Prospective evaluation of perinatal risk factors for cerebral palsy and delayed development in high risk infants.

Prematurity, intrauterine infection and perinatal brain injury have been reported to be significant risk factors of cerebral palsy (CP). We examined the perinatal predictors of cerebral palsy and delayed development (DD) in 184 high risk infants. Thirty-five infants were diagnosed as cerebral palsy and delayed development at 12 months corrected age. Antenatal, intrapartum, and neonatal factors were prospectively evaluated in 2 groups of high risk infants compared with controls; Group A (n = 79), infants weighing less than 2,000 g; Group B (n = 43), infants weighing 2,000 g or more. In univariate analysis, there were no significant antenatal and intrapartum factors associated with cerebral palsy and delayed development in either group. We found that significant postnatal risk factors of CP in group A included sepsis (p = 0.008), BPD (bronchopulmonary dysplasia) (p = 0.028), IVH (intraventricular hemorrhage) (p = 0.042), ventriculomegaly (VM) (p = 0.001) and a longer duration of mechanical ventilation (p = 0.001); while in group B, sepsis (p = 0.047) and neonatal seizure (p = 0.027) were significant risk factors. In multivariate analysis, sepsis in group B was a moderate risk factor of CP (OR (odds ratio) 1.47; 95% CI (confidence interval) 1.02-2.13). In conclusion, neonatal sepsis may contribute to the development of cerebral palsy and delayed development. We suggest that high risk infants who have sepsis should be carefully followed for cerebral palsy and delayed development. The prevention of cerebral palsy may be feasible by decreasing neonatal risk factors such as sepsis during the neonatal period.     

Elevated levels of lipopolysaccharide-binding protein and soluble CD14 in plasma in neonatal early-onset sepsis

No data on lipopolysaccharide-binding protein (LBP) in newborns with sepsis have been available up to now. We therefore determined levels of LBP and soluble CD14 (sCD14) in plasma of healthy and septic neonates in order to evaluate their potential diagnostic role. The study included prospectively collected patient samples of two recently published studies on cytokine expression in neonatal sepsis. Twenty-nine septic patients were enrolled in the present analysis. Samples--either cord blood or peripheral blood--from patients admitted within the first 24 h of life for suspicion of sepsis and cord blood samples of a control group of 40 healthy mature infants delivered spontaneously were analyzed. For seven patients of the septic group, a second sample collected between 24 and 48 h of life was available. Levels of sCD14 and LBP in plasma were determined by an enzyme immunoassay using recombinant CD14 and LBP as standards. LBP and sCD14 were correlated to cytokine plasma levels. In septic neonates, LBP (median, 36.6 versus 7.8 microg/ml; P < 0.001) and sCD14 (median, 0.42 versus 0.28 microg/ml; P < 0.001) levels were highly elevated when compared to those of healthy neonates and strongly correlated to granulocyte colony-stimulating factor (G-CSF), interleukin-1beta (IL-1beta), IL-6, and IL-8 levels. LBP levels in septic neonates analyzed between 24 and 48 h of life even increased when compared to samples obtained at or shortly after delivery (median, 36.6 versus 60 microg/ml; P = 0.038). In summary, levels of LBP in plasma of neonates with early-onset sepsis are significantly elevated; the elevated plasma levels seem to persist for more than 24 h, which could provide the clinician with a prolonged time period to identify the newborn with bacterial sepsis.     

T helper type 2-polarized invariant natural killer T cells reduce disease severity in acute intra-abdominal sepsis

Sepsis is characterized by a severe systemic inflammatory response to infection that is associated with high morbidity and mortality despite optimal care. Invariant natural killer T (iNK T) cells are potent regulatory lymphocytes that can produce pro- and/or anti-inflammatory cytokines, thus shaping the course and nature of immune responses; however, little is known about their role in sepsis. We demonstrate here that patients with sepsis/severe sepsis have significantly elevated proportions of iNK T cells in their peripheral blood (as a percentage of their circulating T cells) compared to non-septic patients. We therefore investigated the role of iNK T cells in a mouse model of intra-abdominal sepsis (IAS). Our data show that iNK T cells are pathogenic in IAS, and that T helper type 2 (Th2) polarization of iNK T cells using the synthetic glycolipid OCH significantly reduces mortality from IAS. This reduction in mortality is associated with the systemic elevation of the anti-inflammatory cytokine interleukin (IL)-13 and reduction of several proinflammatory cytokines within the spleen, notably interleukin (IL)-17. Finally, we show that treatment of sepsis with OCH in mice is accompanied by significantly reduced apoptosis of splenic T and B lymphocytes and macrophages, but not natural killer cells. We propose that modulation of iNK T cell responses towards a Th2 phenotype may be an effective therapeutic strategy in early sepsis.     

