Interleukin-10 and the monocyte/macrophage-induced inflammatory response in septic shock

Facing stress and inflammation: From the cell to the planet

As identified in 1936 by Hans Selye, stress is shaping diseases through the induction of inflammation. But inflammation display some yin yang properties. On one hand inflammation is merging with the innate immune response aimed to fight infectious or sterile insults, on the other hand inflammation favors chronic physical or psychological disorders. Nature has equipped the cells, the organs, and the individuals with mediators and mechanisms that allow them to deal with stress, and even a good stress (eustress) has been associated with homeostasis. Likewise, societies and the planet are exposed to stressful settings, but wars and global warming suggest that the regulatory mechanisms are poorly efficient. In this review we list some inducers of the physiological stress, psychologic stress, societal stress, and planetary stress, and mention some of the great number of parameters which affect and modulate the response to stress and render it different from an individual to another, from the cellular level to the societal one. The cell, the organ, the individual, the society, and the planet share many stressors of which the consequences are extremely interconnected ending in the domino effect and the butterfly effect.

Molecular mechanisms of Sepsis attacking the immune system and solid organs

Remarkable progress has been achieved in sepsis treatment in recent times, the mortality rate of sepsis has experienced a gradual decline as a result of the prompt administration of antibiotics, fluid resuscitation, and the implementation of various therapies aimed at supporting multiple organ functions. However, there is still significant mortality and room for improvement. The mortality rate for septic patients, 22.5%, is still unacceptably high, accounting for 19.7% of all global deaths. Therefore, it is crucial to thoroughly comprehend the pathogenesis of sepsis in order to enhance clinical diagnosis and treatment methods. Here, we summarized classic mechanisms of sepsis progression, activation of signal pathways, mitochondrial quality control, imbalance of pro-and anti- inflammation response, diseminated intravascular coagulation (DIC), cell death, presented the latest research findings for each mechanism and identify potential therapeutic targets within each mechanism.

During Sepsis and COVID-19, the Pro-Inflammatory and Anti-Inflammatory Responses Are Concomitant

The most severe forms of COVID-19 share many features with bacterial sepsis and have thus been considered to be a viral sepsis. Innate immunity and inflammation are closely linked. While the immune response aims to get rid of the infectious agent, the pro-inflammatory host response can result in organ injury including acute respiratory distress syndrome. On its side, a compensatory anti-inflammatory response, aimed to dampen the inflammatory reaction, can lead to immunosuppression. Whether these two key events of the host inflammatory response are consecutive or concomitant has been regularly depicted in schemes. Initially proposed from 2001 to 2013 to be two consecutive steps, the concomitant occurrence has been supported since 2013, although it was proposed for the first time in 2001. Despite a consensus was reached, the two consecutive steps were still recently proposed for COVID-19. We discuss why the concomitance view could have been initiated as early as 1995.

CD3D and CD247 are the molecular targets of septic shock

Septic shock is a serious systemic disease with circulatory failure and abnormal cell metabolism caused by sepsis. However, the relationship between CD3D and CD247 and septic shock remains unclear. The septic shock datasets GSE33118 and GSE142255 profiles were generated from the gene expression omnibus databases GPl570, GPl17586. Differentially expressed genes (DEGs) were screened and weighted gene co-expression network analysis was performed. The construction and analysis of protein-protein interaction (PPI) network, functional enrichment analysis, gene set enrichment analysis (GSEA) were performed. Gene expression heat map was drawn. Immune infiltration analysis was performed. Comparative toxicogenomics database (CTD) analysis were performed to find the disease most related to the core gene. Targets can was used to screen miRNAs regulating the hub DEGs. 467 DEGs were identified. According to the gene ontology analysis, they were mainly enriched in the regulation of immune response, cell activation, signaling receptor activity, enzyme binding. Kyoto encyclopedia of genes and genomes analysis showed that they were mainly enriched in the TCR signaling pathway, Fc epsilon RI signaling pathway. GSEA showed that the DEGs were mainly enriched in immune response regulation, cell activation, TCR signaling pathway, Fc epsilon RI signaling pathway. Positive regulation of Fc receptor signaling pathway, PID IL12 2 pathway, immune response was observed in go enrichment items in the enrichment items of metascape. PPI networks got 5 core genes. Gene expression heat map showed that 5 core genes (CD247, Lck, cd3e, cd3d, ITK) were lowly expressed in the sepsis shock samples and highly expressed in the normal samples. CTD analysis showed that 5 core genes (CD247, Lck, cd3e, cd3d, ITK) were found to be associated with hemorrhage and necrosis. Low expression of cd3d, CD247 was observed in septic shock, and the lower the level of cd3d, CD247, the worse the prognosis.

Complement C5 inhibition protects against hemolytic anemia and acute kidney injury in anthrax peptidoglycan-induced sepsis in baboons

Late-stage anthrax infections are characterized by dysregulated immune responses and hematogenous spread of Bacillus anthracis, leading to extreme bacteremia, sepsis, multiple organ failure, and, ultimately, death. Despite the bacterium being nonhemolytic, some fulminant anthrax patients develop a secondary atypical hemolytic uremic syndrome (aHUS) through unknown mechanisms. We recapitulated the pathology in baboons challenged with cell wall peptidoglycan (PGN), a polymeric, pathogen-associated molecular pattern responsible for the hemostatic dysregulation in anthrax sepsis. Similar to aHUS anthrax patients, PGN induces an initial hematocrit elevation followed by progressive hemolytic anemia and associated renal failure. Etiologically, PGN induces erythrolysis through direct excessive activation of all three complement pathways. Blunting terminal complement activation with a C5 neutralizing peptide prevented the progressive deposition of membrane attack complexes on red blood cells (RBC) and subsequent intravascular hemolysis, heme cytotoxicity, and acute kidney injury. Importantly, C5 neutralization did not prevent immune recognition of PGN and shifted the systemic inflammatory responses, consistent with improved survival in sepsis. Whereas PGN-induced hemostatic dysregulation was unchanged, C5 inhibition augmented fibrinolysis and improved the thromboischemic resolution. Overall, our study identifies PGN-driven complement activation as the pathologic mechanism underlying hemolytic anemia in anthrax and likely other gram-positive infections in which PGN is abundantly represented. Neutralization of terminal complement reactions reduces the hemolytic uremic pathology induced by PGN and could alleviate heme cytotoxicity and its associated kidney failure in gram-positive infections.

β-Sitosterol Alters the Inflammatory Response in CLP Rat Model of Sepsis by Modulation of NFκB Signaling

Purpose

Sepsis originates from the host inflammatory response, especially to bacterial infections, and is considered one of the main causes of death in intensive care units. Various agents have been developed to inhibit mediators of the inflammatory response; one prospective agent is β-sitosterol (βS), a phytosterol with a structure similar to cholesterol. This study is aimed at evaluating the effects of βS on the biomarkers of inflammation and liver function in cecal ligation and puncture- (CLP-) induced septic rats.

Methods

Thirty male Wistar rats were divided equally into six groups as follows: sham, CLP, CLP+dexamethasone (DX, 0.2 mg/kg), CLP+βS (1 mg/kg), CLP+imipenem (IMI, 20 mg/kg), and CLP+IMI (20 mg/kg)+βS (1 mg/kg). Serum levels of IL-1β, IL-6, IL-10, AST, ALT, and liver glutathione (GSH) were assessed by ELISA. Liver expression levels of TNF-α and NF-κBi mRNAs were evaluated by RT-qPCR.

