Genetic variation in proinflammatory and anti-inflammatory cytokine production in multiple organ dysfunction syndrome

HM-chromanone alleviates hyperglycemia and inflammation in mice with endotoxin-induced insulin resistance

This study was designed to investigate whether (E)-5-hydroxy-7-methoxy-3-(2'-hydroxybenzyl)-4-chromanone alleviates inflammation and hyperglycemia in mice with endotoxin-induced insulin resistance. (E)-5-hydroxy-7-methoxy-3-(2'-hydroxybenzyl)-4-chromanone (10, 30, and 50 mg/kg bodyweight) was orally pre-administered to C57BL/6 J mice. An hour later, lipopolysaccharides (20 mg/kg bodyweight) was administered intraperitoneally to induce endotoxins. Blood samples were collected from the tail vein of the mice every 0, 30, and 90 min. The results indicated that (E)-5-hydroxy-7-methoxy-3-(2'-hydroxybenzyl)-4-chromanone effectively regulated blood glucose levels in mice with endotoxin-induced insulin resistance. Furthermore, (E)-5-hydroxy-7-methoxy-3-(2'-hydroxybenzyl)-4-chromanone significantly reduced the phosphorylation of mammalian target of rapamycin, ribosomal protein S6 kinase 1, and protein kinase C θ. Additionally, (E)-5-hydroxy-7-methoxy-3-(2'-hydroxybenzyl)-4-chromanone suppressed the phosphorylation of c-Jun-NH2-terminal kinase and IkB kinase β, thereby decreasing the phosphorylation of inhibitor of nuclear factor kappa-B α and activating the nuclear factor-κB and activator protein-1 in the liver. Therefore, the expression of tumor necrosis factor-α, interleukin-6, and interleukin-1β was significantly reduced by suppressing the nuclear factor-κB and activator protein 1 activity. Suppression of mammalian target of rapamycin, S6 kinase 1, protein kinase C θ, c-Jun-NH2-terminal kinase, and IkB kinase β also ameliorated insulin resistance by reducing the phosphorylation of insulin receptor substrate-1 serine 307, thereby decreasing hyperglycemia. These findings suggest that (E)-5-hydroxy-7-methoxy-3-(2'-hydroxybenzyl)-4-chromanone can alleviate hyperglycemia and inflammation in mice with endotoxin-induced insulin resistance.

Variants in TNF and NOS3 (eNOS) genes associated with sepsis in adult patients

BACKGROUND

Sepsis is a life-threatening condition caused by a dysregulated host response to infections and is a leading cause of death in hospitalized patients. The present study aimed to elucidate the possible association between sepsis and the tumor necrosis factor (TNF) gene -308G/A (rs1800629) polymorphism, as well as endothelial nitric oxide synthase (eNOS, NOS3) gene -786T/C (rs2070744), 4a/4b (27 bp-VNTR in intron 4, rs61722009) and 894G/T (Glu298Asp, rs1799983) polymorphisms.

METHODS

In total, 188 septic adult cases and 188 healthy controls were enrolled. Genomic DNAs from the controls and patients were analyzed by polymerase chain reaction and restriction fragment length polymorphism methods.

RESULTS

There were significant associations between the G/G genotype and G allele of the TNF -308G/A (rs1800629) polymorphism in the sepsis group (p < 0.001). The presence of the T/C genotype (p = 0.002) and C allele (p = 0.001) of the -786T/C (rs2070744) was markedly associated with an increased risk of sepsis. However, no significant associations were found with 4a/4b (27 bp-VNTR in intron 4, rs61722009) and 894G/T (Glu298Asp, rs1799983) polymorphisms. Higher 4bGC and lower 4bTT haplotype frequencies were associated with sepsis.

CONCLUSIONS

Our results strongly suggest that TNF gene (-308G/A, rs1800629) and NOS3 gene -786T/C (rs2070744) polymorphisms may modify individual susceptibility to sepsis in the Turkish population.

Association of TGFβ1 codon 10 (T>C) and IL-10 (G>C) cytokine gene polymorphisms with longevity in a cohort of Italian population

Longevity is a complex process controlled by both environmental and genetic factors. We evaluated the association of four cytokine gene polymorphisms with longevity in an Italian cohort. A sample of 1019 subjects aged 10 to 100 and belonging to the North-Italian population was genotyped for IL-6 (G>C, rs1800796), IL-10-1082 (G>A, rs1800896), TNF-α-308 (G>A, rs1800629), and TGFβ1 codon 10 (T>C, rs1800471) gene polymorphisms. The association between cytokine gene polymorphisms and longevity was evaluated by dividing the sample into four age groups: 10 to 24, 25 to 49, 50 to 85, and 86 to 100. We observed a significant decrease in the frequency of IL-10 A allele in the 25 to 49 (P = 1.1 × 10^-3 ), 50 to 85 (P < 1 × 10^-4 ), and 86 to 100 (P = 2 × 10^-3 ) age groups compared to that in the youngest age group. Similarly, we found a significant decrease (P < 1 × 10^-4 ) in the frequency of TGFβ1 C allele in the 50 to 85 and 86 to 100 age groups compared to that in the 10 to 24 and 25 to 49 age groups. Previously, high levels of TGFβ1 were detected in elderly subjects, suggesting that this cytokine could counterbalance the harmful effects of inflammation. Similarly, IL-10 has strong anti-inflammatory properties and can inhibit the production of proinflammatory cytokines. In the literature, the lowest levels of functional cytokines were found to be associated with TGFβ1 (T>C) and IL-10 (G>A) gene polymorphisms, with consequent increase in the duration of inflammation and cancer risk. For these reasons, it is plausible to observe low rates of these mutations in elderly subjects, as found in our study.

