Interleukin-1 receptor antagonist in newborn babies and pregnant women

New-onset ulcerative colitis in pregnancy associated to toxic megacolon and sudden fetal decompensation: Case report and literature review

Ulcerative colitis (UC) is a chronic inflammatory disease rarely arising during gestation. Because the available information is based on case reports or small retrospective studies, diagnosis may be difficult and treatment is still controversial. A case of toxic megacolon developing in late pregnancy associated to a sudden fetal decompensation is described. Diagnostic and clinical topics of acute UC onset in pregnancy are debated.A primipara, 34 years old, 33/0 weeks of gestation, was admitted with a diagnosis of preterm labor, associated to acute bloody diarrhea (up to 10 daily motions) and cramping abdominal pain. A diagnosis of new-onset early-stage UC was made by sigmoidoscopy. An intensive care regimen including hydrocortisone, antibiotics and parenteral nutrition was immediately started. Magnetic resonance imaging of maternal abdomen, fostered by the worsening patient conditions, evidenced dilatation of the entire colon and a severely hampered of fetal muscular tone.Toxic megacolon complicated by superimposed Clostridium difficile infection was associated to a sudden fetal decompensation diagnosed by chance during maternal abdominal magnetic resonance imaging. An emergency cesarean section was mandatory. According to a senior surgeon's decision, total colectomy was not immediately performed following cesarean section with reference to the absence of colonic perforation. We obtained a good short-term maternal outcome and an uncomplicated neonatal course. Counseling of those patients must be focused on timely and multidisciplinary intervention in order to improve the course of maternal disease and to prevent fetal distress.

IL-1 receptor antagonist therapy mitigates placental dysfunction and perinatal injury following Zika virus infection

Zika virus (ZIKV) infection during pregnancy causes significant adverse sequelae in the developing fetus, and results in long-term structural and neurologic defects. Most preventive and therapeutic efforts have focused on the development of vaccines, antivirals, and antibodies. The placental immunologic response to ZIKV, however, has been largely overlooked as a target for therapeutic intervention. The placental inflammatory response, specifically IL-1β secretion and signaling, is induced by ZIKV infection and represents an environmental factor that is known to increase the risk of perinatal developmental abnormalities. We show in a mouse model that maternally administrated IL-1 receptor antagonist (IRA; Kineret, or anakinra), following ZIKV exposure, can preserve placental function (by improving trophoblast invasion and placental vasculature), increase fetal viability, and reduce neurobehavioral deficits in the offspring. We further demonstrate that while ZIKV RNA is highly detectable in placentas, it is not correlated with fetal viability. Beyond its effects in the placenta, we show that IL-1 blockade may also directly decrease fetal neuroinflammation by mitigating fetal microglial activation in a dose-dependent manner. Our studies distinguish the role of placental inflammation during ZIKV-infected pregnancies, and demonstrate that maternal IRA may attenuate fetal neuroinflammation and improve perinatal outcomes.

Differential induction of cytokines by human neonatal, adult, and elderly monocyte/macrophages infected with dengue virus

Immunosuppressive status against infections in monocytes from neonates and elderly subjects has been reported. The interaction between dengue virus and monocytes/macrophages plays an important role during dengue disease. The aim of this study was to determine the cytokine response of monocytes from individuals with different ages after infection with dengue virus. Monocyte/macrophage cultures from neonatal, adult, and elderly subjects (n=10 each group) were incubated with all four dengue virus types (DENV-1 to -4). After 1 and 3 days of culture, cytokine concentrations (TNF-α, IL-6, and IL-1β) were determined in culture supernatants by enzyme-linked immunosorbant assay. Increased production of all studied cytokines was induced by the different viral types in monocyte/macrophage cultures regardless of their source. However, lower cytokine concentrations were found in neonatal and elderly monocytes. The relative monocyte/macrophage immunosuppressive status observed in neonates and the elderly could be relevant during dengue infection in those age groups and important in innate and adaptive immunity responses against this virus.