Serial Examination of Serum IL-8, IL-10 and IL-1Ra Levels is Significant in Neonatal Seizures Induced by Hypoxic-Ischaemic Encephalopathy(1)

We investigated changes in the levels of significant cytokines in relation to neonatal seizures, a pattern of cytokine concentrations serially and the severity of brain insult. The hypoxic–ischaemic encephalopathy‐induced seizure group consisted of 13 patients, and another 15 normal newborns were enrolled as a control group. All of the initial samples were obtained within the first 24 h of admission, and the second samples were obtained between 48 and 72 h in both groups. Only the third samples were taken in the seizure group on the 5th day. During neonatal seizures, the levels of most cytokines increased within 24 h, and, in particular, the levels of interleukin (IL)‐8 significantly increased (P < 0.05). After 48–72 h of seizure onset, the levels of most cytokines decreased, especially, IL‐1Ra; however, IL‐8 and IL‐10 remained increased (P < 0.05). During the prognosis, one patient who was diagnosed with quadriplegic cerebral palsy at 6 months of age presented extreme elevation of IL‐1beta, IL‐1Ra, IL‐6, IL‐8, IL‐10 and tumor necrosis factor‐alpha in the initial sample, reflecting the severity of brain damage. A significant increase in IL‐8 may serve as a biomarker for earlier detection of brain damage in neonatal seizure, if detected within 24 and 48–72 h of the seizure.     

Increased levels of interferon-gamma (IFN-gamma), IL-4 and transforming growth factor-beta (TGF-beta) mRNA expressing blood mononuclear cells in human HIV infection.

Evidence has been presented for the involvement of IFN-gamma, IL-4 and TGF-beta in AIDS. Measured plasma levels may, however, poorly reflect in vivo production, since cytokines act auto- and paracrinally and have very short half life in plasma. In situ hybridization with complementary DNA oligonucleotide probes was used to enumerate blood mononuclear cells expressing cytokine messenger RNA (mRNA). HIV-infected patients had elevated blood levels of cells expressing each of the cytokines, with predominance for cells expressing TGF-beta mRNA. All AIDS patients included had elevated numbers of IL-4 mRNA-expressing cells, and levels of cells expressing this cytokine correlated inversely with counts of CD4+ cells in blood, reflecting the involvement of Th2-like cells in later stages of HIV infection. The described approach should be useful in further studies of cytokines in HIV infection and other diseases.     

Incomplete Th2 skewing of cytokines in plasma of patients with squamous cell carcinoma of the head and neck

Levels of cytokines, and in particular those that reflect Th1 or Th2 bias, were measured in the plasma of patients with head and neck squamous cell carcinomas (HNSCC). Compared with plasma cytokine levels of age-matched controls, cytokine levels in HNSCC patients suggested a shift to a Th2 bias as levels of the Th2 cytokines interleukin-4 (IL-4), IL-6, and IL-10 were increased, and levels of the Th1 cytokine interferon-γ (IFN-γ) were decreased. However, levels of the Th1 cytokines IL-2 and granulocyte macrophage–colony-stimulating factor (GM-CSF) were increased, which is not consistent with full Th2 skewing. Assessment of cytokine levels in patients with malignancies other than HNSCC demonstrated many similarities to HNSCC patients, but HNSCC patients exhibited a more pronounced increase in GM-CSF levels and a decline in IFN-γ levels. For most cytokines there was no association between the shifts in cytokine levels in HNSCC patients and either the extent of tumor burden or extent of metastasis. However, patients with large HNSCC tended to be the population that demonstrated increased levels of IL-4 and IL-6. These results suggest skewing toward a Th2 bias in HNSCC patients, with the Th2 shift being incomplete and indicative of the presence, rather than the extent, of malignant disease.     