A randomized controlled trial of high parenteral protein feeding in septic children: the role of tumor necrosis factor-alpha-308 polymorphism

BACKGROUND Septic children cause high protein degradation and inadequate nutritional intake would worsen the outcomes. In addition, there are conflicting results of association between tumor necrosis factor-α (TNFA)-308 polymorphism and poorer outcomes. This study was aimed to investigate the impact of high protein feeding in septic children and to examine the role of the TNFA-308 polymorphism in outcome of sepsis. METHODS In this randomized controlled trial, septic children were randomly assigned to receive either high protein feeding (amino acid of 4 g/kg of body weight [kgBW]/day) or standard nutrient (amino acid of 2 g/kgBW/day) for three days in the pediatric intensive care unit of four hospitals in Indonesia. The patient’s enrollment was done between April 2016 and May 2017. The primary outcome was the pediatric logistic organ dysfunction (PELOD) score. TNFA-308 polymorphism was investigated using restriction fragment length polymorphism method in both groups. PELOD score was analyzed as mean differences and gene polymorphism was analyzed with mortality in a subgroup. RESULTS There were 40 children in each group. PELOD score on day-1 (22.4 versus 20.5, p = 0.429), day-2 (20.5 versus 19.8, p = 0.815), and day-3 (18.8 versus 19.8, p = 0.772) were not lower in high protein feeding compared to standard feeding. TNFA-308 polymorphism had no role in mortality of both groups (high protein, p = 0.426; standard, p = 0.456). CONCLUSIONS From this study, researchers concluded that a high protein intervention did not significantly decrease the PELOD score, length of stay, and duration of ventilator use in both groups.

The Role of TNF-α as a Proinflammatory Cytokine in Pathological Processes

TNF-α is a member of the vast cytokine family being considered a proinflammatory substance produced many by macrophages and other cells belonging to the innate immunity, many of them classified as indeed Antigen Presenting Cells (APCs) involved in the complex chemotactic process of activation of the adaptive immunity. The aim of this work was to accomplish a literature review concerning the main pathologies that have TNF-α as a modulating agent in other to bring light to the main interactions present in the inflammation installed.

The Duffy antigen receptor for chemokines, ACKR1,- 'Jeanne DARC' of benign neutropenia

Benign neutropenia, observed in different ethnic groups, is the most common form of neutropenia worldwide. A specific single nucleotide polymorphism, rs2814778, located at the promoter of the ACKR1 (previously termed DARC) gene, which disrupts a binding site for the GATA1 erythroid transcription factor, resulting in a ACKR1-null phenotype, was found to serve as a predictor of low white blood cell and neutrophil counts in African-Americans and Yemenite Jews. Individuals with benign neutropenia due to the ACKR1-null allele have been found to have an increased susceptibility to human immunodeficiency virus infection and, on the other hand, a protective effect against malaria. The associated protective effect may explain the spread of the ACKR1-null allele by natural selection. The reviewed relationships between ACKR1 polymorphism and various pathological states may have important clinical implications to individuals with and without benign neutropenia. Potential mechanisms for ACKR1 (previously termed DARC) modulation during neutrophil recruitment to inflammation, and chemokine bioavailability in the circulation and in local tissue are reviewed and discussed.

The LPS Responsiveness in BN and LEW Rats and Its Severity Are Modulated by the Liver

Differences in LPS responsiveness influence the outcome of patients with sepsis. The intensity of the response is highly variable in patients and strain dependent in rodents. However, the role of the liver for initiating the LPS response remains ill defined. We hypothesize that hepatic LPS uptake is a key event for initiating the LPS response. In the present study, the severity of the LPS-induced inflammatory response and the hepatic LPS uptake was compared in two rat strains (Lewis (LEW) rats and Brown Norway (BN) rats). Using a transplantation model, we demonstrated the decisive role of the liver. The expression of hepatic TNF-α, IL-6, and IL-1β mRNA levels in BN rats was significantly lower than that in LEW rats. LEW rats were sensitized to LPS via G-CSF pretreatment. Sensitization caused by G-CSF pretreatment induced severe liver injury and mortality in LEW rats, but not in BN rats (survival rate: 0% (LEW) versus 100% (BN), p < 0.01). LEW rats presented with higher liver enzymes, more alterations in histology, and higher expression of caspase 3 and higher cytokines levels. One of the reasons could be the increased hepatic LPS uptake, which was only observed in LEW but not in BN livers. Using the transplantation model revealed the decisive role of the LPS responsiveness of the liver. Injection of LPS to the high-responding LEW recipient before transplantation of a low-responder BN liver resulted in a 50% survival rate. In contrast, injecting the same dose of LPS into the high-responding LEW recipient after transplanting the low-responding BN liver resulted in a 100% survival rate. The severity of inflammatory response in different strains might be related to the differences in hepatic LPS uptake. This observation suggests that the liver plays a genetically defined decisive role in modulating the inflammatory severity.

TNFα Variation During the Menstrual Cycle and Thereafter: A New Explanation for Gender-Based Disparities in ICU Admission Rates, Trauma Outcomes, and General Mortality

BACKGROUND

Multiple studies have found gender-based disparities in intensive care unit (ICU) admission rates and in complications following trauma. Female gender was associated with lower mortality when comparing patients less than 50 years of age. These data suggest an important role for cycle rather than gender itself. Our previous results indicate a crucial role for tumor necrosis factor alpha (TNFα) in inducing nososocomial infections.

HYPOTHESIS

Cycle is important for TNF and other female hormone productions.

METHODS

Six older than 60 years old volunteers in both genders, 40 young female volunteers (no contraceptive drug, n = 18, contraceptive drug, n = 9, lactation, n = 9, pregnant, n = 4) were collected with following exclusion criteria, malignant disease, inflammation, infection, trauma and taking non-steroid anti-inflammatory drugs and antibiotics. Females were studied on days 1 and 14 of cycle. Serum TNFα was determined by HS TNF ELISA. Female hormones were also determined.

RESULTS

Serum TNFα, estradiol, and progesterone individual values in volunteers with cycle (no contraceptive drug) demonstrate marked interindividual differences on day 1 and day 14 of cycle. It can be seen beside interindividual differences the personal difference between TNFα, estradiol, and progesterone values on day 1 and day 14.Serum TNFα, estradiol, and progesterone individual values in volunteers with no cycle (contraceptive drug yes) demonstrate marked interindividual differences on day 1 and day 14 of cycle. It can be seen beside interindividual differences the personal difference between TNFα, estradiol, and progesterone values on day 1 and day 14; furthermore, seemingly lower estradiol values on day 1 and day 14 between groups can be seen. A significant decrease was demonstrated in serum progesterone values on day 14 of group with contraceptive drug compared with group with no contraceptive one.A significant negative correlation is demonstrated between serum progesterone and serum TNFα values on day 14.A marked significant difference in serum TNFα values between volunteers with cycle and with no cycle, like contraceptive, lactation pregnancy (trimesters P1, P2, P3), and climax.

