Systemic Release Of Inflammatory Cytokines Research Articles

Elevation of neutrophil-derived factors in patients after multiple trauma.

Trauma represents one of the leading causes of death worldwide. Traumatic injuries elicit a dynamic inflammatory response with systemic release of inflammatory cytokines. Disbalance of this response can lead to systemic inflammatory response syndrome or compensatory anti-inflammatory response syndrome. As neutrophils play a major role in innate immune defence and are crucial in the injury-induced immunological response, we aimed to investigate systemic neutrophil-derived immunomodulators in trauma patients. Therefore, serum levels of neutrophil elastase (NE), myeloperoxidase (MPO) and citrullinated histone H3 (CitH3) were quantified in patients with injury severity scores above 15. Additionally, leukocyte, platelet, fibrinogen and CRP levels were assessed. Lastly, we analysed the association of neutrophil-derived factors with clinical severity scoring systems. Although the release of MPO, NE and CitH3 was not predictive of mortality, we found a remarkable increase in MPO and NE in trauma patients as compared with healthy controls. We also found significantly increased levels of MPO and NE on Days 1 and 5 after initial trauma in critically injured patients. Taken together, our data suggest a role for neutrophil activation in trauma. Targeting exacerbated neutrophil activation might represent a new therapeutic option for critically injured patients.

Inflammatory Dendritic Cells Contribute to Regulate the Immune Response in Sickle Cell Disease.

Sickle cell disease (SCD), one of the most common hemoglobinopathies worldwide, is characterized by a chronic inflammatory component, with systemic release of inflammatory cytokines, due to hemolysis and vaso-occlusive processes. Patients with SCD demonstrate dysfunctional T and B lymphocyte responses, and they are more susceptible to infection. Although dendritic cells (DCs) are the main component responsible for activating and polarizing lymphocytic function, and are able to produce pro-inflammatory cytokines found in the serum of patients with SCD, minimal studies have thus far been devoted to these cells. In the present study, we identified the subpopulations of circulating DCs in patients with SCD, and found that the bloodstream of the patients showed higher numbers and percentages of DCs than that of healthy individuals. Among all the main DCs subsets, inflammatory DCs (CD14+ DCs) were responsible for this rise and correlated with higher reticulocyte count. The patients had more activated monocyte-derived DCs (mo-DCs), which produced MCP-1, IL-6, and IL-8 in culture. We found that a CD14+ mo-DC subset present in culture from some of the patients was the more activated subset and was mainly responsible for cytokine production, and this subset was also responsible for IL-17 production in co-culture with T lymphocytes. Finally, we suggest an involvement of heme oxygenase in the upregulation of CD14 in mo-DCs from the patients, indicating a potential mechanism for inducing inflammatory DC differentiation from circulating monocytes in the patients, which correlated with inflammatory cytokine production, T lymphocyte response skewing, and reticulocyte count.

Toxic shock syndrome with a cytokine storm caused by Staphylococcus simulans: a case report

BackgroundExotoxins secreted from Staphylococcus aureus or Streptococcus pyogenes act as superantigens that induce systemic release of inflammatory cytokines and are a common cause of toxic shock syndrome (TSS). However, little is known about TSS caused by coagulase-negative staphylococci (CoNS) and the underlying mechanisms. Here, we present a rare case of TSS caused by Staphylococcus simulans (S. simulans).Case presentationWe report the case of a 75-year-old woman who developed pneumococcal pneumonia and bacteremia from S. simulans following an influenza infection. The patient met the clinical criteria for probable TSS, and her symptoms included fever of 39.5 °C, diffuse macular erythroderma, conjunctival congestion, vomiting, diarrhea, liver dysfunction, and disorientation. Therefore, the following treatment was initiated for bacterial pneumonia complicating influenza A with suspected TSS: meropenem (1 g every 8 h), vancomycin (1 g every 12 h), and clindamycin (600 mg every 8 h). Blood cultures taken on the day after admission were positive for CoNS, whereas sputum and pharyngeal cultures grew Streptococcus pneumoniae (Geckler group 4) and methicillin-sensitive S. aureus, respectively. However, exotoxins thought to cause TSS, such as TSS toxin-1 and various enterotoxins, were not detected. The patient’s therapy was switched to cefazolin (2 g every 8 h) and clindamycin (600 mg every 8 h) for 14 days based on microbiologic test results. She developed desquamation of the fingers on hospital day 8 and was diagnosed with TSS. Conventional exotoxins, such as TSST-1, and S. aureus enterotoxins were not detected in culture samples. The serum levels of inflammatory cytokines, such as neopterin and IL-6, were high. CD8+ T cells were activated in peripheral blood. Vβ2+ population activation, which is characteristic for TSST-1, was not observed in the Vβ usage of CD8+ T cells in T cell receptor Vβ repertoire distribution analysis.ConclusionsWe present a case of S. simulans-induced TSS. Taken together, we speculate that no specific exotoxins are involved in the induction of TSS in this patient. A likely mechanism is uncontrolled cytokine release (i.e., cytokine storm) induced by non-specific immune reactions against CoNS proliferation.