Results

Serum concentrations of IL-1β, IL-6, IL-10, ALT, and AST and mRNA levels of TNF-α and NF-κBi were all significantly higher in septic rats than in normal rats (p < 0.05). Liver GSH content was markedly lower in the CLP group than that in the sham group. βS-treated rats had remarkably lower levels of IL-1β, IL-6, IL-10, TNF-α, NF-κBi, AST, and ALT (51.79%, 62.63%, 41.46%, 54.35%, 94.37%, 95.30%, 34.87%, and 46.53% lower, respectively) and greater liver GSH content (35.71% greater) compared to the CLP group (p < 0.05).

Conclusion

βS may play a protective role in the septic process by mitigating inflammation. This effect is at least partly mediated by inhibition of the NF-κB signaling pathway. Thus, βS can be considered as a supplementary treatment in septic patients.

Immunosuppression is Inappropriately Qualifying the Immune Status of Septic and SIRS Patients

Immunosuppression is the most commonly used concept to qualify the immune status of patients with either sterile systemic inflammatory response syndrome (SIRS) or sepsis. In this review we attempt to demonstrate that the concept of immunosuppression is an oversimplification of the complex anti-inflammatory response that occurs in patients dealing with a severe sterile or infectious insult. Particularly, the immune status of leukocytes varies greatly depending on the compartment from where they are derived from. Furthermore, although certain functions of immune cells present in the blood stream or in the hematopoietic organs can be significantly diminished, other functions are either unchanged or even enhanced. This juxtaposition illustrates that there is no global defect. The mechanisms called reprogramming or trained innate immunity are probably aimed at preventing a generalized deleterious inflammatory reaction, and work to maintain the defense mechanisms at their due levels.

Interleukin-10, Interferon Gamma, Interleukin-2, and Soluble Interleukin-2 Receptor Alpha Detected during Peritonitis in the Dialysate and Serum of Patients on Continuous Ambulatory Peritoneal Dialysis

Objective

To analyze interleukin (IL)-10, interferon gamma (IFN-y), IL-2, and soluble IL-2 receptor alpha (sIL2Rα) in the dialysate and serum of patients on continuous ambulatory peritoneal dialysis (CAPD).

Design and Patients

Samples from dialysate bags were collected during the initial month of dialysis. During peritonitis, samples were collected from the first three bags on the day of admittance to the hospital and from the night bags on days 3 and 10. Serum samples were drawn on days 1 and 10. .Results: IL-10 was detected in all dialysate samples except one on the first day of infection, with a peak median level of 50 pg/mL and a slow decrease thereafter. In serum the median levels never exceeded detectable levels. Patients infected with Escherichia coli or Staphylococcus aureus had higher IL-10 levels in dialysate on day 3 as compared to the remaining patients (p < 0.05). If the catheter had to be drawn, because of persistent cloudy dialysate, the IL-10 levels remained elevated for a longer time (p<0.05). IFN-y and IL-2were detected only in the dialysate of patients infected with either S. aureusor S. epidermidis. Only one serum sample showed increased IFN-y. SIL-2Rα was found in all the serum and dialysis samples from the first day of infection. Contrary to the analyzed cytokines, the receptor showed several fold higher levels in serum as compared to the dialysate. During the infection the receptor levels in the dialysate increased, while they remained stationary in the serum, indicating a local production.

Conclusion

This is the first time IL-10 has been demonstrated in the dialysate during peritonitis in CAPD patients. In view of its role as a suppressor of the immune and inflammatory responses, it is a potentially important observation, which might have clinical implications in the future.

Interleukin 1 receptor antagonist (IL1RA) gene polymorphism and levels associated with adverse outcome in severe community-acquired pneumonia in children: A hospital-based study in India

BACKGROUND

High morbidity and mortality due to community-acquired pneumonia (CAP) is seen in children under 5 years of age in India. Besides identified risk factors for CAP, there may be a phenotype-genotype association with cytokines, resulting in enhanced inflammatory response resulting in the adverse outcome (AO), namely complications and death.

AIM

To assess the association of IL1RA gene polymorphism on serum levels of IL1RA and with AO in children under 5 years of age hospitalized with WHO-defined severe CAP.

METHOD

A prospective cohort study with nested case-control design conducted in a tertiary care teaching hospital after obtaining institutional ethical approval. Included were children between 2 and 59 months of age hospitalized with WHO-defined severe CAP with consistent radiological abnormalities. Excluded were those with suspected or proven cystic fibrosis, pulmonary tuberculosis, malignancy, immunodeficiency, and congenital heart disease. Polymerase chain reaction (PCR) was used to analyze the Variable Number of Tandem Repeats (VNTRs) of IL1RA gene polymorphism and ELISA test to detect serum levels of IL1RA.

RESULTS

From 2014 to 2016, of 420 screened cases, 350 were eligible and included, of which 132 (37.7%) had no complication and 218 (62.3%) had AO, which included complications like empyema, pyopneumothorax, acute respiratory distress syndrome (ARDS), and septic shock of these 24 (6.9%) expired. Higher risk of AO was seen in A2A2 genotype (OR 11.18, p 0.0001) and lower in A1A1 genotype (OR 0.18, P < 0.0001). Serum IL1RA (ng/mL) was statistically significantly elevated in CAP with AO (2.55 ± 1.44) versus uncomplicated (0.87 ± 0.52) (P < 0.0001).

CONCLUSION

In IL1RA gene, A1A1 genotype was associated with lower risk and A2A2 genotype with increased the risk of AO. Higher serum levels of IL1RA were found in A2A2 genotype indicating possibly enhanced inflammatory response resulting in AO of CAP.

Host response biomarkers in the diagnosis of sepsis: a general overview

Critically ill patients who display a systemic inflammatory response syndrome (SIRS) are prone to develop nosocomial infections. The challenge remains to distinguish as early as possible among SIRS patients those who are developing sepsis. Following a sterile insult, damage-associated molecular patterns (DAMPs) released by damaged tissues and necrotic cells initiate an inflammatory response close to that observed during sepsis. During sepsis, pathogen-associated molecular patterns (PAMPs) trigger the release of host mediators involved in innate immunity and inflammation through identical receptors as DAMPs. In both clinical settings, a compensatory anti-inflammatory response syndrome (CARS) is concomitantly initiated. The exacerbated production of pro- or anti-inflammatory mediators allows their detection in biological fluids and particularly within the bloodstream. Some of these mediators can be used as biomarkers to decipher among the patients those who developed sepsis, and eventually they can be used as prognosis markers. In addition to plasma biomarkers, the analysis of some surface markers on circulating leukocytes or the study of mRNA and miRNA can be helpful. While there is no magic marker, a combination of few biomarkers might offer a high accuracy for diagnosis.

Risk factor analysis for bone marrow histiocytic hyperplasia with hemophagocytosis: an autopsy study

The excessive release of inflammatory cytokines occasionally induces life-threatening hemophagocytosis referred to as hemophagocytic syndrome (HPS). A similar condition, histiocytic hyperplasia with hemophagocytosis (HHH), is often seen in bone marrow collected during autopsy. Unlike HPS, the pathogenesis of HHH remains unclear. Therefore, we performed a clinicopathological analysis of HHH from 70 autopsy cases at the University of Fukui Hospital. HHH was detected in 29 of 70 autopsies (41.4 %) and was significantly complicated with hematological diseases (p < 0.05) and sepsis (p < 0.05). The percentage of macrophages in bone marrow (BM) nucleated cells was significantly increased in HHH (p < 0.001). Data from medical records indicated no significant changes, except for the minimum values of white blood cell counts (p < 0.05) and platelet counts (p < 0.05) in HHH patients as compared with non-HHH patients. Concentrations of inflammatory mediators including IL-1β, IL-6, and IL-8 were significantly increased in HHH patients. Multivariate risk factor analysis identified hematological diseases (odds ratio (OR), 11.71), ≥15 % BM macrophages (OR, 9.42), sepsis (OR, 7.77), and high serum IL-6 levels (OR, 1.00) as independent risk factors for HHH. HHH with hypocellular BM, the most aggressive form of HHH, was recognized in 8 of 29 HHH patients and was associated with ≥25 % BM macrophages (p < 0.001), leukocytopenia (p < 0.05), and high IL-8 levels (p < 0.05). None of the HHH patients fulfilled the diagnostic criteria of HPS. These findings suggest that HHH is a different entity from HPS and that it preferentially develops under conditions of excessive inflammation and its associated risks, such as hematological diseases and sepsis.

