The effect of continuous veno-venous hemofiltration or direct hemoperfusion with polymyxin B-immobilized fiber on neutrophil respiratory oxidative burst in patients with sepsis and septic shock

Does Hemoperfusion Increase Survival in Acute Paraquat Poisoning? A Retrospective Multicenter Study

The efficacy of hemoperfusion (HP) in patients with acute paraquat poisoning (PQ) remains controversial. We conducted a multi-center retrospective study to include acute PQ-poisoned patients admitted to two tertiary medical centers between 2005 and 2015. We used the Severity Index of Paraquat Poisoning (SIPP) to stratify the severity of PQ-poisoned patients. The indication to start HP was a positive result for the semiquantitative urine PQ test and presentation to the hospital was within 24 h. Early HP was defined as the first session of HP performed within five hours of PQ ingestion. A total of 213 patients (100 HP group, 113 non-HP group) were eligible for the study. The overall 60-day mortality of poisoned patients was 75.6% (161/213). Multivariate Cox regression analysis showed no statistically significant difference in 60-day survival between HP and non-HP groups (95% confidence interval (CI): 0.84–1.63, p = 0.363). Further subgroup analysis in the HP group showed early HP (95% CI: 0.54–1.69, p = 0.880), and multiple secessions of HP (95% CI: 0.56–1.07, p = 0.124) were not significantly related to better survival. Among acute PQ-poisoned patients, this study found that HP was not associated with increased 60-day survival. Furthermore, neither early HP nor multiple secessions of HP were associated with survival.

Successful Recovery from COVID-19-associated Acute Respiratory Failure with Polymyxin B-immobilized Fiber Column-direct Hemoperfusion

An 83-year-old man was hospitalized for coronavirus disease 2019 (COVID-19) after a 10-day history of a persistent fever. Chest computed tomography showed extensive non-segmental ground glass opacity. Despite the initiation of lopinavir and ritonavir, respiratory failure progressed. Two days of polymyxin B-immobilized fiber column-direct hemoperfusion (PMX-DHP) with adjunctive corticosteroid prevented his respiratory condition from worsening. For rapidly progressive COVID-19 cases, the early use of PMX-DHP may avoid the need for mechanical ventilation by suppressing local inflammation of the lung.

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.

Effect of hemoperfusion using polymyxin B-immobilized fibers on acute lung injury in a rat sepsis model

Direct hemoperfusion using polymyxin B-immobilized column (PMX-DHP) is recognized as an effective treatment for septic shock. However, whether its efficacy is limited to cardiovascular dysfunction remains unknown. Therefore, we planned to examine the effects of PMX-DHP in an acute lung injury model. [Materials and methods] Rats were assigned to either PMX-DHP group or control group (n= 7 in each). A lung injury was created by the intratracheal instillation of LPS. In PMX-DHP group, an arteriovenous extracorporeal circuit using PMX column was applied for three hours. The same procedure using a dummy column was applied in control group. The lung microcirculation was observed, and adherent leukocytes, RBC velocity, and the arterial PaO2 were calculated. Pathological changes and the wet/dry weight ratio of the lungs were examined. [Results] Adherent leukocytes and platelets to the lung venules were recognized at 3 hours, and their numbers increased over time. Treatment with PMX-DHP significantly suppressed these events and helped maintenance of the blood flow and PaO2 levels. The lung edema and the histologic damages were also suppressed. [Conclusions] PMX-DHP improved the microcirculation by suppressing leukocyte and platelet adhesion. PMX-DHP had beneficial effects in a model for acute lung injury.

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.

Emerging drugs for the treatment of sepsis

INTRODUCTION

Despite improvement in medical care, severe sepsis and septic shock remain an unmet medical need. Their incidence is steadily increasing and the worldwide mortality ranges between 30% and 50%. This generates the need for agents that modulate the immune function of the host.

AREAS COVERED

Available agents can be divided into three categories according to their mechanism of action: i) agents that block bacterial products and inflammatory mediators. Hemoperfusion with polymyxin B embedded fiber device that blocks bacterial lipopolysaccharides (LPS) has given promising clinical results. Blockade of TNF-α with afelimomab and CytoFab appears promising; ii) modulators of immune function. Hydrocortisone stress replacement, intravenous infusion of clarithromycin and immunonutrition with omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) have all yielded positive clinical results. Recombinant thrombomodulin for patients with disseminated intravascular coagulation appears a promising alternative; and iii) immunostimulation. Meta-analysis of conducted trials disclosed the decrease of mortality in septic shock after administration of immunoglobulin preparations enriched with IgM.

