Modulation of human leukocyte antigen-DR on monocytes and CD16 on granulocytes in patients with septic shock using hemoperfusion with polymyxin B-immobilized fiber

The role of polymyxin B-immobilized hemoperfusion in reducing mortality and enhancing hemodynamics in patients with sepsis and septic shock: A systematic review and meta-analysis

Purpose

Polymyxin B-immobilized hemoperfusion (PMX-HP) is a therapeutic strategy for removing circulating endotoxins from patients with sepsis or septic shock. However, the survival advantage of PMX-HP treatment remains controversial for patients with sepsis/septic shock. Therefore, this study collected all the clinical trials to assess the effect and the safety of PMX-HP treatment.

Methods

PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials were searched for eligible trials fromtheir inception through June 30, 2023. All clinical trials that investigated the effect of polymyxin B hemoperfusion in patients who died with sepsis or septic shock within 28-day mortality were eligible. The Cochrane Risk of Bias Assessment instrument and the ROBINS-I tool were used to assess the risk of bias.

Results

A total of 30 trials, including 25680 adult patients, were included. PMX-HP decreased 28-day mortality (OR 0.75, 95 % CI 0.65-0.88; p＜0.00001). Subgroup analysis revealed that 28-day mortality was significantly reduced after PMX-HP treatment in the mixed infection site group and in the age under 70 years old group. PMX-HP might also lower endotoxin levels (MD -1.22, 95 % CI -1.62 - 0.81, p < 0.00001) and improve SOFA scores (MD -2.11, 95 % CI -3.80- 0.43, p = 0.01). PMX-HP was not linked to the development of significant adverse events (p = 0. 05).

Conclusion

Our findings suggest that PMX-HP therapy can reduce 28-day mortality in individuals with sepsis or septic shock. The therapeutic effect may be due to the ability of PMX-HP to lower endotoxin levels and enhance hemodynamics. However, further assessment of the clinical effects of PMX-HP on sepsis or septic shock is required.

Extracorporeal Blood Purification in Burns: For Whom, Why, and How?

Patients with serious thermal burn injuries require immediate and specialized care in order to minimize morbidity and mortality. Optimal fluid resuscitation, nutritional support, pulmonary care, burn wound care, and infection control practices represent key aspects of patient care in burn centers. When severely burned, the patient usually presents a systemic inflammatory response syndrome, soon balanced by a counter anti-inflammatory response syndrome. These may lead to immune dysregulation/exhaustion favoring infectious complications that dramatically impair the prognosis of burn patients. This narrative review provides an overview of the main concepts, current understanding, and potential applications of extracorporeal blood purification techniques for burn patient management. Current understanding of burn patients' immune responses is reported. Hypotheses and data on the potential value of immunoregulation are reviewed. Finally, how extracorporeal blood purification may be of interest in this specific population is discussed.

Cellular Immuno-Profile in Septic Human Host: A Scoping Review

Simple Summary

Septic shock is a life-threatening disease caused by a dysregulated host response to infection, affecting millions of people every year and killing more than 25% directly despite advances in modern medicine. This pathology is characterized by apoptosis-induced depletion of immune cells and immunodepression. Many alterations in the expression of surface markers of neutrophils and monocytes have been described in septic patients. There is no specific treatment but the early identification and diagnosis of the pathology as well as timely treatment can greatly improve patient outcomes. The aim of this study was to inspect the recently published literature to inform the clinician about the most up-to-date techniques for the study of immune cell phenotypes and on the function of leukocytes of extracorporeal and non-blood purification treatments proposed for sepsis were also analyzed. The most important alteration observed in septic neutrophils is the activation of a survival program capable of resisting apoptotic death. As regards adaptive immunity, sepsis-induced apoptosis leads to lymphopenia in patients with septic shock and this process involves all types of T cells (CD4, CD8 and Natural Killer), except for regulatory T cells, favoring immunosuppression. Several promising therapies that target the host’s immune response to sepsis are currently under evaluation.

Abstract

Innate and adaptive immune system cells play a critical role in the host response to sepsis. Sepsis is a life-threatening disease characterized by apoptosis-induced depletion of immune cells and immunodepression, which contribute to morbidity and mortality. Many alterations in the expression of surface markers of neutrophils and monocytes have been described in septic patients. The aim of this study was to inspect the recently published literature to inform the clinician about the most up-to-date techniques for the study of circulating leukocytes. The impact on cell phenotypes and on the function of leukocytes of extracorporeal and non-blood purification treatments proposed for sepsis were also analyzed. We conducted a systematic review using Pubmed/Medline, Ovid/Willey, the Cochrane Library, the Cochrane Controlled Trials Register, and EMBASE, combining key terms related to immunological function in sepsis and selected the most relevant clinical trials and review articles (excluding case reports) published in the last 50 years. The most important alteration in neutrophils during sepsis is that they activate an anti-apoptotic survival program. In septic monocytes, a reduced characteristic expression of HLA-DR is observed, but their role does not seem to be significantly altered in sepsis. As regards adaptive immunity, sepsis leads to lymphopenia and immunosuppression in patients with septic shock; this process involves all types of T cells (CD4, CD8 and Natural Killer), except for regulatory T cells, which retain their function. Several promising therapies that target the host immune response are currently under evaluation. During the worldwide pandemic caused by SARS-CoV-2, it was useful to study the “cytokine storm” to find additional treatments, such as the oXiris^® filter. This therapy can decrease the concentration of inflammatory markers that affect the severity of the disease.

MHCII Expression on Peripheral Blood Monocytes in Canine Lymphoma: An Impact of Glucocorticoids

Simple Summary

Loss or decreased expression of human leukocyte antigen—D-related (HLA-DR) on the surface of monocytes is related to the dysfunction of the immune system and was reported in human neoplasia, including lymphoma. Canine lymphoma is frequently presented as a valuable comparative model for studies on human non-Hodgkin’s lymphoma. However, there are no studies on the expression of analogue proteins—MHCII antigens—on monocytes in canine lymphoma. In this study, we have evaluated the changes in the expression of MHCII on monocytes in the blood of dogs with lymphoma before any treatment and in dogs that had previously received glucocorticoids. Glucocorticoids are often used by clinicians as first drugs after diagnosis for immediate health improvement and are known to impact monocyte number. We have shown an increase in the percentage of MHCII− monocytes, regardless of treatment. However, only in dogs that had received glucocorticoids were changes in the proportion of MHCII+ and MHCII− monocytes reflected also by the changes in the number of MHCII− monocytes in the blood, which was significantly higher. Evaluating the changes in canine monocytes might be helpful in the diagnosis of various tumor types, monitoring of the treatment or assessing the immune status of dogs.

Abstract

An increase in the percentage of monocytes with reduced HLA-DR expression and immunosuppressive properties has been reported in numerous human neoplastic diseases, including lymphoma. However, there are no analogous studies on phenotypical variations in the peripheral blood monocytes in dogs with lymphoma. The aim of this study was to determine the difference in the expression of the MHCII molecule on peripheral blood monocytes in dogs with lymphoma before any treatment (NRG) and in dogs that had previously received glucocorticoids (RG) in comparison to healthy dogs. Flow cytometry immunophenotyping of peripheral blood leukocytes was performed using canine-specific or cross-reactive antibodies against CD11b, CD14 and MHCII. In the blood of dogs with lymphoma (NRG and RG), compared to that of healthy ones, the MHCII+ and MHCII− monocytes ratio was changed due to an increase in the percentage of MHCII− monocytes. The number of MHCII− monocytes was significantly higher only in RG dogs compared to healthy ones, which might result from the release of these cells from the blood marginal pool due to the action of glucocorticoids. Our results encourage further studies to assess if changes in MHCII expression affect immune status in dogs with lymphoma.

