Hypercytokinemia with 2009 pandemic H1N1 (pH1N1) influenza successfully treated with polymyxin B-immobilized fiber column hemoperfusion. Intensive Care Med. 2010;36:906-907. [PMID: 20224904 DOI: 10.1007/s00134-010-1830-8]

The comparison of the mortality rates of plasmapheresis/hemoperfusion therapy with current treatment among Covid-19 patients

Background

There is no definitive treatment for COVID-19. Hemoperfusion and plasmapheresis have only been studied in a few cases of COVID-19. In this study, plasmapheresis-hemoperfusion and current treatment for COVID-19 patients were compared for mortality.

Methods

In this cross-sectional study, 103 patients with COVID-19 underwent hemoperfusion, plasmapheresis, and conventional medical treatment in educational hospitals in Ahvaz, Iran. A census method was used to include the patients in the study. The data from the hospital file were used to complete a checklist containing demographic information, clinical findings, and paraclinical findings for all patients.

Results

There was not a statistically significant difference (P-value = 0.051) between the plasmapheresis group (78.8%), the hemoperfusion group (71.9%), and the current treatment group (52.6%) in mortality rates. Hemoperfusion had a median survival time of 18.9 days, plasmapheresis had a median survival time of 16.9 days, and current treatment had a median survival time of 13.5 days. In terms of patient survival time, there was no significant difference (P-value = 0.181). Multiple regression results showed that death rates in the hemoperfusion (P = 0.393) and plasmapheresis (P = 0.073) groups were not statistically different from those in the current treatment group.

Conclusion

As a result of this study, there were no differences between the treatment groups in regard to death rates or patient survival times.

Inter-Fighting between Influenza A Virus NS1 and β-TrCP: A Novel Mechanism of Anti-Influenza Virus

Influenza A virus (IAV) prevents innate immune signaling during infection. In our previous study, the production of pro-inflammatory cytokines was associated with Cullin-1 RING ligase (CRL1), which was related to NF-κB activation. However, the underlying mechanism is unclear. Here, an E3 ligase, β-transducin repeat-containing protein (β-TrCP), was significantly downregulated during IAV infection. Co-IP analysis revealed that non-structural 1 protein (NS1) interacts with β-TrCP. With co-transfection, an increase in NS1 expression led to a reduction in β-TrCP expression, affecting the level of IκBα and then resulting in repression of the activation of the NF-κB pathway during IAV infection. In addition, β-TrCP targets the viral NS1 protein and significantly reduces the replication level of influenza virus. Our results provide a novel mechanism for influenza to modulate its immune response during infection, and β-TrCP may be a novel target for influenza virus antagonism.

Polymyxin B Hemoperfusion in Pediatric Septic Shock: Single-Center Observational Case Series

OBJECTIVES

To evaluate the use of direct hemoperfusion with polymyxin B-immobilized fiber (PMX-DHP) as adjunctive therapy during pediatric patients with septic shock.

DESIGN

Prospective observational study.

SETTING

Nine-bed PICUs at university referral hospital.

PATIENTS

Children (30 d to 15 yr) with septic shock and Pediatric Logistic Organ Dysfunction (PELOD)-2 score greater than or equal to 10 or Pediatric Risk of Mortality (PRISM) 3 score greater than or equal to 15, who were also receiving at least one inotrope.

INTERVENTION

Patients received 2-4 hour treatment with PMX-DHP 20R column on 2 consecutive days.

