Relationship between effect of polymyxin B-immobilized fiber and high-mobility group box-1 protein in septic shock patients

PAMPs and DAMPs in Sepsis: A Review of Their Molecular Features and Potential Clinical Implications

Sepsis is a serious organ dysfunction caused by a dysregulated immune host reaction to a pathogen. The innate immunity is programmed to react immediately to conserved molecules, released by the pathogens (PAMPs), and the host (DAMPs). We aimed to review the molecular mechanisms of the early phases of sepsis, focusing on PAMPs, DAMPs, and their related pathways, to identify potential biomarkers. We included studies published in English and searched on PubMed® and Cochrane®. After a detailed discussion on the actual knowledge of PAMPs/DAMPs, we analyzed their role in the different organs affected by sepsis, trying to elucidate the molecular basis of some of the most-used prognostic scores for sepsis. Furthermore, we described a chronological trend for the release of PAMPs/DAMPs that may be useful to identify different subsets of septic patients, who may benefit from targeted therapies. These findings are preliminary since these pathways seem to be strongly influenced by the peculiar characteristics of different pathogens and host features. Due to these reasons, while initial findings are promising, additional studies are necessary to clarify the potential involvement of these molecular patterns in the natural evolution of sepsis and to facilitate their transition into the clinical setting.

Targeting circulating high mobility group box-1 and histones by extracorporeal blood purification as an immunomodulation strategy against critical illnesses

Both high mobility group box-1 (HMGB1) and histones are major damage-associated molecular patterns (DAPMs) that mediate lethal systemic inflammation, activation of the complement and coagulation system, endothelial injury and multiple organ dysfunction syndrome in critical illnesses. Although accumulating evidence collectively shows that targeting HMGB1 or histones by their specific antibodies or inhibitors could significantly mitigate aberrant immune responses in multiple critically ill animal models, routine clinical use of such agents is still not recommended by any guideline. In contrast, extracorporeal blood purification, which has been widely used to replace dysfunctional organs and remove exogenous or endogenous toxins in intensive care units, may also exert an immunomodulatory effect by eliminating inflammatory mediators such as cytokines, endotoxin, HMGB1 and histones in patients with critical illnesses. In this review, we summarize the multiple immunopathological roles of HMGB1 and histones in mediating inflammation, immune thrombosis and organ dysfunction and discuss the rationale for the removal of these DAMPs using various hemofilters. The latest preclinical and clinical evidence for the use of extracorporeal blood purification to improve the clinical outcome of critically ill patients by targeting circulating HMGB1 and histones is also gathered.

The value of postoperative HLA-DR expression and high mobility group box 1 level in predictive diagnosis of sepsis in percutaneous nephrolithotomy surgery

OBJECTIVE

To analyze the value of postoperative human leukocyte antigen-DR (HLA-DR) expression and high mobility group box 1 (HMGB1) level in predictive diagnosis of postoperative sepsis for patients with percutaneous nephrolithotomy (PCNL) surgery.

METHODS

The present prospective observational study included 387 patients with renal calculus who received PCNL surgery from January 2017 to October 2020 in our hospital. After exclusion criteria, 33 patients with sepsis and 78 patients with no sepsis remained. All patients received PCNL surgery. Sepsis definition is according to the third international consensus definitions for sepsis and septic shock (Sepsis-3). The data of the HMGB1, c-reactive protein (CRP), interleukin-6 (IL-6), procalcitonin (PCT) and HLA-DR expression were collected within admission and 24 h and 72 h after surgery. Postoperative HMGB1 levels and HLA-DR expression at 24 h and 72 h were respectively compared between the two groups using t test. ROC cure was used to analyze the value of postoperative HLA-DR expression and HMGB1 level in predictive diagnosis of sepsis.

RESULTS

The positive rate of urine culture and the time of hospitalization time in patients with sepsis were significantly higher than those in patients with no sepsis. Sepsis group had higher levels of HMGB1 at post-24 h ((93.07 ± 11.37) ng/mL vs (75.41 ± 4.85) ng/mL), p < 0.05) and 72 h ((96.58 ± 12.12) ng/mL vs (81.16 ± 8.86) ng/mL), p < 0.05) than nosepsis group. Meanwhile, sepsis group had lower expression of HLA-DR at post-24 h ((50.01 ± 7.42) % vs (69.32 ± 10.58) %), p < 0.05) and 72 h ((54.85 ± 9.45) % vs (69.98 ± 11.00) %), p < 0.05) than non-sepsis group. ROC analysis showed that the HLA-DR expression at postoperative 24 h had highest predictive value in the diagnosis of sepsis, the AUC of HLA-DR was 0.934, cutoff value 56.19%, with sensitivity 89.7%, specificity 81.8%.

