Interleukin-10 and its role in clinical immunoparalysis following pediatric cardiac surgery

OBJECTIVE: A systemic insult is associated with subsequent hyporesponsiveness to endotoxin (as measured by ex vivo tumor necrosis factor [TNF]-alpha production) and an increased risk of late nosocomial infection in some patients. When combined with low monocyte surface major histocompatibility complex class II expression, this state of altered host defense is now commonly referred to as immunoparalysis. This study was undertaken to delineate the relationship between observed levels of the anti-inflammatory cytokine interleukin-10, common genetic polymorphisms that influence these levels, and the occurrence and severity of endotoxin hyporesponsiveness in children following elective cardiac surgery requiring cardiopulmonary bypass. DESIGN: A prospective observational clinical study. SETTING: A tertiary pediatric cardiac center. PATIENTS: Thirty-six infants and children <2 yrs of age undergoing elective cardiac surgery requiring cardiopulmonary bypass. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We investigated the production of TNF-alpha, interleukin-6, interleukin-8, interleukin-1 receptor antagonist, and interleukin-10 in whole blood in response to lipopolysaccharide (Neisseria meningitides 10 ng/mL) in samples drawn before, during, and up to 48 hrs after surgery. Patients were genotyped for the -1082, -819, and -592 interleukin-10 promoter polymorphisms. Whole blood cytokine response to lipopolysaccharide was reduced postoperatively to 100 pg/mL) over the first 48 hrs were more likely to have an uncomplicated short stay (odds ratio 4.7, 95% confidence interval 1-22). CONCLUSIONS: Immediately following cardiac surgery, many children become relatively refractory to lipopolysaccharide stimulation. This immunoparalysis appears to be related in part to high circulating levels of interleukin-10 and places these patients at increased risk of postoperative complications. Interleukin-10 genotype may be a risk factor for immunoparalysis.     

Cytokine responses and myocardial injury in coronary artery bypass grafting

OBJECTIVE: Cardiopulmonary bypass is acknowledged to be one of the major causes of a complex systemic inflammatory response after cardiac surgery, and it may contribute to postoperative complications and even multiple organ dysfunction. We here compared the cytokine responses and the degree of myocardial injury after coronary artery bypass grafting with or without cardiopulmonary bypass. METHODS: Nine patients underwent off-pump revascularization and 13 with cardiopulmonary bypass. Plasma levels of tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-6, IL-8 and IL-10 were measured before anesthesia induction, and 5 min, 1, 4, and 20 h after reperfusion to the myocardium. Levels of the MB isoenzyme of creatine kinase (CK-MB) were also measured after the operation. RESULTS: Levels of TNF-alpha were low in both groups. A delayed elevation of IL-6 was noted in the off-pump group. IL-8 and IL-10 levels were significantly higher in the CPB than in the off-pump patients after reperfusion (p=0.006 and 0.001 respectively). Postoperative CK-MB levels were significantly higher in the CPB than in the off-pump group (p=0.001). Cytokine levels correlated with CK-MB values. CONCLUSION: The results indicated that off-pump revascularization was associated with reduced cytokine responses and less severe myocardial injury. The degree of myocardial injury, as defined by CK-MB release, correlated with cytokine release. Intervention designed to reduce cytokine responses in cardiac surgery may be advantageous for patients with severe comorbidity.     

Human whole blood interleukin-1-beta production: kinetics, cell source, and comparison with TNF-alpha.

Because removal of monocytes from their natural milieu may alter their subsequent immune response patterns, we have compared the production of interleukin-1 beta (IL-1-beta) and tumor necrosis factor alpha (TNF-alpha) by cultured human whole blood to that by purified monocytes. IL-1-beta was released in a dose-dependent fashion by whole blood after stimulation with lipopolysaccharide. Immunofluorescence studies indicated that monocytes were the main producers of IL-1-beta in whole blood cultures. On a per monocyte basis, after stimulation with 10 micrograms/ml lipopolysaccharide, much more IL-1-beta was released by cultured whole blood (56.2 +/- 8.3 ng/10(6) monocytes) than by purified mononuclear cells maintained in tissue culture medium (7.1 +/- 2.6 ng/10(6) monocytes). However, maintaining purified mononuclear cells in autologous plasma restored IL-1-beta release to levels observed in whole blood cultures. IL-1-beta release by whole blood peaked at 9 to 12 hours, in contrast to release of TNF-alpha, which peaked at 6 hours. In parallel with protein production, IL-1-beta messenger RNA levels peaked later and were more sustained than TNF-alpha messenger RNA levels. These experiments suggest that plasma augments the stimulatory effect of endotoxin and that IL-1-beta and TNF-alpha have differing kinetics in whole blood.     