CONCLUSION

For homogenous group of female patients not the gender and age are important but the cycle itself.

Association between Interleukin-10-1082 G/A and Tumor Necrosis Factor- 308 G/A Gene Polymorphisms and Respiratory Distress Syndrome in Iranian Preterm Infants

Cytokine polymorphisms may contribute to the prevalence of respiratory distress syndrome. The present study was done to investigate the frequency of interleukin- (IL-) 10 and tumor necrosis factor- (TNF-) α gene polymorphisms and their association with the risk of RDS in preterm infants. One-hundred and nineteen patients with RDS and 119 healthy preterm infants were enrolled. PCR restriction fragment length polymorphism was used to determine the frequency of IL-10 and TNF-α genotypes at -1082 A and -308 A, respectively. One-hundred and nineteen out of 238 infants had RDS (50%). The age of the mothers and gestational age ranged 17–45 (mean: 28.6 ± 5.3) years and 24–34 (mean: 34.3 ± 2.38) weeks, respectively. Totally, 23 deaths were recorded in the RDS group. Incidence of TNF-α-308 A/A and TNF-α-308 G/A was 84% and 16%, respectively. TNF-a-308 G/G was not found in both groups. Prevalence of IL-10-1082 G/G and IL-10-1082 G/A variants was 65.5% and 34.5%, respectively. IL-10-1082 A/A was not found in both groups. The incidence of the allele G in the IL-10-1082 polymorphism was lower in RDS group (P < 0.05). We found that the risk of RDS was correlated to sex, gestational age, and IL-10-1082.

Effect of Various Genetic Polymorphisms on the Incidence and Outcome of Severe Sepsis

Several genetic polymorphisms have been identified in patients with sepsis and severe sepsis, such as the tumor necrosis factor-α (TNF-α) and TNF-β genes, the interleukin-1 (IL-1) family, the IL-6, the IL-10, the CD-14, the Toll-like receptors, plasminogen activator inhibitor type 1, and the factor V 1691G-A mutations. In this study, the relationship between the TNF-α 308G/A, the IL-6-174 G/C, the PAI-1, the FVL, the EPCR, and the Cathepsin G (Ars 125 Ser) polymorphisms and the development and outcome of sepsis in pediatric patients was studied. TNF-α 308 G/A, PAI-1 4G/4G, and EPCR mutations influence the risk of severe sepsis in children. IL-6 174 G/C, FVL, and Cathepsin G (Ars 125 Ser) did not influence the incidence and mortality of severe sepsis.

Genetic variation in the TNF gene is associated with susceptibility to severe sepsis, but not with mortality

Background

Tumor necrosis factor (TNF) and TNF receptor superfamily (TNFR)-mediated immune response play an essential role in the pathogenesis of severe sepsis. Studies examining associations of TNF and lymphotoxin-α (LTA) single nucleotide polymorphisms (SNPs) with severe sepsis have produced conflicting results. The objective of this study was to investigate whether genetic variation in TNF, LTA, TNFRSF1A and TNFRSF1B was associated with susceptibility to or death from severe sepsis in Chinese Han population.

Methodology/Principal Findings

Ten SNPs in TNF, LTA, TNFRSF1A and TNFRSF1B were genotyped in samples of patients with severe sepsis (n = 432), sepsis (n = 384) and healthy controls (n = 624). Our results showed that rs1800629, a SNP in the promoter region of TNF, was significantly associated with risk for severe sepsis. The minor allele frequency of rs1800629 was significantly higher in severe sepsis patients than that in both healthy controls (P_adj = 0.00046, odds ratio (OR)_adj = 1.92) and sepsis patients (P_adj = 0.002, OR_adj = 1.56). Further, we investigated the correlation between rs1800629 genotypes and TNF-α concentrations in peripheral blood mononuclear cells (PBMCs) of healthy volunteers exposed to lipopolysaccharides (LPS) ex vivo, and the association between rs1800629 and TNF-α serum levels in severe sepsis patients. After exposure to LPS, the TNF-α concentration in culture supernatants of PBMCs was significantly higher in the subjects with AA+AG genotypes than that with GG genotype (P = 0.007). Moreover, in patients with severe sepsis, individuals with AA+AG genotypes had significantly higher TNF-α serum concentrations than those with GG genotype (P_adj = 0.02). However, there were no significant associations between SNPs in the four candidate genes and 30 day mortality for patients with severe sepsis.

Conclusions/Significance

Our findings suggested that the functional TNF gene SNP rs1800629 was strongly associated with susceptibility to severe sepsis, but not with lethality in Chinese Han population.

Genetic polymorphisms within tumor necrosis factor gene promoter region: a role for susceptibility to ventilator-associated pneumonia

Debatable findings exist among various studies regarding the impact of single nucleotide polymorphisms (SNPs) within the promoter region of the tumor necrosis factor (TNF) gene for susceptibility to infections. Their impact was investigated in a cohort of mechanically ventilated patients who developed ventilator-associated pneumonia (VAP). Two-hundred and thirteen mechanically ventilated patients who developed VAP were enrolled. Genomic DNA was extracted and SNPs at the -376, -308 and -238 position of the promoter region of the TNF gene were assessed by restriction fragment length polymorphisms. Monocytes were isolated from 47 patients when they developed sepsis and stimulated by bacterial endotoxin for the production of TNFα and of interleukin-6 (IL-6). Patients were divided into two groups; 166 patients bearing only wild-type alleles of all three studied polymorphisms; and 47 patients carrying at least one A allele of the three studied SNPs. Time between start of mechanical ventilation and advent of VAP was significantly shorter in the second group than in the first group (log-rank: 4.416, p: 0.041). When VAP supervened, disease severity did not differ between groups. Stimulation of TNFα and of IL-6 was much greater by monocytes for patients carrying A alleles. Carriage of at least one A allele of the three studied SNPs at the promoter region of the TNF-gene is associated with shorter time to development of VAP but it is not associated with disease severity. Findings may be related with a role of the studied SNPs in the production of pro-inflammatory cytokines.