Effects of dexmedetomidine on inflammatory mediators after tourniquet-induced ischemia-reperfusion injury: a randomized, double-blinded, controlled study.

Tourniquet use during total knee arthroplasty (TKA) produces ischemia-reperfusion injury (IRI), with systemic release of inflammatory cytokines and reactive oxygen species upon tourniquet release. We conducted a randomized, placebo-controlled, double-blind trial to examine whether dexmedetomidine (DEX) as an adjunct during general anesthesia in patients undergoing unilateral TKA could attenuate the rise in inflammatory cytokines and oxidative stress. Sixty-eight patients were randomized to either the control or DEX group. DEX was administered at a loading dose of 0.5 μg/kg, followed by an infusion of 0.4 μg/kg/h. We measured serum levels of malondialdehyde (biomarker of oxidative stress) and proinflammatory cytokines (interleukin-6 [IL-6] and tumour necrosis factor-α [TNF-α]) preinduction (baseline), 60 and 90 min post-tourniquet release. We also assessed hemodynamics, intraoperative remifentanil consumption, and postoperative pain scores and analgesic consumption. Malondialdehyde was higher than baseline after tourniquet release in both groups (P≤0.001), but the levels were similar between groups at all times. TNF-α was significantly higher than baseline at 60 min post-tourniquet release only in the control group (P=0.009). Serum IL-6 increased significantly above baseline at 60 and 90 min post-tourniquet release in both groups (P<0.001). At 90 min, IL-6 was significantly lower in the dexmedetomidine group than in the control group (P=0.049). Remifentanil consumption, heart rate, and pain scores were significantly lower in the dexmedetomidine group. Our results suggest that dexmedetomidine as an adjunct to general anesthesia attenuated the rise in proinflammatory cytokines, providing protective effects in tourniquet-induced IRI.

Phase I/IIb trial: In-situ vaccine for metastatic colorectal cancer.

TPS871 Background: Except for MSI-H tumors, CRC does not respond to immunotherapy. CRC does respond to the graft vs. tumor (GVT) immune effect that occurs after allogeneic stem cell transplantation. GVT is associated with GVHD toxicity which limits the clinical application. A bioengineered allograft (BAG) has been developed which can elicit host-mediated GVT-like effects without GVHD toxicity, chemotherapy conditioning or a HLA-matched donor. BAG are Th1 memory cells derived from blood of healthy donors with CD3/CD28 microbeads attached. These cells have immunomodulatory properties which enable modulation of Th1/Th2 balance and dysregulation of immunosuppressive circuits. We are evaluating the safety and efficacy of BAG in third-line mCRC. Methods: The study uses a standard 3+3 design followed by an expansion phase with the optimal dosing pattern. The protocol has four components: (A) priming; (B) in-situ vaccination; (C) extravasation and trafficking; and (D) counter immune suppression/avoidance. Priming involves intradermal injections of BAG cells which activates NK cells and develops allo-specific Th1/Tc1 immunity. In-Situ vaccination involves tumor cryoablation to release endogenous HSP which chaperone tumor neoantigens, followed immediately by the intralesional injection of BAG cells as adjuvant. Released HSP are engulfed and processed by immature dendritic cells (DC) attracted to the tissue damage. The inflammatory microenvironment created by the BAG and the subsequent allo-rejection response amplified by the priming induces DC maturation. These DC display processed tumor antigens on upregulated MHCI/II and express co-stimulatory CD80/86 enabling priming of a tumor-specific Th1/Tc1 response. CD40L and interferon-gamma expressed by BAG activates allo-specific and tumor-specific memory cells upon intravenous infusion, permitting trafficking to tumor. The host rejection of BAG releases endogenous danger signals creating a sustained systemic inflammatory cytokine release which serves to counter-regulate immunosuppressive mechanisms. Longitudinal CT scans biopsies, PBMC and serum samples are collected for analysis to verify immune events within each phase of the protocol. Clinical trial information: NCT02380443.