Adenosine A2A receptor hyperexpression in patients with severe SIRS after cardiopulmonary bypass

OBJECTIVE: Adenosine (ADO) is an endogenous nucleoside, which has been involved in blood pressure failure during severe systemic inflammatory response syndrome (severe SIRS) after cardiac surgery with cardiopulmonary bypass (CPB). Adenosine acts via its receptor subtypes, namely A1, A2A, A2B, or A3. Because A2A receptors are implicated in vascular tone, their expression might contribute to severe SIRS. We compared adenosine plasma levels (APLs) and A2A ADO receptor expression (ie, B, K, and mRNA amount) in patients with or without postoperative SIRS. PATIENTS:: This was a prospective comparative observational study. Forty-four patients who underwent cardiac surgery involving CPB. Ten healthy subjects served as controls. MEASUREMENTS AND RESULTS: Among the patients, 11 presented operative vasoplegia and postoperative SIRS (named complicated patients) and 33 were without vasoplegia or SIRS (named uncomplicated patients). Adenosine plasma levels, K, B, and mRNA amount (mean +/- SD) were measured on peripheral blood mononuclear cells. Adenosine plasma levels, B, and K were significantly higher in complicated patients than in uncomplicated patients (APLs: 2.7 +/- 1.0 vs 1.0 +/- 0.5 micromol l, P < 0.05; B: 210 +/- 43 vs 65 +/- 26 fmol/mg, P < 0.05; K: 35 +/- 10 vs 2 +/- 1 nM, P < 0.05). In uncomplicated patients, APLs remain higher than in controls (1 +/- 0.5 vs 0.6 +/- 0.25 micromol/L; P < 0.05).Mean arterial pressure was inversely correlated to APLs (R = -0.58; P < 0.001) and B (R = -0.64; P < 0.001) leading to an increased requirement of vasoactive drugs during the postoperative period in vasoplegic patients. CONCLUSIONS: High expression of A2A ADO receptor and high APLs may be a predictive factor of postoperative severe SIRS after CPB.     

Activated peripheral blood mononuclear cells in IgA nephropathy express platelet-derived growth factor B-chain messenger RNA.

We investigated platelet-derived growth factor (PDGF) A- and B-chain messenger RNA expression in peripheral blood mononuclear cells or T cells obtained from 26 patients with IgA nephropathy and 15 healthy age-matched control subjects. Most patients with IgAN (88%) showed elevated PDGF B-chain expression in peripheral blood mononuclear cells; no PDGF B-chain expression was detected in peripheral blood mononuclear cells of normal control subjects. In T cells from both patients with IgAN and normal control subjects, however, PDGF B-chain messenger RNA expression was not detected. A positive correlation was noted between PDGF B-chain messenger RNA levels and urinary protein excretion. The PDGF B-chain messenger RNA expression in peripheral blood mononuclear cells also correlated with histopathologic changes in renal tissue obtained from patients with IgAN. Sixty-five percent of patients with grade III or IV histopathologic findings showed strong PDGF B-chain gene expression in their peripheral blood mononuclear cells. We could not detect PDGF A-chain messenger RNA expression in either peripheral blood mononuclear cells and T cells obtained from patients with IgAN and from healthy control subjects. These studies suggest that abnormally regulated PDGF B-chain expression in peripheral blood mononuclear cells may be associated with the progression of IgAN and may be useful as an indicator of disease activity.     