Up-to-date information on polymyxin B-immobilized fiber column direct hemoperfusion for septic shock

Endotoxin adsorption therapy by polymyxin B-immobilized fiber column direct hemoperfusion (PMX-DHP) has been used for the treatment of septic shock patients. Endotoxin, an outer membrane component of Gram-negative bacteria, plays an important role in the pathogenesis of septic shock. Endotoxin triggers a signaling cascade for leukocytes, macrophage, and endothelial cells to secrete various mediators including cytokines and nitric oxide, leading to septic shock and multiple organ dysfunction syndrome. PMX-DHP directly adsorbed not only endotoxin but also monocytes and anandamide. It reduced blood levels of inflammatory cytokines such as interleukin (IL)-1, IL-6, tumor necrosis factor-alpha and IL-17A, adhesion molecules, plasminogen activator inhibitor 1, and high mobility group box-1. As a result, PMX-DHP increased blood pressure and reduced the dose of vasoactive-inotropic agents. PMX-DHP improved monocyte human leukocyte antigen-DR expression in patients with severe sepsis and septic shock. A post hoc analysis of EUPHRATES (Evaluating the Use of Polymyxin B Hemoperfusion in Randomized Controlled Trial of Adults Treated for Endotoxemia and Septic Shock) trial has shown that PMX-DHP significantly reduced 28-day mortality compared with the control group in septic shock patients with endotoxin activity assay level between 0.60 and 0.89. Longer duration of PMX-DHP may be another strategy to bring out the beneficial effects of PMX-DHP. Further studies are needed to confirm the efficacy of PMX-DHP treatment for septic shock.

Therapeutic Rationale for Endotoxin Removal with Polymyxin B Immobilized Fiber Column (PMX) for Septic Shock

Endotoxin removal therapy with polymyxin B immobilized fiber column (PMX) has been clinically applied for sepsis and septic shock patients since 1994. The effectiveness and usefulness of this therapy have been demonstrated for more than a quarter of a century. However, a documented survival benefit has not yet been demonstrable in a large, multicenter, randomized and controlled trial. Following the findings derived from a large sepsis clinical trial with PMX in North America, a new trial is ongoing to determine if PMX has a long-term survival benefit when administered to septic patients. Another approach to support a survival benefit from intervention with PMX is to utilize a detailed analysis available from a large clinical data base. The endotoxin adsorption capacity of PMX columns in vitro and the effectiveness of PMX columns can be further demonstrable in animal models. The capability of PMX and details of its mechanism of action to intervene in the sepsis cascade and impede organ dysfunction in septic patients is not fully understood. The surface antigen expression in monocytes and neutrophils are improved after PMX therapy. Immunomodulatory effects as a result of endotoxin removal and/or other mechanisms of action have been suggested. These effects and other potential immune effects may explain some of the improved effects upon organ dysfunction of sepsis and septic shock patients. Endotoxemia may be involved in the pathophysiology of other diseases than sepsis. A rapid diagnostic method to detect and target endotoxemia could allow us to practice precision medicine and expand the clinical indications of endotoxin removal therapy.

A Novel Surface Modification and Immobilization Method of Anti-CD25 Antibody on Nonwoven Fabric Filter Removing Regulatory T Cells Selectively

Anti-CD25 antibodies were immobilized on polypropylene (PP) nonwoven fabrics to specifically remove mouse regulatory T cells (Tregs) from mouse spleen cells. PP fibers were coated with peptide nanosheets, which were prepared by self-assembling of a mixture of X-poly(sarcosine)-b-(l-Leu-Aib)6 (X: glycolic acid or a phenylboronic acid) and Y-poly(sarcosine)-b-(d-Leu-Aib)6 (Y: glycolic acid or diazirine derivative). Anti-CD25 antibodies were immobilized by covalent linking between the sugar moiety of the antibody and the phenylboronic acid group on the peptide nanosheet. The removal rate of mouse Tregs from the mouse spleen cells was more than 95% only by passing the filters, while the nonspecific removal rates of other cells were less than 15%. The coating of peptide nanosheets on PP fibers was very effective to provide a suitable environment for the immobilized antibody to interact with the counterpart cells while the coating suppressed nonspecific adsorption of other cells.

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.

The effect of polymyxin B hemoperfusion on modulation of human leukocyte antigen DR in severe sepsis patients

BACKGROUND

Recent randomized trials have not found that polymyxin B hemoperfusion (PMX-HP) improves outcomes for patients with sepsis. However, it remains unclear whether the therapy could provide benefit for highly selected patients. Monocyte human leukocyte antigen (mHLA-DR) expression, a critical step in the immune response, is decreased during sepsis and leads to worsening sepsis outcomes. One recent study found that PMX-HP increased mHLA-DR expression while another found that the treatment removed HLA-DR-positive cells.

METHODS

We conducted a randomized controlled trial in patients with blood endotoxin activity assay (EAA) level ≥ 0.6. Patients in the PMX-HP group received a 2-h PMX-HP treatment plus standard treatment for 2 consecutive days. Patients in the non-PMX-HP group received only standard treatment. The primary outcome compared the groups on median change in mHLA-DR expression between day 3 and baseline. Secondary outcomes compared the groups on the mean or median change in CD11b expression, neutrophil chemotaxis, presepsin, cardiovascular Sequential Organ Failure Assessment (CVS SOFA) score, vasopressor dose, and EAA level between day 3 and baseline. We further compared the groups on mortality, ICU-free days, ventilator-free days, dialysis dependence status, renal recovery, serum creatinine, vasopressor-free days, and major adverse kidney events (MAKE 28), measured on day 28.

RESULTS

Fifty-nine patients were randomized to PMX-HP (n = 29) and non-PMX-HP (n = 30) groups. At baseline, mHLA-DR expression, CD11b, neutrophil chemotaxis, and clinical parameters were comparable between groups. The median change in mHLA-DR expression between day 3 and baseline was higher in PMX-HP patients than in patients receiving standard therapy alone (P = 0.027). The mean change in CD11b between day 3 and baseline was significantly lower in the PMX-HP group than in the non-PMX-HP group (P = 0.002). There were no significant changes from baseline in neutrophil chemotaxis, presepsin, CVS SOFA scores, vasopressor doses, or EAA level between groups. On day 28 after enrollment, mortality, ICU-free days, ventilator-free days, dialysis dependence status, renal recovery, serum creatinine, vasopressor-free days, and MAKE 28 were comparable between groups.

CONCLUSION

PMX-HP improved mHLA-DR expression in severe sepsis patients. Future studies should examine the potential benefit of PMX-HP in patients with low mHLA-DR expression.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02413541 . Registered on 3 March 2015.

