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.

Targeting Cytokines, Pathogen-Associated Molecular Patterns, and Damage-Associated Molecular Patterns in Sepsis via Blood Purification.

Sepsis is characterized by a dysregulated immune response to infections that causes life-threatening organ dysfunction and even death. When infections occur, bacterial cell wall components (endotoxin or lipopolysaccharide), known as pathogen-associated molecular patterns, bind to pattern recognition receptors, such as toll-like receptors, to initiate an inflammatory response for pathogen elimination. However, strong activation of the immune system leads to cellular dysfunction and ultimately organ failure. Damage-associated molecular patterns (DAMPs), which are released by injured host cells, are well-recognized triggers that result in the elevation of inflammatory cytokine levels. A cytokine storm is thus amplified and sustained in this vicious cycle. Interestingly, during sepsis, neutrophils transition from powerful antimicrobial protectors into dangerous mediators of tissue injury and organ dysfunction. Thus, the concept of blood purification has evolved to include inflammatory cells and mediators. In this review, we summarize recent advances in knowledge regarding the role of lipopolysaccharides, cytokines, DAMPs, and neutrophils in the pathogenesis of sepsis. Additionally, we discuss the potential of blood purification, especially the adsorption technology, for removing immune cells and molecular mediators, thereby serving as a therapeutic strategy against sepsis. Finally, we describe the concept of our immune-modulating blood purification system.

Comparison of myoglobin clearance in three types of blood purification modalities.

Myoglobin, which can cause acute kidney injury, has a relatively high molecular weight and is poorly cleared by diffusion. We compared and examined myoglobin clearance by changing the blood purification membrane and modality in patients with a myoglobin blood concentration ≥ 1000 ng/ml. We retrospectively analyzed three patient groups based on the following three types of continuous hemofiltration (CHF): AN69ST membrane, polymethylmethacrylate (PMMA) membrane, and high-flow hemodiafiltration (HDF) with increased dialysate flow rate using the PMMA membrane. There was no significant difference in clearance in CHF between AN69ST and PMMA membranes. However, the high-flow HDF group showed the highest myoglobin clearance (p = 0.003). In the PMMA membrane, changing the treatment modality to high-flow HDF increased clearance above the theoretical value, possibly due to internal filtration. To remove myoglobin by kidney replacement therapy from patients with hypermyoglobinemia, a modality such as high-flow HDF would be desirable.

Adsorption kinetics of high mobility group box 1 protein in a polyacrylonitrile hemofiltration membrane.

The high mobility group box 1 protein (HMGB1) is recognized as a prototypical endogenous danger cytokine in sepsis. We previously reported that a polyacrylonitrile (AN69ST) membrane rapidly adsorbed HMGB1. Herein, an in vitro hemofiltration system was designed to assess the HMGB1 adsorption capacity, adsorption sites, and adsorption mechanism of the AN69ST membrane. HMGB1 was repeatedly added seven times during hemofiltration. A rapid decrease in circulating HMGB1 was observed after every addition with no sign of saturation. Presence of HMGB1 on the filter membrane was observed on both membrane surfaces and within the bulk layer using a high concentration of HMGB1 by immunoelectron microscopy. We hypothesized that the addition of heparin to the membrane surface or filtration rate would contribute to the adsorption mechanism. We could not measure the influence of heparin and filtration. Although the membrane was too large to saturate under the µg/mL HMGB1 conditions, our results show that the AN69ST membrane has a robust absorption capacity that could be used to treat sepsis.

Impact of Blood Type O on Mortality of Sepsis Patients: A Multicenter Retrospective Observational Study.

ABO blood groups have been implicated as potential risk factors for various diseases. However, no study has investigated the association between sepsis mortality and ABO blood types. We aimed to evaluate the impact of these blood types on mortality in patients with sepsis and septic shock. This retrospective observational study was conducted at two general hospitals in Japan. Patients diagnosed with sepsis or septic shock were included and divided into four groups based on blood type (O, A, B, and AB). The association between type O vs. other types and 28- and 90-day mortalities was evaluated using multivariate logistic regression analysis adjusted for age, sex, and Sequential (Sepsis-related) Organ Failure Assessment score. This study included 415 patients, of whom 131 (31.6%), 171 (41.2%), 81 (19.5%), and 32 (7.7%) had type O, A, B, and AB, respectively. Blood type O was not associated with 28-day (odds ratio: 1.7 p = 0.08) or 90-day mortality (odds ratio: 1.53, p = 0.091). However, type O was significantly associated with higher 90-day mortality (odds ratio: 3.26, p = 0.009) in patients with septic shock. The role of ABO blood type in risk stratification for septic shock and the mechanisms that potentially affect the prognosis of sepsis patients need further investigation.