Cardiopulmonary bypass decreases cytokine production in lipopolysaccharide-stimulated whole blood cells: roles of interleukin-10 and the extracorporeal circuit

OBJECTIVE: To determine whether cardiopulmonary bypass (CPB) alters the ex vivo cytokine production of whole blood cells stimulated by lipopolysaccharide (LPS) and to assess the roles of interleukin (IL)-10 and an extracorporeal circuit (ECC) in the alteration. DESIGN: Prospective, controlled study. SETTING: Biochemistry laboratory and surgical intensive care unit in a university hospital. PATIENTS: Seventeen consecutive adult patients undergoing coronary artery bypass grafting or valve surgery with normothermic CPB and eight healthy volunteers. INTERVENTIONS: Blood samples for cytokine measurement were drawn from patients before and during (at 60, 90, 120, 180 and 360 mins) CPB and were cultured with and without LPS and with and without anti-IL-10 antibodies. Blood was also drawn from healthy subjects and sampled for cytokine analysis before and during circulation in an isolated ECC. MEASUREMENTS AND MAIN RESULTS: The concentrations of ex vivo tumor necrosis factor (TNF)-alpha, IL-6, IL-8, and IL-10, measured by enzyme-linked immunosorbent assay, were reduced in both experimental settings. In patients on CPB, LPS hyporesponsiveness was detected at 60 mins after the onset of CPB and was maximal at 120 mins (78% to 86% decreases from pre-CPB levels) but was transient, except for TNF-alpha. The plasma concentration of IL-10 peaked at 90 mins after the start of CPB, but the role of IL-10 in LPS hyporesponsiveness appears limited because anti-IL-10 antibodies significantly increased ex vivo production of IL-6 but not TNF-alpha or IL-8. In the isolated ECC study, no IL-10 was detected in plasma, yet the ex vivo production of the cytokines (except IL-8) was decreased (by 66% to 95%). CONCLUSION: Our results demonstrate the following: a) CPB induces an early and transient LPS hyporesponsiveness of whole blood as measured by cytokine production; b) IL-10 seems only partly involved in this process, and its role is restricted to an in vivo situation; and c) contact of blood with an ECC is sufficient to induce LPS hyporesponsiveness.     

Mechanical ventilation alters the immune response in children without lung pathology

OBJECTIVE: This study was undertaken to examine the hypothesis that mechanical ventilation in association with anesthesia would alter the cytokine profile in infants without preexisting lung pathology. DESIGN AND SETTING: Prospective observational study in pediatric intensive care unit in a university hospital. PATIENTS: Twelve infants who were subjected to an uncomplicated diagnostic cardiac catheterization procedure were studied. All subjects were ventilated with a volume control mode, 0.3 FIO(2), 4 cmH(2)O PEEP, and 10 ml/kg tidal volume. Volatile (servoflurane) anesthetics were given. MEASUREMENTS AND RESULTS: Tracheal aspirates and blood samples were obtained before and after 2 h of mechanical ventilation. In tracheal aspirates and in supernatants of stimulated whole-blood cultures cytokine concentrations were measured. In the tracheal aspirates the immune balance was characterized by a proinflammatory response pattern, with a significant increase in TNF-alpha and IL-6 concentrations; concentrations of anti-inflammatory mediators remained very low. The functional capacity of peripheral blood leukocytes to produce INF-gamma, TNF-alpha, and IL-6 in vitro was significantly decreased. This was accompanied by a significant decrease in the killing activity of natural killer cells. CONCLUSIONS: Two hours of servoflurane and mechanical ventilation using a tidal volume of 10 ml/kg is associated with remarkable changes in the immune response in infants without preexisting lung pathology undergoing cardiac catheterization. In the lungs the immune balance favors a proinflammatory response pattern without detectable concentrations of anti-inflammatory mediators. The Th1 immune response by peripheral blood leukocytes was decreased. The observed change in Th1/Th2 balance in favor of Th2 cytokine activity may be a systemic adaptation to the proinflammatory milieu in the lung.     

Ex vivo T-lymphocyte derived cytokine production in SIRS patients is influenced by experimental procedures

Ex vivo production of interleukin-2 (IL-2), IL-4, IL-5, and IL-10 by peripheral blood mononuclear cells (PBMC) was studied in 13 septic patients with infectious systemic inflammatory response syndrome (SIRS) and 13 patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) (noninfectious SIRS). We have investigated the levels of cytokines after activation by either concanavalin A (ConA), phytohemagglutinin (PHA), or anti-CD3 antibodies. In whole blood assays, ConA-induced IL-10 was significantly reduced in both groups of patients compared with healthy controls. In sepsis patients, IL-2, IL-5, and IL-10 productions by isolated PBMC were diminished on ConA-induced activation but not in response to PHA and anti-CD3; in CPB patients, only anti-CD3-induced IL-10 production was significantly reduced. Our data indicate that subtle modifications of the reactivity of circulating cells occur during infectious and noninfectious SIRS. Production of both Th1 and Th2 cytokines can be down-regulated; however, the nature of the SIRS, of the cell population, and of the activator may influence the observation.     