CONCLUSION

Postoperative HLA-DR and HMGB1 can both be used as a predictive diagnosis of sepsis for patients with renal calculus received PCNL surgery. HighlightsSepsis group had higher levels of high mobility group box 1 at post-24 h and 72 h than nosepsis group.Sepsis group had lower expression of HLA-DR at post-24 h and 72 h than nosepsis group.Postoperative HLA-DR and HMGB1 can both be used as a predictive diagnosis of sepsis for patients with renal calculus received PCNL surgery.

Fecal HBD-2 and Claudin-3 may be potential biomarkers to predict the deterioration of necrotizing enterocolitis: A prospective study

BACKGROUND AND PURPOSE

Necrotizing enterocolitis (NEC) is a critical gastrointestinal disease. We aim to explore the value of fecal human β-defensin 2 (HBD-2), Claudin-3, high-mobility group box-1 protein (HMGB-1), and resistin-like molecule β (Relmβ) as well as some laboratory metrics to predict the deterioration of NEC.

METHODS

Infants diagnosed with NEC at Stage II were enrolled in our study. Those who progressed to Stage III were included in the Stage III group and the rest were included in the Stage II group. Clinical data and laboratory metrics of the infants were collected. Fecal samples of HBD2, HMGB-1, Claudin-3, and Relmβ collected during their enrollment were determined by using enzyme-linked immunosorbent assay (ELISA) kits. Student's t-test, the Mann-Whitney U test, the chi-square test, receiver operating characteristic (ROC), and logistic regression analysis were performed.

RESULTS

Sixty infants diagnosed with NEC at Stage II were enrolled in our study, with 27 in the Stage III group (n = 27) and 33 in the Stage II group (n = 33). Although many of these NEC cases were late preterm and term infants, the infants in the Stage III group had a lower gestational age (P < 0.05). The incidence of gestational diabetes mellitus, peritonitis, intestinal adhesion, and sepsis was higher and more infants in the Stage III group underwent surgeries (P < 0.05). The levels of HBD-2 and Claudin-3 were higher and neutrophil count was lower in the Stage III group than in the Stage II Group, and the area under the curve (AUC) was 0.754, 0,755, and 0.666, respectively (P < 0.05). HBD-2 ≥ 1649.02 ng/g and Claudin-3 ≥ 2488.71 pg/g were included in the multivariate stepwise logistic regression analysis (P < 0.05), and the AUC of the model was 0.805 (95% CI: 0.688-0.922).

CONCLUSION

Fecal HBD-2 and Claudin-3 may be potential biomarkers to predict the deterioration of NEC from Stage II to Stage III.

Anti-endotoxin Properties of Polymyxin B-immobilized Fibers

Polymyxin B is an antibiotic that shows strong bactericidal activity against Gram-negative bacteria, by binding to and inactivating endotoxin. Systemic administration of polymyxin B in humans is restricted because of its nephrotoxicity and neurotoxicity, and this compound was therefore considered a strong candidate ligand for the extracorporeal selective adsorption of circulating endotoxin in the blood. Toraymyxin® is a direct hemoperfusion column that uses polymyxin B attached to an insoluble carrier to bind endotoxin in the blood. In 1994, the Japanese National Health Insurance system approved the use of Toraymyxin for the treatment of endotoxemia and septic shock.In this chapter, we will review the development, clinical use, and efficacy of Toraymyxin, examine the structure of the Toraymyxin column, and comment on the current position of Toraymyxin in the treatment of severe sepsis and septic shock. We will also highlight some potential new applications of Toraymyxin for pulmonary diseases.

Sphingosine-1-Phosphate (S1P) Is a Feasible Biomarker in Predicting the Efficacy of Polymyxin B-Immobilized Fiber Direct Hemoperfusion (PMX-DHP) in Patients with Septic Shock

PURPOSE

The aim of this study was to identify a useful biomarker to predict the efficacy of polymyxin B-immobilized fiber direct hemoperfusion (PMX-DHP) in patients with septic shock.

METHODS

The 44 patients included in this study were divided into two groups. Group A had an increase in systolic blood pressure (SBP) over 30 mmHg after PMX-DHP treatment. Group B had an increase in SBP less than 30 mmHg after PMX-DHP treatment. We evaluated the clinical characteristics and demographics of both groups. We also assessed whether the cause of sepsis affected the efficacy of PMX-DHP and compared the prognosis of both groups. Finally, we investigated whether there were any significant differences in the levels of sepsis-related biomarkers, including sphingosine-1-phosphate (S1P), between both groups before PMX-DHP in an effort to identify a biomarker that could predict the efficacy of PMX-DHP.