Mechanisms of sepsis-induced immunosuppression and immunological modification therapies for sepsis

Surgical injury can be a life-threatening complication, not only due to the injury itself, but also due to immune responses to the injury and subsequent development of infections, which readily result in sepsis. Sepsis remains the leading cause of death in most intensive care units. Unfavorable outcomes of several high-profile trials in the treatment of sepsis have led researchers to state that sepsis studies need a new direction. The immune response that occurs during sepsis is characterized by a cytokine-mediated hyper-inflammatory phase, which most patients survive, and a subsequent immunosuppressive phase. Therefore, therapies that improve host immunity might increase the survival of patients with sepsis. Many mechanisms are responsible for sepsis-induced immunosuppression, including apoptosis of immune cells, increased regulatory T cells and expression of programmed cell death 1 on CD4+ T cells, and cellular exhaustion. Immunomodulatory molecules that were recently identified include interleukin-7, interleukin-15, and anti-programmed cell death 1. Recent studies suggest that immunoadjuvant therapy is the next major advance in sepsis treatment.

Septic shock from descending necrotizing mediastinitis - combined treatment with IgM-enriched immunoglobulin preparation and direct polymyxin B hemoperfusion: a case report

Background

Descending necrotizing mediastinitis is a common and progressive polymicrobial infection involving the neck and chest with a high death rate (10 to 40%). From a microbiological point of view, descending necrotizing mediastinitis is sustained by Gram-positive bacteria (43–62%), anaerobes (46–78%), and, rarely, Gram-negative bacteria. Data collected during the Antibiotic Resistance-Istituto Superiore di Sanità project confirmed that Italy is positioned among the countries with the highest levels of resistance in most pathogenic species under surveillance. In particular, 32.9% of Klebsiella pneumoniae isolates were resistant to carbapenem, 33.6% of Staphylococcus aureus to methicillin, and 28.7% and 43.9% of Escherichia coli isolates to third-generation cephalosporins and fluoroquinolones, respectively.

Case presentation

We describe the case of a 38-year-old white man with septic shock due to descending necrotizing mediastinitis sustained by multidrug-resistant Gram-negative and Gram-positive bacteria treated after surgery with an IgM-enriched immunoglobulin preparation and polymyxin B hemoperfusion therapy.

Conclusion

Despite the contrasting data on the use of immunoglobulins and polymyxin B hemoperfusion in septic shock and the lack of literature in cases of acute mediastinitis caused by both Gram-negative and Gram-positive multidrug-resistant bacteria, we obtained an improvement in clinical conditions and the survival of our patient, against all odds.

Clinical effects of direct hemoperfusion using a polymyxin B-immobilized fiber column in clinically amyopathic dermatomyositis-associated rapidly progressive interstitial pneumonias

Background

Rapidly progressive interstitial pneumonias (RPIPs) associated with clinically amyopathic dermatomyositis (CADM) are highly resistant to therapy and have a poor prognosis. Multimodal therapies, including direct hemoperfusion using a polymyxin B-immobilized fiber column (PMX-DHP), have a protective effect on RPIPs. We evaluated the effects of PMX-DHP on CADM-associated RPIPs.

Methods

We retrospectively enrolled 14 patients with CADM-associated RPIPs and acute respiratory failure treated with PMX-DHP, corticosteroids, and immunosuppressive agents. Clinical manifestations were compared between survivors and non-survivors at 90 days after PMX-DHP.

Results

The survival rate at 90 days after PMX-DHP was 35.7% (5/14). Before PMX-DHP, the survivor group exhibited a significantly higher PaO₂/FiO₂ (P/F) ratio and serum surfactant protein-D (SP-D) levels and significantly lower lactate dehydrogenase (LDH) and ferritin levels than the non-survivor group. Platelet counts were significantly decreased after PMX-DHP therapy in both groups, but remained higher in the survivor group than the non-survivor group over the course of treatment. Anti-melanoma differentiation-associated gene 5 (MDA-5) antibody positive patients demonstrated a poor 90-day survival rate, lower platelet counts and P/F ratio, and higher LDH levels than anti-MDA-5 antibody negative patients.

Conclusions

CADM-associated RPIPs with anti-MDA-5 antibody is associated with a very poor prognosis. A higher P/F ratio and SP-D level, lower LDH and ferritin levels, higher platelet counts, and anti-MDA-5 antibody negativity are important prognostic markers in patients with CADM-associated RPIPs treated with PMX-DHP.

Potential survival benefit of polymyxin B hemoperfusion in patients with septic shock: a propensity-matched cohort study

BACKGROUND

The purpose of this study was to investigate whether polymyxin B hemoperfusion (PMX-HP) improves the survival of patients with septic shock.

METHODS

This was a retrospective, multicenter study conducted on patients treated during a 3-year period. We performed propensity-score analyses of the Japan Septic Disseminated Intravascular Coagulation (JSEPTIC DIC) study database. The study included data on 1723 patients with septic shock aged 16 years or older. Furthermore, we divided patients into to PMX-HP- and non-PMX-HP-treated groups. The primary endpoint was all-cause hospital mortality; secondary endpoints included intensive care unit (ICU) mortality and number of ICU-free days (ICUFDs) in the first 28 days.

RESULTS

Of 1,723 eligible patients, 522 had received PMX-HP. Propensity score matching created 262 matched pairs (i.e., 262 patients in each of the non-PMX-HP and PMX-HP groups). The proportion of all-cause hospital mortality was significantly lower in the PMX-HP group than in the non-PMX-HP group (32.8% vs. 41.2%; odds ratio (OR): 0.681; 95% confidence interval (CI): 0.470-0.987; P = 0.042). The number of ICUFD in the first 28 days was significantly higher in the PMX-HP group than in the non-PMX-HP group (18 (0-22) vs. 14 (0-22) days, respectively; P = 0.045). On the other hand, there was no significant difference in ICU mortality between the two groups (21.8% vs. 24.4%; OR: 0.844; CI: 0.548-1.300; P = 0.443).

CONCLUSIONS

Our results strongly suggest that PMX-HP reduces all-cause hospital mortality and length of ICU stay in patients with septic shock.

Efficacy of direct hemoperfusion using polymyxin B-immobilized fiber column (PMX-DHP) in rapidly progressive interstitial pneumonias: results of a historical control study and a review of previous studies

BACKGROUND

Direct hemoperfusion using polymyxin B-immobilized fiber column (PMX-DHP) therapy has been approved for sepsis-associated acute respiratory distress syndrome, but its efficacy for other rapidly progressive interstitial pneumonias (RPIPs) is unclear. The purpose of this study was to examine the efficacy of PMX-DHP therapy for acute respiratory failure in patients with RPIPs, when compared with a historical control receiving conventional treatment without PMX-DHP.

METHODS

This study comprised 77 patients with RPIPs in our institute between January 2002 and December 2015. The initial 36 patients between January 2002 and March 2007 were treated without PMX-DHP (historical control group), and the following 41 patients between April 2007 and December 2015 were treated with PMX-DHP (PMX-DHP group) once daily for two successive days concurrently with corticosteroids and/or immunosuppressive agents. The 90-day mortality and clinical factors were compared between the groups. Cox proportional hazards models were constructed to analyze 90-day mortality and identify predictors.

RESULTS

The 90-day mortality rate was significantly lower in the PMX-DHP group than in the controls (41.5% versus 66.7%, p = 0.019). PMX-DHP therapy was significantly associated with mortality (hazard ratio 0.505; 95% confidence interval, 0.270-0.904; p = 0.032). There were significant differences in the serial changes in the PaO₂/FiO₂ ratio, SOFA score, and blood neutrophil counts from days 0-5 after PMX-DHP between the survivor and non-survivor groups ( p = 0.015, p < 0.001, p = 0.035, respectively). The improved PaO₂/FiO₂ ratio on day 3 significantly correlated with the change in blood neutrophil counts (r_s = -0.431, p = 0.006).