-592 and -1082 interleukin-10 polymorphisms in pulmonary tuberculosis with type 2 diabetes

OBJECTIVE

To determine the polymorphisms of Interleukin-10 (IL-10) (-592, -1082) in pulmonary tuberculosis (PTB) with and without type 2 diabetes (T2D).

METHODS

We studied a Mexican mestizo population of 37 patients with TB in remission (TBr) and 40 with active pulmonary TB (PTB), 21 patients with TB + T2D, 47 blood donors accepted, and 13 healthy health-care workers with tuberculin skin test positive. Determination of IL-10 polymorphisms was performed by real-time Polymerase chain reaction.

RESULTS

IL-10-592C/A presented in a greater proportion in healthy individuals than in patients with type 2 diabetes and TB in a not quite significant statistically manner. IL-10-1082A/A presented more frequently in the group of patients with both diseases, not being statistically significant in comparison with the group of healthy subjects.

CONCLUSIONS

This study describes two important new findings. First, it reveals that the IL-10 (-592 A/A and -592 C/C) polymorphisms were found in a greater proportion in a group of patients with T2D and TB than in healthy subjects. Second, the study provides evidence that the (-1082 G/G) polymorphism presented with greater frequency in healthy individuals than in patients with both of these diseases.

Regulation of interleukin-10 gene expression in macrophages engulfing apoptotic cells

Apoptosis and the rapid clearance of apoptotic cells (ACs) by professional or nonprofessional phagocytes are normal and coordinated processes that ensure controlled cell growth and stress response with nonpathological outcomes. Uptake of ACs by phagocytes is thought to suppress autoimmune responses through the release of anti-inflammatory cytokines such as interleukin-10 (IL-10), transforming growth factor-beta (TGF-beta), and inhibition of proinflammatory cytokines. The production of pro- and anti-inflammatory cytokines by phagocytes is highly regulated as part of an intrinsic mechanism to prevent inflammatory and autoimmune reactions in a physiological state. Production of IL-10 by phagocytes during clearance of ACs is critical to ensuring cellular homeostasis and suppression of autoimmunity. The molecular mechanism whereby IL-10 production is induced by ACs is only beginning to be understood. This review summarizes our recent work in this aspect of an essential physiological and homeostatic process.

The value of neopterin and procalcitonin in patients with sepsis

OBJECTIVE

Neopterin (NT) is a compound of low molecule-based pteridine. It is secreted by macrophages as a response to the stimulation of cytokines such as interferon-gamma, interferon-1beta, tumor necrosis factor alpha or bacteria compounds such as lipopolysaccharides. Procalcitonin (PCT) levels may increase in the course of bacterial, parasitic, and fungal infections. Therefore, it can be used for the differential diagnosis of the infection, especially in cases of serious inflammation. In this study, the role of NT, and PCT in sepsis as a prognostic factor, and the relationship between the two parameters are examined.

METHODS

From November 1, 2005 through December 31, 2005, fifty patients with sepsis admitted to the Department of the Infectious Diseases and Clinical Microbiology and/or Department of Anaesthesiology and Reanimation were enrolled in the study. Patients were divided in two subgroups according to their survival: group I (n=23) nonsurviving patients and group II (n=27) surviving patients.

RESULTS

Serum NT levels have been found to be increased in group I (median: 15 ng/mL, range: 2-69) when compared to group II (median: 5 ng/mL, range: 2-130). The difference was statistically significant (P=0.03). Other laboratory parameters and PCT levels (group I median: 0.13; group II median: 0.08; P<0.05) were not different between the two groups.

CONCLUSIONS

NT was found to be a prognostic factor in patients with sepsis.

The septic shock-associated IL-10 -1082 A > G polymorphism mediates allele-specific transcription via poly(ADP-Ribose) polymerase 1 in macrophages engulfing apoptotic cells

The biallelic IL-10 single nucleotide polymorphism at -1082 of the promoter region linked to individual variation in cytokine inducibility has been strongly implicated in several pathological conditions including the development of, and outcomes in, septic shock during pneumococcal infection, acute respiratory distress syndrome, and cardiac dysfunction. However, the molecular basis of the single nucleotide polymorphism-mediated variable IL-10 production levels has not been explored. In this study, we report that the -1082G > A alleles in the promoter region of the human IL-10 gene physically interact with a nuclear protein in an allele-specific manner that results in different levels of IL-10 transcription. This protein has been identified as poly(ADP-ribose) polymerase 1 (PARP-1). We show that PARP-1 acts as a transcription repressor, and its DNA-binding activity is strongly regulated in macrophages that engulf apoptotic cells but not stimulated with LPS. These findings unveil a novel role of PARP-1 in the regulation of IL-10 production in an allele-dependent way, which determines individual susceptibility to sepsis-induced inflammatory pathology and the immunological sequelae in a physiological process in which clearance of infection-induced apoptotic cells by professional phagocytes triggers the cytokine synthesis.

IL-10 helps control pathogen load during high-level bacteremia

During relapsing fever borreliosis, a high pathogen load in the blood occurs at times of peak bacteremia. Specific IgM Abs are responsible for spirochetal clearance so in absence of B cells there is persistent high-level bacteremia. Previously, we showed that B cell-deficient mice persistently infected with Borrelia turicatae produce high levels of IL-10 and that exogenous IL-10 reduces bacteremia. This suggested that IL-10 helps reduce bacteremia at times of high pathogen load by a B cell-independent mechanism, most likely involving innate immunity. To investigate this possibility, we compared B. turicatae infection in RAG2/IL-10(-/-) and RAG2(-/-) mice. The results showed that IL-10 deficiency resulted in significantly higher bacteremia, higher TNF levels, and early mortality. Examination of the spleen and peripheral blood showed markedly increased apoptosis of immune cells in infected RAG2/IL-10(-/-) mice. Neutralization of TNF reduced apoptosis of leukocytes and splenocytes, increased production of IFN-gamma by NK cells, increased phagocytosis in the spleen, decreased spirochetemia, and rescued mice from early death. Our results indicate that at times of high pathogen load, as during peak bacteremia in relapsing fever borreliosis, IL-10 protects innate immune cells from apoptosis via inhibition of TNF resulting in improved pathogen control.