Maternal fish oil supplementation in pregnancy reduces interleukin-13 levels in cord blood of infants at high risk of atopy.

BACKGROUND AND OBJECTIVES: The epidemiological association between higher dietary n-3 polyunsaturated fatty acids (PUFA) and lower prevalence of asthma, has led to interest in the role of early dietary modification in allergic disease prevention. In this study we examined the effects of maternal n-3 (PUFA)-rich fish oil supplementation on cord blood (CB) IgE and cytokine levels in neonates at risk of developing allergic disease. METHODS: In a randomized double-blind, placebo-controlled trial, 83 atopic pregnant women received either fish oil capsules (n = 40) containing 3.7 g n-3 PUFA/day or placebo capsules (n = 43) from 20 weeks gestation until delivery. CB cytokine levels (IL-4, IL-5, IL-6, IL-10, IL-12, IL-13, TNF-alpha and IFN-gamma) and total IgE levels were measured and compared between the two groups. Fatty acid composition of red cell membranes was analysed by gas chromatography and the relationships among PUFA, cytokine and IgE levels were examined. RESULTS: Maternal fish oil supplementation resulted in a significant increase in n-3 PUFA levels (P < 0.001) in neonatal erythrocyte membranes. Neonates whose mothers had fish oil supplementation had significantly lower plasma IL-13 (P < 0.05) compared to the control group. There was also a significant inverse relationship between levels of n-3 PUFA in neonatal cell membranes and plasma IL-13. There was no difference in levels of IgE and the other cytokines measured. CONCLUSIONS: This study provides preliminary evidence that increasing neonatal n-3 PUFA levels with maternal dietary supplementation can achieve subtle modification of neonatal cytokine levels. Further assessment of immune function and clinical follow-up of these infants will help determine if there are any significant effects on postnatal immune development and expression of allergic disease.     

Preterm infants have deficient monocyte and lymphocyte cytokine responses to group B streptococcus

Group B streptococcus (GBS) is an important cause of early- and late-onset sepsis in the newborn. Preterm infants have markedly increased susceptibility and worse outcomes, but their immunological responses to GBS are poorly defined. We compared mononuclear cell and whole-blood cytokine responses to heat-killed GBS (HKGBS) of preterm infants (gestational age [GA], 26 to 33 weeks), term infants, and healthy adults. We investigated the kinetics and cell source of induced cytokines and quantified HKGBS phagocytosis. HKGBS-induced tumor necrosis factor (TNF) and interleukin 6 (IL-6) secretion was significantly impaired in preterm infants compared to that in term infants and adults. These cytokines were predominantly monocytic in origin, and production was intrinsically linked to HKGBS phagocytosis. Very preterm infants (GA, <30 weeks) had fewer cytokine-producing monocytes, but nonopsonic phagocytosis ability was comparable to that for term infants and adults. Exogenous complement supplementation increased phagocytosis in all groups, as well as the proportion of preterm monocytes producing IL-6, but for very preterm infants, responses were still deficient. Similar defective preterm monocyte responses were observed in fresh whole cord blood stimulated with live GBS. Lymphocyte-associated cytokines were significantly deficient for both preterm and term infants compared to levels for adults. These findings indicate that a subset of preterm monocytes do not respond to GBS, a defect compounded by generalized weaker lymphocyte responses in newborns. Together these deficient responses may increase the susceptibility of preterm infants to GBS infection.     