Influence of granulocyte-macrophage colony-stimulating factor (GM-CSF) on whole blood endotoxin responsiveness following trauma, cardiopulmonary bypass, and severe sepsis.

Major surgery, multiple injury, and severe sepsis lead to an impaired immune response. The suppressed status of the immune system is reflected by a reduced TNFalpha production of whole blood after stimulation with endotoxin in vitro and by a decreased HLA-DR expression on monocytes. In the present study, the effect of the immunostimulating hematopoetic growth factor GM-CSF on whole blood cultures of multiple injury, cardiac surgery, and severe sepsis patients was investigated. Endotoxin-induced TNFalpha production and HLA-DR expression was reduced in blood cultures of these patients compared to healthy donors. Preincubation with GM-CSF in vitro increased cytokine production in volunteers' and all patients' blood specimens in a dose-dependent manner. The elevation of cytokine response in cardiopulmonary bypass patients' blood, caused by in vitro preincubation with GM-CSF, equaled that of normal patients, whereas GM-CSF caused a lower rise of TNFalpha-producing capacity in blood of multiple-injury and sepsis patients. Further, GM-CSF treatment in vitro increased the down-regulated HLA-DR expression on monocytes prepared after cardiac surgery to a degree comparable to preoperative levels. Finally, GM-CSF incubation in vitro elevated TNFalpha synthesis in normal monocytes and in cells treated with a combination of the anti-inflammatory mediators IL-10, TGFbeta, and PGE2. These experiments show that hyporesponsiveness of whole blood induced by trauma, sepsis, or cardiac surgery is not irreversible but can be, at least in vitro, overridden by the immunostimulating compound GM-CSF.     

Influence of methylprednisolone on cytokine balance during cardiac surgery

OBJECTIVE: To determine the influence of methylprednisolone on the cytokine balance during cardiac surgery. DESIGN: Prospective, randomized, nonblinded study. SETTING: University hospital. PATIENTS: Twenty-one patients on cardiopulmonary bypass undergoing aortocoronary bypass surgery. INTERVENTIONS: According to a randomized sequence, the patients either received methylprednisolone (30 mg/kg) [corrected] before cardiopulmonary bypass and before declamping of the aorta (MPS group, n = 11) or received nothing (control group, n = 10). MEASUREMENTS AND MAIN RESULTS: Serum proinflammatory cytokines (interleukin [IL]-8, IL-6) and anti-inflammatory cytokines (IL-10, IL-1ra) were measured by enzyme-linked immunosorbent assays. Serum IL-6 and IL-8 concentrations in the control group (15.2 +/- 4.1 and 14.1 +/- 1.9 pg/mL, preoperatively) increased to 242 +/- 70.1 and 97.3 +/- 18.3 pg/mL at 60 mins after declamping of the aorta (p < .01, p < .01, respectively). The increases were greater than those from 2.5 +/- 0.6 and 2.5 +/- 0.5 pg/mL to 109.5 +/- 29.0 and 33 +/- 4.1 pg/mL in the MPS group for IL-6 and IL-8, respectively. Serum IL-10 concentrations increased significantly 60 mins after declamping of the aorta compared with its preoperative value in the two groups (the control group, from 1.0 +/- 0 to 537.9 +/- 61.7 pg/mL; the MPS group, from 0.3 +/- 0.2 to 654.9 +/- 24 pg/mL [p < .01, p < .01, respectively]). No difference was found between the two groups. Similarly, serum IL-1ra concentrations in the two groups increased the preoperative value in the control group from 304 +/- 120 to 44,374 +/- 14,631 pg/mL and in the MPS group from 616.5 +/- 109.6 to 35,598 +/- 9,074 pg/mL at 60 mins after declamping of the aorta (p < .01, p < .01, respectively). There was no difference between the two groups. CONCLUSIONS: Methylprednisolone reduces the production of IL-6 and IL-8 but not that of IL-10 and IL-1ra. These results suggest that one of the mechanisms of the cytoprotective effect of methylprednisolone may be to make changes in the proinflammatory and anti-inflammatory cytokine balance.     