Lower blood return temperature than core temperature as a causal factor of decreased cardiac output assessed by transpulmonary thermodilution during blood purification.

We aimed to evaluate whether cardiac output assessed by transpulmonary thermodilution during blood purification is affected by the difference between the blood return temperature and core temperature. We applied different blood return temperatures using a thermostat bath during blood purification in four pigs. After the blood return temperature stabilized and blood purification process stopped, the cardiac output assessed by transpulmonary thermodilution was measured. The thermostat bath was set at 35°C, 40°C, 45°C, and 50°C, with the order changed at random; four measurements were made at each temperature. Cardiac function was evaluated by echocardiography when ice-cold saline was administered in a pig. A decrease in the blood return temperature resulted in decreased cardiac output assessed by transpulmonary thermodilution, whereas an increase resulted in increased cardiac output assessed by transpulmonary thermodilution. Echocardiography revealed that the change in the blood return temperature did not affect the left ventricular ejection fraction.

Involvement of ionic interactions in cytokine adsorption of polyethyleneimine-coated polyacrylonitrile and polymethyl methacrylate membranes in vitro.

Polyethyleneimine-coated polyacrylonitrile (AN69ST) and polymethyl methacrylate (PMMA) membranes are effective cytokine-adsorbing hemofilters; however, the cytokine-adsorption mechanism remains elusive. This study investigated the involvement of ionic interactions in cytokine adsorption to a negatively charged AN69ST membrane and neutral-charged PMMA membrane. Experimental hemofiltration was performed for 30 min in a closed-loop circulation system using AN69ST and PMMA hemofilters. Tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-8 concentrations in the test solutions were measured at baseline and at 10 min and 30 min into hemofiltration. To investigate the involvement of ionic interactions in cytokine adsorption, cytokine clearance (CL) was calculated at 10 min into hemofiltration and with three types of solutions at various pH levels (7.6, 7.2, and 6.8). During AN69ST hemofiltration, the CLs of TNF-α, IL-6, and IL-8 were 38 ± 6 mL/min, 23 ± 7 mL/min, and 78 ± 3 mL/min, respectively, demonstrating a relationship with their respective isoelectric points. During PMMA hemofiltration, the CL of IL-6 peaked at 31 ± 76 mL/min, with no relationship observed between the CL and isoelectric point. When the pH of the test solution shifted from 7.6 to 6.8, the CLs of TNF-α, IL6, and IL-8 increased in the AN69ST hemofilter; whereas, no such trend was observed in the PMMA hemofilter. These results indicated that Ionic interactions play a role in cytokine adsorption by the AN69ST membrane but not the PMMA membrane and highlight the clinical relevance of this finding, as well as the potential practical applications for further hemofilter design.

In vitro Evaluation of Linezolid and Doripenem Clearance with Different Hemofilters.

