Early induction of IL-1 receptor antagonist (IL-1Ra) in infants and children undergoing surgery

Pediatric Perioperative Stress Responses and Anesthesia

Surgical stress responses cause an array of endocrinological, metabolic and immunological changes in patients. The landmark studies in the 1980s showed that adequate anesthesia dramatically improved the outcomes of pediatric surgical patients by attenuating stress hormonal responses, pointing out the harm of 'inadequate' anesthesia. Subsequent studies questioned the role of administering very high-dose anesthetics to further attenuate stress responses. Here we review the feature of surgical stress responses in pediatric patients including their difference from those in adult patients. Overall, pediatric patients show minimal or no resting energy expenditure change postoperatively. In adult patients, increased resting energy expenditure has been described. Pediatric patients demonstrated robust cortisol and catecholamine responses than adult patients. However, the duration of these surges is often short-lived. Systemic proinflammatory and anti-inflammatory cytokine levels have been measured. Pediatric patients showed less proinflammatory cytokine elevation, but had similar anti-antiinflamatory responses. We also review in detail the immunological changes in response to surgical stress. Based on our current knowledge, we attempted to understand the underlying mechanism how adequate anesthesia dramatically improved the outcome of patients. Although more work is needed to be done, understanding how pediatric patients respond to perioperative stress, and its mechanism and consequence will allow us to direct us into a better, perioperative management in this population.

The multifaceted effects of polysaccharides isolated from Dendrobium huoshanense on immune functions with the induction of interleukin-1 receptor antagonist (IL-1ra) in monocytes

Dendrobium huoshanense is a valuable and versatile Chinese herbal medicine with the anecdotal claims of cancer prevention and anti-inflammation. However, its immunological activities are limited to in vitro studies on a few cytokines and immune cell functions. First, we investigated the effects of polysaccharides isolated from DH (DH-PS) on inducing a panel of cytokines/chemokines in mice in vivo and human in vitro. We found that DH polysaccharides (DH-PS) induced TH1, TH2, inflammatory cytokines and chemokines in mouse in vivo and human cells in vitro. Secondly, we demonstrated that DH-PS expanded mouse splenocytes in vivo including CD4⁺ T cells, CD8⁺ T cells, B cells, NK cells, NKT cells, monocytes/macrophages, granulocytes and regulatory T cells. Notably, DH-PS induced an anti-inflammatory molecule, IL-1ra, in mouse and human immune cells, especially monocytes. The serum level of IL-1ra elicited by the injection of DH-PS was over 10 folds of IL-1β, suggesting that DH-PS-induced anti-inflammatory activities might over-ride the inflammatory ones mediated by IL-1β. The signaling pathways of DH-PS-induced IL-1ra production was shown to involve ERK/ELK, p38 MAPK, PI3K and NFκB. Finally, we observed that IL-1ra level induced by DH-PS was significantly higher than that by F3, a polysaccharide extract isolated from another popular Chinese herbal medicine, Ganoderma lucidum. These results indicated that DH-PS might have potential applications for ameliorating IL-1-induced pathogenic conditions.

Inflammatory response in children after laparoscopic vs open Nissen fundoplication: randomized controlled trial

We performed a randomized controlled trial to compare the inflammatory and immune responses to Nissen fundoplication in infants and children undergoing either open or laparoscopic surgery.

METHODS

Forty children undergoing Nissen fundoplication were randomized to laparoscopy or open surgery using minimization with respect to age, neurologic status, and operating surgeon. Intraoperative and postoperative analgesias were standardized. Inflammatory markers (plasma malondialdehyde, nitrate plus nitrite level, and cytokines) and monocyte class II major histocompatibility complex expression were measured preoperatively, at end of surgery, 4, 24, and 48 hours postoperatively. Postoperative changes were compared between open and laparoscopic groups.

