Blood purification for hypercytokinemia

A Larger Membrane Area Increases Cytokine Removal in Polymethyl Methacrylate Hemofilters

Blood purification is performed to control cytokines in critically ill patients. The relationship between the clearance (CL) and the membrane area during adsorption is not clear. We hypothesized that the CL increases with the hydrophobic area when hydrophobic binding contributes to cytokine adsorption. We investigated the relationship between the hemofilter membrane area and the CL of the high mobility group box 1 protein (HMGB-1) and interleukin-6 (IL-6). We performed experimental hemofiltration in vitro using polymethyl methacrylate membranes CH-1.8W (1.8 m²) and CH-1.0N (1.0 m²), as well as polysulfone membrane NV-18X (1.8 m²). After adding 100 mg of HMGB1 or 10 μg of IL-6 into the test solution, experimental hemofiltration was conducted for 360 min in a closed-loop circulation system, and the same amount of HMGB1 and IL-6 was added after 180 min. With CH-1.8W and CH-1.0N, both HMGB-1 and IL-6 showed a rapid concentration decrease of more than 70% at 180 min and 360 min after the re-addition. At 15 min, the CL of HMGB-1 was CH-1.8W: 28.4 and CH-1.0N: 19.8, and that of IL-6 was CH-1.8W: 41.1 and CH-1.0N: 25.4. CH-1.8W and CH-1.0N removed HMGB1 and IL-6 by adsorption and CH-1.8W was superior in CL, which increased with a greater membrane area.

Changes in acute blood purification therapy in critical care: republication of the article published in the Japanese Journal of Artificial Organs

Acute blood purification therapy is an essential artificial organ in critical care. In the review article, looking back on the history, we describe our present knowledge and techniques of acute blood purification therapy in critical care. The topics include continuous hemodiafiltration (CHDF), online HDF as an artificial liver support, blood purification therapy aiming to remove pathogenic substances of sepsis, a procedure for connecting a CRRT device into an extra-corporeal membrane oxygenation circuit, and replacement fluid for CHDF. We also raise remaining issues and clarify the future direction of acute blood purification therapy in critical care. This review was created based on a translation of the Japanese review written in the Japanese Journal of Artificial Organs in 2017 (Vol. 46, No. 1, pp. 67-70), with adding some references.

Clinical study of blood purification therapy in critical care in Japan: results from the survey research of the Japan Society for Blood Purification in Critical Care in 2013

To clarify the clinical status of blood purification therapy (BPT) in critical care in Japan, we conducted a cohort study using data from a nationwide registry of the Japan Society for Blood Purification in Critical Care in 2013. We enrolled 2227 patients treated with BPT (female, 39.1%; mean age, 65.5 ± 12.1 years) in the intensive care units of 43 facilities. Patient characteristics, modes of BPT, and survival rate for each disease were investigated. In total, BPT was performed 3053 times. Continuous renal replacement therapy (CRRT) (57.9%) was the most common mode of BPT, followed by intermittent renal replacement therapy (20.2%) and direct hemoperfusion with the polymyxin B-immobilized fiber column (PMX-DHP) (11.5%). Nafamostat mesilate (84.9%) was most frequently used as the anticoagulant. The 28-day survival rate was 56.8% in all patients. The most common mode for acute kidney injury (AKI) and multiple organ failure was CRRT, while PMX-DHP and CRRT were most common for sepsis. There was no significant difference in survival rates among AKI stages 1-3. Survival rate (38.3%) was significantly lower in patients with acute lung injury (ALI) than in those with multiple organ failure (41.8%) and those with sepsis (46.6%). Multivariate regression analysis revealed that the APACHE II score and the presence of acute ALI and acute hepatic failure were significantly associated with death. This large-scale cohort study showed the clinical status of BPT in Japan. Further investigations are required to clarify the efficacy of BPT for critically ill patients.

Serum levels of interleukin-6 may predict organ dysfunction earlier than SOFA score

Aim

To investigate the clinical utility of interleukin‐6 (IL‐6), procalcitonin (PCT), and C‐reactive protein (CRP) as predictive markers in consideration of the time‐course changes in critically ill patients with organ dysfunction.

Methods

Serum levels of IL‐6, PCT, CRP, and Sequential Organ Failure Assessment (SOFA) scores were measured sequentially in 92 patients during their initial 5 days following admission to the intensive care unit. Maximum values were analyzed. Patients were assigned to a low ( ≤ 8), intermediate ( > 8 and ≤ 16), or high ( > 16 and ≤ 24) SOFA score group.

Results

There were significant differences in the maximum serum levels of IL‐6 and PCT among the three SOFA score groups (IL‐6, P < 0.0001; PCT, P = 0.0004). Specifically, comparisons between the groups revealed significant differences in IL‐6 levels (low versus intermediate, P = 0.0007; intermediate versus high, P = 0.0010). The probability of patients with the maximum value was greatest on day 1 (56.5%) for IL‐6, on day 1 (39.1%) or day 2 (38.0%) for PCT, on day 3 (39.1%) for CRP, and on day 1 (43.5%) for SOFA score. The median (interquartile range) peak day of IL‐6 was day 1 (1–2), which was significantly earlier than that of SOFA score at day 2 (1–3) (P = 0.018).