Long-term cannabinoid type 2 receptor agonist therapy decreases bacterial translocation in rats with cirrhosis and ascites

Intestinal hyperpermeability, impaired peritoneal macrophages (PMs) phagocytosis, and bacterial translocation (BT), resulting in increased systemic and local infection/inflammation such as spontaneous bacterial peritonitis (SBP) together with increased tumor necrosis factor-α (TNFα) levels, are all implicated in the pathogenesis of cirrhosis-related complications. Manipulation of the cannabinoid receptors (CB1R and CB2R), which are expressed on the gut mucosa and PMs, has been reported to modulate intestinal inflammation and systemic inflammatory cytokine release. Our study aims to explore the effects of chronic CB1R/CB2R agonist/antagonist treatments on relevant abnormalities in cirrhotic ascitic rats. Vehicle, archidonyl-2-chloroethylamide (ACEA, CB1R agonist), JWH133 (CB2R agonist), and AM630 (CB2R antagonist) were given to thioacetamide (TAA) and common bile duct ligation (BDL) cirrhotic rats with ascites for two weeks and various measurement were performed. Compared to sham rats, CB2Rs were downregulated in cirrhotic rat intestines and PMs. The two-week JWH133 treatment significantly decreased systemic/intestinal oxidative stress, TNFα and inflammatory mediators, infection, intestinal mucosal damage and hyperpermeability; the JWH133 treatment also decreased bacterial overgrowth/adhesion, BT and SBP, upregulated intestinal tight junctions and downregulated the PM TNFα receptor/NFκBp65 protein expression in cirrhotic rats. Acute and chronic JWH133 treatment corrected the TNFα-induced suppression of phagocytosis of cirrhotic rat PMs, which then could be reversed by concomitant AM630 treatment. Our study suggests that CB2R agonists have the potential to treat BT and various relevant abnormalities through inhibition of systemic/intestinal oxidative stress, inflammatory cytokines and TNFα release in cirrhosis. Overall, the chronic CB2R agonist treatment affects multiple approach mechanisms, and its direct effect on the hyperdynamic circulation is only minor.

Addition of ascorbic acid solution to stored murine red blood cells increases posttransfusion recovery and decreases microparticles and alloimmunization

The storage of red blood cells (RBCs) results in numerous changes, which over time result in decreased recovery of transfused RBCs. In addition (at least in animal models), stored RBCs can be more immunogenic and also stimulate the systemic release of inflammatory cytokines in transfusion recipients. One component of the RBC storage lesion is the accumulation of oxidative damage. We tested the hypothesis that adding a chemical antioxidant (ascorbic acid) to stored RBCs would improve the quality of the stored RBCs. RBCs were harvested from FVB.HOD mice that express an RBC-specific model transgene (HOD) and stored for 14 days with either ascorbic acid in saline or saline alone. Twenty-four-hour posttransfusion recovery of RBCs was tracked by flow cytometry. Alloimmunization was monitored by flow cytometry crossmatch. Cytokines were monitored by multiplex bead arrays. RBCs stored under standard conditions had decreased 24-hour posttransfusion recovery and increased induction of both alloantibodies and interleukin (IL)-6 and monocyte chemoattractant protein (MCP)-1 secretion in the mouse recipients. Addition of ascorbic acid from 3.6 to 10.8 mmol/L resulted in a significant decrease in microparticle formation, an improved RBC 24-hour posttransfusion recovery (p<0.01), and a decrease in recipient alloimmunization (p=0.0001). Induction of MCP-1 and IL-6 secretion was not decreased by ascorbic acid. These data indicate that the addition of ascorbic acid solution to RBCs during storage has a beneficial effect on recovery and immunogenicity of RBCs, but not cytokine induction. The addition of ascorbic acid (or other antioxidants) to human RBCs may have beneficial effects.