Differential oxidative stress induced by dengue virus in monocytes from human neonates, adult and elderly individuals

Changes in immune response during lifespan of man are well known. These changes involve decreased neonatal and elderly immune response. In addition, it has been shown a relationship between immune and oxidative mechanisms, suggesting that altered immune response could be associated to altered oxidative response. Increased expression of nitric oxide (NO) has been documented in dengue and in monocyte cultures infected with different types of dengue virus. However, there is no information about the age-dependent NO oxidative response in humans infected by dengue virus. In this study, monocyte cultures from neonatal, elderly and adult individuals (n = 10 each group) were infected with different dengue virus types (DENV- 1 to 4) and oxidative/antioxidative responses and apoptosis were measured at days 1 and 3 of culture. Increased production of NO, lipid peroxidation and enzymatic and nonenzymatic anti-oxidative responses in dengue infected monocyte cultures were observed. However, neonatal and elderly monocytes had lower values of studied parameters when compared to those in adult-derived cultures. Apoptosis was present in infected monocytes with higher values at day 3 of culture. This reduced oxidant/antioxidant response of neonatal and elderly monocytes could be relevant in the pathogenesis of dengue disease.

Alterations in cognitive function and behavioral response to amphetamine induced by prenatal inflammation are dependent on the stage of pregnancy

Maternal infection during human pregnancy has been associated with the development of schizophrenia in the adult offspring. The stage of development and the maternal inflammatory response to infection, which undergoes quantitative and qualitative changes throughout gestation, are thought to determine critical windows of vulnerability for the developing brain. In order to investigate how these two factors may contribute to the outcome in the offspring, we studied the inflammatory response to turpentine (TURP) injection (100 μl/dam) and its consequences in the adult offspring, in pregnant rats at gestational day (GD) 15 or 18, which correspond to late first and early second trimester of human pregnancy, respectively. Maternal inflammatory response to TURP was different between the two GDs, with fever and circulating levels of the pro-inflammatory interleukin (IL)-6 significantly attenuated at GD 18, compared to GD 15. In the adult offspring, TURP challenge at GD 15 induced a significant decrease in pre-pulse inhibition (PPI) of acoustic startle, increased latency in the cued task of the Morris-water maze, prolonged conditioned fear response and enhanced locomotor effect of amphetamine. In contrast, the same immune challenge at GD 18 induced only a prolonged conditioned fear response. These results suggest a window of vulnerability at GD 15, at which TURP seems to affect several behaviors that are strongly modulated by dopamine. This was supported by increased tyrosine hydroxylase expression in the nucleus accumbens of the adult offspring of mothers treated at GD 15.

Suppression of the febrile response in late gestation: evidence, mechanisms and outcomes

Fever is a beneficial host defence response. However, fever caused by the immune stimulant, lipopolysaccharide (LPS), are attenuated in many species during pregnancy, particularly near term. A number of parallel mechanisms may be responsible, and these vary in magnitude according to the time of gestation, type of inflammatory stimulus and species of animal. Some studies report a reduction in the plasma levels of circulating pro-inflammatory cytokines such as tumour necrosis factor-alpha, interleukin-1beta and interleukin-6 along with increased levels of anti-inflammatory cytokines such as interleukin-1 receptor antagonist. Associated with the attenuated febrile response to LPS is a reduction in the activation of the prostaglandin synthesising enzyme, cyclo-oxygenase 2, resulting in reduced levels of the obligatory prostaglandin mediators of the febrile response in the brain. There is also a reduction in the sensitivity of the brain to the pyrogenic action of prostaglandins, which does not appear to be due to a change in the levels of hypothalamic EP3 prostaglandin receptors. The suppression of fever at term may be important for the health of the neonate because fever in pregnant mothers may be harmful to the late-term foetus and neonate.