CONCLUSIONS

PMX-DHP therapy may be effective in RPIPs patients accompanied by acute respiratory failure and is expected to reduce mortality rates.

Leukocytapheresis for the treatment of acute exacerbation of idiopathic interstitial pneumonias: a pilot study

OBJECTIVE

Idiopathic interstitial pneumonias (IIPs) are a group of heterogeneous diffuse parenchymal lung disorders of unknown etiology. An acute exacerbation (AE) is an acute respiratory deterioration that occurs in IIPs. The prognosis of AE of IIPs (AE-IIPs) is extremely severe; however, no established therapies exist. We aimed to evaluate the efficacy of leukocytapheresis (LCAP) to treat patients with AE-IIPs.

PATIENTS AND METHODS

Six chronic IIPs patients who developed AE were enrolled in this study. We performed LCAP on days 2, 3, 9 and 10 in all six patients. All patients were also treated with high-dose corticosteroids and a continuous administration of low-molecular-weight heparin. We observed 30-day survival after the diagnosis of AE to evaluate the efficacy of LCAP. We also assessed oxygenation, high-resolution computed tomography (HRCT) findings, and certain chemical mediators in the peripheral blood.

RESULTS

Five of six patients survived more than 30 days. One patient died of progressive respiratory failure. Oxygenation and HRCT findings tended to improve in all survivors. The serum levels of lactate dehydrogenase, high mobility group box-1, and interleukin-18 were significantly decreased statistically post-LCAP. No severe adverse events occurred.

CONCLUSION

We suggest that LCAP is a safe and effective therapy for treating patients with AE-IIPs. J. Med. Invest. 64: 110-116, February, 2017.

Polymyxin B Hemoperfusion for Sepsis and Septic Shock: A Systematic Review and Meta-Analysis

BACKGROUND

To evaluate the efficacy and safety of direct hemoperfusion with polymyxin B-immobilized fiber (PMX-DHP) therapy in patients with sepsis.

DESIGN

A systematic review and meta-analysis of four major databases: Cochrane Central Register of Controlled Trials, MEDLINE, Scopus, and Science Citation Index Expanded.

STUDY SELECTION

Randomized controlled trials comparing PMX-DHP with conventional therapy on the outcome of mortality in patients with severe sepsis/septic shock.

DATA EXTRACTION

Two reviewers independently applied eligibility criteria, assessed quality, and extracted data. Primary outcomes were mortality and adverse events. We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to rate quality of evidence and grade the strength of recommendation.

RESULTS

In seven trials enrolling 841 patients, assessment for risk of bias indicated variations in study quality from high (n = 4) to unclear (n = 3) resulting from a lack of adequate randomization, blinding, and incomplete outcomes. Polymyxin B-immobilized fiber therapy was associated with lower mortality (risk ratio, 0.65; 95% confidence interval [CI], 0.47-0.89; p = 0.007; I² = 72%). Significant heterogeneity among trials was explained partly by study venue and baseline mortality rate. Meta-regression analysis revealed a significant negative slope between effect size of PMX-DHP therapy and baseline mortality rate in individual studies (p = 0.003), suggesting the probability of a beneficial effect with PMX-DHP increased with increasing baseline risk. Polymyxin B-immobilized fiber therapy did not increase the risk of hemoperfusion-related adverse events. The quality of the body of evidence was considered low for both mortality and adverse events.

CONCLUSIONS

Polymyxin B-immobilized fiber therapy was associated with reduced mortality in sepsis/septic shock. Based on the low quality of evidence, therapeutic use of PMX-DHP for survival benefit may be recommended conditionally for patients with high risk of death. Additional large randomized controlled trials are needed to confirm or refute this evidence.

Clinical Effects of a Longer Duration of Polymyxin B-Immobilized Fiber Column Direct Hemoperfusion Therapy for Severe Sepsis and Septic Shock

Polymyxin B-immobilized fiber column direct hemoperfusion (PMX-DHP) therapy is widely used for the treatment of severe sepsis and septic shock, and is generally performed for 2 h. Although previous studies demonstrated the efficacy of PMX-DHP therapy, it currently remains unclear whether its optimal duration is 2 h. This retrospective study analyzed 37 patients with septic shock who showed a poor clinical response to 2 h of PMX-DHP, and underwent a longer duration of this therapy. The mean duration of PMX-DHP therapy was 15.8 ± 7.9 h, and none of the patients developed adverse events, which enabled the therapy to be performed safely. The pressure catecholamine index [CAIP = catecholamine index/mean arterial pressure; catecholamine index = dopamine + dobutamine + (adrenaline + noradrenaline) × 100 μg/kg per min], as an indicator of hemodynamics, improved significantly in the survival group in the period between the start and 24 h after the end of PMX-DHP therapy (P < 0.01), and between 2 h after the start of and the end of this therapy (P < 0.05). In addition, the P/F ratio improved significantly in the group of surviving patients with acute respiratory distress syndrome (ARDS) in the period between the start and 24 h after the end of PMX-DHP therapy (P < 0.01), and between 2 h after the start of and the end of this therapy (P < 0.01). These results suggest that a longer duration of PMX-DHP therapy can be expected to improve the hemodynamics and pulmonary oxygenation capacity of patients with severe sepsis/septic shock. Strict prospective studies are needed in the future.

IMMUNE CELL PHENOTYPE AND FUNCTION IN SEPSIS

Cells of the innate and adaptive immune systems play a critical role in the host response to sepsis. Moreover, their accessibility for sampling and their capacity to respond dynamically to an acute threat increases the possibility that leukocytes might serve as a measure of a systemic state of altered responsiveness in sepsis.The working group of the 14th Acute Dialysis Quality Initiative (ADQI) conference sought to obtain consensus on the characteristic functional and phenotypic changes in cells of the innate and adaptive immune system in the setting of sepsis. Techniques for the study of circulating leukocytes were also reviewed and the impact on cellular phenotypes and leukocyte function of nonextracorporeal treatments and extracorporeal blood purification therapies proposed for sepsis was analyzed.A large number of alterations in the expression of distinct neutrophil and monocyte surface markers have been reported in septic patients. The most consistent alteration seen in septic neutrophils is their activation of a survival program that resists apoptotic death. Reduced expression of HLA-DR is a characteristic finding on septic monocytes, but monocyte antimicrobial function does not appear to be significantly altered in sepsis. Regarding adaptive immunity, sepsis-induced apoptosis leads to lymphopenia in patients with septic shock and it involves all types of T cells (CD4, CD8, and Natural Killer) except T regulatory cells, thus favoring immunosuppression. Finally, numerous promising therapies targeting the host immune response to sepsis are under investigation. These potential treatments can have an effect on the number of immune cells, the proportion of cell subtypes, and the cell function.

Release and cellular origin of extracellular vesicles during circulation of whole blood over adsorbent polymers for lipid apheresis

Whole blood lipid apheresis is clinically applied in patients with familial hypercholesterolemia to reduce low density lipoprotein and other apolipoprotein B 100 containing lipoproteins. Here, the hemocompatibility of two polyacrylate-coated polyacrylamide-based polymers for lipid apheresis by evaluating the adhesion of blood cells to the adsorbent polymers, their respective activation, as well as the release of microvesicles during circulation of whole blood over the polymers was studied. Characterization of the adsorbents by scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy revealed differences with respect to their surface morphology and their surface chemical composition. Despite these differences, equivalent amounts of leukocytes and platelets adhered to both polymers during circulation of whole blood over the adsorbent columns. The release of phosphatidylserine-exposing microvesicles, in contrast, increased significantly with increasing surface roughness and with the amount of polyacrylate groups at the adsorbent surface. The majority of microvesicles generated during blood-material contact were platelet-derived, and their release was associated with enhanced thrombin generation. Microvesicles were present in free and in cell-bound form, and 75% of all monocytes, but only 0.2% and 2.3% of red blood cells and platelets, respectively, were associated with microvesicles, pointing to a role of monocytes in the clearance of released microvesicles. Taken together, microvesicles are sensitive indicators for biomaterial-induced activation of blood cells in apheresis. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 636-646, 2017.