Fever and inflammatory cytokine response in rats injected subcutaneously with viral double-stranded RNA analog, polyinosinic:polycytidylic acid (Poly-I:C)

The objective of this study was to determine whether viral double-stranded RNA analog, polyinosinic:polycytidylic acid (Poly-I:C), is pyrogenic in rats when administered subcutaneously, thus determining whether rats can serve as an experimental model to investigate the regulation of local and systemic inflammatory responses to a Toll-like receptor(TLR)-3 agonist. Rats implanted intraperitoneally with temperature-sensitive radiotelemeters were injected subcutaneously in the skin of the tail with saline, 100 μg kg −1 Poly-I:C, or 1000 μg kg −1 Poly-I:C. In a separate group of rats blood and tail-skin samples were taken 3 and 24 h after injections to assess changes in local and systemic inflammatory cytokine release. Injection of 1000 μg kg −1 Poly-I:C induced an acute fever, which lasted for approximately seven hours. The fever was associated with elevated local tissue concentrations of interleukin(IL)-1β, IL-6, and cytokine-induced neutrophil chemoattractant (CINC)-1, and elevated plasma concentration of CINC-1. Cytokine concentrations had returned to background concentrations by 24 h after the injection. Injection of 100 μg kg −1 Poly-I:C failed to induce fever, but did induce significant increases in the local tissue, but not circulating, concentration of CINC-1 within 3 h of the injection. Tissue CINC-1 concentrations had returned to background concentrations by 24 h after the injection. In conclusion, when administered at great enough concentrations, subcutaneously injected Poly-I:C is pyretic in rats, and the pyresis is associated with elevated concentrations of local and systemic inflammatory mediators. Thus the rat can be used to study signaling pathways induced by localized, subcutaneous administration of this TLR-3 agonist that mimics viral infection.

Diarrhea during the Conditioning Regimen Is Correlated with the Occurrence of Severe Acute Graft-versus-Host Disease through Systemic Release of Inflammatory Cytokines

Graft-versus-host disease (GVHD) is a major obstacle to the success of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Although many indicators have been used to predict GVHD, the prediction of GVHD remains very difficult. Determining how to predict the occurrence of acute GVHD (aGVHD) as exactly as possible has been a huge challenge so far. Systemic release of inflammatory cytokines during the conditioning regimen and early-phase post-HSCT plays a crucial role in the generation of aGVHD; additionally, the conditioning regimen causes the damage to the intestinal tract. Diarrhea is a common symptom of intestinal tract damage during the conditioning regimen. We therefore performed a prospective study to investigate the relationship between diarrhea related to the conditioning regimen, systemic release of inflammatory cytokines during the conditioning regimen and the early-phase post-HSCT, and the development of aGVHD. This study demonstrated that duration of diarrhea was >5.5 days, with a maximal volume >8.72 mL/kg and a mean volume of diarrhea for days -3 to 0 >7.94 mL/kg were risk factors of grade II to IV aGVHD. Diarrhea with any 1 risk factor was defined as severe diarrhea. Furthermore, this study first confirmed that the correlation between diarrhea and aGVHD was related to the serum levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 during the conditioning regimen and during the early phase after transplantation. Our study demonstrated that diarrhea related to the conditioning regimen could be used as a marker for the prediction of aGVHD and further explain the possible mechanism underlying the linkage described here. Therefore, for the patients with severe diarrhea related to the conditioning regimen, low-dose glucocorticoid may be used to reduce the levels of inflammatory cytokine release by a damaged intestinal tract, and possibly further reduce the occurrence of aGVHD. For these patients, prophylaxis of aGVHD may be need to be adjusted individually.