MEASUREMENTS AND MAIN RESULTS

We enrolled six children aged 21-167 months old (median, 99-mo old), with a body weight of 10-50 kg (median, 28 kg). All six patients had both PELOD-2 greater than or equal to 10 and PRISM-3 greater than or equal to 15, required invasive mechanical ventilation, and received standard treatment for septic shock before enrollment. We observed significant improvement in PELOD-2 score from baseline to 72 hours after the start of PMX-DHP (mean [95% CI] from 14.3 [12.2-16.5] to 6.0 [0.3-11.7]; p = 0.006). The vasoactive inotropic score (VIS) and lactate concentration also significantly decreased from baseline to 72 hours (VIS, 60 mmol/L [25-95 mmol/L] to 4.0 mmol/L [44.1-12 mmol/L]; p = 0.003; lactate, 2.4 mmol/L [1.0-3.8 mmol/L] to 1.0 mmol/L [0.5-1.5 mmol/L]; p = 0.01). Five of six patients survived. There was no device-related adverse event in these patients.

CONCLUSIONS

In this case series of treatment with PMX-DHP as adjunctive therapy in children with refractory septic shock and high baseline severity, we have shown that patient recruitment is feasible. We have also found that clinical hemodynamic and severity of illness scores at 72 hours may be potential end points for testing in future randomized controlled trials.

Endotoxin Adsorbent Therapy in Severe COVID-19 Pneumonia

INTRODUCTION

Uncontrolled systemic inflammation may occur in severe coronavirus disease 19 (COVID-19). We have previously shown that endotoxemia, presumably from the gut, may complicate COVID-19. However, the role of endotoxin adsorbent (EA) therapy to mitigate organ dysfunction in COVID-19 has not been explored.

METHODS

We conducted a retrospective observational study in COVID-19 patients who received EA therapy at the King Chulalongkorn Memorial Hospital, Bangkok, Thailand, between March 13 and April 17, 2020. Relevant clinical and laboratory data were collected by inpatient chart review.

RESULTS

Among 147 hospitalized COVID-19 patients, 6 patients received EA therapy. All of the 6 patients had severe COVID-19 infection with acute respiratory distress syndrome (ARDS). Among these, 5 of them were mechanically ventilated and 4 had complications of secondary bacterial infection. The endotoxin activity assay (EAA) results of pre-EA therapy ranged from 0.47 to 2.79. The choices of EA therapy were at the discretion of attending physicians. One patient was treated with oXiris® along with continuous renal replacement therapy, and the others received polymyxin B hemoperfusion sessions. All patients have survived and were finally free from the mechanical ventilation as well as had improvement in PaO2/FiO2 ratio and decreased EAA level after EA therapy.

CONCLUSIONS

We demonstrated the clinical improvement of severe COVID-19 patients with elevated EAA level upon receiving EA therapy. However, the benefit of EA therapy in COVID-19 ARDS is still unclear and needs to be elucidated with randomized controlled study.

PMX-DHP Therapy for Dyspnea and Deoxygenation in Severe COVID-19 Pneumonia: A Case Series

Hypercytokinemia induced by coronavirus disease-19 (COVID-19) is associated with severe pulmonary involvement, which may lead to respiratory failure. These conditions play an important role in the worsening of clinical symptoms in patients with severe COVID-19. There is no established treatment for hypercytokinemia. We report on two patients whose clinical symptoms improved after direct hemoperfusion using polymyxin B-immobilized fiber column (PMX-DHP), following the administration of the anti-inflammatory agent tocilizumab. Case A was a 70-year-old man diagnosed with COVID-19 pneumonia. Despite treatment with ciclesonide and favipiravir, supplemental oxygen was administered due to the worsening of dyspnea with tachypnea. Although tocilizumab was started on day 6, the patient deteriorated into deoxygenation, presenting with the PaO₂/F_IO₂ (P/F) ratio of 92. On days 8 and 10, the patient received PMX-DHP therapy. On day 11, his dyspnea improved. On day 13, his P/F ratio began to improve, and oxygen therapy was discontinued on day 18. The patient recovered without requiring mechanical ventilation. Case B was a 70-year-old man diagnosed with COVID-19 pneumonia and treated with favipiravir, starting on day 0. Despite starting ciclesonide inhalation and tocilizumab on day 2, his P/F ratio was 53. On day 5, he received PMX-DHP therapy. On day 6, his dyspnea improved, as did his P/F ratio, reaching 81 on day 8. Finally, his clinical symptoms resolved, and he was discharged from the intensive care unit without requiring mechanical ventilation. These cases indicate that PMX-DHP therapy might be a suitable treatment option for dyspnea and deoxygenation in COVID-19 pneumonia, especially in cases where an anti-inflammatory agent, such as tocilizumab, has failed to achieve the desired effect.