RESULTS

There were no significant changes in circulating malondialdehyde, nitrates plus/ nitrite, interleukin-10, or tumor necrosis factor alpha in the postoperative period in either group. Interleukin-1 receptor antagonist (IL-1rA) and IL-6 were significantly increased in both groups, with a tendency for greater elevation of IL-1rA in the open group. Monocyte major histocompatibility complex expression fell significantly in both groups; however, this fall appeared to be slightly more marked in the open group.

CONCLUSIONS

The postoperative cytokine response is similar in children undergoing open and laparoscopic Nissen fundoplication. This trial indicates that laparoscopy may partly reduce postoperative immune suppression.

Potential prophylactic measures against postoperative immunosuppression: could they reduce recurrence rates in oncological patients?

BACKGROUND

Removing the primary tumor is indispensable for eliminating the major pool of metastasizing cells, but the surgical procedure itself is suspected of promoting metastases. This adverse effect is attributed to several mechanisms acting in synergy, including mechanical release of tumor cells, enhanced angiogenesis, secretion of growth factors, and immunosuppression. Here we provide new insights into mechanisms of postoperative immunosuppression and assess the assumptions underlying the hypothesis that, by suppressing cell-mediated immunity (CMI), surgery may render the patient vulnerable to metastases that otherwise could have been controlled.

METHODS

An extensive review of relevant articles in English identified by using the MEDLINE database and cross-referencing.

RESULTS

Current literature suggests that (1) CMI can control minimal residual disease, especially if surgery is performed early; (2) major surgery transiently but markedly suppresses CMI through multiple mechanisms now better understood; (3) surgical stress promotes experimental metastasis through immunosuppression, but the clinical evidence remains indirect because of ethical limitations.

CONCLUSIONS

Minimizing postoperative immunosuppression seems feasible, may limit recurrence, and should be introduced into the broader array of considerations when planning oncological surgeries. In the short run, physicians could try to avoid immunosuppressive anesthetic approaches, inadvertent hypothermia, excessive blood transfusions, and untended postoperative pain. When feasible, minimally invasive surgery should be considered. In the long run, clinical trials should evaluate prophylactic measures, including perioperative immunostimulation and several antagonists to cytokines and hormones specified herein.

The soluble tumor necrosis factor receptor I is an early predictor of local infective complications after colorectal surgery

The clinical implications of increased cytokine levels after major surgery remain unclear. In this study, systemic concentration of a spectrum of cytokines, including interleukins IL-6, IL-8, IL-10, IL-1ra, and soluble tumor necrosis factor receptor-I (sTNF-RI) was examined in patients with and without postoperative septic complications following colorectal surgery. Although there were no significant changes in IL-1beta, TNF-alpha, and IL-8 serum levels during the observation period, there was a significant rise in IL-6, IL-1ra, and sTNF-RI concentrations in the entire group of patients between postoperative day 1 and 14. There were no differences between the group without and with local complications when IL-6, IL-1ra, and IL-10 were examined. The serum levels of sTNF-RI, IL-1ra, and IL-6 were found to be sensitive indicators of the pro- and anti-inflammatory response to the surgical trauma, but only sTNF-RI turned out to be a sensitive early marker of local septic postoperative complications in patients with colorectal carcinoma.

Cytokine imbalance in the pathogenesis of rheumatoid arthritis: the role of interleukin-1 receptor antagonist

OBJECTIVES

To summarize the role of cytokine imbalance in the pathogenesis of rheumatoid arthritis.

METHODS

The literature on cytokines in rheumatoid arthritis from American and European medical journals was reviewed.