EXPERT OPINION

The underlying pathophysiologic mechanisms in septic patients are highly individualized. As such, specific tools should be developed in the near future to define these differences and tailor therapeutic strategies accordingly.

Endotoxin removal devices for the treatment of sepsis and septic shock

A substantial body of experimental and clinical evidence suggests that neutralising or removing lipopolysaccharide endotoxin would be an effective adjunctive approach to the management of Gram-negative sepsis. Polymyxins are a group of cyclic cationic polypeptide antibiotics. Although they have useful antimicrobial activity against Gram-negative bacteria, their clinical use has been limited because of toxicity. However, in addition to their antimicrobial property, polymyxins can bind to and neutralise endotoxin. Thus, investigators have explored the possibility of using polymyxin bound to a solid-phase carrier for specific haem-adsorption in patients with sepsis, thereby retaining the lipopolysaccharide-binding properties but minimising systemic toxic effects. This system has been widely used in Japan for many years, but convincing clinical evidence of efficacy is lacking. A recent Italian study has some promising data. Although polymyxin has been the principal agent used to explore this approach, other molecules have the ability to bind endotoxin, and some of these have very recently been proposed as the basis for other endotoxin-removal devices. The available evidence is reviewed to assess the potential use of such devices in clinical practice.

Therapeutic effect of direct hemoperfusion with a polymyxin B-immobilized fiber column in the treatment of HIV-negative severe pneumocystis pneumonia

BACKGROUND

Direct hemoperfusion with a polymyxin B-immobilized fiber column (PMX-DHP) has been shown to improve oxygenation in cases of diffuse alveolar damage, but little is known about its effectiveness in treating pneumocystis pneumonia (PCP) in HIV-negative immunosuppressed patients.

OBJECTIVES

This study was aimed at investigating the effect of PMX-DHP in treating non-HIV-related PCP.

METHODS

Between October 2005 and September 2008, 6 patients with non-HIV-related PCP were treated with 2 sessions of PMX-DHP at an attending physician's discretion when severe hypoxemia developed despite conventional treatments including high-dose corticosteroid, whereas 9 patients in a similar condition were treated without PMX-DHP. Changes in oxygenation and radiographic findings in the PMX-DHP group and adverse events associated with PMX-DHP were investigated retrospectively, as were the outcomes for both treatment groups.

RESULTS

There was an improvement in PaO(2)/FiO(2) during each PMX-DHP session, from 148.8 ± 52.5 to 188.2 ± 79.3 mm Hg (p = 0.02). After 2 sessions of PMX-DHP, an improvement in PaO(2)/FiO(2), from 131.8 ± 37.4 to 213.3 ± 87.3 mm Hg, was observed (p = 0.04), but no significantly different improvement was detected on the following day. The radiographic findings improved in 4 patients during PMX-DHP. The in-hospital mortality was similarly high in both groups (50% in the PMX-DHP group vs. 67% in the non-PMX-DHP group). No significant adverse events associated with PMX-DHP were observed except for advanced thrombocytopenia in 1 patient.

CONCLUSION

PMX-DHP may serve as an adjunct in the treatment of non-HIV-related PCP, temporarily alleviating severe hypoxemia even in cases refractory to conventional treatments.

Removal of 2-arachidonylglycerol by direct hemoperfusion therapy with polymyxin B immobilized fibers benefits patients with septic shock

Arachidonylethanolamide (AEA) and 2-arachidonylglycerol (2-AG) are endocannabinoids involved in septic shock, and 8-epi prostaglandin F2alpha (F2-isoprostane) is a biomarker of oxidative stress in biological systems. Because the antibiotic polymyxin B absorbs endocannabinoids as well as endotoxins, direct hemoperfusion therapy with polymyxin B-immobilized fibers (PMX-DHP) decreases serum levels of endocannabinoids. To investigate the features of sepsis and determine the proper use of PMX-DHP, we measured the changes in levels of endocannabinoids and F2-isoprostane in patients with septic shock. Twenty-six patients with septic shock, including those with septic shock induced by peritonitis, underwent laparotomy for drainage. Endocannabinoids absorption with PMX-DHP was examined in two groups of patients: patients whose mean arterial blood pressure (mABP) had increased more than 20 mm Hg (responder group; N = 13); and patients iwhose mABP did not increase or had increased no more than 20 mm Hg (non-responder group; N = 13). Levels of AEA did not change after PMX-DHP in either the non-responder or responder groups, whereas levels of 2-AG decreased significantly after PMX-DHP in the responder group, but not in the non-responder group. F2-isoprostane gradually increased after PMX-DHP treatment; on the other hand, levels of F2-isoprostane remained constant in the responder group. Patients with septic shock are under considerable oxidative stress, and 2-AG plays an important role in the cardiovascular status of these patients. The removal of 2-AG by PMX-DHP benefits patients with septic shock by stabilizing cardiovascular status and decreasing long-term oxidative stress.

