Polymyxin B-immobilized Fiber Column Hemoperfusion Research Articles

A successful application of adult polymyxin B-immobilized fiber column hemoperfusion to a neonate with septic shock.

A successful application of adult polymyxin B-immobilized fiber column hemoperfusion to a neonate with septic shock.

Extended Sessions of Polymyxin-B Immobilized Fiber Column Hemoperfusion Ameliorate Renal Outcome and Mortality in Septic Shock with Acute Kidney Injury

Background/Aims: Polymyxin-B (PMX) treatment has been reported to decrease mortality in patients with septic shock and acute kidney injury (AKI). In this study, we aimed to evaluate whether extended sessions of PMX (Ext-PMX) immobilized fiber column hemoperfusion ameliorate clinical outcomes in patients complicated with septic shock and AKI without surgical control. Methods: Twenty-two patients with nonsurgical septic shock and AKI who received PMX were included. They were divided according to the duration of PMX treatment: Ext-PMX and standard PMX (Std-PMX). Results: The mean blood pressure increased and inotrope requirement decreased within 24 h after PMX initiation. The median value of predicted mortality was 52.5%, and the ­28-day mortalities in the Ext-PMX and Std-PMX groups were 44.4 and 75% respectively. Renal replacement therapy (RRT) was also initiated in 17 patients, and renal insufficiency was recovered. Conclusion: Ext-PMX combined with RRT improved clinical outcomes in patients with nonsurgical septic shock and AKI.

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

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. 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.

Polymyxin B-immobilized fiber column hemoperfusion mainly helps to constrict peripheral blood vessels in treatment for septic shock.

BackgroundPolymyxin B-immobilized fiber column hemoperfusion (PMX) has been reported to be effective for patients with septic shock. It remains unclear, however, how the efficacy of PMX varies according to the characteristics and underlying conditions of the patients treated. The objective of the present study was to clarify the factors that result in clinical efficacy of PMX treatment.MethodsWe retrospectively investigated 78 consecutive patients with severe sepsis or septic shock who underwent PMX treatment. We reviewed the demographic data, routine biochemistry, microbiological data, infection focus, Acute Physiology and Chronic Health Evaluation (APACHE) II score, Sequential Organ Failure Assessment (SOFA) score, change in mean arterial pressure (MAP), inotropic score, vasopressor dependency index, plasma levels of endotoxin and lactate, PaO2/FIO2 ratio, and survival time. We also divided the patients into two groups for comparison, namely, those whose inotropic scores improved after PMX treatment (improvement group) and those whose inotropic scores did not improve (non-improvement group).ResultsThe inotropic score and the vasopressor dependency index significantly decreased from 18.1 to 9.9 (p < 0.05) and from 0.27 to 0.14 (p < 0.05), respectively, after PMX treatment in the overall study population, while no significant change in the PaO2/FIO2 ratio was observed (p = 0.96). The inotropic score at pre-PMX treatment was significantly higher in the improvement group than in the non-improvement group (p < 0.01). The improvement of the PaO2/FIO2 ratio after PMX treatment was significant in the improvement group (p < 0.05).ConclusionsThe improvement group’s inotropic score was higher, because of peripheral blood vessels dilatation and requirement for more catecholamines. Therefore, our study suggests that PMX treatment is particularly useful for improving hemodynamics in septic shock patients with excessively dilated peripheral blood vessels.

Polymyxin B-immobilized fiber column hemoperfusion removes endotoxin throughout a 24-hour treatment period

PurposeThe purpose of this study was to evaluate the extent of endotoxin adsorption by polymyxin B-immobilized fiber column hemoperfusion (PMX) performed for a 24-hour treatment period in patients with septic shock. Materials and methodsNineteen patients with septic shock were retrospectively studied. The plasma endotoxin concentrations of blood drawn from the radial artery and from the outlet circuit of the PMX column were measured by kinetic turbidimetric limulus assay using an MT-358 Toxinometer (Wako Pure Chemical Industries, Ltd, Osaka, Japan) after 24 hours of PMX treatment. The endotoxin removal rate was defined by the following equation: ([radial artery endotoxin concentration − outlet circuit of PMX column endotoxin concentration]/radial artery endotoxin concentration) × 100%. ResultsThe patients had a median Acute Physiology and Chronic Health Evaluation II score of 29 at intensive care unit admission and a 28-day mortality of 47%. Before the start of the PMX treatment, the median radial arterial plasma endotoxin concentration was 16.48 pg/mL. After 24 hours of PMX treatment, the median radial plasma endotoxin concentration had decreased to 1.857 pg/mL, and the concentration at the outlet circuit of the PMX column was further decreased to 0.779 pg/mL. The median endotoxin removal rate was 74.4%. ConclusionThese findings suggest that 24-hour PMX treatment was effective in removing endotoxin continuously throughout the entire treatment period.