Multiple leucocyte activation markers to detect neonatal infection

Diagnosis of congenital or neonatal infection is often based on clinical signs. However, clinical symptoms of infections may not be specific, and for this reason early diagnosis is often determined on results of laboratory tests, which may not currently be adequate. A more reliable method of detection of infection may be the demonstration of activated lymphocytes, which can be conducted rapidly and before the isolation of the infected organism. We have shown that detection of up-regulation of CD45RO, an activated/memory isoform of CD45 present on T cells, provides a reasonably sensitive screening test for neonatal infection. We also showed that dual expression of CD45RA/CD45RO was up-regulated early during the infective process in neonates with documented infection. However, other leucocytes are also activated during the infective process. To improve the sensitivity of the neonatal infection screening test and to identify the types of leucocytes involved in the immune response to the infective organism, we studied further the up-regulation of a comprehensive range of surface activation markers on T cells, monocytes and natural killer (NK) cells from a group of 17 newborn patients with positive culture, a group of 40 possibly infected patients based on clinical signs and a control group. 'Normal' ranges were established for each activation marker for each leucocyte subset from 1 to 7 and 7-14-day-old newborns <35 weeks' gestation and 35-40 weeks' gestation. There was a significant increase in the percentage of T cells expressing CD25 in the peripheral blood from infants at 2 weeks of age. Expression of HLA-DR on T cells, CD25 and CD69 on monocytes and HLA-DR on NK cells was also increased significantly in the peripheral blood from infants at 2 weeks of age and may reflect a maturation of these functional surface molecules. Up-regulation of CD69 on NK cells was the most sensitive marker for neonatal sepsis (positive in 13/16 patients). CD69 and CD25 expression was increased significantly on T cells in 11/17 and 10/17 patients, respectively. A combination of CD45RA/CD45RO and CD45RO identified 11/16 infected patients. Measurement of CD69 expression on NK cells with CD45RA, CD45RO, CD25 and CD69 expression on T cells resulted in a significant increase in at least two leucocyte activation markers from infected patients. In conclusion, this is the first report of the up-regulation of CD69 on NK cells as a sensitive marker of neonatal infection. A combination of this marker with CD45RA, CD45RO, CD25 and CD69 expression on peripheral blood derived T cells is the most sensitive and specific for neonatal infection.     

Maternal cytokine production patterns in women with pre-eclampsia

PROBLEM: To determine the levels of cytokines produced upon mitogenic or antigenic stimulation of maternal peripheral blood mononuclear cells (PBMC) from women with pre-eclampsia. METHOD OF STUDY: PBMC from 54 women with a history of successful pregnancy and 32 women undergoing pre-eclamptic delivery were stimulated with a mitogen or with autologous placental cells or with trophoblast antigens, and the levels of cytokines released into the culture supernatants then assessed by enzyme-linked immunosorbent assay. RESULTS: Significantly higher levels of the Th1 cytokines, interferon-gamma, and tumor necrosis factor-alpha were produced by the pre-eclamptic group than by the normal pregnancy group, which on the contrary showed significantly greater production of the Th2 cytokines, interleukin (IL)-4, IL-5, IL-6 and IL-10. A comparison of the ratios of Th2 to Th1 cytokines indicates a higher Th1 cytokine bias in pre-eclampsia as compared with normal pregnancy. CONCLUSIONS: These data are suggestive of a maternal pro-inflammatory cytokine bias in pre-eclampsia.     

Differential effects of Chlamydia pneumoniae infection on cytokine levels in human T lymphocyte- and monocyte-derived cell cultures

Continuous cultures of human lymphocyte- and monocyte-derived cell lines were examined for levels of immunoregulatory cytokines important in resistance to the intracellular opportunistic bacterium Chlamydia pneumoniae (Cp), a ubiquitous pathogen widely disseminated in the population and hypothesized to be involved in chronic inflammatory diseases such as atherosclerosis and neurological diseases like multiple sclerosis and Alzheimer's disease. The results of this study showed that the continuous human T lymphocyte cell line MOLT-4 and the continuous monocytic cell line THP-1 were readily infected by Cp in vitro as shown by immunofluorescence microscopy for Cp lipopolysaccharide (LPS). The 16S rRNA expression determined by real-time RT-PCR increased rapidly after infection of either cell line with these bacteria. The THP-1 cells infected with Cp showed increased levels of the immunoregulatory cytokine IL-12 and also of TNFalpha and IL-10 compared to cultures stimulated with heat-killed Cp (KCp) or Escherichia coli LPS as a control. Stimulation of MOLT-4 cells with KCp or E. coli LPS also induced the Th1 cytokines IFNgamma and IL-12 and the Th2 cytokine IL-10, but infection with viable Cp induced higher Th1 cytokine levels. These results suggest that Cp infection induces a predominant Th1 cytokine profile by T cells, in addition to induction of TNFalpha by monocytes/macrophages. Such effects are likely involved in antibacterial immunity against Cp infection.     