Lipopolysaccharide-induced liver apoptosis is increased in interleukin-10 knockout mice

Although IL-10 down-regulates pro-inflammatory cytokine secretion by hepatic Kupffer cells, the mechanisms underlying its hepatoprotective effects are not fully clear. This study tested the hypothesis that IL-10 protects the liver against pro-inflammatory cytokines by counteracting their pro-apoptotic effects. Wild type and IL-10 knockout mice were treated with bacterial lipopolysaccharide and sacrificed 1, 4, 8, and 12 h later. Plasma ALT activity was measured as a marker of liver injury. Liver pathology and TUNEL response were assessed by histology. Plasma levels and whole liver mRNA levels were measured for TNF-alpha, IL-1 beta, TGF-beta1, IL-10, and their respective receptors. Hepatic mRNA levels were measured for several pro-apoptotic adaptors/regulators, including FasL, Fas receptor, FADD, TRADD, Bad, Bak, Bax, and Bcl-X(S), and anti-apoptotic regulators, including Bcl-w, Bcl-X(L), Bcl-2, and Bfl-1. Caspase-3 activity in the liver was determined as well as immunohistochemistry for IL-1RII, TGF-betaRII and Fas receptor. At all time points the livers from IL-10 knockout mice displayed a significantly increased number of apoptotic nuclei compared to wild type mice. Changes in plasma cytokine levels and their liver mRNA levels were consistent with suppression by IL-10 of pro-inflammatory cytokine secretion. In addition, pro-inflammatory cytokine receptor mRNA levels (TNF-alpha, TGF-beta, and IL-1 beta) were markedly up-regulated by LPS at all time points in IL-10 knockout mice as compared to wild type mice. Expression of the pro-inflammatory cytokine receptor IL-1RII was similarly increased as shown by immunostaining. The mRNA levels of a typical pro-apoptotic cytokine, TRAIL, were increased and LPS also up-regulated the mRNA expression of other apoptotic factors to a larger extent in IL-10 knockout mice than in their wild type counterparts, suggestive of an IL-10 anti-apoptotic effect. In the livers of knockout mice, markedly increased caspase-3 activity was already evident at the 1-h time point following LPS administration, while in the wild type animals this increase was delayed. Immunostaining also indicated that LPS increased hepatic expression of the pro-apoptotic receptors Fas and TGF-betaRII in IL-10 knockout mice. The data presented in this study show that: (i) IL-10 modulates not only the secretion of pro-inflammatory cytokines, but also the receptors of these cytokines, and ii) IL-10 protects the liver against LPS-induced injury at least in part by counteracting pro-inflammatory cytokine-induced liver apoptosis.

Interleukin-10-1082 promoter polymorphism in association with cytokine production and sepsis susceptibility

OBJECTIVE

To investigate the -1082 (A/G) polymorphism in the promoter of the IL-10 gene in terms of IL-10 production from stimulated peripheral blood mononuclear cells (PBMC) and to evaluate the relationship of this polymorphism with susceptibility to severe sepsis and the outcome of the disease.

DESIGN

Case-control study.

SETTING

Research laboratory of Molecular Biology and Immunology and University Hospital ICU, Faculty of Medicine, Trakia University.

PATIENTS

A total of 53 healthy volunteers and 33 patients in ICU meeting the criteria for severe sepsis were included.

MEASUREMENTS AND RESULTS

The amplification refractory mutation system PCR was used for IL-10-1082 polymorphism detection. Isolated PBMC were stimulated with either C3-binding glycoprotein (C3bgp), lipopolysaccharide (LPS), phytohemagglutinin (PHA),or pokeweed mitogen (PWM). IL-10 production was measured in culture supernatants. The AA genotype was associated with lower IL-10 production in LPS-, PHA- or PWM-stimulated healthy PBMC. Patients with severe sepsis had significant elevation of A allele, compared with healthy controls (74.2% vs 52.8%; p=0.0062). Carriage of at least one copy of IL-10-1082 G allele in sepsis patients and in healthy controls resulted in a statistically significant increase in IL-10 production from stimulated PBMC. Surviving sepsis patients had a significant decrease of IL-10-1082 allele G frequency, compared with controls (17% vs 47.2%; p=0.012). An association between increased IL-10 production and poor outcome from sepsis was observed.

CONCLUSION

The A allele of the -1082 polymorphism in the interleukin-10 gene promoter is associated with sepsis susceptibility, whereas G allele is associated with higher stimulated interleukin-10 production and increased mortality in severe sepsis.

Influence of Toll-Like Receptor 4, CD14, Tumor Necrosis Factor, and Interleukine-10 Gene Polymorphisms on Clinical Outcome in Japanese Critically Ill Patients

The innate recognition of microbial components and subsequent activation of cytokine network are important in the pathophysiology of sepsis. Recently, functional gene polymorphisms in molecules associated with these responses were demonstrated. On the other hand, it has been claimed that there are ethnic differences in genetic polymorphisms. This study investigated toll-like receptor (TLR) 4, CD14, tumor necrosis factor (TNF)-alpha and -beta, and interleukin (IL)-10 gene polymorphisms in 197 Japanese critically ill patients and 214 healthy control subjects to evaluate the influence of these polymorphisms on clinical outcome. No Japanese participant carrying TLR4Asp299Gly or Thr399Ile was detected. No association of CD14-159C/T polymorphisms with genotype frequency or sepsis mortality was observed. Frequency of TNF-alpha-308 GA genotype was significantly higher in the sepsis group than in the control group and TNF-alpha-308GA and IL-10-592CC genotypes were related to poor outcome of sepsis. Ethnic differences in genetic variations are very important issues and the frequencies in this study differ from those previously reported in Caucasians. In conclusion, this study may indicate that TNF-alpha-308G/A and IL-10-592C/A polymorphisms involved in subsequent activation of cytokine network had a larger effect on clinical outcome in patients with sepsis than TLR4Asp299Gly, Thr399Ile, and CD14-159C/T polymorphisms associated with the initial host-microbial interaction.

Missing effects of zinc in a porcine model of recurrent endotoxemia

Background

Chronic human sepsis often is characterised by the compensatory anti-inflammatory response syndrome (CARS). During CARS, anti-inflammatory cytokines depress the inflammatory response leading to secondary and opportunistic infections. Proved in vitro as well as in vivo, zinc's pro-inflammatory effect might overcome this depression.

Methods

We used the model of porcine LPS-induced endotoxemia established by Klosterhalfen et al. 10 pigs were divided into two groups (n = 5). Endotoxemia was induced by recurrent intravenous LPS-application (1.0 μg/kg E. coli WO 111:B4) at hours 0, 5, and 12. At hour 10, each group received an intravenous treatment (group I = saline, group II = 5.0 mg/kg elementary zinc). Monitoring included hemodynamics, blood gas analysis, and the thermal dilution technique for the measurement of extravascular lung water and intrapulmonary shunt. Plasma concentrations of IL-6 and TNF-alpha were measured by ELISA. Morphology included weight of the lungs, width of the alveolar septae, and rate of paracentral liver necrosis.

Results

Zinc's application only trended to partly improve the pulmonary function. Compared to saline, significant differences were very rare. IL-6 and TNF-alpha were predominately measured higher in the zinc group. Again, significance was only reached sporadically. Hemodynamics and morphology revealed no significant differences at all.

Conclusion

The application of zinc in this model of recurrent endotoxemia is feasible and without harmful effects. However, a protection or restoration of clinical relevance is not evident in our setting. The pulmonary function just trends to improve, cytokine liberation is only partly activated, hemodynamics and morphology were not influenced. Further pre-clinical studies have to define zinc's role as a therapeutic tool during CARS.

Plasma hepatocyte growth factor is increased in early-phase sepsis

To elucidate the involvement of hepatocyte growth factor (HGF) in systemic inflammatory response syndrome (SIRS) and sepsis, we investigated the plasma levels of HGF, as well as those of various proinflammatory and anti-inflammatory cytokines, in 50 patients who visited our emergency department (ED). The patients were divided into four groups, depending on the existence of SIRS and infection: group 1 (G1), no infection and no SIRS; group 2 (G2), infection and no SIRS; group 3 (G3), no infection and SIRS; and group 4 (G4), infection and SIRS (e.g., sepsis). We found that plasma HGF levels in G4 were significantly higher than those in the groups without infection (G1 and G3). However, the correlations between HGF and other cytokines were comparatively low compared with those between any other pairs of cytokines, suggesting independent regulation of HGF production in vivo. High plasma HGF was significantly correlated with the presence of infection and with serum total bilirubin (TB) level on multivariate logistic regression analysis. Considering HGF's known functions, we speculated that high plasma HGF levels may indicate the occurrence or necessity for tissue protection and regeneration after acute systemic insults in sepsis.