RESULTS

PMX-DHP significantly increased SBP regardless of the cause of sepsis. Although there was some tendency, PMX-DHP did not significantly improve the prognosis of effective cases in comparison with non-effective cases, probably because of the limited number of patients included. Among the sepsis-related biomarkers, only S1P values were significantly different between the two groups before PMX-DHP, and S1P levels were significantly increased after treatment in the effective cases.

CONCLUSION

S1P levels prior to PMX-DHP can be used to predict its efficacy. In addition, continuous monitoring of S1P levels can indicate the effectiveness of PMX-DHP in patients with septic shock.

HMGB1-RAGE pathway drives peroxynitrite signaling-induced IBD-like inflammation in murine nonalcoholic fatty liver disease

Recent clinical studies found a strong association of colonic inflammation and Inflammatory bowel disease (IBD)-like phenotype with NonAlcoholic Fatty liver Disease (NAFLD) yet the mechanisms remain unknown. The present study identifies high mobility group box 1 (HMGB1) as a key mediator of intestinal inflammation in NAFLD and outlines a detailed redox signaling mechanism for such a pathway. NAFLD mice showed liver damage and release of elevated HMGB1 in systemic circulation and increased intestinal tyrosine nitration that was dependent on NADPH oxidase. Intestines from NAFLD mice showed higher Toll like receptor 4 (TLR4) activation and proinflammatory cytokine release, an outcome strongly dependent on the existence of NAFLD pathology and NADPH oxidase. Mechanistically intestinal epithelial cells showed the HMGB1 activation of TLR-4 was both NADPH oxidase and peroxynitrite dependent with the latter being formed by the activation of NADPH oxidase. Proinflammatory cytokine production was significantly blocked by the specific peroxynitrite scavenger phenyl boronic acid (FBA), AKT inhibition and NADPH oxidase inhibitor Apocynin suggesting NADPH oxidase-dependent peroxynitrite is a key mediator in TLR-4 activation and cytokine release via an AKT dependent pathway. Studies to ascertain the mechanism of HMGB1-mediated NADPH oxidase activation showed a distinct role of Receptor for advanced glycation end products (RAGE) as the use of inhibitors targeted against RAGE or use of deformed HMGB1 protein prevented NADPH oxidase activation, peroxynitrite formation, TLR4 activation and finally cytokine release. Thus, in conclusion the present study identifies a novel role of HMGB1 mediated inflammatory pathway that is RAGE and redox signaling dependent and helps promote ectopic intestinal inflammation in NAFLD.

Successful treatments with polymyxin B hemoperfusion and recombinant human thrombomodulin for fulminant Clostridium difficile-associated colitis with septic shock and disseminated intravascular coagulation: a case report

BACKGROUND

Clostridium difficile (CD)-associated colitis (CDAC) is endemic and a common nosocomial enteric disease encountered by surgeons in modern hospitals due to prophylactic or therapeutic antibiotic therapies. Currently, the incidence of fulminant CDAC, which readily causes septic shock followed by multiple organ dysfunction syndromes, is increasing. Fulminant CDAC requires surgeons to perform a prompt surgery, such as subtotal colectomy, to remove the septic source. It is known that fulminant CDAC is caused by the shift from an inflammatory response at a local mucosal level to a general systemic inflammatory reaction in which CD toxin-induced mediators' cascades disseminate. Recently, it has been proven that polymyxin B hemoperfusion (PMX-HP) improves septic shock and recombinant human thrombomodulin (rhTM) controls disseminated intravascular coagulation (DIC). In addition, clinically and basically, it has been shown that these treatments can control serous chemical mediators. Therefore, it is considered that these treatments are promising ones for patients with fulminant CDAC. In the current report, we present that these treatments without surgery contributed to the improvement of sepsis due to fulminant CDAC.

CASE PRESENTATION

We encountered a case who developed fulminant CDAC with septic shock and DIC after laparoscopic gastrectomy for gastric cancer. At admission to the intensive care unit, his APACHE II score was 22, which indicated an estimated risk of hospital death of 42.4 %. Our therapies were not the subtotal colectomy to remove septic sources but the combination treatments with both PMX-HP and rhTM. These combination therapies resulted in excellent outcomes, namely the dramatic improvement of septic shock and DIC and the patient's survival. We speculate that these combination therapies completely inhibit the CD toxin-induced mediators' cascades and correspond to the removal of septic sources.

CONCLUSIONS

We recommend both PMX-HP and rhTM for patients who develop fulminant CDAC with septic shock and DIC to increase the survival benefit and replace the need for surgical treatment.

Sepsis caused by Listeria monocytogenes during chemotherapy for small cell carcinoma of the thymus

BACKGROUND

Listeria monocytogenes is a facultative intracellular parasitic bacterium that is Gram positive, catalase positive, oxidase negative, and a facultative anaerobe. It is known to infect humans through food. It is a bacillus with low virulence, but can cause meningitis and sepsis in infants and immunocompromised patients.