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.

Direct hemoperfusion using a polymyxin B-immobilized polystyrene column for COVID-19

Objective

To evaluate the efficacy and safety of direct hemoperfusion using a polymyxin B‐immobilized polystyrene column (PMX‐DHP) in severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2)‐positive pneumonia patients.

Methods

This study was a case series conducted at a designated infectious diseases hospital. Twelve SARS‐CoV‐2‐positive patients with partial pressure of arterial oxygen/percentage of inspired oxygen (P/F) ratio < 300 were treated with PMX‐DHP on two consecutive days each during hospitalization. We defined day 1 as the first day when PMX‐DHP was performed. PMX‐DHP efficacy was assessed on days 7 and 14 after the first treatment based on eight categories. Subsequently, improvement in P/F ratio and urinary biomarkers on days 4 and 8, malfunctions, and ventilator and extracorporeal membrane oxygenation avoidance rates were also evaluated.

Results

On day 14 after the first treatment, disease severity decreased in 58.3% of the patients. P/F ratio increased while urine β2‐microglobulin decreased on days 4 and 8. Cytokine measurement pre‐ and post‐PMX‐DHP revealed decreased levels of interleukin‐6 and the factors involved in vascular endothelial injury, including vascular endothelial growth factor. Twenty‐two PMX‐DHPs were performed, of which seven and five PMX‐DHPs led to increased inlet pressure and membrane coagulation, respectively. When the membranes coagulated, the circuitry needed to be reconfigured. Circuit problems were usually observed when D‐dimer and fibrin degradation product levels were high before PMX‐DHP.

Conclusions

Future studies are expected to determine the therapeutic effect of PMX‐DHP on COVID‐19. Because of the relatively high risk of circuit coagulation, coagulation capacity should be assessed beforehand.

Polymyxin B haemoperfusion treatment for respiratory failure and hyperferritinaemia due to COVID-19

A 69-year-old man with a history of type 2 diabetes and high blood pressure was diagnosed with coronavirus disease 2019 (COVID-19). He had hyperferritinaemia and respiratory failure. Despite the initiation of favipiravir and high-dose corticosteroid and ceftriaxone, his respiratory failure progressed and serum ferritin levels increased. After polymyxin B-immobilized fibre column direct haemoperfusion (PMX-DHP) therapy, there was improvement of the respiratory failure and hyperferritinaemia. We report the first case of COVID-19-induced hyperferritinaemia and severe respiratory failure successfully treated by PMX-DHP.

Successful Recovery from COVID-19-associated Acute Respiratory Failure with Polymyxin B-immobilized Fiber Column-direct Hemoperfusion

An 83-year-old man was hospitalized for coronavirus disease 2019 (COVID-19) after a 10-day history of a persistent fever. Chest computed tomography showed extensive non-segmental ground glass opacity. Despite the initiation of lopinavir and ritonavir, respiratory failure progressed. Two days of polymyxin B-immobilized fiber column-direct hemoperfusion (PMX-DHP) with adjunctive corticosteroid prevented his respiratory condition from worsening. For rapidly progressive COVID-19 cases, the early use of PMX-DHP may avoid the need for mechanical ventilation by suppressing local inflammation of the lung.

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.