Laparoscopically assisted colorectal surgery provides better short-term clinical and inflammatory outcomes compared to open colorectal surgery

INTRODUCTION

Changes in immune function after surgery may influence overall outcome, length of hospital stay, susceptibility to infection and perioperative tumour dissemination in cancer patients. Our aim was to elaborate on postoperative differences in the immune status and the intensity of the systemic inflammatory response between two groups of prospectively enrolled patients with colorectal cancer, namely patients undergoing laparoscopically assisted or open colorectal surgery.

MATERIAL AND METHODS

Blood samples from 77 patients were taken before surgery and then 3 h, 24 h and 4 days after surgery. The inflammatory response was determined by leukocyte counts, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and procalcitonin levels (PCT). Immune status was determined by phenotypic analysis of lymphocyte populations and the activation of mononuclear cells. CD64 expression and cytokine expression were also determined.

RESULTS

Patients undergoing laparoscopically assisted surgery had less intraoperative blood loss (p = 0.002), earlier resumption of diet (p = 0.002) and shorter hospital stay (p = 0.02). Numbers of total leukocytes (p = 0.12), CRP (p = 0.002) and PCT (p = 0.23) were remarkably higher 4 days after surgery in patients who underwent an open colorectal procedure. There was an important decrease in monocyte HLA-DR expression 3 h after surgery in patients undergoing laparoscopically assisted surgery (p = 0.03).

CONCLUSIONS

Our study suggests that minimally invasive surgery provides better short-term clinical outcomes for patients with resectable colorectal cancer. The acute inflammatory response is less pronounced. Post-surgical immunological disturbance in both groups is similar, but we observed a divergent effect of different surgical approaches on the expression of HLA-DR on monocytes. However, our results corroborate the results of previous studies.

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.

Polymyxin B-immobilized fiber columns: A column to breathe new life into the treatment of interstitial lung disease?

Acute exacerbations of idiopathic pulmonary fibrosis (IPF) is a severe respiratory condition with high mortality rate. Direct hemoperfusion with polymyxin B-immobilized fiber columns (PMX-DHP) was originally introduced for the treatment of septic shock. Application of PMX-DHP to the treatment of acute exacerbations of IPF may improve oxygenation and survival of the patients with the disease. In addition to acute exacerbations of IPF, PMX-DHP has been applied to acute respiratory failure from various causes; an amyopathic dermatomyositis patient who developed rapidly progressive interstitial lung disease (ILD) with elevated anti-CADM-140/MDA5 autoantibody and a patient with severe amiodarone pulmonary toxicity. It is also demonstrated that PMX-DHP performed on the first day of steroid pulse therapy may improve the prognosis of patients with rapidly progressive ILDs in a case-control setting. PMX treatment decreases not only various circulating molecules but also inflammatory cells, in particular activated monocytes, producing such mediators. Although the incidence of acute exacerbations of IPF is too low for proper randomization, in order to test the effects of PMX-DHP on the disease, a cohort or case-control analytic study needs to be conducted, preferably from more than one center or research group.

Human leukocyte antigen DR surface expression on CD14+ monocytes during adverse events after hematopoietic stem cell transplantation

The human leukocyte antigen DR surface expression on CD14+ monocytes reflects the degree to which these cells have been activated. Given the central role monocytes and macrophages play in the immune system, a decreased human leukocyte antigen DR expression on CD14+ monocytes results in a hallmark of altered immune status during systemic inflammatory response syndrome. We hypothesize that human leukocyte antigen DR expression might be similarly altered after hematopoietic stem cell transplantation and during post-transplant complications. Using flow cytometry, this study investigates the human leukocyte antigen DR surface expression of CD14+ monocytes in 30 pediatric and young adult patients up to 1 year after hematopoietic stem cell transplantation. Normal values were derived from a control group of healthy children, adolescents, and young adults. Human leukocyte antigen DR expression decreased significantly prior and during bacterial infection or sepsis. By contrast, human leukocyte antigen DR expression levels were elevated before and at the time of viremia. Human leukocyte antigen DR expression was also elevated during acute graft-versus-host disease. In contrast, the expression was reduced when patients had hepatic veno-occlusive disease. A significant decrease of human leukocyte antigen DR expression was associated with a relapse of the underlying disease and before death. Human leukocyte antigen DR expression on CD14+ monocytes appears to be a promising parameter that might allow identification of patients at risk after hematopoietic stem cell transplantation.

New trends in polymyxin B hemoperfusion: from 2006 to 2013

Endotoxin, one of the principal components on the outer membrane of Gram-negative bacteria, is considered a key and early component in the pathogenesis of sepsis. Polymyxin B bound to polystyrene fibers (PMX) is a medical device capable of removing circulating endotoxin by adsorption. The most comprehensive analysis to date of clinical experience with this device remains a meta-analysis of 28 studies between 1998 and 2006. This showed that PMX hemoperfusion was associated with improved blood pressure and a reduction in dopamine dose, improved PaO2/FiO2 ratio and lower mortality. Since this meta-analysis, over 50 additional studies on PMX have been published. The majority are observational, with small sample sizes. Notable among the newer studies is the increasing interest in the use of PMX therapy in interstitial pneumonias and idiopathic pulmonary fibrosis, as well as in longer treatment duration and earlier initiation of PMX therapy in an attempt to further improve clinical outcomes. These observational data highlight important aspects of PMX therapy worthy of more rigorous investigation in future studies.

Effects of direct hemoperfusion with polymyxin B-immobilized fiber on rapidly progressive interstitial lung diseases

OBJECTIVE

Direct hemoperfusion with polymyxin B-immobilized fiber columns (PMX-DHP) has been used for the treatment of septic shock. It was recently suggested that PMX-DHP may also be effective in acute exacerbations of idiopathic pulmonary fibrosis (IPF). However, all previous reports are case series without controls. The aim of the study was to determine the effects of PMX-DHP on the prognosis of the patients with rapidly progressive interstitial lung diseases (ILDs) in a case-control setting.

METHODS

We herein retrospectively examined the clinical records of consecutive patients with acute exacerbation of IPF or rapidly progressive ILDs treated in our institute. We excluded those who had been treated with steroid pulse therapy for lung diseases, including those who had been taking more than 15 mg of oral prednisolone daily, or had undergone an operation within one month before the onset of acute respiratory failure. We compared the results of the laboratory tests and survivals between patients treated with and without PMX-DHP.

RESULTS

Twenty-six patients were enrolled in the study. Among them, 13 patients were treated with PMX-DHP in addition to immunosuppressive therapy, including steroid pulse therapy. The mean survival time of patients treated with PMX-DHP tended to be longer than patients not treated with PXM-DHP (p=0.067). Six patients who underwent PMX-DHP on the first day of steroid pulse therapy had significantly longer survival times than those who were treated with standard medication alone (p<0.01).