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Introduction: Polymyxin B-immobilized fiber column hemoperfusion (PMX-DHP) improves hemodynamics and pulmonary oxygenation in patients with septic shock. However, optimal duration time for PMX-DHP remains unclear. Methods: This retrospective cohort study conducted in a single hospital between February 2004 and March 2010 included all patients with septic shock who required PMX-DHP. All patients were principally treated according to the strategy of Surviving Sepsis Campaign Guidelines. In conventional 2-hour group, PMX-DHP was performed for 2 hours (and then the second PMX-DHP was performed 24 hours after the end of the first treatment). The endpoint for continuous long-duration (>12hours) PMX-DHP (by a change of column approximately every 24 hours, if necessary) was determined by improvement of MAP (>65mmHg), normalization of lactate levels (<2mmol/L) and withdrawal in vasopressor/inotropic agents in each individual patient. Univariate differences between groups were assessed using Mann-Whitney U test. Multivariable regression analysis was used to develop propensity score-based models adjusted for baseline characteristics between two groups. Primary endpoint was 28-day mortality. Results: 101 patients (males 60%, mean age 70.7 years: 47 in the continuous long-duration group and 54 in the conventional 2-hour group) were treated with PMX-DHP for septic shock (abdomen, lung, urinary tract, soft tissue and others). Endotoxin levels were measured. Isolated microorganisms and sites were obtained. Baseline characteristics (group A vs. group B): mean age 73.0 vs. 68.7 P=0.24, males 62% vs. 59% P=0.80, gram negative infection 74% vs. 76% P=0.87, abdominal surgery 34% vs. 76% P<0.001, abdominal infection 43% vs. 80% P<0.001, malignancy 23% vs. 15% P=0.27, chronic dialysis 11% vs. 7% P=0.57, APACHE II score 27 (25-33) vs. 25 (23-29) P=0.002, SOFA score 9 (8-12) vs. 9 (7-10) P=0.08, PaO2/FiO2 ratio 227 (151-309) vs. 264 (183-377) P=0.203, MAP (mmHg) 53 (50-60) vs. 61 (56-75) P<0.001, catecholamine index (CAI) 11(8-15) vs. 9 (8-12) P=0.34, lactate levels (mmol/L) after fluid resuscitation 4.3 (2.3-5.9) vs. 2.7 (1.8-4.2) P=0.024, RRT 49% vs. 28% P=0.029. Total duration time (hours) was 38 (21-48) vs. 3.0 (2.1-5.0) (p<0.001). Crude 28-day mortality was 25.5% vs. 35.2% (HR 0.65 [95%CI 0.31-1.34] P=0.24). After adjustment for these baseline imbalances, multivariable Cox regression analysis identified continuous long-duration PMX-DHP (adjusted HR 0.25 [95%CI 0.11-0.59] P=0.002), malignancy (adjusted HR 2.75 [95%CI 1.20-6.30] P=0.02), abdominal infection (adjusted HR 0.38 [95%CI 0.17-0.86] P=0.02) and RRT (adjusted HR 3.46 [95%CI 1.56-7.64] P=0.002) as independent predictors of 28-day mortality. Propensity score for receiving continuous long-duration PMX-DHP was calculated by using multivariable logistic regression and included three independent variables comprising abdominal infection (adjusted odds ratio 0.13 [95%CI 0.04-0.37] P<0.001), MAP (adjusted odds ratio 0.90 [95%CI 0.85-0.95] P<0.001) and CAI (adjusted odds ratio 0.88 [95%CI 0.79-0.99] P=0.038). Propensity score analysis identified continuous long-duration PMX-DHP as an independent predictor of 28-day mortality (propensity score-matched analysis (PS±0.03) HR 0.18 [95%CI 0.04-0.82] P=0.013, regression adjustment with propensity score HR 0.27 [95%CI 0.11-0.65] P=0.003, inverse-probability-of-treatment-weighted (IPTW) HR 0.29 [95%CI 0.13-0.68] P=0.016, standardized mortality ratio-weighted (SMRW) HR 0.24 [95%CI 0.11-0.52] P=0.011. Multiple regression analysis revealed that duration time for PMX-DHP could be formulated as follows: Duration time (hours) = 64 - 0.85 x MAP + 2.24 x lactate levels (R 20.21). The significant side effects in continuous long-duration PMX-DHP were not shown. Conclusions: Continuous long-duration PMX-DHP improves 28-day mortality compared with conventional 2-hour PMX-DHP for septic shock. Optimal duration time for PMX-DHP can be predicted from MAP and lactate levels before PMX-DHP.