Alleles carried at positions -819 and -592 of the IL10 promoter affect transcription following stimulation of peripheral blood cells with Streptococcus pneumoniae

IL-10 inhibits the production of many pro-inflammatory cytokines. Polymorphisms in the IL10 gene promoter at positions -1082G-->A, -819C-->T and -592C-->A occur as three haplotypes, ATA, GCC and ACC. These influence several infectious and inflammatory diseases including community-acquired pneumonia, where a role for IL-10 is suggested by fluctuations in plasma levels of the cytokine. However, the effects of the haplotypes on IL-10 production are unclear. We stimulated peripheral blood mononuclear cells (PBMC) from at least five individuals homozygous for each of the three haplotypes with lipopolysaccharide (LPS, 10 microg/ml) or heat-killed Streptococcus pneumoniae (10(7)cfu/ml) and measured IL-10 mRNA by RT-PCR. Following S. pneumoniae stimulation, PBMC with the ATA haplotype had higher IL-10 mRNA levels than those with the GCC haplotype at 4 h (independent t-test; P=0.024), or the ACC haplotype at 4 h ( P<0.0001) and 8 h ( P=0.007). Following LPS stimulation, IL-10 mRNA levels were not significantly influenced by the IL10 haplotype, but similar trends were observed, consistent with the variable outcome of published studies. The results suggest that the -819 and/or -592 alleles affect transcription.

Pneumococcal septic shock is associated with the interleukin-10-1082 gene promoter polymorphism

Polymorphisms in the tumor necrosis factor and interleukin-10 genes, linked to cytokine inducibility, may influence the inflammatory response to infection. We studied the biallelic interleukin-10-1082 promoter, the tumor necrosis factor-alpha-308 promoter, and the lymphotoxin-alpha polymorphisms with regard to the development of septic shock in pneumococcal infection. Sixty-nine patients with pneumococcal disease (61 patients with community-acquired pneumonia, 5 patients with meningitis, and 3 patients with pneumonia and meningitis) and 50 age-matched control subjects were included. The polymorphisms were determined by the polymerase chain reaction. In patients with pneumococcal disease, the lipopolysaccharide-stimulated tumor necrosis factor and interleukin-10 release from whole blood were measured by ELISA. Sepsis severity was documented according to standard criteria. No significant genotypic differences were seen between patients and control subjects. Thirteen of 69 patients with pneumococcal disease developed septic shock. Interleukin-10 allele G homozygous patients had the highest risk for septic shock (odds ratio of 6.1; 95% confidence interval, 1.4-27.2; corrected p = 0.024). The stimulated interleukin-10 release was highest in interleukin-10 G homozygous patients (p = 0.04). In conclusion, interleukin-10 polymorphism, associated with high interleukin-10 inducibility, might influence the outcome of pneumococcal infection via induced immunosuppression and impaired bacterial clearance.

Proinflammatory and anti-inflammatory cytokine responses in preterm infants with systemic infections

OBJECTIVE

A prospective study to investigate the pattern of proinflammatory and anti-inflammatory cytokine responses in preterm infants with systemic infection.

METHODS

Very low birthweight infants in whom infection was suspected when they were > 72 hours of age were eligible. A full sepsis screen was performed in each episode. Key cytokines of both proinflammatory and anti-inflammatory pathways, including interleukin (IL) 2, IL4, IL5, IL6, IL10, interferon (IFN) gamma, and tumour necrosis factor (TNF) alpha, were measured at 0 (at the time of sepsis evaluation), 24, and 48 hours by flow cytometric analysis or immunoassay.

RESULTS

Thirty seven of the 127 episodes of suspected clinical sepsis were proven infection or necrotising enterocolitis. Both proinflammatory (IL2, IL6, IFNgamma, TNFalpha) and anti-inflammatory (IL4, IL10) cytokines were significantly increased in infected infants compared with non-infected infants. Significant correlations were observed between IL6 and TNFalpha or IL10 as well as IL10 and IFNgamma in infected infants. In the subgroup analysis, plasma IL6, IL10, and TNFalpha concentrations, and IL10/TNFalpha and IL6/IL10 ratios were significantly elevated in patients with disseminated intravascular coagulation compared with infected infants without. The IL10/TNFalpha ratios had decreased significantly 48 hours after the onset, whereas the IL6/IL10 ratio showed only a non-significant decreasing trend. Further, the IL6/IL10 ratio in the deceased infant was disproportionally increased at presentation and continued to increase despite treatment.

CONCLUSION

The results indicate that the counter-regulatory mechanism between the proinflammatory and anti-inflammatory cytokine pathways is probably operational in preterm infants of early gestation. High plasma IL6, IL10, and TNFalpha concentrations, and IL10/TNFalpha and IL6/IL10 ratios signify severe infection, but transiently elevated plasma IL10 concentration or IL10/TNFalpha ratio does not necessarily indicate a poor prognosis.

TRALI: correlation of antigen-antibody and monocyte activation in donor-recipient pairs

BACKGROUND

TRALI may be a severe reaction associated with transfusion of plasma-containing blood components. TRALI has usually been associated with antibodies against granulocytes and HLA class I antigens, but more recently with antibodies against HLA class II and monocytes. TRALI cases were investigated to determine correlation between antigen and antibody. Additionally, activation of monocytes by TRALI serums was studied.

STUDY DESIGN AND METHODS

Sixteen cases of TRALI were investigated. All patients were typed for HLA antigens. Implicated donors were screened for HLA antigens and antibodies against granulocytes and monocytes. In 6 cases, recipient monocyte activation was measured in vitro after incubation with TRALI and control serums. In four cases, monocyte activation was measured after incubation of TRALI serums against a panel of monocytes of known HLA antigen type.

RESULTS

In 14 of the 16 cases (87.5%), antigen-antibody correlation was identified. TRALI monocytes, incubated with implicated TRALI serum (n = 6), expressed significantly greater cytokine and tissue factor (p < 0.05, repeated-measures ANOVA) than controls. Panel monocytes incubated with TRALI serum showed increased expression of cytokine and/or tissue factor when corresponding antigen was present.

CONCLUSION

In most cases of TRALI, a correlation between antigen and antibody can be identified. Activation of monocytes and their subsequent release of cytokines may play a role in the pathogenesis of TRALI.

Influence of interleukin-10 polymorphisms on interleukin-10 expression and survival in critically ill patients

OBJECTIVE

To determine the functionality of identified polymorphisms in the promoter and upstream regions of the interleukin-10 gene in terms of release of interleukin-10 from lipopolysaccharide-stimulated whole blood from healthy volunteers and to evaluate the relationship of interleukin-10 polymorphisms to interleukin-10 release, development of sepsis, and mortality in critically ill patients.

DESIGN

Observational study.

SETTING

The academic unit of anesthesia and intensive care, university laboratories, and ten-bed general intensive care unit in a university teaching hospital.

SUBJECTS

A total of 132 healthy volunteers plus 67 consecutive critically ill patients recruited within 24 hrs of admission to the intensive care unit, regardless of diagnosis.

MEASUREMENTS

Plasma interleukin-10 levels were measured by enzyme-linked immunosorbent assay. Single nucleotide polymorphisms were detected by restriction fragment length polymorphism analysis. Dinucleotide repeat polymorphisms were identified after polymerase chain reaction using a DNA size analyzer.

MAIN RESULTS

Stimulated interleukin-10 release in critically ill patients was significantly lower than in healthy subjects (p < .0001). In addition, in the patients who developed sepsis, interleukin-10 release at admission to the intensive care unit was significantly lower than in patients who did not subsequently develop sepsis (median [range] 1.47 [0.13-6.90] ng/mL compared with 4.93 [0.03-16.80] ng/mL, p = .001). The A allele of the single nucleotide polymorphism at -592 base pairs was associated with lower interleukin-10 release and higher mortality in critically ill patients. Other polymorphisms were not linked to interleukin-10 release, sepsis, or mortality.