CASE PRESENTATION

A case of 75-year-old Japanese female with small cell carcinoma of the thymus and pleural dissemination is described. She was treated with carboplatin and etoposide and showed a partial response. However, the tumor recurred 6 months later. Therefore, we again administered carboplatin and etoposide. Though peritoneal dissemination was suspected based on abdominal computed tomography findings after two courses, the assessment was stable disease. She was occasionally treated for constipation. She developed chills, rigor, and diarrhea, necessitating admission on the 7th day of the third course of chemotherapy. We suspected intestinal infection, and cefepime was thus administered. However, her blood pressure dropped and neutropenia manifested on the 4th day of admission. We therefore switched the antibiotic from cefepime to meropenem and also administered granulocyte-colony stimulating factor. Listeria monocytogenes was detected by two blood cultures, and the antimicrobial medication was thus switched to ampicillin, in consideration of sensitivity. Her general condition improved and she was able to leave the hospital on the 19th day after admission.

CONCLUSIONS

During chemotherapy, factors such as impaired bowel movements, malnutrition, and myeloablation can contribute to the development of severe infections. It is necessary to comprehensively assess a patient's state and treat all aspects of illness.

The effects of polymyxin B-immobilized fiber hemoperfusion on respiratory impairment in endotoxemic pigs

PURPOSE

This study investigated the effects of direct hemoperfusion with polymyxin B-immobilized fibers (PMX-DHP) on respiratory impairment in endotoxemic pigs.

MATERIALS AND METHODS

Thirteen anesthetized, mechanically ventilated pigs were divided into PMX-DHP (n=7) and control (n=6) groups. All pigs were hemodynamically monitored with the pulse index contour cardiac output (PiCCO) system (Pulsion Medical Systems, Munich, Germany) and infused intravenously with live Escherichia coli (LD50). In the PMX-DHP group, an arteriovenous extracorporeal circuit with a PMX column was applied for 30 to 150 minutes after endotoxin injection. We analyzed the laboratory data, arterial blood gas levels, and PiCCO variables (extravascular lung water [EVLW] and pulmonary vascular permeability index [PVPI]). Furthermore, we performed computed tomography of the chest in all pigs. The data were statistically analyzed with Student's t-test, the chi-square test, and the Mann-Whitney U-test.

RESULTS

With PMX-DHP endotoxemia significantly decreased and blood pressure increased 150 minutes after endotoxin injection. PiCCO revealed more cases of decreased EVLW in the PMX-DHP group. PVPI increased after endotoxin infusion in both groups. Computed tomography showed improvements in the PMX-DHP group. The survival rate was greater in the PMX-DHP group (100%) than in the control group (71%).

CONCLUSION

PMX-DHP is effective for treating respiratory impairment and contributes to the decreased mortality rate in the endotoxemic pigs.

HMGB1 in health and disease

Complex genetic and physiological variations as well as environmental factors that drive emergence of chromosomal instability, development of unscheduled cell death, skewed differentiation, and altered metabolism are central to the pathogenesis of human diseases and disorders. Understanding the molecular bases for these processes is important for the development of new diagnostic biomarkers, and for identifying new therapeutic targets. In 1973, a group of non-histone nuclear proteins with high electrophoretic mobility was discovered and termed high-mobility group (HMG) proteins. The HMG proteins include three superfamilies termed HMGB, HMGN, and HMGA. High-mobility group box 1 (HMGB1), the most abundant and well-studied HMG protein, senses and coordinates the cellular stress response and plays a critical role not only inside of the cell as a DNA chaperone, chromosome guardian, autophagy sustainer, and protector from apoptotic cell death, but also outside the cell as the prototypic damage associated molecular pattern molecule (DAMP). This DAMP, in conjunction with other factors, thus has cytokine, chemokine, and growth factor activity, orchestrating the inflammatory and immune response. All of these characteristics make HMGB1 a critical molecular target in multiple human diseases including infectious diseases, ischemia, immune disorders, neurodegenerative diseases, metabolic disorders, and cancer. Indeed, a number of emergent strategies have been used to inhibit HMGB1 expression, release, and activity in vitro and in vivo. These include antibodies, peptide inhibitors, RNAi, anti-coagulants, endogenous hormones, various chemical compounds, HMGB1-receptor and signaling pathway inhibition, artificial DNAs, physical strategies including vagus nerve stimulation and other surgical approaches. Future work further investigating the details of HMGB1 localization, structure, post-translational modification, and identification of additional partners will undoubtedly uncover additional secrets regarding HMGB1's multiple functions.