INTRODUCTION: Renal replacement therapy (RRT) is widely used in the treatment of septic acute kidney injury. However, little is known about how the adsorption properties of hemofilters used in RRT affect antibiotic concentration. Because a cytokine-adsorption membrane is frequently used in RRT, it is important to determine the antibiotic adsorption capacity of this membrane. OBJECTIVE: The present study aimed to investigate the antibiotic adsorption capacity of different hemofilter membranes by in vitro experiments using 2 antibacterial agents (linezolid and doripenem). METHODS: We performed experimental hemofiltration in vitro using polyacrylonitrile (AN69ST), polymethylmethacrylate (PMMA), and polysulfone (PS) hemofilters for 1,440 min. The test solution was a 1,000-mL substitution fluid containing 30 µg/mL linezolid and 120 µg/mL doripenem. We measured drug concentrations at the inlet, outlet, and filtrate ports of the hemofilters for 1,440 min and calculated the sieving coefficient (SC) and adsorption rate (Ra) of the drugs onto the hemofilters. RESULTS: The amount of linezolid adsorbed onto AN69ST, PMMA, and PS membranes was decreased relative to that in the control group at 15 min (p < 0.05). However, no SC for linezolid was obtained thereafter. The Ra of linezolid onto AN69ST, PMMA, and PS membranes was higher than that in the control group (p < 0.05). In contrast, no significant differences were observed in the concentrations and Ra values of doripenem adsorbed onto AN69ST, PMMA, and PS membranes compared with those in the control group. CONCLUSIONS: Doripenem was not adsorbed onto PMMA, PS, and AN69ST membranes. Linezolid was adsorbed onto PMMA, PS, and AN69ST membranes, but only temporarily, and this did not affect drug bioavailability.

Suppressive effects of the neutrophil elastase inhibitor sivelestat sodium hydrate on interleukin-1ß production in lipopolysaccharide-stimulated porcine whole blood.

OBJECTIVE: Sivelestat sodium hydrate (Siv) is expected to be an effective therapy for acute respiratory distress syndrome, although its mechanism of action is not understood. In this study, we investigated which myeloid cells-derived cytokines were suppressed by Siv. METHODS: Continuous hemofiltration was performed by circulating fresh porcine blood through a semi-closed circuit. To ensure that leukocytes survived for 360 min, 5% glucose, heparin, and air were continuously injected. The control group received continuous administration of lipopolysaccharide (LPS) only, whereas the Siv group received LPS and Siv. Complete blood count, levels of various cytokines, and other variables were compared between the groups. RESULTS: Interleukin (IL)-1ß level was significantly suppressed in the Siv group compared with that in the control group (p<0.05). CONCLUSIONS: The results suggested that Siv suppressed the production of IL-1ß and possibly other cytokines by myeloid cells. Whether this suppression of cytokine production is caused directly by Siv or mediated via suppression of granulocyte elastase should be evaluated in the future.

A CO2 removal system using extracorporeal lung and renal assist device with an acid and alkaline infusion.

The patients with respiratory failure need high tidal volume by mechanical ventilation, which lead to the ventilator-induced lung injury. We developed an extracorporeal lung and renal assist device (ELRAD), comprising acid infusion, membrane lung, continuous hemodiafiltration and alkaline infusion. To evaluate this system, we conducted in vivo studies using experimental swine which were connected to the new system. In vivo experiments consist of four protocols; baseline = hemodiafiltration only (no O2 gas flow to membrane lung); membrane lung = "Baseline" plus O2 gas flow to membrane lung; "Acid infusion" = "Membrane lung" plus continuous acid infusion; ELRAD = "Acid infusion" plus continuous alkaline infusion. We changed the ventilatory rate of the mechanical ventilation to maintain PCO2 at 50-55 mmHg during the four protocols. The results showed that there was statistically no significant difference in the levels of pH, HCO3-, and base excess when each study protocol was initiated. The amount of CO2 eliminated by the membrane lung significantly increased by 1.6 times in the acid infusion protocol and the ELRAD protocol compared to the conventional membrane lung protocol. Minute ventilation in the ELRAD protocol significantly decreased by 0.5 times compared with the hemodiafiltration only protocol (P < 0.0001), the membrane lung (P = 0.0006) and acid infusion protocol (P = 0.0017), respectively. In conclusion, a developed CO2 removal system efficiently removed CO2 at low blood flow and reduced minute ventilation, while maintaining acid-base balance within the normal range.

Differential effect of lactate in predicting mortality in septic patients with or without disseminated intravascular coagulation: a multicenter, retrospective, observational study.