Stress doses of hydrocortisone reduce severe systemic inflammatory response syndrome and improve early outcome in a risk group of patients after cardiac surgery

OBJECTIVE: Severe systemic inflammation with a vasodilatory syndrome occurs in about one third of all patients after cardiac surgery with cardiopulmonary bypass. Hydrocortisone has been used successfully to reverse vasodilation in septic patients. We evaluated if stress doses of hydrocortisone attenuate severe systemic inflammatory response syndrome in a predefined risk group of patients after cardiac surgery with cardiopulmonary bypass. DESIGN: Randomized, nonblinded, controlled trial. SETTING: Anesthesiologic intensive care unit for cardiac surgical patients of an university hospital. PATIENTS: After a risk analysis, we enrolled 91 patients into a prospective randomized trial. Patients were included according to the evaluated criteria (preoperative ejection fraction, duration of cardiopulmonary bypass, type of surgery). INTERVENTIONS: The treatment group received stress doses of hydrocortisone perioperatively: 100 mg before induction of anesthesia, then 10 mg/hr for 24 hrs, 5 mg/hr for 24 hrs, 3 x 20 mg/day, and 3 x 10 mg/day. MEASUREMENTS AND MAIN RESULTS: We measured various laboratory (e.g., lactate) and clinical variables (e.g., duration of ventilation and length of stay in the intensive care unit), characterizing the patients' outcome. The two study groups did not differ regarding age, preoperative medication, duration of the cardiopulmonary bypass, and type of surgery. The patients in the treatment group had significantly lower concentrations of IL-6 and lactate, higher antithrombin III concentration, lower need for circulatory and ventilatory support and for transfusions, lower Therapeutic Intervention Scoring System values, and shorter length of stay in the intensive care unit and in the hospital. The mortality rate did not differ significantly between the groups. CONCLUSIONS: Although we acknowledge the limitations of a nonblinded interventional trial, stress doses of hydrocortisone seem to attenuate systemic inflammation in a predefined risk group of patients after cardiac surgery with cardiopulmonary bypass and improve early outcome.     

Cytokine promoter polymorphisms in Taiwanese patients with Graves' disease

OBJECTIVES: This study aimed to examine the association between promoter polymorphisms of Th1 and Th2 cytokine genes [interleukin-4 (IL-4 T-34C, A-81G, C-285T and T-589C), IL-6 (G-174C), IL-10 (A-592C and T-819C) and tumour necrosis factor-alpha (TNF-alpha G-238A and G-308A)] and Graves' disease (GD) in Taiwanese population. DESIGN AND METHODS: Genomic DNA was extracted from peripheral blood cells of 137 GD patients and 189 control subjects. Cytokine gene polymorphisms were analyzed by polymerase chain reaction and restriction fragment length polymorphism. RESULTS: Genotype frequencies of TNF-alpha G-238A or G-308A between control and GD subjects were significantly different. Frequencies of the high TNF-alpha secreting alleles (-238*A and -308*A) and IL-10 -819*C allele were significantly increased in GD patients. No significant differences regarding IL-4 or IL-6 gene polymorphisms between GD patients and control subjects were found. CONCLUSIONS: Our data demonstrated that TNF-alpha G-238A and G-308A genotypes were strongly associated with GD incidence.     

Mesenteric injury after cardiopulmonary bypass: role of poly(adenosine 5'-diphosphate-ribose) polymerase