Nuclear antigens and auto/alloantibody responses: friend or foe in transplant immunology

In addition to cellular immune responses, humoral immune responses, mediated by natural antibodies, autoantibodies, and alloantibodies, have increasingly been recognized as causes of organ transplant rejection. In our previous studies, we have demonstrated the induction of antinuclear antibodies against histone H1 and high-mobility group box 1 (HMGB1), in both experimental and clinical liver transplant tolerance. The active induction of antinuclear antibodies is usually an undesirable phenomenon, but it is often observed after liver transplantation. However, the release of nuclear antigens and its suppression by neutralizing antibodies are proposed to be important in the initiation and regulation of immune responses. In this review article, we summarize the current understanding of nuclear antigens and corresponding antinuclear regulatory antibodies (Abregs) on infection, injury, inflammation, transplant rejection, and tolerance induction and discuss the significance of nuclear antigens as diagnostic and therapeutic targets.

Activation of peroxisome proliferator-activated receptor γ by rosiglitazone inhibits lipopolysaccharide-induced release of high mobility group box 1

Peroxisome proliferator-activated receptors (PPARs) are shown to modulate the pathological status of sepsis by regulating the release of high mobility group box 1 (HMGB1), a well-known late proinflammatory mediator of sepsis. Ligand-activated PPARs markedly inhibited lipopolysaccharide- (LPS) induced release of HMGB1 in RAW 264.7 cells. Among the ligands of PPAR, the effect of rosiglitazone, a specific ligand for PPARγ, was superior in the inhibition of HMGB1 release induced by LPS. This effect was observed in cells that received rosiglitazone before LPS or after LPS treatment, indicating that rosiglitazone is effective in both treatment and prevention. Ablation of PPARγ with small interfering RNA or GW9662-mediated inhibition of PPARγ abolished the effect of rosiglitazone on HMGB1 release. Furthermore, the overexpression of PPARγ markedly potentiated the inhibitory effect of rosiglitazone on HMGB1 release. In addition, rosiglitazone inhibited LPS-induced expression of Toll-like receptor 4 signal molecules, suggesting a possible mechanism by which rosiglitazone modulates HMGB1 release. Notably, the administration of rosiglitazone to mice improved survival rates in an LPS-induced animal model of endotoxemia, where reduced levels of circulating HMGB1 were demonstrated. Taken together, these results suggest that PPARs play an important role in the cellular response to inflammation by inhibiting HMGB1 release.

Effectiveness of early start of direct hemoperfusion with polymyxin B-immobilized fiber columns judging from stabilization in circulatory dynamics in surgical treatment patients

Background:

Septic shock remains a major cause of multiple organ failure and is associated with a high mortality rate. In 1994, direct hemoperfusion using a polymyxin B-immobilized fiber column (PMX; Toray Industries Inc., Tokyo Japan) was developed in Japan and has since been used for the treatment of septic shock arising from endotoxemia.

Materials and Method:

We treated 36 patients with septic shock using direct hemoperfusion with PMX. The patients were analyzed in two groups based on whether they had undergone surgery prior to DHP-PMX treatment (surgical group: surgical treatment before DHP-PMX, medical group: no surgical treatment). In surgical group, DHP-PMX was started within three hours after the surgical treatment. Various factors were measured before and after DHP-PMX.

Results:

The mean Acute Physiology and Chronic Health Evaluation (APACHE) II score was 27.4 ± 8.8, and the mean sepsis-related organ failure assessment (SOFA) score was 11.8 ± 4.9 before DHP-PMX. The SOFA score was significantly higher (P = 0.0091) and the PaO2/FiO2 ratio (P/F ratio) was significantly lower (P = 0.0037) in medical group than in surgical group prior to DHP-PMX. A chi-square test showed that the survival rate in surgical group was significantly better than in medical group (P = 0.0027). The survival rate of surgical group (84.2%) was judged to be very good because the predicated survival rate based on the APACHE II score (25.0) was only 46.5%. On the other hand, the survival rate of medical group (35.3%) was almost equal to that predicted by the APACHE II score (30.6; predicted survival rate, 27.4%).

Conclusion:

The results of this study suggest the utility of early DHP-PMX in surgical group.

HMGB1 is a therapeutic target for sterile inflammation and infection

A key question in immunology concerns how sterile injury activates innate immunity to mediate damaging inflammation in the absence of foreign invaders. The discovery that HMGB1, a ubiquitous nuclear protein, mediates the activation of innate immune responses led directly to the understanding that HMGB1 plays a critical role at the intersection of the host inflammatory response to sterile and infectious threat. HMGB1 is actively released by stimulation of the innate immune system with exogenous pathogen-derived molecules and is passively released by ischemia or cell injury in the absence of invasion. Established molecular mechanisms of HMGB1 binding and signaling through TLR4 reveal signaling pathways that mediate cytokine release and tissue damage. Experimental strategies that selectively target HMGB1 and TLR4 effectively reverse and prevent activation of innate immunity and significantly attenuate damage in diverse models of sterile and infection-induced threat.