BACKGROUND: We examined whether high lactate level in septic patients was associated with 90-day mortality based on the patients' disseminated intravascular coagulation (DIC) status. METHODS: We conducted a multicenter, retrospective, observational study of patients admitted to the intensive care unit (ICU) with a suspicion of severe infection and diagnosed with sepsis. Regression analyses were performed to estimate the interaction effect between DIC status and the lactate level. Then, the association between the lactate level and 90-day mortality was assessed in the DIC and non-DIC subgroups. RESULTS: The data of 415 patients were analyzed. We found a significant interaction between DIC status and the lactate level for predicting 90-day mortality (p interaction = 0.04). Therefore, we performed a subgroup analysis and found that high lactate concentration was significantly associated with 90-day mortality in the DIC group (odds ratio = 2.31, p = 0.039) but not in the non-DIC group. CONCLUSIONS: In patients with DIC, a high lactate level significantly predicted 90-day mortality; no such association was found in the non-DIC group. Thus, DIC status may serve as a possible effect modifier of lactate level in predicting mortality in patients with sepsis.

In Vitro Study of Endotoxin Adsorption by a Polymyxin B-Immobilized Fiber Column.

BACKGROUND: Polymyxin B-immobilized fiber (PMX-F) columns are used as therapeutic interventions for septic shock. The clinical efficacy has been reported for 2-h applications, but their ability to adsorb endotoxin over longer treatments has not been fully elucidated. We hypothesized that PMX-F columns are capable of endotoxin removal for more than 2 h. METHOD: We designed closed circuits incorporating either a PMX-F column with an 8.5-mL priming volume (PMX-01R) or a sham-control column, and used inactivated fetal bovine serum as the circulating perfusate. Endotoxin was continuously injected at a fixed rate for 24 h, and perfusate endotoxin concentrations were measured at fixed time points. PMX-01R endotoxin adsorption was calculated from the difference in the endotoxin concentrations. RESULTS: PMX-01R endotoxin adsorption increased continuously in a virtually linear manner. CONCLUSIONS: The PMX-01R column showed sustained endotoxin adsorption for at least 24 h. This indicated that PMX-F columns would be capable of clinical endotoxin removal for 24 h.

Evidence and Perspectives on the Use of Polymyxin B-Immobilized Fiber Column Hemoperfusion among Critically Ill Patients.

BACKGROUND: Sepsis frequently leads to multiple organ failure due to the uncontrolled amplification and spread of inflammation, even if the infectious source is controlled. Lipopolysaccharide (LPS), a typical pathogen-associated molecular pattern (PAMP), is adsorbed by the polymyxin B-immobilized fiber column (PMX). PMX has been used for decades in Europe. Results of a North American randomized controlled trial (RCT) on PMX have recently been announced in a press release; results of large-scale observational studies and meta-analyses have also been reported in the last several years. SUMMARY: To date, 3 multicenter RCTs on PMX hemoperfusion have been conducted outside of Japan. All of them enrolled postoperative patients with sepsis or septic shock secondary to intra-abdominal infection. However, confidence in the level of evidence provided by these RCTs is very low. Results from recent propensity-matched analyses and meta-analyses indicate that PMX hemoperfusion may improve survival outcomes among patients with sepsis. LPS is an important causative PAMP in sepsis; it triggers the immune response. PMX adsorbs LPS by using a polymyxin B-immobilized fiber that has high affinity for LPS. Moreover, PMX has other mechanisms of action, such as endogenous cannabinoid and activated neutrophil and monocyte adsorption, monocyte surface antigen alteration, and regulation of apoptosis in renal tubular cells. Furthermore, clinical research shows that PMX hemoperfusion can improve patients' hemodynamic status and pulmonary oxygenation and can sustain its endotoxin adsorption capability beyond 2 h. Improved pulmonary oxygenation among patients with sepsis-associated acute respiratory distress syndrome is linked to the effectiveness of PMX hemoperfusion in treating acute exacerbations of idiopathic pulmonary fibrosis (AE-IPF). Key Messages: Meta-analysis indicates that PMX hemoperfusion may improve the survival outcomes of patients with sepsis; LPS adsorption is an important treatment modality in sepsis. Many novel findings on the mechanisms of action of PMX, beyond endotoxin adsorption, have been reported. Additionally, a prolonged duration of PMX hemoperfusion has been shown to be efficacious, and beneficial effects on AE-IPF have been demonstrated. The use of PMX hemoperfusion for the correct duration and at the right time in appropriate patients may lead to favorable therapeutic outcomes.