A dual role for interleukin-1 in hippocampal-dependent memory processes

Ample research demonstrates that pathophysiological levels of the pro-inflammatory cytokine interleukin-1 (IL-1) produces detrimental effects on memory functioning. However, recent evidence suggests that IL-1 may be required for the normal physiological regulation of hippocampal-dependent memory. To substantiate the physiological role of IL-1 in learning and memory we examined the induction of IL-1 gene expression following a learning experience, and the effects of IL-1 signaling blockade, by either genetic or pharmacological manipulations, on memory functioning. We show that IL-1 gene expression is induced in the hippocampus 24h following fear-conditioning in wild type mice, but not in two mouse strains with impaired IL-1 signaling. Moreover, we report that mice with transgenic over-expression of IL-1 receptor antagonist restricted to the CNS (IL-1raTG) display impaired hippocampal-dependent and intact hippocampal-independent memory in the water maze and fear-conditioning paradigms. We further demonstrate that continuous administration of IL-1ra via osmotic minipumps during prenatal development disrupt memory performance in adult mice, suggesting that IL-1 plays a critical role not only in the formation of hippocampal-dependent memory but also in normal hippocampal development. Finally, we tested the dual role of IL-1 in memory by intracerebroventricular (ICV) administration of different doses of IL-1beta and IL-1ra following learning, providing the first systematic evidence that the involvement of IL-1 in hippocampal-dependent memory follows an inverted U-shaped pattern, i.e., a slight increase in brain IL-1 levels can improve memory, whereas any deviation from the physiological range, either by excess elevation in IL-1 levels or by blockade of IL-1 signaling, results in impaired memory.

Interleukin-1 receptor antagonist as a modulator of gender differences in the febrile response to lipopolysaccharide in rats

Febrile responses to bacterial pathogens are attenuated near term of pregnancy in several mammalian species. It is unknown, however, whether this reflects a fundamental physiological adaptation of female rats or whether it is specific to pregnancy. The aims of this study therefore were 1) to determine whether febrile responses to the bacterial endotoxin lipopolysaccharide (LPS) are attenuated in female vs. male rats and, if so, to identify possible mechanisms involved in modulating this and 2) to assess whether plasma concentrations of the anti-inflammatory cytokine, interleukin-1 receptor antagonist (IL-1ra), an important regulator of fever, are dependent on the physiological state of the female and could therefore be involved in modulating febrile responses. We found febrile responses were attenuated in cycling female vs. male rats and also in near-term pregnant dams vs. cycling females after intraperitoneal injection of LPS (0.05 mg/kg). Plasma levels of IL-1ra were significantly greater in female rats after injection of LPS, particularly during pregnancy, than in males. This was accompanied by attenuated levels of hypothalamic IL-1β and cyclooxygenase-2 mRNA, two key mediators of the febrile response, in female rats. Furthermore, increasing plasma levels of IL-1ra in male rats by intraperitoneal administration of the recombinant antagonist attenuated hypothalamic mRNA levels of these mediators after LPS. These data suggest that there is a fundamental difference in febrile response to LPS between the genders that is likely regulated by IL-1ra. This may be an important mechanism that protects the developing fetus from potentially deleterious consequences of maternal fever during pregnancy.

Naturally acquired regulatory mechanism of perioperative cytokine response in neonates

The inflammatory reaction is known to be controlled in neonates. We clarified the characteristics of cytokine profile in neonatal patients and assess its clinical significance. Serum levels of interleukin (IL)-6 and IL-1 receptor antagonist (ra) were determined in 152 pediatric patients and 33 each of maternal and cord bloods. Supernatant IL-1ra levels of cultured monocytes and granulocytes stimulated with IL-1beta or LPS, and IL-1ra mRNA expression of granulocytes were assayed in 15 each of cord and healthy adult bloods. Although surgical stress in neonates was heavier than that in infants, there was no difference in the occurrence of postoperative morbidity and mortality. In neonates, the perioperative serum level of IL-1ra was significantly raised, and the postoperative IL-6 response was well controlled. The serum concentration of IL-1ra in cord blood was not different from that in maternal blood, whereas, the serum concentration of IL-6 in cord blood was significantly reduced than that in maternal blood. In granulocytes, significantly more IL-1ra was produced from cord than from adult blood. An IL-1ra predominant immune status in neonates may be a naturally acquired adaptation system and play a crucial role in attenuating acute inflammatory reaction in a vulnerable host defense.