RESULTS

An important role of interleukin (IL)-1 and tumor necrosis factor (TNF)-alpha in the mediation of tissue damage in the rheumatoid joint has been well established over the past 10 years. The IL-1 family consists of 2 agonists, IL-1alpha and IL-1beta, and a specific naturally occurring receptor antagonist, IL-1Ra. Both forms of IL-1 induce intracellular responses through binding to the type 1 IL-1 receptor (IL-1R) on target cells. IL-1Ra binds to IL-1R with an avidity equal to that of IL-1 but fails to stimulate the cells, thus functioning as an inhibitor of IL-1 binding. Endogenous production of IL-1Ra is an important anti-inflammatory mechanism both in animal models of disease and in human disease. In the rheumatoid synovium, an imbalance exists in this system, because the relative levels of production of IL-1Ra are not adequate to effectively block the proinflammatory effects of IL-1. Studies in different animal models of inflammatory arthritis indicate that a deficiency of IL-1Ra relative to IL-1 leads to more severe disease and even to the spontaneous development of arthritis as observed in IL-1Ra knockout mice. A restoration of the balance between IL-1Ra and IL-1 in human disease can theoretically be achieved through the administration of recombinant IL-1ra protein, gene therapy with the IL-1Ra complementary DNA, or stimulation of production of endogenous IL-1Ra.

CONCLUSIONS

An imbalance between proinflammatory cytokines and cytokine antagonists or inhibitors may be one factor predisposing to initiation or perpetuation of rheumatoid synovitis.

Balance of proinflammatory and antiinflammatory cytokines at thoracic cancer operation

BACKGROUND

A homeostatic balance of proinflammatory and antiinflammatory cytokines is thought to be important for the maintenance of health. Cytokine baseline levels and response patterns to cardiac and nonmalignant abdominal operations have been investigated. The purpose of this study was to investigate the cytokine patterns at operation for thoracic cancer; the hypothesis tested was that cytokine baseline levels and response patterns would be unique for patients with malignant disease undergoing thoracic operation.

METHODS

Ten patients undergoing pulmonary tumor resections were studied. Blood samples were collected at six perioperative time points.

RESULTS

The cytokine response of these patients differed from patients undergoing cardiac operations: baseline tumor necrosis factor-alpha (39.1 pg/mL) and interleukin-10 (76.76 pg/mL) were elevated without significant changes. Interleukin-1 receptor antagonist became elevated postoperatively (871.6 pg/mL) compared with baseline (332.8 pg/mL) (p < 0.01). The level of tumor necrosis factor soluble receptor-2 was elevated at baseline (4,823.3 pg/mL) and remained elevated postoperatively (7,293.4 pg/mL) (p < 0.01).

CONCLUSIONS

Our hypothesis was supported; a separate pattern of proinflammatory and antiinflammatory cytokine levels and responses to thoracic operation was determined. This pattern may be indicative of tumor burden or detrimental to tumor surveillance; it merits further evaluation.

Interleukin-1 receptor antagonist: role in biology

The interleukin-1 receptor antagonist (IL-1Ra) is a member of the IL-1 family that binds to IL-1 receptors but does not induce any intracellular response. Two structural variants of IL-1Ra have previously been described: a 17-kDa form that is secreted from monocytes, macrophages, neutrophils, and other cells (sIL-1Ra) and an 18-kDa form that remains in the cytoplasm of keratinocytes and other epithelial cells, monocytes, and fibroblasts (icIL-1Ra). An additional 16-kDa intracellular isoform of IL-1Ra has recently been described in neutrophils, monocytes, and hepatic cells. Both of the major isoforms of IL-1Ra are transcribed from the same gene through the use of alternative first exons. The two promoters regulating transcription of the secreted and intracellular forms have been cloned, and some of the functional cis-acting DNA regions have been characterized. The production of IL-1Ra is stimulated by many substances including adherent IgG, other cytokines, and bacterial or viral components. The tissue distribution of IL-1Ra in mice indicates that sIL-1Ra is found predominantly in peripheral blood cells, lungs, spleen, and liver, while icIL-1Ra is found in large amounts in skin. Studies in transgenic and knockout mice indicate that IL-1Ra is important in host defense against endotoxin-induced injury. IL-1Ra is produced by hepatic cells with the characteristics of an acute phase protein. Endogenous IL-1Ra is produced in numerous experimental animal models of disease as well as in human autoimmune and chronic inflammatory diseases. The use of neutralizing anti-IL-1Ra antibodies has demonstrated that endogenous IL-1Ra is an important natural antiinflammatory protein in arthritis, colitis, and granulomatous pulmonary disease. Treatment of human diseases with recombinant human IL-1Ra showed an absence of benefit in sepsis syndrome. However, patients with rheumatoid arthritis treated with IL-1Ra for six months exhibited improvements in clinical parameters and in radiographic evidence of joint damage.