Influence of Blood Purification and Differential Injection Sites of Cold Saline on Transpulmonary Thermodilution Values.

We aimed to investigate the effects of blood purification and cold saline injection sites on the transpulmonary thermodilution values. We measured the cardiac output of eight pigs in every combination of cold saline injection (left jugular and femoral veins) and blood purification sites (right jugular and femoral veins), with or without blood purification. We examined the influence of the difference between the presence and absence of blood purification, vascular sites for blood purification, and sites for cold saline injection on the transpulmonary thermodilution values. Cardiac output measured during blood purification using transpulmonary thermodilution was underestimated; however, there was no difference between vascular sites. Cardiac output measured via injection of cold saline into the femoral vein was higher than that obtained through injection of cold saline into the jugular vein, with or without blood purification.

Novel Blood Purification System for Regulating Excessive Immune Reactions in Severe Sepsis and Septic Shock: An Ex Vivo Pilot Study.

Promising results have been reported with blood purification as adjuvant treatment; however, the immunological mechanisms remain unclear. We have been developing a new blood purification system for regulating excessive immune reactions in severe sepsis and septic shock using a granulocyte adsorbing column (Adacolumn [Ada]), and a cytokine-adsorbing hemofilter (AN69ST hemofilter [AN69]). Fresh porcine blood was circulated for 6 h in five experimental groups including Ada and AN69 to assess the effects of leukocyte adsorption, phagocytic activity and adhesiveness of granulocytes. In the present study, we found that Ada mainly adsorbed granulocytes and monocytes, but not lymphocytes. The phagocytic activity level of granulocytes decreased, and adhesiveness increased, but the number of CD11b-positive cells markedly decreased in the current system. Elevated cytokine levels (IL-1ß, IL-8 and IL-10) at the outlet of Ada were significantly lower than at the outlet of AN69 due to cytokine adsorption. Further studies are needed to better understand cellular interactions.

In vitro evaluation of high mobility group box 1 protein removal with various membranes for continuous hemofiltration.

The high mobility group box 1 protein (HMGB1) is an alarmin that plays an important role in sepsis and has been recognized as a promising target with a wide therapeutic window; however, no drugs and devices are currently in practical use. We hypothesized that hemofilters composed of porous membranes or cytokine-adsorbing membranes could remove HMGB1 from the blood. We performed experimental hemofiltration in vitro using four types of hemofilters composed of different membranes specifically designed for continuous hemofiltration. The test solution was a 1000-mL substitution fluid containing 100 µg of HMGB1 and 35 g of bovine serum albumin. Experimental hemofiltration was conducted for 360 min in a closed loop circulation system. Among the four membranes, surface-treated polyacrylonitrile (AN69ST) showed the highest capacity to adsorb HMGB1; it adsorbed nearly 100 µg of HMGB1 in the initial 60 min and showed a markedly high clearance rate (60.8 ± 5.0 mL/min) at 15 min. The polymethylmethacrylate membrane had half of the adsorption capacity of the AN69ST membrane. Although the highest sieving coefficient for HMGB1 was obtained with the high cut-off polyarylethersulfone membrane, which correlated with a constant filtrate clearance rate, albumin loss was observed. However, no such removal of both HMGB1 and albumin was observed with the polysulfone membrane and tubing. We conclude that continuous hemofiltration using the AN69ST membrane is a promising approach for HMGB1-related sepsis.

AN69: Evolution of the world's first high permeability membrane.