Elevated Levels of Lipopolysaccharide-Binding Protein and Soluble CD14 in Plasma in Neonatal Early-Onset Sepsis

No data on lipopolysaccharide-binding protein (LBP) in newborns with sepsis have been available up to now. We therefore determined levels of LBP and soluble CD14 (sCD14) in plasma of healthy and septic neonates in order to evaluate their potential diagnostic role. The study included prospectively collected patient samples of two recently published studies on cytokine expression in neonatal sepsis. Twenty-nine septic patients were enrolled in the present analysis. Samples—either cord blood or peripheral blood—from patients admitted within the first 24 h of life for suspicion of sepsis and cord blood samples of a control group of 40 healthy mature infants delivered spontaneously were analyzed. For seven patients of the septic group, a second sample collected between 24 and 48 h of life was available. Levels of sCD14 and LBP in plasma were determined by an enzyme immunoassay using recombinant CD14 and LBP as standards. LBP and sCD14 were correlated to cytokine plasma levels. In septic neonates, LBP (median, 36.6 versus 7.8 μg/ml; P < 0.001) and sCD14 (median, 0.42 versus 0.28 μg/ml; P < 0.001) levels were highly elevated when compared to those of healthy neonates and strongly correlated to granulocyte colony-stimulating factor (G-CSF), interleukin-1β (IL-1β), IL-6, and IL-8 levels. LBP levels in septic neonates analyzed between 24 and 48 h of life even increased when compared to samples obtained at or shortly after delivery (median, 36.6 versus 60 μg/ml; P = 0.038). In summary, levels of LBP in plasma of neonates with early-onset sepsis are significantly elevated; the elevated plasma levels seem to persist for more than 24 h, which could provide the clinician with a prolonged time period to identify the newborn with bacterial sepsis.     

新生儿严重细菌感染血浆降钙素原与CRP和IL-6临床价值对比研究

目的：比较新生儿败血症及败血症休克血降钙素原（PCT）与C反应蛋白（CRP）和白介素-6（IL-6）的变化，探讨血中前降钙素原作为新生儿严重细菌感染诊断指标的敏感性、可靠性及对预后评估的作用。方法：采用半定量固相免疫测定法测定108例新生儿败血症（40例合并败血症休克）的血浆PCT水平，并比较同期CRP和IL-6水平。结果：新生儿败血症患儿血浆PCT阳性检出率明显高于正常对照组；其中败血症休克组尤为明显；败血症休克患儿发生率及死亡率随PCT值升高而升高；PCT与血清CRP、IL-6水平呈正相关；PCT的敏感性（87．5％）、特异性（82．4％）、阳性预测值（74．5％）和准确性（84．3％）最高。结论：新生儿败血症及败血症休克时PCT升高较早，且随病情的加重持续升高。PCr对新生儿败血症及败血症休克诊断指标的敏感性、可靠性及对预后评估优于CRP和IL-6。     

Altered miRNAs Expression Profiles and Modulation of Immune Response Genes and Proteins During Neonatal Sepsis

Purpose

The dysregulated expression of miRNAs in the immune system may be critical for immune responses to pathogens and evolve into the inflammation seen in sepsis. The aim of this study is to explore the important role of miRNAs in the regulation of the immune response during neonatal sepsis.

Methods

Using a microarray we performed the miRNA expression profiling of peripheral blood leukocytes from neonates with sepsis and uninfected neonates. Based on the predicted target genes of these miRNAs we selected 26 immune-related miRNAs out of the differentially expressed miRNAs for further testing by quantitative PCR. We simultaneously detected the immune response genes by PCR array and plasma cytokine levels using a protein chip to investigate the effect of the altered miRNAs on the immune response in neonatal sepsis.

Results

There were 10 immune regulatory miRNAs whose expression was significantly changed more than two fold in the neonates with sepsis compared with the uninfected neonates. The expression levels of 11 immune response genes and the plasma levels of 15 cytokines or receptors were significantly up- or down-regulated in the neonates with sepsis compared to the uninfected neonates. This comprehensive analysis suggests that the altered miRNAs modulate the immune response during neonatal sepsis in a way that represses the inflammatory response.