Elevated interleukin-1 receptor antagonist levels in pediatric sepsis syndrome

OBJECTIVE

To measure plasma levels of interleukin-1 beta, interleukin-1 receptor antagonist (IL-Ira), and tumor necrosis factor alpha in children with sepsis syndrome.

STUDY DESIGN

A prospective, observational study of 14 patients aged 5 months to 13 years with sepsis syndrome admitted to a pediatric intensive care unit. Cytokine levels were measured by enzyme-linked immunosorbent assay at baseline and at a 12, 24, and 48 hours and compared with the levels of 21 age-matched control subjects.

RESULTS

The mean pediatric risk of mortality score was 16.1. Bacterial and viral sepsis was confirmed in five and three patients, respectively. Compared with the levels in the control subjects (mean level of IL-Ira: 654 pg/ml), the IL-Ira levels were elevated in the septic patients, with mean values of 17855 (p < 0.001), 12771 (p < 0.001), 9182 (p < 0.01), and 2296 pg/ml (p = not significant) at baseline and at 12, 24, and 48 hours, respectively. The IL-Ira level was greater than 1000-fold higher than the IL-1 beta level at all time points in 13 of 14 septic patients.

CONCLUSIONS

At the time of hospital admission, circulating IL-Ira levels in a cohort of children with sepsis syndrome were at concentrations known to block IL-1 receptors. Thus additional benefit from exogenous IL-Ira therapy would be questionable. Further studies are indicated to determine whether there is a population of patients with sepsis who could benefit from administration of exogenous IL-Ira.

Effect of major surgery on neutrophil chemotaxis and actin polymerization in neonates and children

The authors have examined the effect of major surgery in neonates and older children on neutrophil (PMN) chemotaxis and on actin polymerization, an essential early step in PMN movement. Isolated PMNs from the following subjects were studied: healthy adult volunteers (n = 28), healthy newborns (n = 21), newborns undergoing major surgery (n = 7), and older infants and children undergoing major surgery (n = 14). Chemotaxis was measured by a micropore filter assay, and actin polymerization was measured by flow cytometry. Blood samples from surgical patients were obtained preoperatively, hourly during the procedure, immediately postoperatively, and 48 hours after surgery. Mean preoperative newborn PMN chemotaxis was similar to that of healthy newborn PMN, and mean preoperative PMN chemotaxis in children was similar to that of healthy adults. There were no significant alterations in PMN chemotaxis during or after major surgery in neonates or children. Peak PMN actin polymerization, after stimulation with formyl methionyl leucyl phenylalanine (FMLP) (10 nm), was significantly diminished in healthy neonates compared with adults (P < .005). Preoperative surgical neonates had similar peak PMN actin polymerization levels to those of healthy newborns, and older preoperative children had similar levels to adults. PMN actin polymerization did not significantly change during or after major surgery. Despite reductions in PMN chemotaxis and actin polymerization in healthy neonates, there is no further impairment of these PMN functions during or after major surgery. Our data suggest that PMN chemotactic function is resistant to the stress of uncomplicated major surgery in neonates and children.