Association of IL-10-1082 G/G genotype with lower mortality of acute respiratory distress syndrome in a Chinese population

We aimed to investigate whether interleukin-10 (IL-10) -1082 G/G genotype is associated with lower mortality of acute respiratory distress syndrome (ARDS) in a Chinese population. A hospital-based case-control study was conducted in 314 cases of ARDS and 210 controls who were admitted to an intensive care unit with sepsis, trauma, aspiration or massive transfusions. Cases were followed for 30-day mortality. The -1082G/G genotype was associated with lower development of ARDS (OR=0.51; 95% CI 0.34-0.76; P=0.001). Among patients with ARDS, the -1082G/G genotype was associated with lower 30-day mortality (OR=0.44; 95% CI 0.25-0.76; P=0.003). In conclusion, IL-10-1082 G/G genotype is associated with lower development and mortality of ARDS in a Chinese population.

Deviations in circulating TNFα levels and TNFα production by mononuclear cells in healthy human populations

Objectives. Tumor necrosis factor alpha (TNFα) plays a pivotal role in the inflammatory host response. The serum-level of TNFα and the production of TNFα by lympho/monocytes, however, seem to show high individual variations. The goal of the present study was to investigate the variations and inducibility of TNFα-activity in two age-groups of healthy volunteers. Methods. Sixty elderly, healthy volunteers were studied. These persons were free of malignant diseases, and within three months, they did not have any trauma or inflammatory disease and were not taking any steroids or nonsteroid anti-inflammatory drugs. Thirty young volunteers were also included. Blood samples were taken; lympho/monocytes were separated and cultured with or without endotoxin (LPS) stimulation. Serum and culture supernatant TNFα levels were determined by bioassay using WEHI 164 cells. Results. The results indicated significant individual variations in TNFα levels of healthy volunteers irrespective of age. Subgroups with low, middle, and high serum TNF-levels were distinguished. In about 50% of volunteers with low serum-TNFα activity, LPS stimulation failed to increase the TNFα production by isolated lympho/monocytes. Conclusion. Our data suggest a chance to select individuals with enhanced sensitivity for septic complications.

Ethical considerations in the collection of genetic data from critically ill patients: what do published studies reveal about potential directions for empirical ethics research?

Critical illness trials involving genetic data collection are increasingly commonplace and pose challenges not encountered in less acute settings, related in part to the precipitous, severe and incapacitating nature of the diseases involved. We performed a systematic literature review to understand the nature of such studies conducted to date, and to consider, from an ethical perspective, potential barriers to future investigations. We identified 79 trials enrolling 24 499 subjects. Median (interquartile range) number of participants per study was 263 (116.75-430.75). Of these individuals, 16 269 (66.4%) were Caucasian, 1327 (5.4%) were African American, 1707 (7.0%) were Asian Pacific Islanders and 139 (0.6%) were Latino. For 5020 participants (20.5%), ethnicity was not reported. Forty-eight studies (60.8%) recruited subjects from single centers and all studies examined a relatively small number of genetic markers. Technological advances have rendered it feasible to conduct clinical studies using high-density genome-wide scanning. It will be necessary for future critical illness trials using these approaches to be of greater scope and complexity than those so far reported. Empirical research into issues related to greater ethnic inclusivity, accuracy of substituted judgment and specimen stewardship may be essential for enabling the conduct of such trials.

Polymorphisms of genes encoding tumor necrosis factor-alpha, interleukin-10, cluster of differentiation-14 and interleukin-1ra in critically ill patients

PURPOSE

The aim of the study was to determine whether distributions of tumor necrosis factor (TNF)-α(308), interleukin (IL)-10(1082), CD14(159), and IL-1ra gene intron 2 genotypes in critically ill patients are associated with outcome, underlying cause of sepsis, and type of microorganism.

MATERIALS AND METHODS

Blood samples from 106 critically ill white patients were genotyped by method based on polymerase chain reaction for TNF-α(308), IL-10(1082), CD14(159), and IL-1ra gene intron 2.

RESULTS

All patients with TNF-α(308)AA genotype survived; relative risk (RR) of death in patients with AG was 3.250 and with GG, 1.923 (P < .01). In patients with Gram-positive sepsis, IL-10(1082)AA and then AG genotypes were the most frequent ones (odds ratio [OR], 18.67 and 7.20, respectively; P < .01). When comparing IL-10(1082)AA with AG, RR of pancreatitis was 1.80 and OR was 3.40. When AA and GG were compared, RR was 7.33 and OR was 20.00. In patients with GG, RR of peritonitis was 4.07 and OR was 5.88 (P < .01). In patients with Gram-positive sepsis, CD14(159)CT was the most frequent one with OR of 5.25. Distribution of 6 IL-1ra gene intron 2 genotypes showed no significant association.

CONCLUSIONS

Distribution of TNF-α(308) genotypes is associated with outcome, IL-10(1082) with type of microorganism and underlying cause of sepsis, and CD14(159) with type of microorganism.

Clinical relevance of the interleukin 10 promoter polymorphisms in Chinese Han patients with major trauma: genetic association studies

INTRODUCTION

An excessive inflammatory response is thought to account for the pathogenesis of sepsis and multiple organ dysfunction syndrome (MODS) after severe trauma. The interleukin-10 (IL-10) is a potent anti-inflammatory cytokine. The objectives of this prospective study were to investigate the distribution of IL-10 promoter polymorphisms in a cohort of 308 Chinese Han patients with major trauma, and to identify associations of IL-10 promoter polymorphisms with IL-10 production and incidence of sepsis and MODS.

METHODS

A total of 308 patients with major trauma were included in this study. The genotypes of polymorphisms -1082, -819 and -592 were determined by polymerase chain reaction-restriction fragment length polymorphism. The IL-10 levels in the supernatants were determined with enzyme-linked immunoabsorbent assay.