Polymyxins: A Review of the Current Status Including Recent Developments

Introduction: Polymyxins have become the drug of choice for treatment of multidrug-resistant gram-negative bacilli infections in Singapore, simply because these pathogens are only susceptible to either aminoglycosides and polymyxins, or polymyxins only. Furthermore, there is no new antibiotic in the pipeline that targets these difficult-to-treat infections. Materials and Methods: All published literatures (up to end of February 2008) regarding polymyxins are included for review. Results: This review serves to give a summary of polymyxins from the current available literature, highlighting relevant clinical studies and information that help to guide informed prescription of polymyxins, should the need arise. Conclusions: However, there are substantial information gaps that needed to be filled urgently, to preserve the clinical utility of this very last line of antibiotic. Key words: Acinetobacter baumannii, Colistin, Multidrug resistance, Polymyxin B, Pseudomonas aeruginosa

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.

Polymyxin B: similarities to and differences from colistin (polymyxin E)

Hospital-acquired infections due to multidrug-resistant gram-negative bacteria constitute major health problems, since the medical community is continuously running out of available effective antibiotics and no new agents are in the pipeline. Polymyxins, a group of antibacterials that were discovered during the late 1940s, represent some of the last treatment options for these infections. Only two polymyxins are available commercially, polymyxin E (colistin) and polymyxin B. Although several reviews have been published recently regarding colistin, no review has focused on the similarities and differences between polymyxin B and colistin. These two medications have many similarities with respect to mechanism of action, antimicrobial spectrum, clinical uses and toxicity. However, they also differ in several aspects, including chemical structure, formulation, potency, dosage and pharmacokinetic properties.

Two cases of acute exacerbation of interstitial pneumonia treated with polymyxin B-immobilized fiber column hemoperfusion treatment

The effect of polymixin B-immobilized fiber column (PMX) hemoperfusion treatment for acute exacerbation of interstitial pneumonia (IP) has been reported. Here, we report 2 cases of acute exacerbation of IP successfully treated with PMX hemoperfusion. One is a 55-year-old woman who was diagnosed as microscopic polyangiitis (MPA) with IP. The other is a 58-year-old man, diagnosed as having idiopathic pulmonary fibrosis. Both cases were treated with PMX hemoperfusion and other therapies. One died on day 44 and the other is still alive. The PMX hemoperfusion treatment decreased the serum levels of several cytokines and activated neutrophil percentage in bronchoalveolar lavage fluid.

Serratia marcescens serralysin induces inflammatory responses through protease-activated receptor 2

The Serratia marcescens-derived protease serralysin is considered to play an important role in the pathogenesis of infection. Protease-activated receptor 2 (PAR-2) is activated by trypsin and also several other trypsin-like serine proteases, leading to the modulation of inflammatory and immune responses. However, little is known about the activation of PAR-2 by bacterial proteases and its roles in bacterial infection. In this study, we investigated whether S. marcescens serralysin activates host inflammatory responses through PAR-2. Our results demonstrated that serralysin induces interleukin-6 (IL-6) and IL-8 mRNA expression in a human lung squamous cell carcinoma, EBC-l cells. In addition, serralysin activated activator protein 1 (AP-1)-, CCAAT/enhancer-binding protein (C/EBP)-, and nuclear factor-kappaB (NF-kappaB)-driven promoters in EBC-1 cells. An electrophoretic mobility shift assay showed that serralysin activates the binding of AP-1, C/EBPbeta, and NF-kappaB in the cells. Inactivation of serralysin resulted in the failure of transactivation of AP-1-, C/EBP-, and NF-kappaB-driven promoters in the cells. Furthermore, serralysin activated AP-1-, C/EBP-, and NF-kappaB-driven promoters via PAR-2 in HeLa cells. PAR-2 antagonist peptides decreased serralysin-induced transactivation of AP-1-, C/EBP-, and NF-kappaB-driven promoters in EBC-1 cells. Considered together, these results suggest that serralysin requires PAR-2 to activate the critical transcription factors AP-1, C/EBPbeta, and NF-kappaB for host inflammatory responses.