Different release of cytokines into the cerebrospinal fluid following surgery for intra- and extra-axial brain tumours

To elucidate the role of cytokines in brain repair processes and in local inflammation after neurosurgical procedures, cerebrospinal fluid (CSF) samples from 8 patients with intra-axial tumours and 8 patients with extra-axial tumours were analysed for interleukin (IL)-1 beta, IL-1 receptor antagonist (IL-1 ra), IL-6, IL-8, IL-10, and tumour necrosis factor (TNF)-alpha at the beginning and after surgery. Levels of IL-6 and IL-8 increased dramatically in all patients just hours after surgery and fell during subsequent days. IL-1 beta was found only in low amounts in the CSF of both patient groups. Other cytokines demonstrated different courses. In patients with intra-axial tumours IL-1 ra peaked two to four hours after surgery with a subsequent decrease. In patients with extra-axial tumours there was a continuous low-level IL-1 ra release into the CSF without a peak. TNF-alpha was not present in detectable levels in the CSF after surgery for extra-axial tumours but was found to peak two to four hours after surgery for intra-axial tumours. IL-10 was detected in the CSF of both patient groups, but a higher peak was seen after surgery for extra-axial tumours. These results suggest different requirements for the cytokine response and an involvement of different cell types in cytokine release. However, the analysis of the CSF from both patient groups showed no differences in cell counts and populations, with a mild pleocytosis being present in both patient groups after surgery. Therefore, we conclude that after surgery for extra-axial tumours cytokines were predominately produced by non-immune cells stimulated through hypoxia or mechanical irritation. After surgery for intra-axial tumours with a significant brain injury immune cells-activated by necrotic material-seen to be involved in the process of cytokine synthesis. In these cases an additional IL-1ra and TNF-alpha peak was found and these cytokines may be markers for cerebral injury.

An investigation of the effects of heparin, low molecular weight heparin, protamine, and fentanyl on the balance of pro- and anti-inflammatory cytokines in in-vitro monocyte cultures

We report a study conducted to determine if drugs given peri-operatively during cardiac surgery could themselves modulate the balance of pro- and anti-inflammatory cytokines. We determined the cytokine response of 10 separate in vitro monocyte cultures to the administration of drugs at concentrations used during cardiac 'surgery:fentanyl (25 ng.ml-1), heparin 2.5 i.u.ml-1, heparin with an equal concentration of protamine, and enoxaparin 2.5 i.u.ml-1. Fentanyl, heparin and low molecular weight heparin (enoxaparin) led to increased tumour necrosis factor alpha but this did not reach statistical significance. Tumour necrosis factor soluble receptor 1 and 2 was not elevated. Interleukin-1 beta was increased by heparin (p < 0.05), whereas interleukin-1 receptor antagonist was increased by fentanyl (p < 0.05). Protamine blocked the heparin-induced increase in tumour necrosis factor alpha and interleukin-1 beta. These data raise the possibility that endogenous and exogenously administered opioids may be partly contributing to the interleukin-1 receptor antagonist response seen during major surgery.

Immunomodulation: an important concept in modern anaesthesia

This review summarises evidence for immunomodulatory effect of drugs administered peri-operatively. The clinical significance of the balance of pro- and anti-inflammatory cytokines may be seen in certain disease states, for example, meningococcal meningitis and Lyme arthritis. This balance may be altered peri-operatively. Traditionally, these changes are considered to be due to the stress response of surgery, the response to cardiopulmonary bypass, or endotoxaemia. This review presents in vitro evidence suggesting that drugs modulating this cytokine balance include non-steroidal anti-inflammatory agents, phosphodiesterase inhibitors and opioids, acting through effects on intracellular cyclic nucleotide messenger systems. An important consequence of the pro-inflammatory cytokine activity is increased adhesion of neutrophils. Aspects of this process may be inhibited by avoiding low blood flow states, by reducing adhesion molecule expression (for example by use of pentoxifylline), or by use of negatively charged anions such as heparin. Neutrophil activity is generally depressed by intravenous anaesthetic induction agents, but is enhanced by opioids. Natural killer cell activity, which is involved in immunity against tumour cells and virally infected cells is transiently depressed by volatile anaesthetic agents and opioids. In contrast catecholamines enhance natural killer cell activity. Whereas decrease in immunoglobulin levels occur peri-operatively, this is not thought to be as a result of drugs at clinically used concentrations but rather due to haemodilution.