Conclusion

Serum levels of IL‐6 reflected the severity of organ dysfunction in critically ill patients most accurately compared to PCT and CRP. Interleukin‐6 elevated soonest from the insult and reached its peak earlier than SOFA score.

Proteome analysis of hemofilter adsorbates to identify novel substances of sepsis: a pilot study

Blood purification therapy using hemofilters with high adsorbing capabilities has been reported to remove excessive humoral mediators from the blood of patients with sepsis. However, there are insufficient studies of the adsorbates bound to hemofilter membranes. We hypothesized that these adsorbates in acute kidney injury (AKI) patients with sepsis were different from those in patients without sepsis and that proteome analysis of the adsorbates would identify novel substances of sepsis. This study included 20 patients who had AKI upon admission to intensive care units (ICUs) and who received continuous renal replacement therapy using polymethyl methacrylate hemofilters. We isolated adsorbates from the hemofilters after use and performed comprehensive proteome analysis. A total of 429 proteins were identified in these adsorbates. Adsorbates from the hemofilters of patients with sepsis had significantly increased frequency of proteins associated with "immune system process" and "biological adhesion" functions compared to those of non-sepsis patients (P < 0.05). Of 429 proteins, 197 were identified only in sepsis adsorbates. Of these, 3 proteins including carbonic anhydrase 1 (CA1) and leucine-rich alpha-2-glycoprotein (LRG1) were identified in all samples from sepsis patients and have not been previously reported in sepsis patients. Validation analysis of patient serum revealed that patients with sepsis had increased serum levels of CA1 and LRG1 compared to patients without sepsis (P < 0.05). To conclude, there were significant differences in the characteristics of the adsorbates from sepsis and non-sepsis patients. CA1 and LRG1 appear to be novel substances associated with sepsis.

Usefulness of the endotoxin activity assay to evaluate the degree of lung injury

PURPOSE

It has been reported that the Pulse Contour Cardiac Output (PiCCO) is very useful mainly in the field of intensive care and treatment to grasp the pathophysiological conditions of pulmonary edema because of its capability of obtaining data such as Pulmonary Vascular Permeability Index (PVPI) and Extra Vascular Lung Water (EVLW). Furthermore, a high degree of usability of various markers has been reported for better understanding of the pathological conditions in cases with septicemia.

MATERIALS AND METHODS

The correlation between the cardiorespiratory status based upon the PiCCO monitor (EVLW and PVPI) and inflammatory markers including C reactive protein, procalcitonin (PC), and Endotoxin Activity Assay (EAA) were evaluated in 11 severe cases that required treatment with a respirator in an intensive care unit.

RESULTS

The EAA values were significantly higher in patients with abnormal EVLW at 0.46±0.20 compared to the normal EVLW group at 0.21±0.19 (p=0.0064). In a similar fashion, patients with abnormal PVPI values tended to have higher PC levels at 18.9±21.8 compared to normal PVPI cases at 2.4±2.2 (p=0.0676). On the other hand, PVPI was significantly higher in the abnormal EAA group at 3.55±0.48 in comparison with the normal EAA group at 1.99±0.68 (p=0.0029). The abnormal EAA group tended to have higher PVPI values than the normal EAA group.

CONCLUSION

The EAA is a measurement method designed to estimate the activity of endotoxins in the whole blood. Our results suggest that the EAA value, which had the greatest correlation with lung disorders diagnosed by the PiCCO monitoring, reflects inflammatory reactions predominantly in the lungs.

Techniques of extracorporeal cytokine removal: a systematic review of the literature on animal experimental studies

BACKGROUND AND AIMS

Extracorporeal cytokine removal may be desirable. We sought to assess extracorporeal blood purification (EBP) techniques for cytokine removal in experimental animal studies.


METHODS

We conducted a targeted, systematic search and identified 17 articles. We analyzed cytokine clearance, sieving coefficient (SC), ultrafiltrate (UF) concentration, and percentage removal. As this review concerns technical appraisal of EBP techniques, we made no attempts to appraise the methodology of the studies included. Results are in descriptive terms only.


RESULTS

Applying predicted clearance for 80 kg human, high volume hemofiltration (HVHF) techniques and plasmafiltration (PF) showed the highest rates of cytokine removal. High cutoff (HCO)/HF and PF techniques showed modest ability to clear cytokines using low to medium flows. Standard hemofiltration had little efficacy. At higher flows, HCO/HF achieved clearances between 30 and 70 ml/min for IL-6 and IL-10. There was essentially no removal of tumor necrosis factor (TNF)-alpha outside of PF.


