Cytokine Adsorption to Polymyxin B-Immobilized Fiber: An in vitro Study

Advances in understanding the role of interleukins in pulmonary fibrosis (Review)

Pulmonary fibrosis (PF) is a progressive, irreversible disease characterized by heterogeneous interstitial lung tissue damage. It originates from persistent or repeated lung epithelial injury and leads to the activation and differentiation of fibroblasts into myofibroblasts. Interleukins (ILs) are a group of lymphokines crucial for immunomodulation that are implicated in the pathogenesis of PF. However, different types of ILs exert disparate effects on PF. In the present review, based on the effect on PF, ILs are classified into three categories: i) Promotors of PF; ii) inhibitors of PF; and iii) those that exert dual effects on PF. Several types of ILs can promote PF by provoking inflammation, initiating proliferation and transdifferentiation of epithelial cells, exacerbating lung injury, while other ILs can inhibit PF through suppressing expression of inflammatory factors, modulating the Th1/Th2 balance and autophagy. The present review summarizes the association of ILs and PF, focusing on the roles and mechanisms of ILs underlying PF.

Treatment of acute exacerbation in interstitial lung disease secondary to autoimmune rheumatic diseases: More questions than answers

Interstitial lung disease (ILD) is a relevant cause of morbidity and mortality in patients with autoimmune rheumatic diseases (ARDs). In the last years, an acute exacerbation (AE) - defined as an acute, clinically significant respiratory deterioration characterized by evidence of new widespread alveolar abnormality - has been reported to occur in virtually all ILD types, including ARD-ILD. The aim of this review is to describe the available and investigational treatments in patients affected by AE-ARD-ILD in light of the very low quality of evidence available. Currently, management consists of efforts to identify reversible triggers of respiratory decline, such as drugs effective in ARDs and infections, including opportunistic infections, together with supportive treatments. AE-ILD, AE-ARD-ILD and acute respiratory distress syndrome share histopathologically similar findings of diffuse alveolar damage in most cases. Identification of triggers and risk factors might contribute to early diagnosis and treatment of AE-ILD, before the alveolar damage becomes irreversible. In patients with acute respiratory distress syndrome, the role of steroids and immunosuppressants remains controversial. Also, many uncertainties characterize the management of AE-ARD-ILD because of the lack of evidence and of an unquestionable effective therapy. At this time, no effective evidence-based therapeutic strategies for AE-ARD-ILD are available. In clinical practice, AE-ARD-ILD is often empirically treated with high-dose systemic steroids and antibiotics, with or without immunosuppressive drugs. Randomized controlled trials are needed to better understand the efficacy of current and future drugs for the treatment of this clinical relevant condition.

Composite nanofibrous dressing loaded with Prussian blue and heparin for anti-inflammation therapy and diabetic wound healing

Diabetic ulcer is a severe complication of diabetes that can lead to amputation due to the overproduction of pro-inflammatory factors and reactive oxygen species (ROS). In this study, a composite nanofibrous dressing was developed by combining Prussian blue nanocrystals (PBNCs) and heparin sodium (Hep) through electrospinning, electrospraying, and chemical deposition. The nanofibrous dressing (PPBDH) was designed to take advantage of the excellent pro-inflammatory factor-adsorbing capability of Hep and the ROS-scavenging capabilities of PBNCs, resulting in synergistic treatment. It is worth noting that the nanozymes were firmly anchored to the fiber surfaces through slight polymer swelling caused by the solvent during electrospinning, thereby guaranteeing the preservation of the enzyme-like activity levels of PBNCs. The PPBDH dressing was found to be effective in reducing intracellular ROS levels, protecting cells from ROS-induced apoptosis, and capturing excessive pro-inflammatory factors, including chemoattractant protein-1 (MCP-1) and interleukin-1β (IL-1β). Furthermore, a chronic wound healing evaluation conducted in vivo demonstrated that the PPBDH dressing was able to effectively alleviate the inflammatory response and accelerate wound healing. This research presents an innovative approach to fabricate nanozyme hybrid nanofibrous dressings, which have great potential in accelerating the healing of chronic and refractory wounds with uncontrolled inflammation.

Potential survival benefit and early recovery from organ dysfunction with polymyxin B hemoperfusion: perspectives from a real-world big data analysis and the supporting mechanisms of action

Background

Endotoxin (ET) removal therapy with polymyxin B-immobilized fiber column hemoperfusion (PMX-HP) has been used for the treatment of septic shock. Some observational studies reported clinical benefits, particularly in specific subgroups of patients. However, larger randomized controlled trial results have been disappointing.

Main body

The four studies that revealed the survival benefit of PMX-HP were based on the Japanese Diagnosis Procedure Combination (DPC) national inpatient database (J-DPC study). Nevertheless, one J-DPC study and a randomized controlled trial (RCT) conducted in France evaluated PMX-HP in patients with abdominal septic shock and did not report a significant survival benefit. In both studies, the severity of illness was too low to find substantial significant differences in mortality. The results of the J-DPC studies further suggest that some subpopulations of patients could benefit from PMX-HP. Based on these results, this review revisited prior RCTs and other large-scale studies on PMX-HP. In addition, four J-DPC studies and one large-scale study reported a survival benefit with PMX-HP. A secondary analysis of the EUPHRATES trial, the most recent double-blinded RCT of PMX-HP conducted in North America, suggested a survival benefit in patients with high levels of endotoxemia. In the J-DPC studies and the EUPHRATES trial, ventilator-free days, vasoactive drug-free days, and renal replacement-free days were significantly improved in the PMX-HP groups. These findings suggest that PMX-HP can contribute to early recovery from organ dysfunction. The reduction of supportive care likely provides important health and economic benefits for managing patients with septic shock. Finally, the blood levels of mediators or biomarkers related to respiratory, cardiovascular, and renal dysfunction have been reported to be normalized with PMX-HP.