Conclusions

Our investigation demonstrated some miRNAs with altered expression levels and their probable association with the regulation of immune response during neonatal sepsis. The characteristics of the neonatal inflammatory response could be attributed to immature immune function of neonates.     

Age, gender and litter-related variation in T-lymphocyte cytokine production in young pigs

The capacity of farm animals to produce cytokines could be an important determinant of robustness and health. From research in rodents and humans it appears that the production and the balance of T helper 1 (Th1) and T helper 2 (Th2)-type cytokines influences susceptibility to autoimmune and infectious diseases. It is known that pigs show a large variation in many immune response parameters. So far the extent of individual variation in the production of Th1- and Th2-type cytokines in commercial outbred pigs has not been reported. In the current experiment we determined mRNA expression, as well as protein production of cytokines in 32 pigs from eight litters. From each litter two male and two female pigs were tested at 2, 5 and 8 weeks of age. Two Th1-type cytokines, interleukin (IL)-2 and interferon (IFN)-gamma, and two Th2-type cytokines, IL-4 and IL-10, were measured after phytohaemagglutinin (PHA)-stimulation of blood mononuclear cells. Cytokine production and the Th1/Th2-ratio were highly variable. The variation in cytokine protein production was moderately consistent across ages, i.e. pigs that produced high levels of cytokine at 2 weeks of age tended to do so as well at 5 and 8 weeks of age. Cytokine production tended to increase with age, and gilts and boars differed in their IL-2/IL-4 ratio. Unexpectedly, age, gender and litter effects often differed for mRNA and protein production data. We hypothesize that cytokine production is a consistent trait in pigs, especially at the protein production level. Future investigations in more animals and across a wider age range are necessary.     

Impact of herpesvirus infections on the level of proinflammatory cytokines in premature neonatal infants

The aim of this study was to estimate the frequency of HSV and/or CMV among the pathogens causing intrauterine infections (IUI) and to investigate their impact on the level of proinflammatory cytokines in premature neonatal infants. Examinations were performed in 3 neonatal groups: 1) premature neonates with clinical manifestations of IUI; 2) those without IUI; 3) full-term newborns. In group 1, viral (HSV and/or CMV) and bacterial infections were detectable with the same frequency. Quantitative analysis of plasma IL-6 and IL-8 levels and the induced production of these cytokines by blood cells in vitro showed that in Group 1 neonates, IL-6 and IL-8 concentrations were substantially higher and the induced production of these cytokines was lowerthan those in Group 3. The detection of HSV and/or CMV markers in premature newborn infants was attended by a statistically significant rise in plasma IL-6 levels; the identification of the opportunistic bacterial microflora correlated with the higher concentration of IL-8. In Group 1, wiferon produced an immunomodulatory effect, by lowering IL-8 concentrations to the level observed in Group 3.     

白三烯受体拮抗剂对呼吸道合胞病毒肺炎血清Th1/Th2细胞因子水平影响的研究

目的探讨白三烯受体拮抗剂对呼吸道合胞病毒肺炎患儿血清中Th1／Th2细胞因子、半胱氨酰白三烯水平的影响，研究降低呼吸道合胞病毒肺炎发展为哮喘的有效干预途径。方法将37例呼吸道合胞病毒肺炎患儿分为白三烯受体拮抗剂干预组：顺尔宁，4mg qd，疗程12周，糖皮质激素吸入干预组：出院后给予糖皮质激素吸入，200μg qd／bid，疗程12周。两组患儿入院后24h内及疗程结束用酶联免疫法检测CysLTs、IFN-γ、IL-4。另选10例健康同龄儿童血清标本作对照。结果呼吸道合胞病毒肺炎患儿血清中Th1／Th2细胞因子表达存在失衡，血清CysLTs水平明显高于健康对照组（t=7．85，P〈0．05）；顺尔宁干预组和糖皮质激素吸入干预组均能纠正Th1／Th2细胞因子失衡，差异无统计学意义（P〉0．05）。糖皮质激素吸入干预组血清CysLTs水平治疗前后无明显变化，差异无统计学意义（P〉0．05），顺尔宁干预组血清Cys仉水平治疗后明显下降，差异有统计学意义（P〈0．05）。结论呼吸道合胞病毒肺炎患儿存在Th1／Th2细胞因子失衡、血清CysLTs水平较健康同龄儿童明显升高，与哮喘有相似之处。白三烯受体拮抗剂早期干预能纠正Th1／Th2细胞因子失衡，降低血清CysLTs水平。     