RESULTS

The -1082A and -592A alleles were significantly associated with lower lipopolysaccharide-induced IL-10 production in an allele-dose dependent fashion. There was no significant difference for the -819 polymorphism. Except for the -1082 polymorphism, the -819 and -592 polymorphisms were not significantly associated with sepsis morbidity rate and MOD scores.

CONCLUSIONS

Our results further confirm the functionality of the IL-10 promoter single nucleotide polymorphisms in relation to IL-10 production. They also suggest that individual difference in IL-10 production in trauma patients might be at least in part related to genetic variations in the IL-10 promoter region.

DARC on RBC limits lung injury by balancing compartmental distribution of CXC chemokines

The Duffy antigen receptor for chemokines (DARC) has a high affinity for CC and CXC chemokines. However, it lacks the ability to induce cell responses that are typical for classical chemokine receptors. The role of DARC in inflammatory conditions remains to be elucidated. We studied the role of DARC in a murine model of acute lung injury. We found that in Darc-gene-deficient (Darc(-/-)) mice, LPS-induced PMN migration into the alveolar space was elevated more than twofold. In contrast, PMN adhesion to endothelial cells and within the interstitial space was reduced in Darc(-/-) mice. Darc(-/-) mice also exhibited increased microvascular permeability. Elevated PMN migration in Darc(-/-) mice was associated with increased concentrations of two essential CXCR2 ligands, CXCL1 and CXCL2/3 in the alveolar space. In the blood, CXCL1 was mostly associated with RBC in WT mice and with plasma in Darc(-/-) mice. We found that DARC on RBC prevented excessive PMN migration into the alveolar space. In contrast, DARC on non-hematopoietic cells appeared to have only minor effects on leukocyte trafficking in this model. These findings show how DARC regulates lung inflammation by controlling the distribution and presentation of chemokines that bind CXCR2.

Future diagnostic and therapeutic approaches in surgical infections

Despite ongoing efforts to standardize therapy and improve management, the morbidity and mortality associated with surgical infections remain high. Continued innovation is required to improve outcomes further, particularly in the face of the increasing prevalence of multidrug resistant organisms. Although they remain in the experimental stages, a number of recent advances have the potential to have significant impact on the management and outcomes of surgical infections. These include novel diagnostic strategies, antimicrobials targeting microbial virulence factors, novel vaccines, and risk stratification based on genetic profiling.

The severity of Streptococcus pyogenes infections in children is significantly associated with plasma levels of inflammatory cytokines

Cytokines are intimately involved with the innate and adaptive immune response to bacterial infections. This study was designed to determine the expression of inflammatory cytokines in children by the severity of Streptococcus pyogenes (group A Streptococcus [GAS]) infections. The study population consisted of 16 invasive, 20 noninvasive, and 24 pharyngeal colonization, and 21 healthy controls. All children underwent the laboratory tests and cytokine measurement. GAS isolates were analyzed for emm gene typing. Patients with invasive GAS diseases had significantly higher interferon (IFN)-gamma, interleukin (IL)-1beta, IL-6, IL-8, IL-10, and IL-18 than those with noninvasive diseases, colonization, and healthy controls. There was no difference in tumor necrosis factor (TNF)-alpha, IL-12, and IL-2 levels among the groups. Elevated white blood cell counts and levels of C-reactive protein and C3 were detected only in patients with invasive diseases. emm1 and emm12 predominated in invasive disease and colonization. Children with invasive GAS infections exhibited significant up-regulation of plasma levels of IFN-gamma, IL-1beta, IL-6, IL-8, IL-10, and IL-18, and suppression of TNF-alpha and IL-12 during the acute phase of their illness. An exuberant cytokine response was associated with the severity of illness.

Duffy antigen modifies the chemokine response in human endotoxemia

OBJECTIVE

The Duffy receptor is a promiscuous receptor for chemokines and selectively binds CXC and CC chemokines with high affinity. Preclinical data show that presence of the Duffy receptor on red blood cells may influence plasma levels of proinflammatory cytokines and chemokines and be protective during inflammation. This trial was designed to investigate the influence of the Duffy antigen on human inflammation in vivo.

DESIGN

Prospective, analyst-blinded clinical trial.

PATIENTS

A total of 32 healthy male volunteers: 16 Duffy-positive white subjects and 16 Duffy-negative subjects of African descent.

MEASUREMENTS AND MAIN RESULTS

All subjects received an intravenous bolus of 2 ng/kg endotoxin (lipopolysaccharide). Cytokines, chemokines, and their receptors were quantified by enzyme immunoassay, reverse transcriptase-polymerase chain reaction, and flow cytometry.

RESULTS

Plasma levels of tumor necrosis factor, interleukin-6, interleukin-10, and whole blood growth-related oncogen-alpha, monocyte chemoattractant protein-1, and interleukin-8 messenger RNA increased similarly in both groups after lipopolysaccharide infusion. Monocyte chemoattractant protein-1 peak plasma levels were roughly two-fold higher in Duffy-positive subjects compared with Duffy-negative subjects (16 ng/mL vs. 7 ng/mL, p < .0001). Similarly, growth-related oncogen-alpha levels were 2.5-fold higher in Duffy-positive subjects 2 hrs after lipopolysaccharide infusion (210 pg/mL vs. 85 pg/mL; p < .001). Erythrocyte-bound monocyte chemoattractant protein-1, growth-related oncogen-alpha, and interleukin-8 increased 20- to 50-fold in Duffy-positive subjects (p < .00001 vs. baseline).

CONCLUSION

The Duffy antigen substantially alters chemokine concentrations in blood, but it does not have a protective effect during human endotoxemia.

Common TNF-alpha, IL-1 beta, PAI-1, uPA, CD14 and TLR4 polymorphisms are not associated with disease severity or outcome from Gram negative sepsis

BACKGROUND

Several studies have investigated single nucleotide polymorphisms (SNPs) in candidate genes associated with sepsis and septic shock with conflicting results. Only few studies have combined the analysis of multiple SNPs in the same population.