Down-regulation of IRAK-4 is a component of LPS- and CpG DNA-induced tolerance in macrophages

Macrophages are important mediators of the immune response to infection by virtue of, amongst other things, their ability to secrete cytokines (e.g. TNF) that trigger inflammation. However, excessive systemic release of inflammatory cytokines can cause septic shock and ultimately death. Tolerance is an adaptive mechanism that prevents macrophage activation and inflammatory cytokine production. The activation of macrophages by pathogens is largely mediated by Toll-like receptors (TLRs). IRAK-4 and IRAK-1 are proximal protein kinases in TLR signalling pathways; IRAK-1 is activated via its phosphorylation by IRAK-4. The rapid degradation of IRAK-1 following its TLR-induced activation has been proposed to represent a major mechanism for tolerance. Here, we established that IRAK-1 degradation is insufficient to cause tolerance; in the absence of IRAK-1, IRAK-4 likely activates downstream signalling proteins (e.g. NF-κB) via IRAK-2. Significantly, tolerance coincided with IRAK-4 down-regulation, which occurred at the protein level via proteolytic degradation as well as at the mRNA level. Gene silencing experiments confirmed the importance of IRAK-4 for the regulation of TNF expression. The different kinetics of IRAK-4 and IRAK-1 down-regulation may result in both quantitative and qualitative differences in TLR signalling and potentially allow macrophages to temporally modify their inflammatory responses. Furthermore, differences in the kinetics and extent of IRAK-4 down-regulation by TLR ligands may provide a mechanism whereby macrophages can tailor their inflammatory response according to the location and/or type of pathogen detected.

State of the science conference: Initiative to decrease cardiovascular risk and increase quality of care for patients living with HIV/AIDS: executive summary.

With successful antiretroviral therapy, patients infected with the human immunodeficiency virus (HIV) are living longer; however, recent reports suggest increased rates of coronary heart disease (CHD) among HIV-infected patients,1 and cardiovascular disease has become an important cause of morbidity and mortality in this population.2 Increased CHD rates in the HIV population may relate to traditional risk factors, including advancing age, higher smoking rates, dyslipidemia, insulin resistance, and impaired glucose tolerance. Cardiovascular disease may also be due to nontraditional factors, including changes in body composition with loss of subcutaneous fat and/or accumulation of visceral fat in some patients, inflammation, and direct effects of the virus on the vasculature, as well as to direct effects of specific antiretroviral drugs. Important questions remain as to the pathogenesis, detection, and treatment of cardiovascular disease and related risk factors in HIV-infected patients. These questions concern, among other things, the design of adequate trials to determine CHD incidence and the utility of existing CHD guidelines for screening, prevention, treatment, and risk stratification. To ascertain the state of the science with respect to these and related questions, a multidisciplinary conference with interested HIV specialists, cardiologists, endocrinologists, primary care physicians, National Institutes of Health representatives, and patient advocates was convened June 28–30, 2007, in Chicago, Ill, and chaired by Drs Steven Grinspoon and Robert Eckel. The discussions focused on 6 areas of interest, each with its own working group, including the following: (1) the contribution of metabolic and anthropometric abnormalities to cardiovascular disease risk factors (chaired by Drs Carl Grunfeld and Donald Kotler); (2) the epidemiological evidence for cardiovascular disease and its relationship to highly active antiretroviral therapy (HAART; chaired by Drs Judy Currier and Jens Lundgren); (3) the effects of HIV infection and antiretroviral therapy on the heart and vasculature (chaired by Drs Michael Dube …

INHIBITION OF CYCLOOXYGENASE-2 IN EXPERIMENTAL SEVERE ACUTE PANCREATITIS

The standard treatment for acute pancreatitis (AP) is still based on supportive care. The search for a new drug that could change the natural history of the disease is a continuing challenge for many researchers. The aim of this study is to evaluate the effect of a cyclooxygenase-2 (COX-2) inhibitor on experimental AP in rats. The animals were divided into 2 groups: Group 1 (n = 30)-animals with taurocholate-induced AP treated with parecoxib (40 mg/kg). Group 2 (n = 30)-animals with taurocholate-induced AP that received saline. The COX-2 inhibitor (parecoxib) was injected immediately after AP induction, through the penis dorsal vein. The parameters evaluated were histology, serum levels of amylase, IL-6 and IL-10, and mortality rate. The serum levels of IL-6 and IL-10 in the parecoxib-treated group were lower than the control group. The amylase serum levels and the mortality rate remained unchanged in the treated animals. Histologic morphology also was unaltered, except for fat necrosis, which was higher in parecoxib-treated rats. Inhibition of Cox-2 decreases the systemic release of inflammatory cytokines, but has a poor effect on the direct pancreas injury caused by taurocholate.