OBJECTIVES: To investigate the effects of the ultrapotent poly(adenosine 5'-diphosphate-ribose) polymerase (PARP) inhibitor INO-1001 on cardiac and mesenteric function during reperfusion in an experimental model of cardiopulmonary bypass with cardioplegic arrest. DESIGN: Prospective, randomized, and blinded experimental study. SETTING: Research laboratory. SUBJECTS:: Twelve anesthetized dogs underwent cardiopulmonary bypass with hypothermic cardioplegic cardiac arrest. INTERVENTIONS: After 60 mins of hypothermic cardiac arrest, either PARP inhibitor INO-1001 (1 mg/kg, n = 6) or vehicle (control, n = 6) was administered during reperfusion. MEASUREMENTS AND MAIN RESULTS: Left ventricular hemodynamic variables were measured by combined pressure-volume-conductance catheters. Coronary and mesenteric blood flow and vasodilatory responses to acetylcholine and sodium nitroprusside as well as mesenteric lactate and creatinine phosphokinase release were also determined. The administration of INO-1001 led to a significantly improved recovery of left ventricular systolic function (p < .05) after 60 mins of reperfusion. Coronary and mesenteric blood flow were also significantly higher in the INO-1001 group (p < .05). Although the vasodilatory response to sodium nitroprusside was similar in both groups before and after cardiopulmonary bypass and similar in response to acetylcholine before cardiopulmonary bypass, PARP-inhibited dogs had lower mesenteric vascular resistance after cardiopulmonary bypass (p < .05). Mesenteric lactate and creatinine phosphokinase release was significantly lower in the PARP inhibitor treated group (p < .05). CONCLUSION: PARP inhibition with INO-1001 improves the recovery of myocardial function and prevents mesenteric vascular dysfunction and tissue injury after cardiopulmonary bypass with hypothermic cardiac arrest.     

Pre- and postoperative cytokine release after in vitro whole blood lipopolysaccharide stimulation and frequent toll-like receptor 4 polymorphisms

In a prospective cohort study, we examined 62 patients undergoing major surgical cancer therapy for Toll-like receptor 4 (TLR4) gene polymorphisms (Asp299Gly and Thr399Ile) and their influence on cytokine levels pre- and postoperatively, as well as cytokine levels after whole blood lipopolysaccharide (LPS) stimulation. Incidence of the TLR4 gene single nucleotide polymorphism (SNP) Asp299Gly/Thr399Ile was 14.5% (9/62). Overall, mortality was unaffected by the TLR4 SNP. Preoperative cytokine levels were low, with most of the values of cytokines being below the detection levels. After preoperative stimulation of whole blood with 50 pg/mL LPS, TNF-alpha and IL-6 values increased significantly in both groups. However, no significant influence was detectable between the TLR4 SNP group and the wild type group (WT group). Postoperative IL-6 levels, but not TNF-alpha levels, were significantly increased in both groups. Postoperative LPS stimulation resulted in significantly lower TNF-alpha levels compared with preoperative induction, with a more than 2.3-fold decrease in the TLR4 SNP group: 310.83 pg/mL (SD: 117.53) to 134.08 pg/mL (SD: 91.49; P < 0.001) and a 2.2-fold decrease in the WT group: 422.97 pg/mL (SD: 662.57) to 191.68 pg/mL (SD:147.26; P = 0.031). IL-6 levels after stimulation were comparably decreased with similarly no significant difference between the two groups. We conclude that the TLR4 polymorphism Asp299Gly/Thr399Ile has no influence on cytokine release after LPS stimulation in the early and late course after major surgery. The LPS adaptation effect of cytokine release after surgery is furthermore not affected by the presence of the TLR4 polymorphism Asp299Gly/Thr399Ile.     

Increased TNF-alpha production by peripheral blood mononuclear cells in patients with Krabbe's disease: effect of psychosine

BACKGROUND: Inflammatory and/or immune activation occurs both in animal models (twitcher mice) and in the brain of patients with Globoid cell leukodystrophy (GLD) or Krabbe's disease (KD). In this study we evaluated in vitro the cytokine profile of KD patients and the effect of psychosine, the toxic metabolite which plays a role in the demyelination process in these patients. MATERIALS AND METHODS: We studied cytokine production by peripheral blood mononuclear cells (PBMCs) isolated from four KD patients, diagnosed on the basis of clinical criteria. Cells were cultured and stimulated with appropriate agents and the supernatants collected before and after the addition of psychosine. Tumour necrosis factor-alpha (TNF-alpha), interleukin-8 (IL-8) and monocyte chemoattractant factor (MCP)-1) production was evaluated (ELISA method) and compared with a group of 10 normal subjects. RESULTS: We found a significant increase of TNF-alpha release by PBMCs of KD patients compared with healthy subjects; TNF-alpha production was significantly increased after LPS addition. Psychosine was able to induce a further significant increase (P < 0.05) only in cells obtained from KD patients and not from control subjects. No changes were found in IL-8 and MCP-1 production. CONCLUSIONS: The increased TNF-alpha production permits us to confirm the presence of an inflammatory-immune stimulus in KD patients, which may be induced and potentiated by the pathogenetic metabolite psychosine.     