In response to a request from the French government, Rhône-Poulenc started development of a synthetic membrane for dialysis in 1969. When used for patients the new membrane, AN69, showed improved efficiency and clinical outcome. Treatment times could be reduced, peripheral neuropathy improved and patients expressed improved quality of life. This was the introduction of high-flux, volume-controlled dialysis. The polymer used for the AN69 membrane is a copolymer of acrylonitrile and sodium methallylsulfonate, specially selected for the dialysis application. Contrary to most synthetic membranes AN69 is hydrophilic, because the numerous sulfonate groups attract water and create a hydrogel structure which provides high diffusive and hydraulic permeability. In the AN69 membrane the microstructure and the chemical composition offer a unique context for bulk adsorption of low-molecular-weight proteins, the high water content of the hydrogel making the polymer chains easily accessible. The highly specific adsorptive properties - limited on the surface and favored in the membrane structure and with high specificity for basic, medium-sized proteins - distinguish AN69 from other synthetic high-flux membranes as well as from other so-called adsorptive membranes in the field of dialysis. Since its creation in the early 1970s the AN69 membrane has evolved to meet the requirements and challenges of dialysis therapy. Still the basic characteristics of high permeability to fluid and to a wide range of relevant uremic retention products combined with excellent biocompatibility, whether measured by traditional or novel indicators, have remained the hallmark of the membrane. The unique adsorptive capacity has provided a base for further development. The latest version of AN69, HeprAN, has heparin grafting on the inner surface and enhanced adsorption of bacterial products on the outer surface. Modern versions of AN69 are today used in hemodialysis and contemporary modes of convective therapies for a large number of chronic as well as acute renal patients around the world.

Sustained high-efficiency daily diafiltration using a mediator-adsorbing membrane (SHEDD-fA) in the treatment of patients with severe sepsis.

Sustained high-efficiency daily diafiltration using a mediator-adsorbing membrane (SHEDD-fA) is an effective, intensive modality for sepsis treatment. Here we describe the effectiveness of SHEDD-fA, which makes the best use of three principles: dialysis, filtration and adsorption, for mediator removal in the treatment of severe sepsis. SHEDD-fA was initiated after adequate fluid resuscitation and catecholamine support had been provided. A large (2.1 m(2)) polymethylmethacrylate membrane dialyzer was placed in the blood circuit. Operation conditions were as follows: blood flow rate 150 ml/min, filtration rate 1,500 ml/h (post-dilution), and dialysate flow rate 300-500 ml/min over 8-12 h daily. 55 consecutive patients with severe sepsis were studied. The following results were obtained: pressure catecholamine index significantly decreased at 3 h after initiation of septic shock, PaO(2)/F(IO2) significantly increased at 1 h after initiation of septic acute respiratory distress syndrome, a significant decrease in interleukin (IL)-6 level for 3 days was observed, and IL-6 was effectively adsorbed in one pass through the filter. The average sequential organ failure assessment score of patients was 10.1 and the mortality at 28 days was 16.4% (46 survived, 9 died). Because SHEDD-fA is an intensive and high-efficiency modality, removal of useful drugs or nutrients may be observed. Despite the fact that removal of useful substances cannot be ignored, we believe that an appropriate stage or timing can be identified so that we can avoid a vicious cycle and use blood purification with effective diffusion, filtration and adsorption. We demonstrate that SHEDD-fA may be an effective, intensive modality for the treatment of patients with severe sepsis and is a possible modality for cytokine modulation therapy.

A device for adsorbing unbound, unconjugated bilirubin and its effects in vitro and in a hyperbilirubinemic newborn piglet.

AIMS: A novel blood purification material that we previously reported as a superantigen- and cytokine-adsorbing device (SCAD) was evaluated for its ability to adsorb unbound, unconjugated bilirubin (UUBil) in vitro and in vivo. METHODS: In albumin-containing buffer, UUBil was dissolved and circulated through the SCAD column. Also, bilirubin was infused into low-body weight newborn piglets and hemoperfused for 3 h over SCAD columns. RESULTS: In albumin-containing buffer, concentration of bilirubin decreased from 34 to 0.6 mg/dL within 5 h and the SCAD fiber turned brown, indicating that bilirubin was adsorbed onto the surface of the adsorbent and was not degraded during the circulation. Using the hyperbilirubinemia swine, clearances of total bilirubin (TBil), direct bilirubin (DBil), and indirect bilirubin (IdBil) were significantly higher (P<0.01) in the SCAD group compared with the control group. The clearances of TBil, DBil, and IdBil at 3 h after the initiation of the bilirubin infusion were 0.47, 0.53, and 0.45 mL/min, respectively, at a blood flow rate of 2.5 mL/min, and this result indicates that almost 20% of bilirubins were adsorbed to the SCAD column in a single passage. CONCLUSION: These results provide initial evidence that SCAD treatment is effective in the removal of UUBil and can be performed safely in newborn animals.