Defective neutrophil actin polymerisation and chemotaxis in stressed newborns

Abnormalities of polymorphonuclear leukocyte (PMN) function contribute to high rates of postoperative infection in the newborn and to the vulnerability of newborns to overwhelming bacterial and fungal sepsis. The authors investigated (1) the effects of major surgery and sepsis on PMN chemotaxis in the newborn and (2) the role of cytoskeletal rearrangements in regulating chemotaxis. The subjects studied included newborns with sepsis (n = 16), newborns who underwent major surgery (n = 7), healthy full-term newborns (n = 21), and healthy adult volunteers (n = 28). Peak actin polymerisation was diminished in all newborns (relative to the adults) after stimulation with formyl methionyl leucyl phenylalanine (FMLP) (10 nmol/L), and with zymosan activated serum (ZAS) (10%). Major surgery and sepsis in newborns caused no further reduction in actin polymerisation. Changes in PMN shape after stimulation with FMLP were reduced in the newborns. PMN chemotaxis was significantly lower in healthy newborns than in adults (17 +/- 4 microns v 24 +/- 5 microns; P < .0001) and was even lower in septic newborns (11 +/- 4 microns; P < .005). Surgery and anaesthesia did not alter chemotaxis.

Cytokine generation in rabbits during extracorporeal lung assist with a mini hollow fiber lung

To examine host responses to extracorporeal lung assist (ECLA) in small animals, we developed a mini hollow fiber lung of nonmicroporous polyolefin and an extracorporeal bypass circuit with a priming volume of 25 ml. This circuit allowed ECLA of up to 72 h without blood transfusion in 20 rabbits. The ECLA procedure induced the appearance of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1) receptor antagonist (IL-1Ra) in plasma, but not IL-1 beta. However, these changes were observed only at the initial stage of ECLA, and the levels returned to pre-ECLA levels within 24 h. Although leukocytes adhering to the hollow fibers were immunohisto-chemically positive for IL-1 beta and IL-Ra, the plasma levels of these cytokines in response to ECLA were not different from those observed in rabbits given anesthesia and subjected to minor surgery but without ECLA. Thus, ECLA itself is a minor factor in the production of these cytokines.

Recognition of unusual presentation of natural killer cell leukemia

Expansion of the natural killer (NK) subset of lymphocytes represents a rare leukemia phenotype with variations in clinical presentation, morphology, surface phenotype, and effector function. This paper reports on a 5-year-old male patient who had an unusual presentation of an NK cell leukemia that was initially diagnosed as neuroblastoma. A bone marrow (BM) aspirate showed clumps of undifferentiated cells with the following phenotype: CD56bright+, CD33dim+, CD45-, CD2-, CD19-, CD16-, and CD57-. Cytochemistry was noncontributory. The patient, having failed to respond to conventional neuroblastoma chemotherapy, was subsequently diagnosed as having NK cell leukemia based on functional in vitro assays. The patient responded to acute lymphoblastic leukemia (ALL) chemotherapy but relapsed 4 weeks into treatment and eventually died 25 weeks after initial presentation. The cell surface phenotype observed is consistent with a rare NK cell subset, the biology of which has not been well defined. Freshly isolated BM cells killed K562 cells in a conventional 51Cr-release assay. Both interleukin-2 (IL-2) and interferon-alpha (IFN-alpha) induced LAK activity against the Daudi cell line. IL-2 induced proliferation of the leukemic cells. TNF-alpha, IFN-gamma, IL-6, IL-1ra, and TGF-beta levels were assessed and found to be concentrated in BM, in contrast to plasma samples. TNF-alpha was present at a high concentration in BM (150.9 pg/ml), probably a reflection of the associated disease pathology of severe bone pain and pyrexia. In summary, this paper details clinical and laboratory investigations of a leukemia of a rare NK cell subset.