The role of adjuvant immunomodulatory agents for treatment of severe influenza

A severe inflammatory immune response with hypercytokinemia occurs in patients hospitalized with severe influenza, such as avian influenza A(H5N1), A(H7N9), and seasonal A(H1N1)pdm09 virus infections. The role of immunomodulatory therapy is unclear as there have been limited published data based on randomized controlled trials (RCTs). Passive immunotherapy such as convalescent plasma and hyperimmune globulin have some studies demonstrating benefit when administered as an adjunctive therapy for severe influenza. Triple combination of oseltamivir, clarithromycin, and naproxen for severe influenza has one study supporting its use, and confirmatory studies would be of great interest. Likewise, confirmatory studies of sirolimus without concomitant corticosteroid therapy should be explored as a research priority. Other agents with potential immunomodulating effects, including non-immune intravenous immunoglobulin, N-acetylcysteine, acute use of statins, macrolides, pamidronate, nitazoxanide, chloroquine, antiC5a antibody, interferons, human mesenchymal stromal cells, mycophenolic acid, peroxisome proliferator-activated receptors agonists, non-steroidal anti-inflammatory agents, mesalazine, herbal medicine, and the role of plasmapheresis and hemoperfusion as rescue therapy have supportive preclinical or observational clinical data, and deserve more investigation preferably by RCTs. Systemic corticosteroids administered in high dose may increase the risk of mortality and morbidity in patients with severe influenza and should not be used, while the clinical utility of low dose systemic corticosteroids requires further investigation.

Polymyxin B-immobilized fiber column direct hemoperfusion and continuous hemodiafiltration in premature neonates with systemic inflammatory response syndrome

BACKGROUND

There have been no previous studies regarding whether combined use of Polymyxin B-immobilized fiber column direct hemoperfusion (PMX-DHP) and continuous hemodiafiltration (CHDF) is helpful in the treatment of preterm infants with systemic inflammatory response syndrome (SIRS) and hypercytokinemia.

METHODS

A retrospective review was carried out of 18 SIRS infants born at gestational week 24-28. Eight with blood interleukin (IL)-6 ≥ 1000 pg/mL were treated actively with 2 h PMX-DHP followed by 2 h PMX-DHP and CHDF. Ten with IL-6 < 500 pg/mL were treated conventionally (with neither PMX-DHP nor CHDF) and served as controls.

RESULTS

Demographic characteristics were similar except for IL-6, arterial-to-alveolar oxygen tension ratio (a/APO₂ ), and number of immature neutrophils between the two groups. Baseline a/APO₂ was significantly lower in infants with than without active treatment (0.44 vs 0.67, respectively, P = 0.002). After 4 h treatment, the IL-6 decreased to < 500 pg/mL in all eight infants, and a/APO₂ improved significantly to 0.62 (P = 0.006). Bronchopulmonary dysplasia occurred in a similar proportion (63%, 5/8 vs 80%, 8/10, respectively), but the number of days on inhaled oxygen (30 vs 47 days, respectively, P = 0.033) and tracheal intubation (36 vs 51 days, respectively, P = 0.040) was significantly lower in infants with than without active treatment. Prevalence of adverse events was similar (13%, 1/8 vs 50%, 5/10 for active vs conventional treatment, respectively).

CONCLUSION

Active treatment with PMX-DHP and CHDF was helpful in the reduction of days on inhaled oxygen and tracheal intubation in preterm SIRS infants with hypercytokinemia. Further prospective randomized studies are warranted.

[A Case of Acute Respiratory Distress Syndrome (ARDS) Accompanied with Influenza (H1N1) 2009 Successfully Treated with Polymyxin B-immobilized Fiber Column-direct Hemoperfusion (PMX-DHP)]

A 51-year-old man was admitted to our hospital because of fever and diarrhea. Chest X-ray revealed consolidation in the left lower lung field. Ceftriaxone and minocycline were given empirically, under the suspicion of bacterial or atypical pneumonia. In spite of treatment with antibiotics, the disease rapidly progressed to systemic inflammatory response syndrome. The diagnosis of acute respiratory distress syndrome (ARDS) accompanied with influenza (H1N1) 2009 was made because of positive findings of real-time polymerase chain reaction. While multidisciplinary treatment was performed, his condition was further deteriorated suggesting the excessive pro-inflammatory mediators. To remove them, we conducted polymyxin-B immobilized column-direct hemoperfusion (PMX-DHP), and his general condition recovered successfully. PMX-DHP may be a useful treatment choice for ARDS accompanied with influenza.