Direct hemoperfusion with polymyxin B immobilized fiber for abdominal sepsis in Europe

Since direct hemoperfusion with polymyxin B immobilized fiber (PMX-DHP) received its product certification for use in Europe in 1998, several prospective randomized controlled trials (RCTs) have been conducted in European countries. The first RCT, performed in six European academic medical centers in 2005, concluded that PMX-DHP is associated with improved hemodynamic status and cardiac function. Subsequently, a meta-analysis of PMX-DHP was presented in Italy in 2007. This systematic review found positive effects of PMX-DHP on mean arterial pressure and dopamine/ dobutamine use, PaO2/FiO2 ratio, endotoxin removal, and mortality. However, like most trials on extracorporeal therapies, none of the studies was double-blinded. The EUPHAS study, a multicenter RCT performed in ten Italian intensive care units in 2009, found that PMX-DHP improved 28-day survival, blood pressure, vasopressor requirement, and degree of organ failure. However, investigators in Belgium and Canada pointed out that there was no statistical difference in 28-day survival. Two more RCTs, the ABDO-MIX and EUPHRATES studies, the primary end points of which are 28-day mortality, were started in Europe and the United States at the end of 2010. We are hoping that these RCTs will resolve this issue.

Intraoperative direct hemoperfusion with a polymyxin-B immobilized fiber column for treatment of infective endocarditis

PURPOSE

Endotoxin adsorption treatment (direct hemoperfusion using a polymyxin-B immobilized fiber column, or PMX-DHP) is now considered a useful option for treating severe sepsis. However, the efficacy of PMX-DHP for infective endocarditis (IE), in which the causative microorganisms are usually gram-positive cocci, remains unclear. In the present study, we investigated the impact of intraoperative PMX-DHP on clinical parameters during the treatment of IE.

METHODS

From November 2006 to December 2009, a total of 11 patients with active IE underwent emergent surgery using intraoperative PMX-DHP. The perioperative courses of these patients were compared with those of seven patients who underwent emergent surgery for active IE with the conventional method from January 2003 to October 2006.

RESULTS

PMX-DHP was associated with a significant decrease in the postoperative catecholamine dose and duration. Intubation time and intensive care unit length of stay for the PMX-DHP group was significantly shorter than that for the conventional therapy group. There was also a significant difference in the number of failed organs postoperatively between the two groups.

CONCLUSION

Intraoperative PMX-DHP demonstrated several positive effects, such as a drastic decrease in the doses of inotropic agents and shortening of the duration of mechanical ventilation, in patients who underwent emergent surgery for active IE. Intraoperative PMX-DHP can be a useful option for the treatment of critically ill patients with IE.

Association of high mobility group box-1 protein levels with sepsis and outcome of severely burned patients

BACKGROUND

The study was performed to observe the systemic release and kinetics of high mobility group box-1 protein (HMGB1) in burned patients.

METHODS

106 patients were included, and they were divided into three groups with different burn sizes: group I, group II and group III. Healthy volunteers served as normal controls (n=25). The peripheral blood samples were collected on postburn days (PBD) 1, 3, 7, 14, and 21. The blood samples were used to detect levels of HMGB1 in plasma by ELISA kits for human. Gene expression of HMGB1 in peripheral blood mononuclear cells was assessed by real-time quantitative PCR taking GAPDH as the internal standard.

RESULTS

The levels of HMGB1 were significantly elevated on PBD 1-21 in patients with various burn sizes compared with normal controls, and there were obvious differences between group I and group III. The HMGB1 levels were significantly higher in septic patients than those without sepsis on PBD 7-21. Among septic patients, the HMGB1 levels in the survival group were markedly lower than those with fatal outcome on PBD 3-21.

CONCLUSIONS

Extensive burn injury could result in significantly increased HMGB1 levels, which appears to be associated with the development of sepsis and fatal outcome of major burns.

Effectiveness of endotoxin scattering photometry for determining the efficacy of polymyxin B-immobilized fiber treatment in septic shock: report of a case

The limulus test, which has been established as a test for endotoxin measurement, is associated with problems, including that posed by the presence of a response inhibitor factor and the longer time needed for the measurement of low concentrations. On the other hand, the technique of direct hemoperfusion with a polymyxin B immobilized fiber column (DHP-PMX) was developed in Japan in 1994 and has been used for the control of endotoxemia in septic shock. The limulus test, which is a common endotoxin measurement test, has several problems with regard to sensitivity. Therefore, this test is no longer used to determine the effectiveness of DHP-PMX. Here, we describe a patient presenting with colonic perforation who recovered from septic shock with DHP-PMX. This treatment effect was reflected by a decrease in plasma endotoxin levels as demonstrated more readily with endotoxin scattering photometry assay than with the standard limulus test. We conclude that endotoxin measurement with endotoxin scattering photometry is superior to nephelometry in patients with endotoxemia.