Alterations in inflammatory capacity and TLR expression on monocytes and neutrophils after cardiopulmonary bypass

Cardiopulmonary bypass (CPB) is associated with immune paresis, which predisposes to the development of postoperative sepsis. The aims of this study were to characterize the ex vivo cytokine responses to bacterial cell wall components in whole blood from patients undergoing CPB and to determine whether altered leukocyte expression of Toll-like receptors (TLRs) is involved in immune paresis after CPB. We recruited 6 patients undergoing routine cardiac surgery with CPB. Preoperatively, at the end of CPB and 20 h later, blood was obtained, anticoagulated, and leukocyte surface expression of CD14, TLR2, and TLR4 was quantified by flow cytometry. In addition, blood was incubated at 37 degrees C in the presence of peptidoglycan (PepG) and/or lipopolysaccharide (LPS), and plasma cytokines were measured by enzyme immunoassay. At the end of CPB, ex vivo production of tumor necrosis factor alpha, interleukin (IL) 1beta, IL-8, and IL-10 in response to PepG or LPS was virtually abolished (P < 0.05). The following day, there was recovery of all cytokine responses to PepG. Tumor necrosis factor alpha and IL-1beta responses to LPS partially recovered, whereas IL-8 and IL-10 responses recovered. At the end of CPB, there was more than 50% reduction in neutrophil TLR2 and TLR4 expression (P < 0.05), with recovery to baseline the following day. There was a 29% reduction in monocyte TLR4 expression at the end of CPB (P < 0.05) and more than 120% increase in monocyte TLR2 and 4 expression the following day (P < 0.05). In conclusion, reduced ex vivo production of cytokines cannot be fully accounted for by downregulation of TLR expression, although receptor upregulation may contribute to the later recovery of responsiveness.     

The relationship between visceral ischemia, proinflammatory cytokines, and organ injury in patients undergoing thoracoabdominal aortic aneurysm repair

OBJECTIVES: Plasma proinflammatory, anti-inflammatory cytokine, and soluble tumor necrosis factor (TNF) receptor concentrations were examined in hospitalized patients after abdominal and thoracoabdominal aortic aneurysm (TAAA) repair, with and without left atrial femoral bypass. Changes in plasma cytokine concentrations were related to the duration of visceral ischemia and the frequency rate of postoperative, single, or multiple system organ dysfunction (MSOD). DESIGN: Prospective, observational study. SETTING: Two academic referral centers in the United States and The Netherlands. PATIENTS: We included 16 patients undergoing TAAA repair without left atrial femoral bypass, 12 patients undergoing TAAA repair with left atrial femoral bypass, and nine patients undergoing infrarenal aortic aneurysm repair. MEASUREMENTS AND MAIN RESULTS: Timed, arterial blood sampling for proinflammatory and anti-inflammatory cytokine and soluble TNF receptor concentrations (p55 and p75), and prospective assessment of postoperative single and MSOD. Plasma appearance of TNF-alpha, interleukin (IL)-6, IL-8, and IL-10 peaked 1 to 4 hrs after TAAA repair, and concentrations were significantly elevated compared with infrarenal abdominal aortic aneurysm repair (p < .05). Left atrial femoral bypass significantly reduced the duration of visceral ischemia (p < .05) and the systemic TNF-alpha, p75, and IL-10 responses (p < .05). Plasma TNF-alpha concentrations >150 pg/mL were more common in patients with extended visceral ischemia times (>40 mins). Additionally, patients with early peak TNF-alpha concentrations >150 pg/mL and IL-6 levels >1,000 pg/mL developed MSOD more frequently than patients without these elevated plasma cytokine levels (both p < .05). CONCLUSIONS: Thoracoabdominal aortic aneurysm repair results in the increased plasma appearance of TNF-alpha, IL-6, IL-8, IL-10, and shed TNF receptors. The frequency and magnitude of postoperative organ dysfunction after TAAA repair is associated with an increased concentration of the cytokines, TNF-alpha, and IL-6 and the increased plasma levels of these cytokines appear to require extended visceral ischemia times.