Conclusions

These results support the biological rationale for the improvement in organ dysfunction observed in the J-DPC studies and other large-scale studies, including the EUPHRATES trial. Real-world evidence from large data sets suggests an appropriate patient population that are likely to benefit from the utility of PMX-HP for septic shock.

Serum cytokine changes induced by direct hemoperfusion with polymyxin B-immobilized fiber in patients with acute respiratory failure

BACKGROUND

Polymyxin B-immobilized Fiber therapy (PMX-DHP) may improve the prognosis of patients with rapidly progressive interstitial lung diseases (ILDs). However, the mechanisms by which PMX-DHP ameliorates oxygenation are unclear. The present study aimed to clarify the changes in serum cytokine concentrations during PMX-DHP with steroid pulse therapy.

METHODS

Patients with acute respiratory failure (ARF) and rapidly progressive ILDs, acute exacerbation of idiopathic pulmonary fibrosis (IPF), or acute respiratory distress syndrome (ARDS), and treated with PMX-DHP were assessed, including patients with IPF. The serum concentrations of 38 cytokines were compared between the ARF and IPF groups before treatment. In the ARF group, cytokine levels were compared before, immediately after PMX-DHP, and the day after termination of steroid pulse therapy.

RESULTS

Fourteen ARF and eight IPF patients were enrolled. A comparison of the cytokine levels before treatment initiation revealed that EGF, GRO, IL-10, MDC, IL-12p70, IL-15, sCD40L, IL-7, IP-10, MCP-1, and MIP-1β were significantly different between the two groups. In the ARF group treated with PMX-DHP, the concentrations of MDC, IP-10, and TNF-α continuously decreased during treatment (P < 0.01). Further, the cytokine levels of GRO, IL-10, IL-1Ra, IL-5, IL-6, and MCP-1 decreased after the entire treatment period, with no change observed during the steroid-only period (P < 0.01, except GRO and MCP-1). Although PMX-DHP significantly reduced eotaxin and GM-CSF serum levels (P < 0.01 and P < 0.05), these levels did not change after treatment.

CONCLUSIONS

PMX-DHP combined with steroid pulse therapy might reduce GRO, IL-10, IL-1Ra, IL-5, IL-6, and MCP-1 levels in ARF, contributing to better oxygenation in the disorder.

Improved Prognostic Prediction by Combination of Early Initiation of Polymyxin B Hemoperfusion with Modified Gender-Age-Physiology Index in Acute Exacerbation of Idiopathic Pulmonary Fibrosis

INTRODUCTION

Respiratory failure from acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is associated with high mortality. Direct hemoperfusion with polymyxin B-immobilized fiber column (PMX-DHP) has been reported to have beneficial effects on patients with AE-IPF. Whether patient characteristics influence the extent of this benefit remains unclear.

METHODS

We retrospectively examined the records of 30 patients with AE-IPF who underwent PMX-DHP. The favorable factors of survival were determined using Cox proportional hazards analyses.

RESULTS

The 1- and 12-month survival rates after PMX-DHP were 70.0% and 50.0%, respectively. The multivariate analysis revealed that low modified Gender-Age-Physiology (GAP) index (≤8 points) (hazard ratio [HR] 0.317, p = 0.015) and PMX-DHP received within 48 h of steroid pulse (HR 0.289, p = 0.012) were favorable factors. Notably, even in the patients with high modified GAP index (>8 points), that is, more advanced IPF, those who received PMX-DHP within 48 h of steroid pulse had a better prognosis than those who did after 48 h of the steroid pulse (p = 0.032).

CONCLUSIONS

Early PMX-DHP initiation in patients with AE-IPF, specifically within 48 h after the steroid pulse therapy, may improve prognosis regardless of the severity of chronic phase of IPF before AE-IPF.

The effects of direct hemoperfusion with polymyxin B-immobilized fiber in patients with acute exacerbation of interstitial lung disease

BACKGROUND

Acute exacerbation of interstitial lung disease (AE-ILD) causes clinically significant deterioration and has an extremely poor prognosis with high mortality. Recently, several studies reported the effectiveness of direct hemoperfusion with a polymyxin B-immobilized fiber column (PMX-DHP) in patients with AE-ILD as a potential therapy. This study describes the clinical effectiveness and safety of PMX-DHP in patients with AE-ILD.

METHODS

We retrospectively reviewed the medical records of 10 patients (11 episodes) with AE-ILD treated with PMX-DHP from January 2018 to June 2019. We compared laboratory and physiologic data of the ratio of partial pressure arterial oxygen to fraction of inspired oxygen (P/F ratio) and level of inflammatory markers before and after implementation of PMX-DHP.

RESULTS

Ten patients were included according to the 2016 revised definition of acute exacerbation of idiopathic pulmonary fibrosis (IPF). Nine patients had IPF and one patient had fibrotic nonspecific interstitial pneumonia. Most patients (90.9%) were treated with a steroid pulse, and four patients (36.4%) were treated with an immunosuppressant. The median number of PMX-DHP cycles was 2, and the median duration of each cycle was 6 hours. After PMX-DHP, the mean P/F ratio improved (86 [range, 63-106] vs. 145 [86-260], P=0.030) and interleukin-6 and c-reactive protein decreased (79 [35-640] vs. 10 [5-25], P=0.018 and 14 [4-21] vs. 5 [2-6], P=0.019, respectively). The 30-day mortality rate was 27.3% and the 90-day mortality rate was 72.7%.

CONCLUSIONS

PMX-DHP treatment improved P/F ratio and reduced inflammatory markers in AE-ILD patients.