Congestive heart failure induces endothelial cell apoptosis: protective role of carvedilol

OBJECTIVESThe purposes of this study were to determine whether the serum of patients with congestive heart failure (CHF) can induce apoptosis of endothelial cells and to elucidate the underlying mechanisms. Moreover, the effect of the beta-blocker carvedilol was investigated.BACKGROUNDCongestive heart failure is associated with impaired endothelial function in the peripheral systemic vasculature and with systemic release of inflammatory cytokines. Pro-inflammatory cytokines have been shown to induce endothelial cell apoptosis in vitro. Therefore, we hypothesized that CHF is associated with enhanced apoptosis of endothelial cells.METHODSHuman umbilical vein endothelial cells were exposed to the serum of patients with CHF (n = 15) or healthy volunteers (n = 11), and apoptosis was determined by fluorescence staining of the nuclei and demonstration of deoxyribonucleic acid laddering. Moreover, apoptotic membrane particles were detected in plasma samples of patients with CHF.RESULTSThe serum of patients with CHF revealed a significantly enhanced pro-apoptotic activity as compared with age- and gender-matched healthy volunteers (p < 0.001). Furthermore, patients with CHF revealed significantly elevated plasma concentrations of apoptotic membrane particles. Apoptosis of endothelial cells correlated with elevated tumor necrosis factor-alpha (TNF-alpha) (r = 0.585, p = 0.002) and soluble TNF receptor serum levels (r = 0.517, p = 0.007). Carvedilol completely suppressed the increase in apoptosis induced by the serum of patients with CHF. Moreover, carvedilol dose-dependently inhibited TNF-alpha–induced apoptosis. The antiapoptotic activity of carvedilol was mediated by reduced activation of the caspase cascade through inhibition of mitochondrial cytochrome c release. The suppression of apoptosis by carvedilol was due to its antioxidative rather than beta-blocking effects, as the analogue BM91.0228, which has no beta-blocking activity, exerted similar effects.CONCLUSIONSThese findings indicate that endothelial cell apoptosis may play a role in the pathophysiology of heart failure. Inhibition of endothelial cell apoptosis by carvedilol may contribute to the beneficial effects of carvedilol in patients with heart failure.

Humoral Immune Response During Coronary Artery Bypass Grafting

Background —The introduction of limited approaches to the heart and the avoidance of cardiopulmonary bypass (CPB) aim to reduce the invasiveness of CABG by decreasing the systemic release of inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-8, as well as the anti-inflammatory agent IL-10. This study compares the humoral immune response in patients undergoing CABG with standard, minimally invasive, and “off-pump” techniques. Methods and Results —Thirty patients were divided into 3 operative groups: full sternotomy approach plus CPB (group A); full sternotomy approach, off pump (group B); and limited left anterior thoracotomy, off pump (group C). Plasma levels of TNF-α receptors p55 and p75, IL 6, IL-8, and IL-10 were taken at baseline, during CPB, and at 4, 24, and 48 hours and 6 days after surgery. A significant increased release of activated complement factors C5a and C3d, IL-8, and IL-10 was observed in patients subjected to CPB (group A) during the initial period and for a short time after perfusion ( P &lt;0.05). TNF-α receptors p55 and p75 showed a prolonged elevation (up to 48 hours) in the CPB group compared with the 2 off-pump groups. IL-6 showed no different release among the 3 surgical groups throughout the entire period. There was no significant difference in any parameter measured in relation to the type of operative approach. Conclusions —There is an inflammatory, as well as an anti-inflammatory, response during CABG that is related to the general surgical trauma. The release of immune mediators is enhanced by the use of CPB during various perioperative and postoperative phases. The type of operative approach did not influence this immune response.

