL-8 concentration also exceeded 10,000 pg/ml. Only one out of 66 apparently uninfected patients had an AF IL-8 level above 10,000 pg/ml. We therefore suggest that measuring the AF IL-8 levels is of value in cases of suspected intraamniotic infection.

Fetal mononuclear cells show a comparable capacity with maternal mononuclear cells to produce IL-8 in response to lipopolysaccharide in chorioamnionitis

IL-8 is a chemotactic and activating cytokine for neutrophils which eliminate invading bacteria by releasing bactericidal metabolites. Cord blood mononuclear cells (CBMCs) obtained from neonates born to mothers with chorioamnionitis actively produced a significantly higher amount of IL-8 than those of neonates without chorioamnionitis, suggesting that the mononuclear cells of fetuses with chorioamnionitis had been activated in utero. As lipopolysaccharide (LPS) can often be detected in the uteroplacental space in chorioamnionitis, the LPS-mediated activation mechanism of neonatal mononuclear cells was analyzed in vitro to produce IL-8. Neonatal mononuclear cells stimulated with LPS increased IL-8 production in a time- and dose-dependent manner. The ability of term or preterm neonatal mononuclear cells to produce IL-8 was comparable with that of adult (maternal) mononuclear cells, suggesting functional maturity of the neonatal or fetal mononuclear cells to produce IL-8. However, IL-8 production by neonatal CBMCs was down-regulated by dexamethasone, a glucocorticoid which is clinically administered to mothers to promote fetal lung maturity in preterm delivery. Our present study revealed a regulatory mechanism of fetal IL-8 production, suggesting that functionally mature fetal mononuclear cells produce IL-8 in response to LPS in chorioamnionitis and activate the fetal defense mechanism against infection.

Significance of chorioamnionitis

In preterm deliveries, we have reported a high incidence (30-50%) of histologic chorioamnionitis (CAM) in the placenta. There is little evidence about the effects of CAM on preterm infants. We investigated the levels of complements and cytokines in the cord blood, the pathological nature of the placenta, the L/S ratio of gastric and tracheal aspirate of each preterm infant at birth, and assessed the biological effects of CAM on them. CAM stimulates the immunological system by cytokine production (IL6 and IL8) and complement activation in the fetus. It has been suggested that CAM may be one of the factor accelerating fetal maturation of the immunological system such as complement activation and immunoglobulin production, and of surfactant synthesis in the lung. On the contrary, CAM may damage the structures along the lining cells in the airway by accumulating polymorphonuclear cells of the infants with Wilson-Mikity syndrome.