CONCLUSION

These results suggest that PMX-DHP performed on the first day of steroid pulse therapy may improve the prognosis of patients with rapidly progressive ILDs.

Immunomodulation in sepsis: the role of endotoxin removal by polymyxin B-immobilized cartridge

Severe sepsis results in high morbidity and mortality. Immunomodulation strategies could be an adjunctive therapy to treat sepsis. Endotoxin is a component of gram-negative bacteria and plays an important role in the pathogenesis of septic shock when it is recognized by immune cells. Removal of endotoxin could be an effective adjunctive approach to the management of sepsis. Devices to adsorb endotoxin or inflammatory cytokines have been designed as a strategy to treat severe sepsis, especially sepsis caused by gram-negative bacteria. Polymyxin B-immobilized cartridge has been successfully used to treat patients with sepsis of abdominal origin. Although this cartridge was conceived to adsorb endotoxin, several other immunological mechanisms have been elucidated, and this device has also yielded promising results in patients with nonseptic respiratory failure. In this paper, we summarize the immune modulation actions of Polymyxin B-immobilized cartridge to explore its potential usefulness beyond endotoxin elimination.

Changes in monoclonal HLA-DR antigen expression in acute organophosphorus pesticide-poisoned patients

The aim of this study was to investigate changes in human leukocyte antigen (HLA)-DR expression of peripheral blood mononuclear cells (MNCs) in patients with acute organophosphorus pesticide poisoning (AOPP). HLA-DR antigen expression of peripheral blood MNCs was examined in 75 patients with AOPP, including 36 patients without multiple organ dysfunction syndrome (non-MODS) and 39 patients with multiple organ dysfunction syndrome (MODS), as well as in 30 healthy individuals using flow cytometry assay. The associations between HLA-DR antigen expression and certain parameters were analyzed, including acute physiology and chronic health evaluation II (APACHE II) score, serum cholinesterase (ChE) activity, cardiac troponin I (cTnI), cardiac enzymes, and liver and kidney function. The mean fluorescence intensity (MCF) of HLA-DR expression in the AOPP group (21.59±5.36) was significantly lower than that in the control group (27.85±4.86) (P<0.001). The MCF in the MODS group (18.17±4.23) was lower than that in the non-MODS group (25.15±6.15). In addition, the MCF of the deceased patients (15.29±3.97) was lower than that of the surviving patients (22.34±2.76) (P<0.001). The MCF of patients with AOPP and MODS was positively correlated with serum ChE (P<0.01) and negatively correlated with the APACHE II score, creatine kinase isoenzyme, cTnI, lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen and serum creatinine (P<0.05). In conclusion, HLA-DR expression in patients with AOPP was significantly decreased compared with that in healthy individuals; HLA-DR expression may therefore be a good indicator for evaluating AOPP, MODS disease severity, immune function, efficacy of prognosis and prognosis. Examination of HLA-DR antigen expression may be of crucial clinical value.

A Case of Polymyxin b-Immobilized Fiber Column Treatment for Rapidly Progressive Interstitial Pneumonia Associated with Clinically Amyopathic Dermatomyositis

We report a case of rapidly progressive interstitial pneumonia associated with clinically amyopathic dermatomyositis who responded to single course of polymyxin b-immobilized fiber column treatment. Initial treatment with pulsed corticosteroids and cyclophosphamide, intravenous immunoglobulin, and cyclosporine seemed to suppress the activity of interstitial lung disease temporarily, but signs of relapse were detected such as elevation of serum KL-6 level and progressing pulmonary shadows in chest computed tomography scan. After polymyxin b-immobilized fiber column treatment, the areas of pulmonary shadows drastically decreased. Gradually, arterial partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2) ratio recovered, and serum ferritin level and KL-6 level decreased. These findings indicate that polymyxin b-immobilized fiber column treatment could be promising in combination with conventional therapy for rapidly progressive interstitial pneumonia associated with clinically amyopathic dermatomyositis, especially at the early phase of relapse.

[Usefulness of haemoperfusion in the treatment of the severe septic patient: an update]

Haemoperfusion is an extracorporeal technique that removes endotoxin and/or inflammatory mediators by means of an adsorptive mechanism during the passage of the blood through a porous filter. Most of the studies in the literature use polymyxin B as the adsorptive agent. This treatment is based on the assumption that the removal of endotoxin and inflammatory mediators from the circulation attenuates the inflammatory response in sepsis. This review summarizes the theoretical basis, and the experimental and clinical results published to date with the use of haemoperfusion. Although most of the studies show positive results, some doubts have arisen about the suitability of the methods described (small number of cases, low quality of the experimental design, and excessive mortality in the control groups). There are also some inconsistencies regarding the theoretical basis of its use (lack of positive effects after the removal of endotoxin from the circulation using alternative mechanisms, discrepancies regarding the best moment to initiate the therapy, unexplained beneficial effects in the absence of increased endotoxin levels). It is the opinion of the authors that haemoperfusion represents a promising therapy for the treatment of sepsis, but consider that its usefulness requires confirmation in well designed studies before being included in protocols.

Analysis of the efficacy of direct hemoperfusion with polymyxin B-immobilized fiber (PMX-DHP) according to the prognostic factors in patients with colorectal perforation

PURPOSE

Direct hemoperfusion with polymyxin B-immobilized fiber (PMX-DHP) has been reported to improve the outcomes in patients with colorectal perforation. We retrospectively identified prognostic factors in patients with colorectal perforation and considered the efficacy of PMX-DHP based on these prognostic factors.

METHODS

One hundred and fifty-six patients who underwent surgery for colorectal perforation in our department between November 1995 and March 2011 were enrolled in this study. The clinicopathological factors were compared between the survivor and non-survivor groups.

RESULTS

There were 28 patients (17.9 %) who died within 28 days after surgery. According to the multivariate analysis, an Acute Physiology and Chronic Health Evaluation II (APACHE II) score of 17 or more was a significant independent prognostic factor (P = 0.002, odds ratio = 5.39). There was a significant difference in the survival rates between the patients with APACHE II scores of 16 or less and those with scores of 17 or more who had received the PMX-DHP (+) (P < 0.0001).

CONCLUSION

The APACHE II score is useful as a prognostic factor in patients with colorectal perforation, and the survival rate was 50 % or lower among the patients with APACHE II scores of 17 or higher. Therefore, PMX-DHP appears to have limited efficacy in serious cases.

Removal of increased circulating CD4+CD25+Foxp3+ regulatory T cells in patients with septic shock using hemoperfusion with polymyxin B-immobilized fibers

BACKGROUND

Although sepsis-induced immunosuppression has long been considered to be a factor in the late mortality of patients with sepsis, little is known about regulatory T cell (Treg)-mediated immunosuppression and the effect of polymyxin B-immobilized fiber (PMX-F) on sepsis-induced immunosuppression. We sought to investigate the role of CD4(+)CD25(+)Foxp3(+) Tregs in septic patients, and to evaluate the effect of hemoperfusion with PMX-F on the recovery from immunosuppression owing to septic shock.

METHODS

Thirty-two septic patients who had an identified focus of infection in the abdominal cavity were enrolled in this study. Peripheral blood mononuclear cells in the septic patients were examined to evaluate the roles of Tregs and the serum cytokine levels. We also examined the effects of PMX-F therapy on CD4(+) T cells, especially Tregs and serum cytokine levels in patients with septic shock.