Temporal correlation of tumor necrosis factor-alpha release, upregulation of pulmonary ICAM-1 and VCAM-1, neutrophil sequestration, and lung injury in diet-induced pancreatitis

Lung injury is a major cause of patient morbidity in acute pancreatitis. The purpose of this study was to examine the mechanism of pulmonary infiltration and lung injury in acute pancreatitis. Mice were fed a choline-deficient/ethionine-supplemented (CDE) diet for 144 hours to induce severe acute pancreatitis. Serum samples were collected for measurement of biochemical markers of disease and for the detection of tumor necrosis factor-alpha (TNF-α). Cell surface adhesion molecule expression was quantified by the sensitive radiolabeled dual monoclonal antibody technique. Neutrophil sequestration in lung tissue was measured by the myeloperoxidase assay. Lung injury was determined histologically and lung edema was assessed by wet/dry ratios. Pancreatic injury was demonstrated to occur in all CDE-fed mice, which developed significant hyperamylasemia and hypoglycemia by 48 hours ( P <0.0001). Serum TNF-α levels increased significantly by 48 hours over baseline values ( P <0.02). Expression of intracellular adhesion molecule (ICAM-1) in pulmonary endothelia was significantly increased above baseline by 30% at 48 hours ( P <0.02) and peaked at 120 hours by 100% ( P <0.0001). Vascular cellular adhesion molecule (VCAM-1) was constitutively expressed at baseline and was upregulated threefold by 48 hours ( P <0.0001). Neutrophil infiltration increased gradually 24 hours after ICAM-1 and VCAM-1 were upregulated with significant elevation of myeloperoxidase activity over baseline at 72 hours (7.2 ± 1.2 vs. 18.1 ± 2.2 activity units/gram tissue; P <0.05). Neutrophil infiltration peaked at 144 hours (26.24 ± 10.49 activity units/gram tissue P <0.0001), and its kinetics correlated with the onset and progression of morphologic injury as well as increased lung edema. These results show that acute pancreatitis is associated with a systemic release of inflammatory cytokines, followed by increased expression of pulmonary ICAM-1 and VCAM-1, neutrophil infiltration, and histologic lung injury. The adhesion molecule axis may be a potential target for practical intervention to ameliorate lung injury and morbidity in acute pancreatitis.

Leukocytosis and resistance to septic shock in intercellular adhesion molecule 1-deficient mice.

Intercellular adhesion molecule 1 (ICAM-1) is one of three immunoglobulin superfamily members that bind to the integrins lymphocyte function associated 1 (LFA-1) and Mac-1 on leukocytes. We have generated mice that are genetically and functionally deficient in ICAM-1. These mice have elevated numbers of circulating neutrophils and lymphocytes, as well as diminished allogeneic T cell responses and delayed type hypersensitivity. Mutant mice are resistant to lethal effects of high doses of endotoxin (lipopolysaccharide [LPS]), and this correlates with a significant decrease in neutrophil infiltration in the liver. Production of inflammatory cytokines such as tumor necrosis factor alpha or interleukin 1 is normal in ICAM-1-deficient mice, and thus protection appears to be related to a diminution in critical leukocyte-endothelial interactions. After sensitization with D-galactosamine (D-Gal), ICAM-1-deficient mice are resistant to the lethal effect of low doses of exotoxin (Staphylococcus aureus enterotoxin B [SEB]), which has been shown to mediate its toxic effects via the activation of specific T cells. In this model, ICAM-1-mediated protection against SEB lethality correlates with a decrease in the systemic release of inflammatory cytokines, as well as with prevention of extensive hepatocyte necrosis and hemorrhage. ICAM-1-deficient mice sensitized with D-Gal, however, are not protected from lethality when challenged with low doses of endotoxin (LPS). These studies show that the different contribution of ICAM-1 in the activation of either T cells or macrophages is decisive for the fatal outcome of the shock in these two models. This work suggests that anti-ICAM-1 therapy may be beneficial in both gram-positive and -negative septic shock, either by reducing T cell activation or by diminishing neutrophil infiltration.