Polymyxin B hemoperfusion prevents acute kidney injury in sepsis model

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.

Predialysis serum lactate levels could predict dialysis withdrawal in Type 1 cardiorenal syndrome patients

BACKGROUND

Renal replacement therapy (RRT) is an effective rescue therapy for Type 1 cardiorenal syndrome (CRS). Previous studies have demonstrated that type 1 CRS patients with severe renal dysfunction were susceptible to sepsis, and that serum lactate has been correlated with the risk of mortality in patients with sepsis. However, the association between serum lactate level and the prognosis of type 1 CRS patients requiring RRT is unknown.

METHODS

An inception cohort of 500 type 1 CRS patients who received RRT in a tertiary-care referral hospital in Taiwan from August 2011 to January 2018 were enrolled. The outcomes of interest were dialysis withdrawal and 90-day mortality. The results were further externally validated using sampling data of type 1 CRS patients requiring dialysis from multiple tertiary-care centers.

FINDINGS

The 90-day mortality rate was 52.8% and the incidence rate of dialysis withdrawal was 34.8%. Lower pre-dialysis lactate was correlated with a higher rate of dialysis withdrawal and lower rate of mortality. Generalized additive model showed that 4.2 mmol/L was an adequate cut-off value of lactate to predict mortality. Taking mortality as a competing risk, Fine-Gray subdistribution hazard analysis further indicated that a low lactate level (≦ 4.2 mmol/L) was an independent predictor for the possibility of dialysis withdrawal, as also shown in external validation. The interaction of quick Sequential Organ Failure Assessment score and lactate was associated with dialysis dependence in a disease severity-dependent manner. Furthermore, the associations between hyperlactatemia and dialysis dependence were consistent in the patients with and without sepsis.

INTERPRETATION

Serum lactate level is accurate and capable of forecasting the prognosis along with qSOFA severity for clinical decision-making for treating type 1 CRS patients. Further studies are needed to validate our results.

FUNDING

This study was supported by grants from Taiwan National Science Council [104-2314-B-002-125-MY3,106-2314-B-002-166-MY3,107-2314-B-002-026-MY3], National Taiwan University Hospital [106-FTN20,106-P02,UN106-014,106-S3582,107-S3809,107-T02,PC1246,VN109-09,109-S4634,UN109-041], Ministry of Science and Technology of the Republic of China [MOST106-2321-B-182-002,106-2314-B-182A-064,MOST107-2321-B-182-004,MOST107-2314-B-182A-138, MOST108-2321-B-182-003,MOST109-2321-B-182-001, MOST108-2314-B-182A-027], Chang Gung Memorial Hospital [CMRPG-2G0361,CMRPG-2H0161,CMRPG-2J0261, CMRPG-2K0091], and Ministry of Health and Welfare of the Republic of China [PMRPG-2L0011].

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.

Blood Purification Techniques for Sepsis and Septic AKI

Sepsis is the primary cause of acute kidney injury in critically ill patients. During the past decades, several extracorporeal blood purification techniques have been developed for sepsis and sepsis-induced acute kidney injury management. These therapies could act on both the infectious agent itself and the host immune response. In this article, we review the available literature discussing the different extracorporeal blood purification techniques, including high-volume hemofiltration, cascade hemofiltration, hemoperfusion, coupled plasma filtration adsorption, plasma exchange, and specific optimized renal replacement therapy membranes.

Pathogenic functions and diagnostic utility of cytokines/chemokines in EHEC-HUS

Hemolytic - uremic syndrome (HUS) is a severe complication of infection by Shiga toxin (STx)-producing enterohemorrhagic Escherichia coli. Hemolytic - uremic syndrome is defined clinically as a triad of non-immune microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injuries. Neurologic complications such as acute encephalopathy are also observed. In humans, endothelial cells, proximal tubular epithelial cells, mesangial cells, podocytes, intestinal epithelial cells, and monocytes / macrophages are susceptible to STx-mediated injury. Shiga toxin induces the secretion of inflammatory cytokines and chemokines from susceptible cells, including tumor necrosis factor-α interleukin (IL)-1, IL-6, and IL-8. These cytokines and chemokines contribute to the pathogenesis of HUS and encephalopathy by enhancing STx-induced cytotoxicity and inducing inflammatory cell infiltration. Serum cytokine/chemokine levels are therefore useful as indicators of disease activity and predictors of progression from acute kidney injury to chronic kidney disease. Anti-inflammation therapy combined with apheresis to remove excessive cytokines / chemokines and methylprednisolone pulse therapy to suppress cytokine/chemokine production may be an effective treatment regimen for severe E. coli-associated HUS. However, this regimen requires careful monitoring of potential side effects, such as infections, thrombus formation, and hypertension.

Polymyxin B hemoperfusion as a feasible therapy after source control in abdominal septic shock

BACKGROUND

Polymyxin B hemoperfusion (PMX-HP) has been used as a treatment for intra-abdominal septic shock by absorbing and removing endotoxins of gram-negative bacilli.

AIM

To investigate the clinical efficacy of PMX-HP in patients with gram-negative septic shock who underwent abdominal surgery.