CONCLUSIONS

The A allele of the -592 base pair single nucleotide polymorphism in the interleukin-10 gene is associated with lower stimulated interleukin-10 release and increased mortality. Further investigations are required to determine the nature of the functionality and the potential diagnostic and therapeutic aspects of this marker.

Interleukin-10: a complex role in the pathogenesis of sepsis syndromes and its potential as an anti-inflammatory drug

Interleukin (IL)-10 is a pleiotropic cytokine produced by both T cells and macrophages and possesses both anti-inflammatory and immunosuppressive properties. IL-10 circulates in the blood of patients with sepsis syndromes, and increased concentrations of IL-10 have been associated with an adverse clinical outcome. Experimental studies in rodents and primates have demonstrated that endogenously produced and exogenously administered IL-10 can reduce the magnitude of the inflammatory response and improve outcome, primarily in models of endotoxemic and bacteremic shock. However, endogenous IL-10 production and systemic administration can also exacerbate T-cell dysfunction, decrease T-cell apoptosis, reduce antimicrobial function, and increase mortality in other less acute bacterial models of sepsis or after thermal injury. Targeted delivery of IL-10 to individual tissues may obviate the adverse effects of systemic delivery. The potential anti-inflammatory properties of IL-10 will have to be carefully weighed against its immunosuppressive properties when considering its use in patients with acute inflammation and sepsis syndromes.

HLA class II antibodies in transfusion-related acute lung injury

BACKGROUND

Transfusion-related acute lung injury (TRALI) is a serious, sometimes fatal, complication of transfusion. Granulocyte and HLA class I antibodies present in blood donors have been associated with TRALI. HLA class II antibodies have recently been described in a few cases of TRALI.

STUDY DESIGN AND METHODS

Donors involved in TRALI reactions reported to a blood center over an 18-month period were tested for HLA class I and II antibodies as well as granulocyte antibodies, if HLA antibodies were not identified.

RESULTS

HLA class II antibodies were identified, in at least one donor, in 7 (64%) of 11 cases of TRALI. HLA class I antibodies were identified in combination with HLA class II antibodies in 5 of these 7 cases. HLA class I antibodies were exclusively identified in 2 cases. Granulocyte antibodies were identified in 1 case, and no antibodies were identified in another.

CONCLUSION

In addition to HLA class I antibodies, HLA class II antibodies are associated with TRALI. Testing of donors for HLA class II antibodies as well as HLA class I and granulocyte antibodies is recommended as part of the investigation of suspected cases of TRALI.

Interleukin-10 and the interleukin-10 receptor

Interleukin-10 (IL-10), first recognized for its ability to inhibit activation and effector function of T cells, monocytes, and macrophages, is a multifunctional cytokine with diverse effects on most hemopoietic cell types. The principal routine function of IL-10 appears to be to limit and ultimately terminate inflammatory responses. In addition to these activities, IL-10 regulates growth and/or differentiation of B cells, NK cells, cytotoxic and helper T cells, mast cells, granulocytes, dendritic cells, keratinocytes, and endothelial cells. IL-10 plays a key role in differentiation and function of a newly appreciated type of T cell, the T regulatory cell, which may figure prominently in control of immune responses and tolerance in vivo. Uniquely among hemopoietic cytokines, IL-10 has closely related homologs in several virus genomes, which testify to its crucial role in regulating immune and inflammatory responses. This review highlights findings that have advanced our understanding of IL-10 and its receptor, as well as its in vivo function in health and disease.

Inhibition of IgE-induced activation of human mast cells by IL-10

BACKGROUND

IL-10 exhibits anti-inflammatory effects on activated rodent mast cells (MC) in vitro and inhibits allergen-induced airway inflammation in vivo in murine models. The effects of IL-10 on the allergic activation of human MC are presently unknown.

OBJECTIVE

In light of the well-known heterogeneity of mast cell reactivity between animal species, one cannot readily predict the response of human MC to IL-10. Moreover, the impact of IL-10 on MC-derived proinflammatory mediators is still unknown. Thus, the objective of this study was to investigate the effects of IL-10 on the release of inflammatory mediators by IgE/anti-IgE-challenged human cord blood-derived mast cells (CBMC), used as an in vitro model of MC phenotypically similar to human lung MC.

MATERIALS AND METHODS

Highly purified human MC were obtained by a first step of long-term culture of cord blood mononuclear cells in the presence of human recombinant stem cell factor (rhSCF) and of human recombinant IL-6 (rhIL-6), followed by a second step of purification by depletion of contaminating cells with an immunomagnetic

METHOD

The cells were treated with human IgE, then challenged with anti-human IgE, in the presence or the absence of recombinant rhIL-10 used at various concentrations. Histamine, tumour necrosis factor-alpha (TNF-alpha), IL-5 and IL-8 were measured in the various supernatants collected at different times after the beginning of the challenge.

RESULTS

IL-10 inhibited the release of TNF-alpha and of IL-8, but not of IL-5, by activated CBMC. Interestingly, IL-10 also inhibited the release of histamine by activated CBMC, contrasting with data reported for rodent MC.

CONCLUSIONS

These findings suggest that IL-10 might have anti-inflammatory effects on IgE/anti-IgE-challenged human MC by inhibiting their release of TNF-alpha, IL-8 and histamine. These data provide new insights into the control of human mast cell activation and might lead to a better knowledge of the cellular mechanisms controlling allergic reactions.

Endotoxin, endotoxin-neutralizing-capacity, sCD14, sICAM-1, and cytokines in patients with various degrees of alcoholic liver disease

BACKGROUND

Chronic alcohol ingestion leads to endotoxemia which is believed to play an important role in the pathogenesis of alcoholic liver disease (ALD). The purpose of this study was to determine if chronic ethanol consumption, in addition to affecting plasma endotoxin and cytokines, also affects the endotoxin-neutralizing capacity (ENC), sCD14, and sICAM-1, in patients with ALD. A second aim was to identify correlations between these latter parameters, endotoxin, and cytokines, especially IL-10.

METHODS

Hospitalized patients with various degrees of ALD (n = 59), and 20 healthy volunteers were studied. Plasma endotoxin and ENC were determined using our kinetic Limulus amebocyte lysate test. Cytokines, sCD14, and sICAM-1 were measured by enzyme-linked immunosorbent assay.

RESULTS

Patients with ALD exhibited a mild endotoxemia (p < 0.01) and a marked decrease in ENC (p < 0.0002). TNF-alpha (p < 0.05), IL-6 (p < 0.0001), sICAM (p < 0.005), and sCD14 (p < 0.0005) were significantly elevated in all patients with ALD, and IL-10 (p < 0.05) in patients with cirrhotic ALD. With the exception of IL-10, the cytokines correlated with each other and with sICAM-1. No correlations occurred between endotoxin, ENC, and sCD14, and between these and the cytokines and sICAM-1. Elevated levels of endotoxin correlate with acute excessive alcohol ingestion. No gender differences were observed.

CONCLUSIONS

Acute alcohol intoxication rather than severe ALD results in significant endotoxemia. The limited capacity of plasma to neutralize endotoxin in liver injury seems to be an important factor in ALD which may be responsible for the release of endotoxin-induced mediators, such as cytokines, as well as s-ICAM-1, that are relevant in the pathogenesis of ALD.