Polymyxin B-immobilized fiber column hemoperfusion therapy for septic shock.

Polymyxin B-immobilized fiber column hemoperfusion therapy for septic shock.

Polymyxin B-immobilized fiber column hemoperfusion has the ability of endotoxin removal during 24 hours

Endotoxin plays an important role in the pathogenesis of septic shock. Endotoxin adsorption therapy by Polymyxin B-immobilized fiber column (PMX) hemoperfusion has been used for the treatment of septic shock patients in Japan. According to the company's recommendation, the standard duration of PMX treatment for patients with septic shock is 2 hours. However, we have shown that greater than 2 hours duration of PMX treatment significantly improved hemodynamics and significantly decreased administration of norepinephrine than 2 hours duration of PMX treatment. Our hypothesis was that PMX treatment had the ability of endotoxin removal during 24 hours. Therefore, the purpose of this study was to evaluate the endotoxin adsorption ability of 24 hours duration of PMX treatment.

Polymyxin B-immobilized fiber column hemoperfusion has the ability of endotoxin removal during 24 hours

Endotoxin plays an important role in the pathogenesis of septic shock. Endotoxin adsorption therapy by Polymyxin B-immobilized fiber column (PMX) hemoperfusion has been used for the treatment of septic shock patients in Japan. According to the company's recommendation, the standard duration of PMX treatment for patients with septic shock is 2 hours. However, we have shown that greater than 2 hours duration of PMX treatment significantly improved hemodynamics and significantly decreased administration of norepinephrine than 2 hours duration of PMX treatment. Our hypothesis was that PMX treatment had the ability of endotoxin removal during 24 hours. Therefore, the purpose of this study was to evaluate the endotoxin adsorption ability of 24 hours duration of PMX treatment.

Polymyxin B-Immobilized Fiber Column Hemoperfusion Therapy for Septic Shock

Endotoxin, an outer membrane component of gram-negative bacteria, plays an important role in the pathogenesis of septic shock. Endotoxin adsorption therapy by polymyxin B-immobilized fiber column hemoperfusion (PMX) has been used for the treatment of septic shock patients in Japan since 1994. The covalent binding of polymyxin B onto the surface of the polystyrene-based carrier fiber in PMX inactivates the endotoxin in the blood without exerting toxicity. This study was performed as a systematic review to evaluate the efficacy and mechanism of PMX treatment in patients with septic shock. The PubMed database and references from identified articles were used to search and review the literature relating to the efficacy and mechanism of PMX treatment in patients with septic shock. Polymyxin B-immobilized fiber column hemoperfusion adsorbed monocytes, activated neutrophils, and anandamide, as well as endotoxin through direct covalent bond, hydrophobic and ionic interactions, and hydrodynamics, and reduced the blood concentrations of inflammatory cytokines, plasminogen activator inhibitor 1 and adhesion molecules. Polymyxin B-immobilized fiber column hemoperfusion increased blood pressure and reduced the dosage requirements for vasopressive/inotropic agents. The meta-analysis showed that PMX treatment had beneficial effects on the hemodynamics, pulmonary oxygenation, and mortality. These beneficial effects may be attributable to the direct adsorption of endotoxin, monocytes, activated neutrophils, and anandamide, as well as indirect decrease in inflammatory cytokines and other mediators. Polymyxin B-immobilized fiber column hemoperfusion treatment has additional effects on reducing endothelial damage, proapoptotic activity, and immunosuppression. Further studies will be needed to confirm the efficacy and mechanism of PMX treatment in septic shock.