RESULTS

The percentage of Tregs in the CD4(+) T-cell population, and the serum IL-6 and IL-10 levels, were significantly higher among patients with septic shock compared with those without septic shock, and PMX-F therapy significantly decreased the number of Tregs, as well as the serum IL-6 and IL-10 levels. Furthermore, a significant increase in the number of CD4(+) T cells, a significant decrease in the percentage of Tregs in the CD4(+) T-cell population, and a significant decrease in the serum IL-6 and IL-10 levels 24 hours after PMX-F therapy were observed in septic shock survivors compared with nonsurvivors.

CONCLUSION

We found a major increase in the percentage of Tregs in peripheral blood circulating CD4(+) T cells from patients with septic shock, and observed that the removal of Tregs by hemoperfusion with PMX-F might represent a novel strategy for inducing recovery from the immunosuppression associated with sepsis.

Neutralization of IL-10 restores the downregulation of IL-18 receptor on natural killer cells and interferon-γ production in septic mice, thus leading to an improved survival

The objective of the study was to investigate the mechanisms of insufficient interferon-γ (IFN-γ) response to interleukin 18 (IL-18) and the treatment for the insufficient response in septic mice. Interleukin 18 stimulation does not restore IFN-γ production by blood mononuclear cells in septic patients but does restore its production in postoperative patients. Although sepsis impairs the IFN-γ response to IL-18, little is known about why the IL-18/IFN-γ-mediated immune response is ineffective in patients with sepsis. A cecal ligation and puncture was made in C57BL/6 mice following a sublethal lipopolysaccharide challenge to examine their IFN-γ response to IL-18, focusing on natural killer (NK) cells and cytokines. We next examined the effect of neutralization of IL-10 on the NK cell and survival in septic mice. Interleukin 18 injection did not restore IFN-γ production in septic (cecal ligation and puncture) mice. Despite an increase in the numbers of liver NK cells, the IL-18 receptor (IL-18R) expression was decreased in the septic mice compared with sham mice. Serum IL-10 levels were positively correlated with the percentage of liver NK cells, but negatively with their IL-18R expression. Neutralization of IL-10 restored the IL-18R expression on liver NK cells and restored the IFN-γ response in the septic mice, improving their survival. Sepsis might impair IL-18R expression on liver and spleen NK cells and impair the IL-18-mediated IFN-γ response. Neutralization of IL-10 may restore this response in septic hosts, thereby improving survival.

Polymyxin B-immobilized fiber column hemoperfusion therapy for septic shock

Endotoxin, an outer membrane component of gram-negative bacteria, plays an important role in the pathogenesis of septic shock. Endotoxin adsorption therapy by polymyxin B-immobilized fiber column hemoperfusion (PMX) has been used for the treatment of septic shock patients in Japan since 1994. The covalent binding of polymyxin B onto the surface of the polystyrene-based carrier fiber in PMX inactivates the endotoxin in the blood without exerting toxicity. This study was performed as a systematic review to evaluate the efficacy and mechanism of PMX treatment in patients with septic shock. The PubMed database and references from identified articles were used to search and review the literature relating to the efficacy and mechanism of PMX treatment in patients with septic shock. Polymyxin B-immobilized fiber column hemoperfusion adsorbed monocytes, activated neutrophils, and anandamide, as well as endotoxin through direct covalent bond, hydrophobic and ionic interactions, and hydrodynamics, and reduced the blood concentrations of inflammatory cytokines, plasminogen activator inhibitor 1 and adhesion molecules. Polymyxin B-immobilized fiber column hemoperfusion increased blood pressure and reduced the dosage requirements for vasopressive/inotropic agents. The meta-analysis showed that PMX treatment had beneficial effects on the hemodynamics, pulmonary oxygenation, and mortality. These beneficial effects may be attributable to the direct adsorption of endotoxin, monocytes, activated neutrophils, and anandamide, as well as indirect decrease in inflammatory cytokines and other mediators. Polymyxin B-immobilized fiber column hemoperfusion treatment has additional effects on reducing endothelial damage, proapoptotic activity, and immunosuppression. Further studies will be needed to confirm the efficacy and mechanism of PMX treatment in septic shock.

Analysis of membrane antigens on neutrophils from patients with sepsis

The aim of the present study was to assess changes of cell membrane antigens on neutrophils in septic patients. Expression levels of neutrophil membrane antigens were measured employing a FACS calibur flow cytometer with several fluorescence-labeled monoclonal antibodies. Expression levels of the CD14 antigen were higher in patients with sepsis than in healthy individuals. In particular, the expression levels of CD14 increased in patients complicated by septic shock. Expression levels of TLR-4 were higher in patients with sepsis or septic shock than in healthy individuals. Expression levels of CD11b and CD16 were lower in patients with sepsis or septic shock than in healthy individuals and were even lower in those complicated by septic shock. Expression levels of neutrophil membrane antigens in patients with sepsis markedly changed in the acute phase. However, these levels tended to return to those of healthy individuals in the convalescing phase. Analyses of the surface antigens on neutrophils strongly involved in biological defense or tissue injury are informative for understanding the pathology of sepsis and for conducting therapy targeting neutrophils in the future.

Neutralization of interleukin-10 or transforming growth factor-β decreases the percentages of CD4+ CD25+ Foxp3+ regulatory T cells in septic mice, thereby leading to an improved survival

OBJECTIVES

To investigate the role of CD4+ CD25+ Foxp3+ regulatory T cells (Tregs) in septic conditions, and to examine the potential of targeting them for the treatment of sepsis.

BACKGROUND

Sepsis-induced immunosuppression has long been considered a factor in late mortality of patients with sepsis. Although Tregs are central to the maintenance of immunologic homeostasis and tolerance, little is known about Treg-mediated immunosuppression in the late stages of sepsis.

METHODS

Peripheral blood mononuclear cells (MNCs) in septic patients and liver or spleen MNCs collected after a cecal ligation and puncture (CLP) model in C57BL/6 mice were examined to evaluate the roles of Tregs and the correlation of transforming growth factor (TGF)-β or interleukin (IL)-10 with their activity. We next examined the effects of neutralization of TGF-β or IL-10 on the percentages of Tregs in CD4+ T cells and the survival rates of septic mice.

RESULTS

The percentages of Tregs in peripheral blood lymphocytes were significantly increased in patients with sepsis, and there was a significantly positive correlation between serum IL-10 levels and the percentage of Tregs. CLP injury increases the percentages of Tregs in the CD4+ T cells in the spleen, and there was a significantly positive correlation between the percentages of Tregs and the serum IL-10 or TGF-β levels. The neutralization of TGF-β or IL-10 decreased the percentages of Tregs in CD4+ T cells, restored the percentages of CD4+ T cells in spleen MNCs, and improved survival rates in septic mice.

CONCLUSION

We found an increase in the percentages of Tregs in peripheral blood circulating CD4+ T cells from patients with sepsis, and in splenic MNCs from septic mice, and observed that regulation of Tregs by neutralizing IL-10 or TGF-β might represent a novel strategy for treating the immunosuppressive conditions in sepsis.

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.