Interleukin-10 and the Interleukin-10 Receptor

Interleukin-10 (IL-10), first recognized for its ability to inhibit activation and effector function of T cells, monocytes, and macrophages, is a multifunctional cytokine with diverse effects on most hemopoietic cell types. The principal routine function of IL-10 appears to be to limit and ultimately terminate inflammatory responses. In addition to these activities, IL-10 regulates growth and/or differentiation of B cells, NK cells, cytotoxic and helper T cells, mast cells, granulocytes, dendritic cells, keratinocytes, and endothelial cells. IL-10 plays a key role in differentiation and function of a newly appreciated type of T cell, the T regulatory cell, which may figure prominently in control of immune responses and tolerance in vivo. Uniquely among hemopoietic cytokines, IL-10 has closely related homologs in several virus genomes, which testify to its crucial role in regulating immune and inflammatory responses. This review highlights findings that have advanced our understanding of IL-10 and its receptor, as well as its in vivo function in health and disease.

Immunologic response to infection and its role in septic shock

In summary, the invasion of bacteria across mucosal surfaces is met with a vigorous host response that includes complement, antibody formation (thymus-independent and eventually thymus-dependent), phagocytosis, production of antibacterial peptides and proteins, the production of cytokines that result in activation of phagocytes and endothelial cells to attract more phagocytes, and the formation of fibrin to limit the spread of infection. The best summary of immune response to infection was written by Lewis Thomas in 1974.

The ratio of interleukin-6 to interleukin-10 correlates with severity in patients with chest and abdominal trauma

To evaluate the relation between proinflammatory cytokines and antiinflammatory cytokines after major trauma, we measured pro-inflammatory cytokine (interleukin [IL]-6) and antiinflammatory cytokine (IL-10) concentrations after trauma, and evaluated the relationship between the ratio of IL-6 to IL-10 and injury severity. In 20 patients who sustained chest and abdominal trauma, IL-10, IL-6, and lactate concentrations were measured at 0, 1, 2, and 4 days. The Injury Severity Score (ISS), Acute Physiology and Chronic Health Evaluation (APACHE) II score, and the ratio of IL-6 to IL-10 were calculated. IL-6, IL-10, and lactate concentrations were 197.2+/-28.4 (mean +/- SEM), 71.1+/-10.1 pg/mL, and 46.7+/-9.4 mg/dL at entry. These concentrations were significantly decreased at day 4. The ratio of IL-6 to IL-10 was 3.11+/-0.47 at entry and was significantly correlated with ISS (r=.872, P<.01), APACHE II score (r=.887, P<.01). The IL-10, IL-6, and lactate concentrations were elevated immediately after major trauma, and the ratio of IL-6 to IL-10 was correlated with injury severity. This suggests that the ratio of IL-6 to IL-10 may be used to predict the injury severity after trauma.

Partial IL-10 Inhibition of the Cell-Mediated Immune Response in Chronic Beryllium Disease

Chronic beryllium disease (CBD) provides a human disorder in which to study the delayed type IV hypersensitivity response to persistent Ag that leads to noncaseating pulmonary granuloma formation. We hypothesized that, in CBD, failure of IL-10 to modulate the beryllium-specific, cell-mediated immune response would result in persistent, maximal cytokine production and T lymphocyte proliferation, thus contributing to the development of granulomatous lung disease. To test this hypothesis, we used bronchoalveolar lavage cells from control and CBD subjects to evaluate the beryllium salt-specific production of endogenous IL-10 and the effects of exogenous human rIL-10 (rhIL-10) on HLA expression, on the production of IL-2, IFN-γ, and TNF-α, and on T lymphocyte proliferation. Our data demonstrate that beryllium-stimulated bronchoalveolar lavage cells produce IL-10, and the neutralization of endogenous IL-10 does not increase significantly cytokine production, HLA expression, or T lymphocyte proliferation. Second, the addition of excess exogenous rhIL-10 partially inhibited the beryllium-stimulated production of IL-2, IFN-γ, and TNF-α; however, we measured no change in T lymphocyte proliferation or in the percentage of alveolar macrophages expressing HLA-DP. Interestingly, beryllium salts interfered with an IL-10-stimulated decrease in the percentage of alveolar macrophages expressing HLA-DR. We conclude that, in the CBD-derived, beryllium-stimulated cell-mediated immune response, low levels of endogenous IL-10 have no appreciable effect; exogenous rhIL-10 has a limited effect on cytokine production and no effect on T lymphocyte proliferation or HLA expression.

Microbiological and inflammatory effects of murine recombinant interleukin-10 in two models of polymicrobial peritonitis in rats

A protective effect of interleukin-10 (IL-10) against the development of lethal shock has been demonstrated in various animal models. In contrast, the immunosuppressant properties of this mediator have been minimally evaluated in low-mortality models of infections. The clinical, microbiological, and inflammatory effects of murine recombinant IL-10 (mrIL-10) therapy were evaluated in two models of peritonitis in rats, which differed in the degree of severity of peritoneal inflammation 3 days after inoculation of Escherichia coli and Bacteroides fragilis with or without Enterococcus faecalis. The severity of the disease remained unchanged compared to that in control animals. A dose-related decrease in the peritoneal phagocyte count was observed in the treated groups compared to the counts in control animals. The subsequent experiments were performed exclusively in the mixed gram-positive-gram negative model, which exhibits an intense and prolonged inflammatory response with similar criteria. The early effects of mrIL-10 (evaluated 6 h after inoculation), repeated injections of mrIL-10 (four doses injected from 0 to 9 h after bacterial challenge), and pretreatment (two doses injected 6 and 3 h before inoculation) were evaluated. The clinical and microbiological parameters remained unchanged in the treated animals. Decreases in the peritoneal phagocyte count and the peritoneal concentration of tumor necrosis factor were observed following repeated injections of mrIL-10. In summary, our data suggest that mrIL-10 does not worsen the manifestations of sepsis. However, these results need to be confirmed in clinical practice.

Circulating interleukin 6 and interleukin 10 in community acquired pneumonia

BACKGROUND

Inflammatory cytokine concentrations correlate with severity of sepsis. We hypothesised that patients with community acquired pneumonia (CAP) associated with systemic inflammatory response syndrome (SIRS) would have greater interleukin 6 (IL-6) production due to activation of the inflammatory cytokine cascade, matched by a significant anti-inflammatory cytokine response. Interleukin 10 (IL-10) was evaluated as a potential surrogate marker of severity of sepsis in CAP and age related impairment of the cytokine response was studied in elderly patients with CAP.

METHODS

Circulating immunoreactive IL-6 and IL-10 levels were measured in 38 patients with CAP subdivided into a group fulfilling the criteria for SIRS (n = 28) and a non-SIRS group (n = 10) in a variety of age groups and correlated with APACHE II scores.

RESULTS

80% had circulating IL-6 levels (median 46.7 pg/ml, range 4.6-27,000) and 60% had circulating IL-10 levels (median 15.5 pg/ml, range 2.5-765). Concentrations of both were significantly increased in patients with SIRS compared with non-SIRS patients. Those with activation of the inflammatory cytokine cascade (IL-6 positive) produced more IL-10 than IL-6 negative patients. Older patients had a similar cytokine response. Both cytokines correlated positively with APACHE II scores.

CONCLUSIONS

This is the first demonstration of circulating IL-10 in CAP. A greater counter-inflammatory response in patients with SIRS and in IL-6 positive patients suggests a potential immunomodulatory role for IL-10 in controlling the inflammatory cytokine response in CAP. IL-10 concentrations correlate with severity of illness in CAP and may be of prognostic importance. There is no age related impairment in the cytokine response.

Sequential changes in the metabolic response in severely septic patients during the first 23 days after the onset of peritonitis

OBJECTIVE

To quantify the sequential changes in metabolic response occurring in patients with severe sepsis after the onset of peritonitis.

SUMMARY BACKGROUND DATA

Understanding the changes in energy expenditure and body composition is essential for the optimal management of severely septic patients; however, they have not been quantified in the context of modern surgical care.