METHODS

From January 2012 to December 2018, patients who had septic shock secondary to peritonitis were enrolled. They were classified into PMX-HP treated and control groups based on postopreative intervention using PMX-HP. The clinical outcomes were compared using 1:1 propensity score matching methods to balance the overall distribution between the two groups.

RESULTS

After propensity score matching, 40 patients were analyzed (20 patients in the PMX group and 20 patients in the control group). The scores of total Sequential Organ Failure Assessment (SOFA) score, renal SOFA and coagulation SOFA were significantly improved in the PMX group but not in the control group. (from 11.2 ± 5.8 to 4.7 ± 3.5 in PMX group vs 10.0 ± 4.0 to 8.7 ± 7.3 in control group, P = 0.047 from 2.6 ± 1.0 to 0.7 ± 1.0 in PMX group vs 2.6 ± 1.5 to 2.8 ± 1.6 in control group, P = 0.000, from 1.6 ± 1.5 to 1.3 ± 1.3 in PMX group vs 1.2 ± 1.2 to 2.8 ± 1.8 in control group, P = 0.014, respectively). Further, the length of intensive care unit (ICU) stay was significantly shorter in PMX group. However, no statistically significant difference was found in ICU mortality (50% in PMX group vs 50% in control group).

CONCLUSION

PMX-HP is a feasible adjunct treatment for peritonitis in ICU patients with peritonitis for improved organ impairment and to stabilize hemodynamics. It would be helpful to enhance clinical outcomes especially in patients with complete elimination of the source of gram-negative bacilli infection by surgical procedure accompanied with conventional treatment of sepsis.

Blood purification treatment initiated at the time of sepsis diagnosis effectively attenuates serum HMGB1 upregulation and improves patient prognosis

The aim of the present study was to investigate the increase in serum and urine levels of high mobility group box protein 1 (HMGB1) during sepsis and the effect of blood purification treatments on HMGB1 levels and patient prognosis. A total of 40 intensive care patients with sepsis were randomly assigned to different groups (n=10 per group): A control group (sepsis group), a continuous renal replacement treatment (CRRT) group, a hemoperfusion (HP) group and an HP+CRRT group. The blood purification treatments using HP and/or CRRT were performed immediately after the diagnosis of sepsis. HMGB1 levels were measured using ELISA, and Acute Physiology and Chronic Health Evaluation (APACHE) II scores and 30-day survival rates were evaluated. Relative to a healthy control group (n=10), HMGB1 levels were observed to be significantly upregulated during sepsis (P<0.05). Following the initiation of sepsis, serum HMGB1 continued to increase in the sepsis group and was significantly elevated at 24 h (P<0.05), whereas urine HMGB1 levels decreased significantly at 12 and 24 h (P<0.05). Serum HMGB1 levels were significantly positively correlated with APACHE II scores (r=0.7284, P<0.01) and significantly negatively correlated with urine HMGB1 levels (r=−0.5103, P=0.026). Serum HMGB1 levels were significantly reduced in the HP and HP+CRRT groups by 12 and 24 h following the initiation of treatment (both P<0.05). Changes in the urine HMGB1 level differed in each group. Relative to the sepsis group, the APACHE II scores of all blood purification groups were significantly reduced (P<0.05) and the 30-day survival rate of the HP+CRRT group was significantly increased (P=0.0107). The results of the present study indicate that blood purification initiated at the point of diagnosis in patients with sepsis may attenuate serum HMGB1 upregulation, promote urinary excretion of HMGB1 and improve the prognosis of sepsis.

Effects of endotoxin absorber hemoperfusion on microcirculation in septic pigs

BACKGROUND

Endotoxins contribute to systemic inflammatory response and microcirculatory dysfunctions under conditions of sepsis. Polymyxin B hemoperfusion (PMX-HP) is used to remove circulating endotoxins and improve clinical outcomes. This study aims to investigate the effect of PMX-HP on microcirculation in septic pigs.

MATERIALS AND METHODS

By using a septic pig model, we tested the hypothesis that PMX-HP can correct intestinal microcirculation, tissue oxygenation saturation, and histopathologic alterations. A total of 18 male pigs were divided into three groups: (1) sham; (2) sepsis (fecal peritonitis); and (3) sepsis + PMX-HP groups. A sidestream dark field video microscope was used to record microcirculation throughout the terminal ileal mucosa, colon mucosa, kidney surface, and sublingual area. A superficial tissue oxygenation monitor employing the light reflectance spectroscopy technique was used to measure the tissue oxygen saturation. Hematoxylin and eosin staining was used for histologic examination.

RESULTS

The perfused small vessel density and tissue oxygen saturation of the ileal mucosa at 6 h were higher in the sepsis + PMX-HP group than those in the sepsis group. The fluid amount and norepinephrine infusion rate between the sepsis group and sepsis + PMX-HP groups did not differ significantly. The histologic score for the ileal mucosa was lower in the sepsis + PMX-HP group than that in the sepsis group. Finally, the urine output was higher in the sepsis + PMX-HP group than it was in the sepsis group.

CONCLUSIONS

This study demonstrates that PMX-HP attenuates microcirculatory dysfunction, tissue desaturation, and histopathologic alterations in the ileal mucosa in septic pigs.