High-mobility-group box chromosomal protein 1 as a new target for modulating stress response

Major surgical procedures induce a systemic inflammatory response syndrome (SIRS) characterized by the overproduction of proinflammatory cytokines, which induces excessive stress and may trigger postoperative complications. This has prompted the hypothesis that drugs which relieve SIRS might improve the postoperative course of major surgery. One of the most promising targets for these drugs is high-mobility-group box chromosomal protein 1 (HMGB1). In 1999, HMGB1 was found to be a key late mediator of sepsis. It is now known to be associated with various kinds of acute and chronic inflammation, and is recognized as one of the most important danger signals in stress response. In this article, we present the latest information about HMGB1 and discuss its promise as a novel target for modulating stress response.

A longer duration of polymyxin B-immobilized fiber column hemoperfusion improves pulmonary oxygenation in patients with septic shock

Endotoxin plays an important role in the pathogenesis of septic shock. Exposure of endothelial cells to endotoxin activates endothelial cells and increases the surface expression of adhesion molecules, markers of endothelial damage in organ dysfunction. Endotoxin adsorption therapy by polymyxin B-immobilized fiber column (PMX) hemoperfusion has been used for the treatment of septic shock patients. In this study, we measured plasma concentrations of endotoxin and soluble adhesion molecules in septic shock patients before and after the PMX treatment then observed on the relationships between actual duration of use and various outcomes. Sixteen patients with septic shock were studied. The 28-day mortality rate was 50%. The elevated plasma concentrations of endotoxin decreased after the PMX treatment in the survivors but not in the nonsurvivors. The norepinephrine dose and plasma concentrations of soluble endothelial leukocyte adhesion molecule 1 and soluble intercellular adhesion molecule 1 significantly (P < 0.05) decreased in the PMX greater-than-2-h (prolonged) group than in the PMX 2-h (conventional) group (-17.8 +/- 14.6 vs. -1.8 +/- 2.7 microg/min, -143.0 +/- 111.0 vs. 0 +/- 2.8 ng/mL, and -126.2 +/- 144.9 vs. 16.5 +/- 108.1 ng/mL, respectively). Changes in the PaO2-FiO2 ratio and the Sequential Organ Failure Assessment score were significantly (P < 0.05) more improved in the PMX greater-than-2-h group than in the PMX 2-h group (75.4 +/- 80.7 vs. 1.2 +/- 49.2 and -0.8 +/- 1.8 vs. 2.2 +/- 1.9 torr, respectively). We thus suggest that a longer duration of PMX treatment may improve the pulmonary oxygenation associated with decreased adhesion molecules in septic shock.

Targeting HMGB1 in inflammation

High mobility group box 1 (HMGB1), a highly conserved, ubiquitous protein present in the nuclei and cytoplasm of nearly all cell types, is a necessary and sufficient mediator of inflammation during sterile and infection-associated responses. Elevated levels of HMGB1 in serum and tissues occur during sterile tissue injury and during infection, and targeting HMGB1 with antibodies or specific antagonists is protective in established preclinical inflammatory disease models including lethal endotoxemia or sepsis, collagen-induced arthritis, and ischemia-reperfusion induced tissue injury. Future advances in this field will stem from understanding the biological basis for the success of targeting HMGB1 to therapeutic improvement in the treatment of inflammation, infection and ischemia-reperfusion induced injury.

Effect of polymyxin B-immobilized fiber hemoperfusion on serum high mobility group box-1 protein levels and oxidative stress in patients with acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is characterized by diffuse inflammation in the lung and resultant permeability edema. Polymyxin B-immobilized fiber (PMX-F) hemoperfusion is effective for sepsis-induced ARDS. High mobility group box-1 protein (HMGB1) is newly recognized as a proinflammatory cytokine. The aim of the study was to determine whether blood HMGB1 levels are increased in patients with ARDS and whether PMX-F treatment affects these levels. Subjects were 20 sepsis-induced patients with ARDS treated by PMX-F column and 20 age-matched healthy volunteers. Polymyxin B-immobilized fiber treatment was carried out twice at a rate of 100 ml/min for 2 hours. Systolic and diastolic blood pressures, the PaO2/FiO2 (PF) ratio and endotoxin, HMGB1, and urinary 8-hydroxy-2'-deoxyguanosine (OHdG) levels were measured before and after PMX-F treatment. Blood endotoxin levels, blood HMGB1 levels, and urinary 8-OHdG levels were significantly higher in patients with ARDS than in healthy volunteers. Systolic and diastolic blood pressures and the PF ratio increased significantly after PMX-F treatments. Polymyxin B-immobilized fiber treatment reduced blood endotoxin, blood HMGB1, and urinary 8-OHdG levels significantly. These data suggest that HMGB1 and oxidative stress play a role in the pathogenesis of ARDS and that PMX-F treatment may ameliorate increased blood HMGB1 and urinary 8-OHdG levels in patients with ARDS.