Pregnancy influences the plasma cytokine response to intraperitoneal administration of bacterial endotoxin in rats

Rats have an attenuated febrile response to intraperitoneal (i.p.) administration of exogenous pyrogen (e.g. bacterial endotoxin) near the term of pregnancy. To investigate possible mechanisms of this unique thermoregulatory response, the present experiments were carried out on 18 non-pregnant and 16 near-term pregnant Sprague-Dawley rats to test the hypothesis that pregnancy alters the balance of pyrogenic cytokines and antipyretic and/or cryogenic (antipyretic/cryogenic) cytokines in response to exogenous pyrogen. To test our hypothesis, we measured plasma levels of interleukin (IL)-1beta, IL-6, interleukin-1 receptor antagonist (IL-1ra) and tumour necrosis factor alpha(TNFalpha) at 2 and 4 h following i.p. administration of 160 microg kg(-1) E. coli lipopolysaccharide (LPS) (i.e. EC100 dose, or the smallest dose that elicits a maximal febrile response in non-pregnant rats) in non-pregnant as well as pregnant rats at day 20 of gestation (term approximately 21 days). In non-pregnant rats, E. coli LPS elicited statistically significant increases in plasma concentrations of IL-1beta, IL-6, IL-1ra and TNFalpha as compared to that observed following administration of vehicle. However in pregnant rats, E. coli LPS elicited statistically significant increases in antipyretic/cryogenic cytokines (IL-1ra and TNFalpha) but not in pyrogenic cytokines (IL-1beta and IL-6). Thus, a differential pyrogenic and antipyretic/cryogenic plasma cytokine response may mediate in part the attenuated febrile response to exogenous pyrogen observed in rats near the term of pregnancy.

Suppression of fever at near term is associated with reduced COX-2 protein expression in rat hypothalamus

The fever response is blunted at near term. As the enzyme cyclooxygenase-2 (COX-2) plays a critical role in fever development, we measured its expression in rat hypothalamus during pregnancy and lactation. Western blot analysis revealed a 72-kDa COX-2-immunoreactive band in non-immune-challenged, pregnant rats at day 15 of pregnancy. In contrast, it was almost undetectable at near term and at lactation day 5. COX-2 was significantly induced at the 15th day of pregnancy and at the 5th lactating day after intraperitoneal lipopolysaccharide (50 microg/kg). However, this COX-2 induction was significantly reduced at near term compared with values before and after term. The protein levels of the EP3 receptor in the hypothalamus, one of the prostaglandin E(2) (PGE(2)) receptors suggested to be a key receptor for fever induction, were unaffected throughout the pregnancy and lactation in both non-immune-challenged and lipopolysaccharide-treated rats. These data suggest that suppression of fever at near term is associated with a significantly reduced induction of COX-2 by lipopolysaccharide, resulting in a reduced production of PGE(2). Altered expression of the EP3 receptor does not seem to be involved in this fever refractoriness at near term.

Peri-OVLT E-series prostaglandins and core temperature do not increase after intravenous IL-1beta in pregnant rats

Rats have an attenuated febrile response to endogenous pyrogen near the term of pregnancy. Given the fundamental role of E-series prostaglandins (PGEs) in mediating the febrile response to blood-borne endogenous pyrogen, the present experiments were carried out to determine whether PGEs increase in the area surrounding the organum vasculosum laminae terminalis (peri-OVLT) of near-term pregnant (P) rats as in nonpregnant (NP) rats after intravenous (iv) administration of recombinant rat interleukin-1beta (rrIL-1beta). Core temperature was measured by telemetry and peri-OVLT interstitial fluid was sampled in 12 NP and 12 P chronically instrumented, Sprague-Dawley rats by microdialysis for determination of total PGEs by radioimmunoassay. Basal core temperatures were higher in NP compared with P rats (NP 37.9 degrees C +/- 0.5, P 36.9 degrees C +/- 0.4; P < 0.05), but basal peri-OVLT PGEs were similar in both groups (NP 260 +/- 153 pg/ml, P 278 +/- 177 pg/ml; P =not significant). Intravenous administration of rrIL-1beta to NP rats produced a significant increase in core temperature with a latency, magnitude, and duration of 10 min, 0.87 degrees C, and at least 170 min, respectively; peri-OVLT PGEs were increased significantly by 30 min and averaged 270% above basal levels throughout the experiment. In P rats, however, neither core temperature nor peri-OVLT PGEs increased significantly after iv administration of rrIL-1beta. Intravenous administration of vehicle did not significantly alter core temperature or peri-OVLT PGEs in either group of rats. Thus peri-OVLT PGEs do not increase in P rats as they do in NP rats after iv administration of rrIL-1beta. The mechanism of this interesting component of the maternal adaptation to pregnancy, which likely plays a major role in mediating the attenuated febrile response to endogenous pyrogen near the term of pregnancy, warrants further investigation.