METHODS

Clinical data and DNA from consecutive adult patients with culture proven Gram negative bacteremia admitted to a Danish hospital between 2000 and 2002. Analysis for commonly described SNPs of tumor necrosis-alpha, (TNF-alpha), interleukin-1 beta (IL-1 beta), plasminogen activator-1 (PAI-1), urokinase plasminogen activator (uPA), CD14 and toll-like receptor 4 (TLR4) was done.

RESULTS

Of 319 adults, 74% had sepsis, 19% had severe sepsis and 7% were in septic shock. No correlation between severity or outcome of sepsis was observed for the analyzed SNPs of TNF-alpha, IL-1 beta, PAI-1, uPA, CD14 or TLR-4. In multivariate Cox proportional hazard regression analysis, increasing age, polymicrobial infection and haemoglobin levels were associated with in-hospital mortality.

CONCLUSION

We did not find any association between TNF-alpha, IL-1 beta, PAI-1, uPA, CD14 and TLR4 polymorphisms and outcome of Gram negative sepsis. Other host factors appear to be more important than the genotypes studied here in determining the severity and outcome of Gram negative sepsis.

Molecular Analysis of Inflammatory Markers in Trauma Patients at Risk of Postinjury Complications

BACKGROUND

Genetic differences associated with individual's immune responses appear to be a major contributing factor to the development of trauma- induced sepsis. Thus, effective treatment of sepsis requires the identification of the patients who are at increased risk for sepsis.

METHODS

Sixty-eight patients, of which the majority had an injury severity score >15, and 118 controls from the same geographic region were genotyped. Cytokine and Toll-like receptor (TLR) genotypes and expressions were tested using polymerase chain reaction (PCR).

RESULTS

Fifty percent of African American and 42% of Caucasian patients developed posttrauma sepsis. Frequency distribution of the polymorphism for some cytokine genes such as Interleukin (IL)-10 low/high and interferon (IFN)-gamma low producer were statistically different between the septic and aseptic patients, for others, such as tumor necrosis factor (TNF)-alpha, IL-6, and IL-18, there was no statistical difference. The TLR-2 genotypes (A/G) were considered a sepsis risk marker as compared with A/A (62.5% versus 37.5%, p < 0.03; relative risk = 2.5) in African American patients. Cytokine mRNA levels correlated with genotype definition, particularly, for IL-10, IL-6, IL-18, and TNF-alpha. A time course study demonstrated a significant difference in cytokines expression profile in septic and aseptic patients before the development of sepsis.

CONCLUSION

Monitoring cytokine expression levels before the disease might predict the outcome of sepsis. A large cohort study is needed to assess the diagnostic potential of the genotypes.

Effect of continuous bioartificial kidney therapy on porcine multiple organ dysfunction syndrome with acute renal failure

The bioartificial kidney (BK) was fabricated with primary culture of human proximal tubular cells growing in a hemofilter. A porcine model with multiple organ dysfunction syndrome, including acute renal failure, was induced by cecal ligation and puncture and bilateral ureteral ligation. The models were treated with BK (group A) or sham BK (group B) or without treatment (group C). Mean arterial pressure (mm Hg) was higher in group A (88.13 +/- 7.62) than in groups B and C (63.50 +/- 11.82, 53.50 +/- 2.52) at 24 hours (p < 0.01). Serum blood urea nitrogen, Cr, K, Pao2, and HCO3 were similar during the treatment periods between groups A and B, which were better than those in group C. In group A, tumor necrosis factor (TNF)-alpha (pg/mL) was 394.42 +/- 35.62 at 24 hours, lower than that of groups B and C (531.76 +/- 30.23, 552.89 +/- 27.81) (p < 0.05). Peak level of interleukin (IL)-10 (pg/mL) was higher in group A (272.36 +/- 48.89) than in groups B and C (106.30 +/- 29.69, 102.59 +/- 10.21) (p < 0.01). There was no difference of serum IL-6 between pretreatment and post-treatment in groups A and B, but serum IL-6 gradually increased in group C. The survival time (hours) was longer in group A than in other groups, which was prolonged by 46.20% and 58.39%. Results indicate that BK can ameliorate mean arterial pressure, decrease serum TNF-alpha, increase serum IL-10, and prolong survival time of pigs with multiple organ dysfunction syndrome and acute renal failure.

Cellular mechanisms in sepsis

Mortality remains very high among septic patients despite the advanced treatments rendered in intensive care units. The development of septic shock is multifactorial. Tissue damage and organ dysfunction may be caused not only by the microorganisms but also by the inflammatory mediators released in response to the infection. Cytokines (tumor necrosis factor, interleukin-1, interleukin-6, interleukin-8, high-mobility group box-1 protein, macrophage migratory inhibitory factor) and noncytokines (nitric oxide, platelet-activating factor, complements, and eicosonoids) may inflict tissue injury and contribute to multiple organ dysfunction and cell death (or apoptosis). Gram-negative bacteria are the most common organisms identified in septic patients. The pathological effects of gram-negative bacteria are conveyed through lipopolysaccharide derived from the bacterial cell membrane. Lipopolysaccharide activates the nuclear factor kappa B, which triggers the release of inflammatory mediators. Protein components from gram-positive bacteria, fungi, or viruses may evoke the activation of nuclear factor kappa B in a similar fashion as lipopolysaccharide. Endogenous anti-inflammatory mediators are released in response to the infection and act to control the overwhelming systemic inflammatory response. The fragile balance between negative and positive feedback on the inflammatory mediators is the key factor that modulates the cellular damage and influences the clinical outcome.

Inactivity and Inflammation in the Critically Ill Patient

Bed rest is a commonly prescribed activity restriction among patients in the ICU. Although bed rest may promote rest, recovery and safety, inactivity related to bed rest also may lead to complications and adverse outcomes. The biological mechanisms that lead to immediate and long-term sequelae from bed rest have not been elucidated. It may be the inflammatory factors common to critical illness combined with bed rest lead to a positive feedback loop, contributing to inflammatory disequilibrium. This disequilibrium has a profound affect on muscles. Muscle decay has serious and long-term adverse outcomes on survivors of critical illness. Mobility therapy may improve inflammatory disequilibrium and preserve muscles, leading to improved functional outcome. Investigations in the laboratory, in healthy people and among patients with systemic inflammatory disease, suggest that activity does not exacerbate inflammation. Clinically, exercise is beneficial to patients with various chronic inflammatory diseases. Further study is needed to best understand the role, duration, and frequency of activity in promoting recovery for critically ill patients.