Sepsis strategies in development

Severe sepsis, defined as inflammation and organ failure due to infection, continues to result in a mortality of approximately 30% despite advances in critical care. Current therapy includes timely administration of antibiotics, source control of infection, aggressive fluid resuscitation, support of failing organs, and use of activated protein C where clinically indicated. Bacterial mediators, including endotoxin and superantigens, as well endogenous proinflammatory cytokines are considered important to the pathogenesis of sepsis-induced organ failure and are being targeted with numerous molecules and removal devices. Additional therapeutic strategies are aimed at restoring the natural anticoagulant levels, blocking deleterious effects of the complement cascade, reversing cytopathic hypoxia, and inhibiting excessive lymphocyte apoptosis. Molecules with pluripotent activity, such as interalpha inhibitor proteins and estrogen-receptor ligands, are also being investigated.

Relationship between treatment resistance to hemoperfusion using a polymyxin B-immobilized fiber column and oxidative stress

Recently, the existence of a relationship was reported between the severity of lung injury and the serum level of F2-isoprostane, a known oxidative stress marker. Recent reports have suggested that direct hemoperfusion with a polymyxin B-immobilized fiber column (DHP-PMX) may improve the oxygenation in patients with acute lung injury and acute respiratory distress syndrome. Because cases of septic shock associated with respiratory diseases have poor outcomes, we selected cases of septic shock associated with respiratory disease to review the characteristics of the treatment-resistant cases. We treated 13 septic shock cases due to respiratory disease using DHP-PMX. The patients were separated into 2 groups for analysis from oxygenation effect immediately after DHP-PMX: A group (7 cases) PaO2/FiO2 ratio increased more than 20%; B group (6 cases) PaO2/FiO2 ratio did not increase more than 20%. Factors were measured before DHP-PMX. The average Acute Physiology and Chronic Health Evaluation II score was 31.2 +/- 9.4, and the average sequential organ failure assessment score was 15.1 +/- 5.3 before DHP-PMX. Four patients survived and 9 died. Only the F2-Isoprostane level was significantly high in B group (p = 0.0228). A relationship between F2-Isoplostane and rebellious cases by DHP-PMX in severe respiratory disease patients became clear.

Bench-to-bedside review: High-mobility group box 1 and critical illness

High-mobility group box 1 (HMGB1) is a DNA-binding protein that also exhibits proinflammatory cytokine-like activity. HMGB1 is passively released by necrotic cells and also is actively secreted by immunostimulated macrophages, dendritic cells, and enterocytes. Although circulating HMGB1 levels are increased relative to healthy controls in patients with infections and severe sepsis, plasma or serum HMGB1 concentrations do not discriminate reliably between infected and uninfected critically ill patients. Nevertheless, administration of drugs that block HMGB1 secretion or of anti-HMGB1 neutralizing antibodies has been shown to ameliorate organ dysfunction and/or improve survival in numerous animal models of critical illness. Because HMGB1 tends to be released relatively late in the inflammatory response (at least in animal models of endotoxemia or sepsis), this protein is an attractive target for the development of new therapeutic agents for the treatment of patients with various forms of critical illness.

Clinical responses and improvement of some laboratory parameters following polymyxin B-immobilized fiber treatment in septic shock

Direct hemoperfusion using a polymyxin B-immobilized fiber column (PMX; Toray Industries Inc., Tokyo, Japan) was first developed in 1994 and has since been used for the treatment of septic shock. Positive clinical data, such as an increase in systolic blood pressure (SBP) and an improved Pao2/Fio2 ratio, have also been reported. We treated 27 septic shock patients using DHP-PMX. The patients were separated into two groups for analysis: those whose Pao2/Fio2 ratio increased after DHP-PMX (9 cases) and those whose Pao2/Fio2 ratio did not increase after DHP-PMX (18 cases). The patients were also separated into two other groups for analysis: those whose SBP increased by more than 30 mm Hg immediately after DHP-PMX (15 cases) and those whose SBP did not increase by more than 30 mm Hg after DHP-PMX (12 cases). The Pao2/Fio2 ratio increased significantly after DHP-PMX in the groups showing improved 2AG and PAI-1 levels (p = 0.0040). The SBP increased significantly in the group showing improved HMGB-1 levels (p < 0.0001). We observed a relationship between hemodynamic improvement and increase of the serum HMGB-1 levels and between improvement of respiratory functions and increase of the serum 2-AG and PAI-1 levels in septic shock patients treated with DHP-PMX.