Maternal depression and risk for postpartum complications: role of prenatal corticotropin-releasing hormone and interleukin-1 receptor antagonist

The pregnancies of 58 healthy adolescents (ages 13 to 19 years) were followed to examine links between symptoms of depression, corticotropin-releasing hormone (CRH), interleukin-1 beta, (IL-1 beta), and IL-1 receptor antagonist (IL-1ra) as possible predictors of maternal and infant outcomes. Maternal psychological adjustment and medical complications during gestation, labor, delivery, and the postpartum period were monitored. Plasma samples collected during gestation were assayed for CRH, IL-1 beta, and IL-1ra. During gestation, symptoms of maternal depression were found to be associated with lower levels of CRH; lower levels of CRH were associated with lower levels of IL-1ra. In addition, lower levels of IL-1ra predicted higher rates of maternal complications after childbirth. IL-1 beta, detected in only 4 mothers, was not associated with any predictor or outcome measures. During gestation, CRH may induce circulating cytokine inhibitors without significantly affecting cytokine production or synthesis. Maternal symptoms of depression during gestation may attenuate the association between CRH and IL-1ra.

Arginine vasopressin does not mediate the attenuated febrile response to intravenous IL-1beta in pregnant rats

Rats have an attenuated febrile response to intravenous endogenous pyrogen [e.g., interleukin-1beta (IL-1beta)] near the term of pregnancy. The present experiments were carried out on 25 nonpregnant and 32 pregnant rats to test the hypothesis that arginine vasopressin functioning as an endogenous antipyretic substance in the central nervous system mediates this attenuated febrile response. An intravenous injection of recombinant rat IL-1beta (rrIL-1beta) after intracerebroventricular vehicle produced a significant increase in core temperature in both nonpregnant and pregnant animals, the magnitude and duration of which was greater in the nonpregnant rats. In nonpregnant rats, intravenous rrIL-1beta after intracerebroventricular vasopressin V1-receptor antagonist accentuated the core temperature response compared with that observed with intravenous rrIL-1beta after intracerebroventricular vehicle. In pregnant animals, however, intravenous rrIL-1beta after intracerebroventricular vasopressin V1-receptor antagonist produced a decrease in core temperature rather than an increase in core temperature, which was observed with intravenous rrIL-1beta after intracerebroventricular vehicle. Thus our data do not support the hypothesis that a pregnancy-related activation of arginine vasopressin as an endogenous antipyretic substance in the central nervous system attenuates the febrile response to intravenous rrIL-1beta near the term of pregnancy in rats.

Cytokine response in cerebrospinal fluid after birth asphyxia

Experimental studies suggest that cytokine-mediated inflammatory reactions are important in the cascade leading to hypoxic-ischemic brain injury. The purpose was to study the content of pro- and antiinflammatory cytokines in cerebrospinal fluid (CSF) of asphyxiated and control infants. Samples of CSF were obtained from 20 infants who fulfilled the criteria of birth asphyxia and from seven newborn control subjects. The concentrations of IL-1beta, IL-8, IL-10, tumor necrosis factor (TNF)-alpha, and granulocyte/monocyte colony-stimulating factor (GM-CSF) were determined with ELISA and of IL-6 using a bioassay. The concentration of IL-6 (pg/mL) was higher in asphyxiated (250, 35-543; median, interquartile range) than in control (0, 0-18) infants (p = 0.001). There was also a significant relationship between IL-6 and the degree of HIE, and between IL-6 and outcome. In addition, the content of IL-8 (pg/mL) was higher (p = 0.009) in the asphyxia group (170, 70-1440), than in the the control group (10, 0-30) and there was an association between IL-8 and degree of HIE. The levels of IL-10, TNF-alpha, GM-CSF, and IL-1beta did not differ between groups. In conclusion, the proinflammatory cytokines IL-6 and IL-8 were markedly elevated in CSF of asphyxiated infants, and the intrathecal levels of these cytokines corresponded to the degree of HIE.