Angiopoietin Balance in Septic Shock Patients With Acute Lung Injury: Effect of Direct Hemoperfusion With Polymyxin B‐Immobilized Fiber

Acute lung injury (ALI) in sepsis is characterized by an increase in microvascular permeability, resulting in pulmonary edema. Several studies have suggested that angiopoietin-1 and -2 play a contributory role in the pathogenesis of ALI. Polymyxin B-immobilized fiber column hemoperfusion is effective for sepsis-induced ALI. We investigated the angiopoietin levels before and after direct hemoperfusion with polymyxin B-immobilized fiber column (PMX) therapy. Enzyme-linked immunoassay was used to measure the serum angiopoietin-1 and -2 levels in 25 patients with septic shock treated with PMX. Eleven of the 25 patients were diagnosed with ALI. There was a significant positive correlation between the angiopoietin-1 level and the PaO(2) /FiO(2) ratio, but there was a significant inverse correlation between the angiopoietin-2 level and the PaO(2) /FiO(2) ratio. The mean angiopoietin-1 level before PMX therapy in the ALI group was significantly lower and the mean angiopoietin-2 level was significantly higher than in the non-ALI group. The mean angiopoietin-1 level of the ALI patients in response to PMX therapy was increased during PMX therapy, but that of the non-ALI patients with newly occurring ALI showed a decreased angiopoietin-1 level. On the other hand, the mean angiopoietin-2 level of the responders was decreased during PMX therapy, but that of patients with newly occurring ALI showed an increased angiopoietin-2 level. This result suggested that each angiopoietin-1 and -2 level may play a role in the pathogenesis of ALI and that PMX therapy ameliorates the angiopoietin balance in patients with ALI in sepsis.

Hypercytokinemia with 2009 pandemic H1N1 (pH1N1) influenza successfully treated with polymyxin B-immobilized fiber column hemoperfusion

In September 2009, a 16-year-old female with no medical history developed fever, general fatigue, and diarrhea. A rapid diagnosis kit at a local clinic showed type A influenza. She was given 10 mg zanamivir inhalation, twice daily. The following day, her body temperature rose to 41.7 C and she experienced respiratory distress. She was transported to our hospital by ambulance. On arrival, her blood pressure was 90/ 40 mmHg, heart rate 150/min, and respiratory rate 35/min. She was administered a large dose of crystalloid fluid and norepinephrine (0.3 lg/kg/min). Mechanical ventilation with endotracheal intubation was begun. Purulent sputum removed by suction contained Gram-positive cocci on a Gram-stained smear. Cultures of blood, urine, and stool testing for various pathogens were negative. Mechanical ventilation was performed in pressure control mode with PaO2/FiO2 (P/F) ratio of 148. Thereafter, a recruitment maneuver was performed, switching to airway pressure release ventilation (APRV) mode. P/F ratio temporarily improved to 224, but then deteriorated to 165. Oseltamivir (150 mg/day), sivelestat sodium hydrate (300 mg/day), and antibiotics (initially ampicillin/ sulbactam 6 g/day) were administered. On day 2, complicated by disseminated intravascular coagulation, no improvement in respiratory status was observed, prompting an increase in oseltamivir dosage to 300 mg/day. Type A influenza was confirmed as 2009 pandemic H1N1 (pH1N1) virus by polymerase chain reaction (PCR). On day 3, methicillin-resistant Staphylococcus aureus (MRSA) was identified in the sputum collected immediately after intubation. Antibiotics were changed to linezolid (12 g/day) plus clindamycin (1,800 mg/day) for MRSA. Serum cytokine levels were highly elevated (Fig. 1). We considered that the severe respiratory failure might be related to hypercytokinemia caused by pH1N1 and MRSA infection. With no improvement in oxygenation, polymyxin B-immobilized fiber column (PMX) hemoperfusion was begun in an attempt to reduce the inflammatory mediators and improve oxygenation. Oxygenation gradually improved; after 1 h, the P/F ratio increased from 144 to 184, and after 8 h to 308. PMX hemoperfusion was performed for 14 h; following cessation, oxygenation declined (P/F ratio 220). On days 4 and 5, PMX hemoperfusion was planned for 18 h on each day, and the P/F ratio increased to 407. Serum inflammatory mediators decreased to normal levels after the PMX treatments. She was extubated and discharged from the hospital. Respiratory failure accounts for a large proportion of pH1N1-related deaths. In influenza A (H5N1) virus infection, hypercytokinemia was observed in fatal cases [1]. We postulated that hypercytokinemia led to respiratory failure. A fatal case of

Polymyxin B-immobilized fiber column hemoperfusion (PMX-DHP) treatment for acute exacerbation of interstitial pneumonia

Polymyxin B-immobilized fiber column hemoperfusion (PMX-DHP) treatment for acute exacerbation of interstitial pneumonia

Polymyxin B-immobilized Fiber Column Hemoperfusion Treatment for Drug-Induced Severe Respiratory Failure: Report of Three Cases

The effects of direct hemoperfusion with polymyxin B-immobilized fiber (PMX-DHP) treatment for acute exacerbation of interstitial pneumonia have been reported. Here, we report 3 severe cases of drug-induced interstitial lung disease (DI-ILD) that were treated with PMX-DHP. Two DI-ILD cases were caused by methotrexate, and the third case was caused by the herbal medicine sanmotsu-ogon-to. The arterial oxygen tension/inspiratory oxygen fraction ratio improved during PMX-DHP treatment in all 3 patients. Finally, 2 patients survived and 1 died. The study findings indicate that PMX-DHP treatment is a viable option for the management of acute respiratory failure in patients with DI-ILD.