Polymyxin-B-immobilized-fiber column hemoperfusion with oseltamivir treatment for ARDS due to influenza H1N1/09

Acute respiratory distress syndrome (ARDS) is one of the severe complications of influenza H1N1/09 infection, resulting in high mortality. Effective treatment strategies for ARDS are needed. This report presents two cases of ARDS due to influenza in Vietnam. Both cases were similar in terms of starting symptoms, the rapid progression to ARDS, and the treatment strategy, direct hemoperfusion with a polymyxin-B-immobilized fiber column (PMX-DHP) and oseltamivir. However, the clinical course of disease and the outcomes were different. For case 1, treatment was initiated on day 4 following the onset of hypoxemia due to ARDS. Symptoms improved rapidly after treatment and the patient was discharged on day 12. For case 2, treatment was initiated on day 9 after the onset of symptoms. Despite intensive therapy, the patient died on day 18. In conclusion, treatment with PMX-DHP and oseltamivir is effective on ARDS due to influenza but only if initiated early.

How to approach and treat viral infections in ICU patients

Patients with severe viral infections are often hospitalized in intensive care units (ICUs) and recent studies underline the frequency of viral detection in ICU patients. Viral infections in the ICU often involve the respiratory or the central nervous system and can cause significant morbidity and mortality especially in immunocompromised patients. The mainstay of therapy of viral infections is supportive care and antiviral therapy when available. Increased understanding of the molecular mechanisms of viral infection has provided great potential for the discovery of new antiviral agents that target viral proteins or host proteins that regulate immunity and are involved in the viral life cycle. These novel treatments need to be further validated in animal and human randomized controlled studies.

Seasonal Human Influenza: Treatment Options

Seasonal influenza can be a self-limiting illness in healthy individuals but is associated with short-term morbidity and economic burden. Influenza can cause significant morbidity and mortality in young children, the elderly, pregnant and post-partum women, patients with co-morbidities and the immunocompromised. Neuraminidase inhibitors (NAIs) are the treatment of choice for influenza due to widespread resistance to the adamantanes. NAIs are efficacious for the treatment of influenza in ambulatory patients with mild illness, when initiated within 48 h of symptom onset. Early treatment with NAIs has been shown to reduce otitis media in children, and lower respiratory tract complications, resulting in antibiotic therapy, in adults. Evidence on the efficacy of NAIs for the prevention of influenza-related complications in at-risk populations, based on reviews of data from randomised trials is inconclusive. However, observational studies suggest that in hospitalised patients early treatment with NAIs has been associated with reduced mortality. NAIs should be initiated as soon as possible in patients at high-risk of influenza-related complications, with suspected or proven influenza, hospitalised patients and patients with severe or progressive disease. NAIs can be considered in previously healthy patients when therapy can be initiated within 48 h of symptom onset. In previously healthy patients, the therapeutic efficacy of oseltamivir is time-dependent, with maximal benefit observed when therapy is initiated within 48 h of symptom onset. However, several observational studies suggest therapeutic benefit beyond 48 h, in hospitalised patients, severe disease, and patients at high risk of complications, including pregnant women. NAIs should be considered in patients at high risk of influenza-related complications who present late. Further studies are needed to define the optimal timing of NAIs. Oseltamivir-resistant virus has been widely reported but is predominantly an issue in H1N1 seasonal influenza. Zanamivir-resistant influenza virus is rare, and inhaled or intravenous (IV) zanamivir is the treatment of choice in proven or suspected oseltamivir-resistant virus. Intubated patients with severe influenza can be treated with oseltamivir (suspension) administered via nasogastric tube. The commercial dry powder formulation of zanamivir should not be administered, via nebulisation, as it has been associated with ventilator malfunction and mortality. In intubated patients, when there are concerns about gastric absorption, IV zanamivir should be obtained under Emergency Investigational New Drug access schemes. Currently available evidence does not support the use of high-dose or extended-duration oseltamivir in patients with severe influenza, but does require further investigation. Extracorporeal membrane oxygenation has not been shown to be superior to conventional management in patients with influenza-associated acute respiratory distress syndrome and should be considered as salvage therapy. Corticosteriods should not be used in the treatment of severe influenza as this has been associated with increased risk of mortality and bacterial superinfection.