CONCLUSIONS

Experimental animal studies indicate that HVHF (especially with HCO filters) and plasmafiltration have the potential to achieve appreciable IL-6 and IL-10 clearances. However, only PF can remove TNF-alpha reliably.

Cytokine removal under hemodiafiltration with endogenous reinfusion in acute kidney injury secondary to angioimmunoblastic T-cell lymphoma: a case report

Angioimmunoblastic T-cell lymphoma shows a high release of cytokines. Different blood purification techniques are employed to control hypercytokinemia. Here we investigated the effects of intermittent supra-hemodiafiltration with endogenous reinfusion on cytokine removal in a patient presenting with acute kidney injury. After the first day of chemotherapy for angioimmunoblastic T-cell lymphoma, a 78-year-old male patient developed acute kidney injury and systemic inflammatory response syndrome due to massive release of inflammatory cytokines. Three sessions of supra-hemodiafiltration were performed. Blood samples for evaluation of renal function and inflammatory mediators were collected at the beginning and the end of each dialytic session. A marked improvement of clinical state and renal function was associated to a significant reduction of inflammatory markers. Our results suggest that renal replacement therapy with supra-hemodiafiltration may remove a wide spectrum of inflammatory mediators and uremic toxins involved in acute kidney injury and systemic inflammatory response syndrome.

Role of apheresis and dialysis in pediatric living donor liver transplantation: a single center retrospective study

In the field of pediatric living donor liver transplantation, the indications for apheresis and dialysis, and its efficacy and safety are still a matter of debate. In this study, we performed a retrospective investigation of these aspects, and considered its roles. Between January 2008 and December 2010, 73 living donor liver transplantations were performed in our department. Twenty seven courses of apheresis and dialysis were performed for 19 of those patients (19/73; 26.0%). The indications were ABO incompatible-liver transplantation in 11 courses, fluid management in seven, acute liver failure in three, renal replacement therapy in two, endotoxin removal in two, cytokine removal in one, and liver allograft dysfunction in one. Sixteen courses of apheresis and dialysis were performed prior to liver transplantation for 14 patients. The median IgM antibody titers before and after apheresis for ABO blood type-incompatible liver transplantation was 128 and eight, respectively (P < 0.05). Eleven courses of apheresis and dialysis were performed post liver transplantation for 10 patients. The median PaO2/FiO2 ratio before and after dialysis for fluid overload was 159 and 339, respectively (P < 0.05). No bleeding or technical complications attributable to apheresis and dialysis occurred. The 1-year survival rate of the patients was 100%. Apheresis and dialysis in pediatric living donor liver transplantation are effective for antibody removal in ABO-incompatible liver transplantation, and fluid management for acute respiratory failure.

Comparison of efficacy between continuous hemodiafiltration with a PMMA membrane hemofilter and a PAN membrane hemofilter in the treatment of a patient with septic acute renal failure

The aim of this study was to investigate whether PMMA-CHDF in the treatment of a patient with septic acute renal failure (septic ARF) is clinically relevant. Thirteen patients were treated with PMMA-CHDF. Thirteen patients were treated with PAN-CHDF. The urinary output significantly increased in PMMA-CHDF group following 24h of the treatment (p<0.05), whereas those did not improve in PAN-CHDF group. The 28-day survival was 84.6% in PMMA-CHDF group and 38.5% in PAN-CHDF group, respectively (p<0.05). We can assume that the cytokine modulation with PMMA-CHDF in the treatment of patients with septic ARF is clinically relevant.

Continuous hemodiafiltration with PMMA Hemofilter in the treatment of patients with septic shock

Septic shock is the most severe form of sepsis. It is widely accepted that cytokines play pivotal roles in the pathophysiology of septic shock. We reported previously that continuous hemodiafiltration (CHDF) using a polymethylmethacrylate (PMMA) membrane hemofilter removed various cytokines from blood continuously and efficiently, mainly by adsorption to membrane matrix of the hemofilter. Furthermore, in April 2000, we introduced to clinical practice a rapid assay system that determines blood levels of IL (interleukin)-6 in approximately 30 min. This enabled us to routinely measure blood IL-6 as an index of cytokine cascade activation in critically ill patients for real-time clinical monitoring of hypercytokinemia. The aim of the present cohort study was to evaluate the clinical efficacy of PMMA-CHDF in septic shock, a typical condition associated with hypercytokinemia. Forty-three patients with septic shock were assessed by monitoring of blood IL-6 level with a rapid assay system and immediate initiation of critical care including PMMA-CHDF for cytokine removal. Following initiation of PMMA-CHDF, early improvement of hemodynamics was noted, as well as an increase in urine output. PMMA-CHDF treatment improved both hypercytokinemia (assessed by measurement of blood IL-6 level) and dysoxia (assessed by measurement of blood lactate level). The present findings suggest that cytokine-oriented critical care using PMMA-CHDF might be an effective strategy for the treatment of septic shock.