エンドトキシン吸着療法（ＰＭＸ）を施行した頸部縦隔ガス壊疽例

We report a case of gas gangrene of the neck, which, although rare, may be fatal if spread to the mediastinum. A 58-year-old man seen for anterior neck swelling, sore throat, mild dyspnea, and epigastralgia was found in computed tomography (CT) to have gas spread from deep neck spaces to the lower tracheal carina of the mediastinum. Tracheotomy and open neck debridement were conducted immediately upon admission, but planned mediastinal drainage via thoracotomy was changed to a transcervical approach via thoracoscopy due to the man's rapidly deteriorating condition. Septic shock and acute respiratory distress syndrome (ARDS) appeared during surgery. Postoperative management included a medical ventilator, antibiotics, gamma globulin, norepinephrine and two-day polymyxin B-immobilized fiber column (PMX) hemoperfusion, after which he recovered and was discharged without sequlae. ARDS treatment requires high positive end-expiratory pressure and low-volume ventilation. PMX is also beneficial.

A LONGER DURATION OF POLYMYXIN B-IMMOBILIZED FIBER COLUMN HEMOPERFUSION IMPROVES PULMONARY OXYGENATION IN PATIENTS WITH SEPTIC SHOCK

Endotoxin plays an important role in the pathogenesis of septic shock. Exposure of endothelial cells to endotoxin activates endothelial cells and increases the surface expression of adhesion molecules, markers of endothelial damage in organ dysfunction. Endotoxin adsorption therapy by polymyxin B-immobilized fiber column (PMX) hemoperfusion has been used for the treatment of septic shock patients. In this study, we measured plasma concentrations of endotoxin and soluble adhesion molecules in septic shock patients before and after the PMX treatment then observed on the relationships between actual duration of use and various outcomes. Sixteen patients with septic shock were studied. The 28-day mortality rate was 50%. The elevated plasma concentrations of endotoxin decreased after the PMX treatment in the survivors but not in the nonsurvivors. The norepinephrine dose and plasma concentrations of soluble endothelial leukocyte adhesion molecule 1 and soluble intercellular adhesion molecule 1 significantly (P < 0.05) decreased in the PMX greater-than-2-h (prolonged) group than in the PMX 2-h (conventional) group (-17.8 +/- 14.6 vs. -1.8 +/- 2.7 microg/min, -143.0 +/- 111.0 vs. 0 +/- 2.8 ng/mL, and -126.2 +/- 144.9 vs. 16.5 +/- 108.1 ng/mL, respectively). Changes in the PaO2-FiO2 ratio and the Sequential Organ Failure Assessment score were significantly (P < 0.05) more improved in the PMX greater-than-2-h group than in the PMX 2-h group (75.4 +/- 80.7 vs. 1.2 +/- 49.2 and -0.8 +/- 1.8 vs. 2.2 +/- 1.9 torr, respectively). We thus suggest that a longer duration of PMX treatment may improve the pulmonary oxygenation associated with decreased adhesion molecules in septic shock.

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.

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.

Beneficial Effect of Polymyxin B-immobilized Fiber Column (PMX) Hemoperfusion Treatment on Acute Exacerbation of Idiopathic Pulmonary Fibrosis

This study was aimed to investigate the effect of polymyxin B-immobilized fiber column (PMX) hemoperfusion treatment on the acute exacerbation of idiopathic pulmonary fibrosis (IPF). Six patients with a clinical diagnosis of idiopathic pulmonary fibrosis (IPF) who developed acute exacerbation were included in this study. Although five of six patients were treated with high-dose corticosteroid therapy, mechanical ventilation was necessary for all six patients due to severe respiratory failure. Blood endotoxin levels were undetectable in all patients. PMX treatment was performed on these six patients. In four of six patients, alveolar-arterial difference of oxygen (AaDO(2)), serum KL-6 and lactate dehydrogenase (LDH) were improved after PMX treatment. These four patients were successfully weaned from mechanical ventilation and survived more than 30 days after the initial PMX treatment. These data suggest a potential beneficial effect of PMX treatment on acute exacerbation of IPF.