Apheresis of activated leukocytes with an immobilized polymyxin B filter in patients with septic shock

In this study, we examined the effects of direct hemoperfusion through filters with immobilized polymyxin B (PMX-DHP) on leukocyte function and plasma levels of cytokines in patients with septic shock. We found that PMX-DHP caused increased expression of C-X-C chemokine receptor 1 (CXCR1) and CXCR2, along with decreased expression of CD64 and CD11b, by circulating neutrophils in patients with septic shock. Plasma levels of cytokines, including interleukin 6 (IL-6), IL-8, IL-10, and high-mobility group box 1, were elevated in patients with septic shock compared with healthy controls, but cytokine levels were not altered by PMX-DHP. These results suggest that PMX-DHP influences neutrophils via a mechanism that does not involve cytokine. Ex vivo perfusion of heparinized blood from patients with sepsis and septic shock through PMX filters in a laboratory circuit caused a significant decrease in neutrophil and monocyte counts. After 120 min of perfusion, neutrophils, monocytes, and lymphocytes were decreased by 78%, 70%, and 10%, respectively, compared with baseline values. Flow cytometric analysis indicated that activated neutrophils with high levels of CD11b/CD64 expression and low levels of CXCR1/CXCR2 expression showed preferential adhesion to PMX filters. Neutrophils isolated from the blood after ex vivo PMX perfusion caused less damage to an endothelial cell monolayer than cells from sham-treated blood, whereas neutrophil phagocytosis of opsonized Escherichia coli was unaffected. These results indicate that PMX-DHP selectively removes activated neutrophils and reduces the ability of circulating cells to cause endothelial damage. Selective removal of activated neutrophils using PMX-DHP may improve the systemic inflammatory response in patients with septic shock.

Clinical review: blood purification for sepsis

Sepsis is the primary cause of death in the intensive care unit. Extracorporeal blood purification therapies have been proposed for patients with sepsis in order to improve outcomes since these therapies can alter the host inflammatory response by non-selective removal of inflammatory mediators or bacterial products or both. Recent technological progress has increased the number of techniques available for blood purification and their performance. In this overview, we report on the latest advances in blood purification for sepsis and how they relate to current concepts of disease, and we review the current evidence for high-volume hemofiltration, cascade hemofiltration, hemoadsorption, coupled plasma filtration adsorption, high-adsorption hemofiltration, and high-cutoff hemofiltration/hemodialysis. Promising results have been reported with all of these blood purification therapies, showing that they are well tolerated, effective in clearing inflammatory mediators or bacterial toxins (or both) from the plasma, and efficacious for improvement of various physiologic outcomes (for example, hemodynamics and oxygenation). However, numerous questions, including the timing, duration, and frequency of these therapies in the clinical setting, remain unanswered. Large multicenter trials evaluating the ability of these therapies to improve clinical outcomes (that is, mortality or organ failure), rather than surrogate markers such as plasma mediator clearance or transient improvement in physiologic variables, are required to define the precise role of blood purification in the management of sepsis.

Direct hemoperfusion with polymyxin-B-immobilized fiber columns improves septic hypotension and reduces inflammatory mediators in septic patients with colorectal perforation

PURPOSE

Although some studies have reported favorable effects of direct hemoperfusion with polymyxin-B-immobilized fiber columns (PMX) for the treatment of septic shock, few studies have demonstrated the efficacy of PMX in studies with a uniform case definition and without any other blood purification techniques.

MATERIALS AND METHODS

Fifty-two patients with severe sepsis or septic shock secondary to colorectal perforation were treated with PMX. Hemodynamic alterations and plasma concentrations of endotoxin, interleukin (IL)-1beta, IL-1 receptor antagonist (IL-1Ra), IL-6, IL-8, and IL-10 were evaluated following PMX treatment.

RESULTS

We observed a significant reduction in plasma endotoxin in the nonsurvivors immediately after PMX treatment compared to before treatment. Systolic blood pressure was markedly increased and circulating levels of IL-1beta, IL-1Ra, and IL-8 were significantly reduced during a 2-h interval of PMX.

CONCLUSIONS

Our findings suggested that PMX treatment appears to adsorb endotoxin and also modulates circulating cytokine during a 2-h interval of direct hemoperfusion in septic patients with such condition.

Effectiveness of polymyxin B-immobilized fiber column in sepsis: a systematic review

INTRODUCTION

Severe sepsis and septic shock are common problems in the intensive care unit and carry a high mortality. Endotoxin, one of the principal components on the outer membrane of gram-negative bacteria, is considered important to their pathogenesis. Polymyxin B bound and immobilized to polystyrene fibers (PMX-F) is a medical device that aims to remove circulating endotoxin by adsorption, theoretically preventing the progression of the biological cascade of sepsis. We performed a systematic review to describe the effect in septic patients of direct hemoperfusion with PMX-F on outcomes of blood pressure, use of vasoactive drugs, oxygenation, and mortality reported in published studies.

METHODS

We searched PubMed, the Cochrane Collaboration Database, and bibliographies of retrieved articles and consulted with experts to identify relevant studies. Prospective and retrospective observational studies, pre- and post-intervention design, and randomized controlled trials were included. Three authors reviewed all citations. We identified a total of 28 publications - 9 randomized controlled trials, 7 non-randomized parallel studies, and 12 pre-post design studies - that reported at least one of the specified outcome measures (pooled sample size, 1,425 patients: 978 PMX-F and 447 conventional medical therapy).

RESULTS

Overall, mean arterial pressure (MAP) increased by 19 mm Hg (95% confidence interval [CI], 15 to 22 mm Hg; p < 0.001), representing a 26% mean increase in MAP (range, 14% to 42%), whereas dopamine/dobutamine dose decreased by 1.8 microg/kg per minute (95% CI, 0.4 to 3.3 microg/kg per minute; p = 0.01) after PMX-F. There was significant intertrial heterogeneity for these outcomes (p < 0.001), which became non-significant when analysis was stratified for baseline MAP. The mean arterial partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2) ratio increased by 32 units (95% CI, 23 to 41 units; p < 0.001). PMX-F therapy was associated with significantly lower mortality risk (risk ratio, 0.53; 95% CI, 0.43 to 0.65). The trials assessed had suboptimal method quality.

CONCLUSION

Based on this critical review of the published literature, direct hemoperfusion with PMX-F appears to have favorable effects on MAP, dopamine use, PaO2/FiO2 ratio, and mortality. However, publication bias and lack of blinding need to be considered. These findings support the need for further rigorous study of this therapy.

Rapidly progressive interstitial pneumonia associated with clinically amyopathic dermatomyositis successfully treated with polymyxin B-immobilized fiber column hemoperfusion

Amyopathic dermatomyositis (ADM) is a clinical subtype of dermatomyositis, characterized by the absence of motor weakness and the presence of normal muscle enzyme levels. ADM is sometimes accompanied by interstitial pneumonia that shows a rapid progressive course associated with a poor prognosis. We describe a 70-year-old man who presented rapidly progressive interstitial pneumonia associated with clinically ADM (C-ADM); he was successfully treated with polymyxin B-immobilized fiber column (PMX) hemoperfusion.

Blood purification therapy for sepsis

Accumulating evidences of underlining pathogenesis of sepsis have contributed to the therapeutic strategy for sepsis. Not only endotoxin and cytokine, but also signal transduction through Toll-like receptors could be a strategic target for the management of sepsis. Blood purification therapy including polymyxin B-immobilized hemoperfusion cartridge and continuous hemodiafiltration has shown the beneficial effect on patients with sepsis in Japan. Although they were initially designed to remove endotoxin and cytokines respectively, they might eliminate unexpected mediators responsible for sepsis. Further elucidation of mechanism and randomized controlled studies are needed to establish the role of blood purification therapy in sepsis.