Increased expression of pro-inflammatory cytokines in placentas of women undergoing spontaneous preterm delivery or premature rupture of membranes

PROBLEM: The objective of this study was to determine the levels of cytokines in the placentas of women undergoing preterm delivery (PTD) or premature rupture of membranes (PROM) as compared with women undergoing normal delivery at term. METHOD OF STUDY: Placentas were obtained from 30 subjects with spontaneous PTD, 30 women with PROM and 30 women with a history of normal delivery at term. Levels of interleukin (IL)-2, interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, TNF-beta, IL-4, IL-5, IL-6 and IL-10 and IL-12 were estimated by ELISA in detergent lysates of placentas from the subjects. RESULTS: We found significantly increased levels of the Th1 cytokines IL-2 and IFN gamma and of the Th1-inducing cytokine IL-12 in placentas from the PTD and PROM groups as compared with those delivering at term. In contrast, the levels of the Th2 cytokines IL-4, IL-6 and IL-10 were significantly higher in placentas from term pregnancy. CONCLUSIONS: These data support our observation of a pro-inflammatory cytokine bias in women with PTD and PROM.     

Antigen dose-dependent differences in IgE antibody production are not due to polarization towards Th1 and Th2 cell subsets

The quality of the humoral immune response against protein antigens in CBA/J mice is dependent on the antigen dose used for immunization: low doses induce high titers of IgE antibodies, whereas high doses promote the production of IgG2a antibodies but inhibit IgE formation. To investigate whether the reciprocal regulation of antibody production is possibly due to a differential activation of Th1 and Th2 cell populations in the two immunization groups, the cytokine pattern of spleen cells from both groups, cultured with antigen in vitro, was analyzed by measurement of intracellular and secreted cytokine levels. The data presented show that in vitro restimulated spleen cells from mice primed with low as well as with high doses of antigen produce predominantly the Th2 cytokines IL-4 and IL-10 but reduced levels of IL-12. The release of IFN-γ is only slightly enhanced compared to unstimulated control cultures. The results indicate that CD4⁺ T cells in both groups belong mainly to the Th2 cell subset. This finding is contradictory to the general allegation that the antigen dose is decisive for the polarization of Th1 versus Th2 immune responses and shows that the antigen dose-dependent regulation of IgE antibody production is not due to differential polarization towards Th1 and Th2 cells.     

Soluble L-selectin, a marker of immune activation, in neonatal infection

L-Selectin is an adhesion molecule shed from the surface of lymphocytes and granulocytes upon activation. Soluble L-selectin in the plasma can thus reflect immune activation and is elevated in several pathological states. Our objective was to evaluate plasma levels of L-selectin as an immune activation marker in neonates and to determine whether it can serve as a marker of infection, either neonatal or congenital, or if it is affected by the mode of delivery and obstetrical or perinatal complications. A solid-phase ELISA was used on 89 sera from neonates less than 2 days of age, according to the manufacturer's instructions. Levels of soluble L-selectin in the neonate were lower than those of older infants and children and comparable to the levels seen in adults. There was no difference between levels of soluble L-selectin of premature (median, 1172 ng/ml) and full-term babies (median, 1151 ng/ml) or between babies born via vaginal (median, 1233 ng/ml) or cesarean delivery (median, 1146 ng/ml). Conditions such as preeclampsia or administration of steroids to the mother did not affect the levels of L-selectin in the neonate. In contrast, the presence of maternal clinical chorioamnionitis resulted in an increase in levels of L-selectin in the neonate (median, 1377 vs 1072 ng/ml, p = 0.02), as did neonatal sepsis (median, 1331 vs 1149 ng/ml, p = 0.026). Soluble L-selectin, and thus immune activation level, is highest in neonates with neonatal infection and needs to be further evaluated as a surrogate marker for diagnosing sepsis in the neonate.