Enhanced expression of interleukin (IL)-1 and IL-6 messenger RNA and bioactive protein after hypoxia-ischemia in neonatal rats

The effect of hypoxia-ischemia (HI) on IL-1, and IL-6 bioactivity in relation to expression of IL-1 alpha, IL-1 beta, and IL-6 mRNA was studied, and the neuroprotective efficacy of IL-1 receptor antagonist (IL-1ra) was evaluated in neonatal rats. HI was induced in 7-d-old rats by unilateral carotid artery ligation and hypoxia for 70-100 min. Animals were killed at different time points up to 14 d after HI, and brains were analyzed for IL-1 and IL-6 bioactivity using bioassays and for mRNA for IL-1 alpha, IL-1 beta, and IL-6 with reverse transcription followed by a polymerase chain reaction. In separate animals, IL-1ra was administered intracerebrally before or after HI, and the extent of brain injury was assessed 14 d after HI. A transient increase of IL-1 bioactivity occurred after HI, reaching a peak at 6 h of recovery. IL-1 beta mRNA followed a similar time course but attained maximum expression at 3 h. IL-6 bioactivity and mRNA were also stimulated by HI and followed a similar time course as IL-1. Pretreatment with IL-1ra reduced HI brain damage from 54.4 +/- 9.3 to 41.4 +/- 10.0% (p < or = 0.01), and IL-1ra posttreatment increased the proportion of animals devoid of brain injury (40%) compared with vehicle-treated controls (13%) (p < or = 0.05). In conclusion, a transient activation of IL-1 and IL-6 occurred after HI, and IL-1ra reduced HI brain injury to a moderate degree.

Response of newborn and adult sheep to pyrogens: relation between fever and brain eicosanoid changes

We investigated whether the weak febrile response to pyrogens in newborns is due to a diminished activation of the putative pyrogen mediator, prostaglandin (PG)E2. Indwelling cannulas in the third ventricle of lambs (age, 5-31 days) and adult ewes were used to collect cerebrospinal fluid (CSF) for radioimmunoassay of PGE2. Intravenous (i.v.) endotoxin caused a smaller increase in body temperature but a larger increase in CSF PGE2 in lambs compared to adults. PGE2 by intracarotid infusion raised body temperature in 5 of 7 trials in 3 lambs and in 4 of 4 trials in 1 adult. Endotoxin given intracerebroventricularly (i.c.v.) induced a rise in temperature and CSF PGE2 in the lamb but, in the adult, these responses were delayed and smaller. Interleukin-1 i.c.v. and PGE2 i.c.v. were weak pyretic agents at both ages. We conclude that the lamb's diminished febrile response to endotoxin i.v. is not caused by a lesser rise in CSF PGE2, rather it may be due, at least in part, to reduced responsiveness to this putative mediator. Regardless of age, the sheep differs from other species in that pyrogen/PGE2 coupling occurs primarily at a site in brain that is better accessible from blood than CSF.

Circulating cytokine concentrations and cytokine production by monocytes from newborn babies and adults

As a possible factor responsible for reduced fever responses in the newborn, we measured plasma cytokine concentrations and cytokine production by neonatal monocytes after lipopolysaccharide or IL (interleukin)-1 alpha stimulation in vitro and compared these data with those obtained from adult plasma and monocytes. Whole blood was collected from afebrile adults (n = 12) and the umbilical cord of normal term infants (n = 12). Plasma and peripheral blood monocytes were prepared by conventional techniques. Significantly lower concentrations of IL-1 alpha, IL-1 beta (P < 0.05, t-test) and IL-6 (P < 0.01, t-test) were found in the plasma of newborn babies compared with that of adults. There was no significant difference in plasma tumour necrosis factor (TNF) concentrations between the adults and newborn babies. Monocytes from newborn babies had the capacity to produce IL-1 alpha and IL-1 beta as readily as adult cells after stimulation with lipopolysaccharide or IL-1 alpha, and produced significantly lower concentrations of TNF and IL-6 than those produced by stimulated adult monocytes (P < 0.01, ANOVA). Our results suggest that the reduced production of IL-6 by monocytes of the newborn during infection could be partly responsible for attenuated fever responses observed in the neonate.