Genetic epidemiology of acute respiratory distress syndrome: implications for future prevention and treatment

The genetic susceptibility to the development of and variable outcomes in acute lung injury/acute respiratory distress syndrome (ALI/ARDS) has become a topic of great interest in the pulmonary and critical care community. Published studies of variable genetic susceptibility to ALI/ARDS already have identified some important candidate genes and potential gene-environment interactions. This article reviews these recent studies, features of the current approach, and implications for future prevention and treatment in ALI. The challenges and potential contributions of genetic epidemiology to the future prevention and treatment in ALI are discussed.

What is new in cytokine research related to trauma/critical care

Cytokines are low molecular weight proteins whose production can be modified by various insults. They have the potential to modify cellular responses to these insults. Recent years have seen a plethora of research in cytokine biology in trauma and critical care.

Interleukin-10 polymorphism in position -1082 and acute respiratory distress syndrome

The GG genotype of the interleukin (IL)-10 promoter polymorphism in position -1082 (-1082GG) has been associated with increased IL-10 production. The current authors hypothesised that the -1082GG genotype is associated with the development of, and outcomes in, acute respiratory distress syndrome (ARDS). A nested case-control study was conducted in 211 Caucasian cases of ARDS and 429 controls who were admitted to an intensive care unit with sepsis, trauma, aspiration or massive transfusions. Cases were followed for organ failure and 60-day mortality. The -1082GG genotype was associated with the development of ARDS, but only in the presence of a significant interaction between the -1082GG genotype and age. Among patients with ARDS, the -1082GG genotype was associated with decreased severity of illness on admission, lower daily organ dysfunction scores and lower 60-day mortality. In conclusion, the high interleukin-10-producing -1082GG genotype may be associated with variable odds for acute respiratory distress syndrome development depending on age. Among those with acute respiratory distress syndrome, the -1082GG genotype is associated with lower mortality and organ failure. Further studies are needed to confirm these findings.

Heterogeneity in lipopolysaccharide responsiveness of endothelial cells identified by gene expression profiling: role of transcription factors

Interindividual differences of endothelial cells in response to endotoxins might contribute to the diversity in clinical outcome among septic patients. The present study was conducted to test the hypothesis that endothelial cells (EC) with high and low proinflammatory potential exist and to dissect the molecular basis underlying this phenomenon. Thirty human umbilical vein endothelial cell (HUVEC) lines were stimulated for 24 h with lipopolysaccharide (LPS) and screened for interleukin (IL)-8 production. Based on IL-8 production five low and five high producers, tentatively called types I and II responders, respectively, were selected for genome-wide gene expression profiling. From the 74 genes that were modulated by LPS in all type II responders, 33 genes were not influenced in type I responders. Among the 41 genes that were increased in both responders, 17 were expressed significantly stronger in type II responders. Apart from IL-8, significant differences in the expression of proinflammatory related genes between types I and II responders were found for adhesion molecules [intercellular adhesion molecule (ICAM-1), E-selectin)], chemokines [monocyte chemoattractant protein (MCP-1), granulocyte chemotactic protein (GCP-2)], cytokines (IL-6) and the transcription factor CCAAT/enhancer binding protein-delta (C/EBP-delta). Type I responders also displayed a low response towards tumour necrosis factor (TNF)-alpha. In general, maximal activation of nuclear factor (NF)-kappaB was achieved in type I responders at higher concentrations of LPS compared to type II responders. In the present study we demonstrate that LPS-mediated gene expression differs quantitatively and qualitatively in types I and II responders. Our results suggest a pivotal role for common transcription factors as a low inflammatory response was also observed after TNF-alpha stimulation. Further studies are required to elucidate the relevance of these findings in terms of clinical outcome in septic patients.

Genetic predisposition for a compromised immune system after multiple trauma

Severe trauma induces sustained changes of the immune response, which are thought to be related to secondary organ dysfunction. Despite a similar injury severity, the extent of the inflammatory response may vary between polytraumatized patients. It is unclear whether inflammatory variability is associated with genetic variations. In this prospective cohort study, patients were included when the following criteria were fulfilled: Injury Severity Score >16, age 18 to 60 years, and a survival >48 h after injury. Four different polymorphisms (TNF-Nco1, IL-1-Taq1, IL-6-174G/C, and IL-8-251A/T) were determined. Patients were separated according to the severity of the systemic inflammatory response syndrome (SIRS; ACCP/SCCM criteria: >2 criteria at 2 consecutive days or at 3 days of the observation period: group +SIRS; <or=2 criteria: group -SIRS). Ninety-seven severely injured patients were included (-SIRS, 56 patients; +SIRS, 41 patients). A significantly higher incidence of the IL-6-174G allele and the IL-6-174G homozygous genotype in +SIRS patients was observed. The IL-6-174G/C polymorphism was associated with the severity of posttraumatic SIRS. This data points toward a genetic predisposition regarding an enhanced inflammatory response after polytrauma that may be associated with adverse outcome.

Interleukin-10 haplotype associated with increased mortality in critically ill patients with sepsis from pneumonia but not in patients with extrapulmonary sepsis

STUDY OBJECTIVE

To test the hypothesis that haplotypes of the interleukin (IL)-10 gene are associated with clinical outcomes, comparing critically ill patients with sepsis from pneumonia vs those with extrapulmonary sepsis.

DESIGN

Genetic association study.

SETTING

Medical/surgical ICUs in a tertiary-care, university-affiliated teaching hospital.

PATIENTS

Of 550 white patients with sepsis, 158 had pneumonia as the principle cause of their sepsis and 392 had an extrapulmonary source of sepsis.

MEASUREMENTS

Haplotypes of the IL-10 gene were defined by measurement of haplotype tag single-nucleotide polymorphisms (SNPs). Primary outcome was 28-day survival. Secondary outcomes were days alive and free of organ dysfunction.