METHODS

Twelve patients with severe sepsis secondary to peritonitis (median APACHE II score = 21.5) had measurements of energy expenditure and body composition as soon as they were hemodynamically stable and 5, 10, and 21 days later. Sequential measurements of acute-phase proteins and cytokine responses were also made.

RESULTS

Resting energy expenditure rose to 49% above predicted and remained elevated throughout the study period. Total energy expenditure was 1.25 x resting energy expenditure. Body fat was oxidized when energy intake was insufficient to achieve energy balance. There was a positive fluid balance of 12.5 1 over the first 2 days after onset of sepsis; thereafter, body water changes closely paralleled body weight changes and were largely accounted for by changes in extracellular water. During the 21 -day study period, there was a loss of 1.21 kg (13%) of total body protein. During the first 10 days, 67% of the protein lost came from skeletal muscle, but after this time it was predominantly from viscera. Intracellular potassium levels were low but did not deteriorate further after hemodynamic stability had been reached. There was a reprioritization of hepatic protein synthesis that was obligatory and independent of changes in total body protein. The cytokine responses demonstrated the complexity, redundancy, and overlap of mediators.

CONCLUSIONS

The period of hypermetabolism in severely septic patients is similar to that previously described, but the fluid changes are larger and the protein loss is greater. Protein loss early on is predominantly from muscle, thereafter from viscera. Fat loss can be prevented and cell function preserved once hemodynamic stability is achieved.

The compensatory anti-inflammatory cytokine interleukin 10 response in pediatric sepsis-induced multiple organ failure

STUDY OBJECTIVES

To determine the circulating anti-inflammatory cytokine interleukin 10 (IL-10) response during the development of sepsis-induced multiple organ failure in children.

DESIGN

Prospective study.

SETTING

University pediatric ICU.

PATIENTS

Fifty-three consecutive children with sepsis and 15 critically ill children without sepsis.

INTERVENTIONS

Plasma IL-10, interleukin 6 (IL-6), and nitrite+nitrate (stable end products of nitric oxide) levels and an organ failure index (OFI indicating the number of failing organ systems) were determined in 53 children on days 1 to 3 of sepsis and in control children on day 1. The effect of exogenous human IL-10 or neutralizing IL-10 antibody on supernatant IL-6 levels in ex vivo whole blood culture from 17 children on day 1 of sepsis.

MEASUREMENTS AND RESULTS

Children with three or more organ failures had higher plasma IL-10 levels than children with less than 3 organ failures (days 1 and 3; p<0.05). Children who developed sequential pulmonary/hepatic/renal failure had higher IL-10 levels (days 1 to 3; p<0.05). Nonsurvivors had higher IL-10 levels (day 3; p<0.05). IL-10 levels correlated with IL-6 levels (days 1 and 2) and nitrite+nitrate levels (days 1 and 3; p<0.05). Whole blood samples incubated ex vivo with exogenous recombinant human IL-10 had decreased supernatant IL-6 levels (p<0.05) and neutralizing IL-10 antibody showed no significant effect.

CONCLUSION

A persistent compensatory anti-inflammatory cytokine response characterizes sepsis-induced multiple organ failure. Administration of exogenous IL-10 may inhibit the early proinflammatory response; however, identification of individual immune responsiveness and possibility of persistent infection could be important to rational use in the later stages of pediatric sepsis.

Strain-dependent cytokine profile and susceptibility to oleic acid anilide in a murine model of the toxic oil syndrome

The toxic oil syndrome (TOS) was caused by the ingestion of an adulterated rapeseed oil containing oleic acid anilide (OAA). It was characterized by lethal symptoms in the acute phase and by symptoms of idiopathic autoimmune diseases in the chronic phase. The pathogenetic mechanisms remain unclear. In a murine model of TOS we demonstrate strain-dependent effects on the immune system after treatment with OAA intraperitoneally. While C57BL/6 (H-2b) mice develop a polyclonal B cell activation without disease symptoms, most A/J (H-2a) mice suffer an acute lethal wasting disease. These differences are reflected in the splenic cytokine gene expression and secretion and in the Ig production. Increased IgE serum levels and reduced TNF-beta mRNA suggest a Th2 cell response in C57BL/6 mice. In A/J mice, splenocytes express IL-1alpha, IL-10, and IFN-gamma mRNA in vivo and secrete high levels of TNF-alpha in vitro. These observations resemble the human condition in TOS with development of either an acute lethal disease or a chronic autoimmune-like disease. As in other chemical-induced reactions genetic susceptibility seems to be important.

Systemic inflammatory response syndrome and organ dysfunction following gastrointestinal surgery

OBJECTIVES

Progression from systemic inflammatory response syndrome (SIRS) to sepsis, severe sepsis, and septic shock has been demonstrated in a variety of patients. However, the presence of SIRS alone was not helpful in predicting the development of multiple organ dysfunction syndrome (MODS) since SIRS includes many nonprogressive conditions. This study was conducted to investigate the clinical significance of SIRS in postoperative patients.

DESIGN

Retrospective study.

SETTING

The surgical department of a university hospital.

PATIENTS

Two hundred ninety-two consecutive patients who received elective common gastrointestinal surgery (esophagectomy, pancreatoduodenectomy, hepatectomy, gastrectomy, colorectal resection, and laparoscopic cholecystectomy) between 1992 and 1995.

INTERVENTIONS

Patients were analyzed for preoperative physiologic status, surgical stress parameters, and postoperative status of SIRS, complications, and end-organ dysfunction.

MEASUREMENTS AND MAIN RESULTS

Duration of SIRS or positive criteria's number of SIRS after surgery significantly correlated with surgical stress parameters (blood loss/body weight and operation time) and peak serum C-reactive protein concentrations. SIRS that continued or reappeared after postoperative day 3 was an early sign of postoperative complications. SIRS continuing consecutively for 2 days after postoperative day 3 had a 70.6% positive predictive value and a 92.5% negative predictive value for postoperative complications. Septic complications and prolongation of SIRS were associated with MODS. Five of six patients who met the SIRS criteria for >30 days developed severe MODS, and three of them died.

CONCLUSIONS

SIRS is a useful criterion for the recognition of postoperative complications and end-organ dysfunctions. Early recovery from SIRS may arrest the progression of organ dysfunction.

Blood interleukin 10 levels parallel the severity of septic shock

PURPOSE

The aim of this study was to investigate the relation between interleukin (IL) 10, tumor necrosis factor alpha (TNF alpha), IL-1, and IL-6 levels in patients with septic shock and relate these cytokine levels to the development of organ failure.

PATIENTS AND METHODS

In 11 patients with septic shock of recent onset, blood was sampled for determinations of TNF, IL-1, IL-6, and IL-10. The degree of organ failure was scored for four organ systems (respiratory, hepatic, renal, hematologic) in the first 48 hours of the study.

RESULTS

The APACHE II score was 21 +/- 4. Three patients died. IL-10 levels were directly correlated with TNF levels (r = 0.73, P < .05) and IL-6 levels (r = 0.67, P < .05); and inversely correlated with total C3 (r = -0.73, P < .05) and CH50 (r = -0.68, P < .05). Both IL-10 and TNF levels were correlated to the organ failure score (r = 0.75 and r = 0.68, both P < .01). Six patients with high IL-10 levels (> 60 pg/mL) had lower C3 (37 +/- 11 v 62 +/- 10 mg/dL) and CH50 (32 +/- 7 v 68 +/- 19%), and higher organ failure scores (5.7 +/- 0.8 v 3.8 +/- 1.3) than those with low IL-10 levels (all P < .05).

CONCLUSION

Although IL-10 has an inhibitory effect on the production of cytokines, it is released together with TNF and IL-6 in patients with septic shock. IL-10 blood levels are directly related to the severity of inflammation and the development of organ failure in septic shock.