RESULTS

Three SNPs in the IL-10 gene (-592 C/A, +734 G/T, and +3367 G/A) identified four major haplotypes: CGG, AGG, CTA, and CTG. Patients with pneumonia who carried one or two copies of the CGG haplotype had greater 28-day mortality (51.4%) than patients who did not carry this haplotype (29.1%, p = 0.007). Carriers of CGG had significantly more cardiovascular dysfunction (and use of vasopressors), renal dysfunction (and requirement of dialysis), hepatic dysfunction, and hematologic dysfunction (p < 0.05 in each case). In contrast, in patients with an extrapulmonary source of infection there was no significant association of the CGG haplotype (or any measured IL-10 genotype) with 28-day mortality or organ dysfunction.

CONCLUSIONS

The IL-10 haplotype - 592C/734G/3367G is associated with increased mortality and organ dysfunction in critically ill patients with pulmonary sepsis but not in similarly ill patients with extrapulmonary sepsis. Therefore, polymorphisms within the IL-10 gene may be predictors of outcome in patients with sepsis from pneumonia.

Genetic variability in the immune-inflammatory response after major burn injury

Thermal injury induces immune dysfunction and alters numerous physiological parameters. Studies have proposed that genetics influence the outcome after traumatic injury and/or sepsis, however, the contribution of genetics to the immune-inflammatory response postburn has not been investigated. In this study, mice of three distinct genetic backgrounds (C57BL/6NCrlBR, BALB/cAnNCrlBR, and 129S6/SvEvTac) were subjected to thermal injury or a sham procedure, and 3 days later, blood and splenic immune cells (splenocytes and macrophages) were isolated for analysis. Splenocytes from the C57BL/6NCrlBR strain displayed suppressed splenic T cell proliferation postinjury, whereas the other strains were unaffected. Burn injury also induced a shift toward a Th2-type T-cell response (suppressed IFN-gamma production) in the C57BL/6NCrlBR strain, but not in the other strains. Macrophages from C57BL/6NCrlBR and 129S6/SvEvTac mice were highly proinflammatory with elevated productive capacity for TNF-alpha and nitric oxide, whereas no such changes were observed in macrophages for BALB/cNCrlBR mice. C57BL/6NCRLBR macrophages produced increased IL-10 levels postburn, and BALB/cNCrlBR macrophages had suppressed IL-10 production postinjury. No differences in fasting blood glucose and insulin were observed after thermal injury. However, significant postburn weight loss was observed in the BALB/cNCrlBR and 129S6/SvEvTac strains, but not in the C57BL/6NCrlBR strain. In summary, these findings support the concept that the immune-inflammatory response postburn is influenced by genetic make-up. Further elucidation of the influence of genetics under such conditions is likely to contribute to the improvement in existing, and development of new, therapeutic regimes for burn patients.

Genetic polymorphisms in sepsis

CONTEXT

Wide variability exists in the susceptibility to and outcome from sepsis even within similar intensive care unit populations. Some of this variability in the host may be due to genetic variation in genes coding for components of the innate immune response.

OBJECTIVE

To review the evidence for a genetic influence on the susceptibility to and outcome from sepsis.

DESIGN

Literature review.

PATIENTS

Variety of adult and pediatric patients with various critical illnesses and infections.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Susceptibility to clinical symptoms of sepsis and outcome as measured by severity of disease and mortality.

RESULTS

Polymorphisms in genes coding for proteins involved in the recognition of bacterial pathogens (Toll-like receptor 4, CD14, Fc(gamma)RIIa, and mannose-binding lectin) and the response to bacterial pathogens (tumor necrosis factor-alpha, interleukin (IL)-1alpha, IL-1beta, IL-1 receptor agonist, IL-6, IL-10, heat shock proteins, angiotensin I converting enzyme, plasminogen activator inhibitor-1) can influence the amount or function of the protein produced in response to bacterial stimuli. Evidence is discussed suggesting that some of these genetic polymorphisms influence the susceptibility to and outcome from sepsis.

CONCLUSION

Host genetic variability in the regulatory and coding regions of genes for components of the innate immune system may influence the susceptibility to and/or outcome from sepsis. The disparate results observed in many studies of polymorphisms in sepsis emphasize the need for future studies to be larger, to include the analysis of multiple polymorphisms, and to be better designed with respect to control populations to identify the degree of influence that genetic variability has on sepsis.

Assessing the quality of case-control association studies on the genetic basis of sepsis

OBJECTIVE

To define methodological standards that would improve the quality and reproducibility of case-control genetic association studies in sepsis.

DESIGN

Summary of the published standards.

RESULTS

Twelve main criteria and measures for evaluation of those criteria were developed from a variety of reviews and editorials on the subject.

CONCLUSIONS

Case-control candidate gene association studies represent an important tool for understanding the role that genes play in the pathogenesis of sepsis. It is important, however, to understand the limitations of these studies and the need for replication.

Genetic Susceptibility to Pneumonia

The persistent mortality from community-acquired pneumonia may be explained by genetic predisposition. Specific mutations or polymorphisms in host response genes that are associated with adverse outcomes from infection can be grouped into four categories: antigen recognition, proinflammatory responses, anti-inflammatory responses, and effector mechanisms. Mannose-binding lectin polymorphisms have a more dominant role in pneumonia when compared with other pattern recognition molecules such as the toll-like receptors. The roles of TNF and lymphotoxin alpha polymorphisms remain unclear despite extensive study. IL-10 and IL-1 receptor antagonist polymorphisms have an important role in the anti-inflammatory response. Specific organ dysfunction, such as ARDS or DIC, may be related to polymorphisms in specific effector genes.

Community-acquired pneumonia: pathophysiology and host factors with focus on possible new approaches to management of lower respiratory tract infections

The present understanding of the pathophysiology of community-acquired pneumonia (CAP) explains the mechanism for many specific manifestations, but does not address adequately why only some patients experience complications. Recent advances in under-standing the genetics of complex illnesses offer hope for a more complete insight into the pathogenesis of CAP. This article reviews genetic variation in the molecules involved in the known patho-genic mechanisms of CAP, including cough, bacterial recognition, inflammation and the compensatory anti-inflammatory response,and organ dysfunction.