Adjunctive therapies and immunomodulating agents for severe influenza

The value of adjunctive immunomodulatory therapies in treating severe influenza and other respiratory viral infections remains uncertain. Although often used, systemic corticosteroids may increase the risk of mortality and morbidity (e.g. secondary infections) in severe influenza and other viral infections, especially if there is delay or lack of effective antiviral therapy. Non‐randomized studies suggest that convalescent plasma appears useful as add‐on therapy for patients with severe acute respiratory syndrome, avian influenza A(H5N1), and influenza A (H1N1) 2009 pandemic [A(H1N1)pdm09), but it is limited by its availability. A recent randomized controlled trial (RCT) comparing hyperimmune globulin prepared from convalescent plasma against normal intravenous gammaglobulin (IVIG) manufactured before 2009 as control in patients with severe A(H1N1)pdm09 infection on standard antiviral treatment has shown that the hyperimmune globulin group who received treatment within 5 days of symptom onset had a lower viral load and reduced mortality compared with the controls. A number of agents with immunomodulatory effects (e.g. acute use of statins, N‐acetylcysteine, macrolides, PPAR agonists, IVIG, celecoxib, mesalazine) have been proposed for influenza management. However, more animal and detailed human observational studies and preferably RCTs controlling for the effects of antiviral therapy and disease severity are needed for evaluating these agents. The role of plasmapheresis and hemoperfusion as rescue therapy also merits more investigation.

Immunopathogenesis of 2009 pandemic influenza

Three years after the pandemic, major advances have been made in our understanding of the innate and adaptive immune responses to the influenza A(H1N1)pdm09 virus and those responses' contribution to the immunopathology associated with this infection. Severe disease is characterized by early secretion of proinflammatory and immunomodulatory cytokines. This cytokine secretion persisted in patients with severe viral pneumonia and was directly associated with the degree of viral replication in the respiratory tract. Cytokines play important roles in the antiviral defense, but persistent hypercytokinemia may cause inflammatory tissue damage and participate in the genesis of the respiratory failure observed in these patients. An absence of pre-existing protective antibodies was the rule for both mild and severe cases. A role for pathogenic immunocomplexes has been proposed for this disease. Defective T cell responses characterize severe cases of infection caused by the influenza A(H1N1)pdm09 virus. Immune alterations associated with accompanying conditions such as obesity, pregnancy or chronic obstructive pulmonary disease may interfere with the normal development of the specific response to the virus. The role of host immunogenetic factors associated with disease severity is also discussed in this review. In conclusion, currently available information suggests a complex immunological dysfunction/alteration that characterizes the severe cases of 2009 pandemic influenza. The potential benefits of prophylactic/therapeutic interventions aimed at preventing/correcting such dysfunction warrant investigation.

Immunomodulation in sepsis: the role of endotoxin removal by polymyxin B-immobilized cartridge

Severe sepsis results in high morbidity and mortality. Immunomodulation strategies could be an adjunctive therapy to treat sepsis. Endotoxin is a component of gram-negative bacteria and plays an important role in the pathogenesis of septic shock when it is recognized by immune cells. Removal of endotoxin could be an effective adjunctive approach to the management of sepsis. Devices to adsorb endotoxin or inflammatory cytokines have been designed as a strategy to treat severe sepsis, especially sepsis caused by gram-negative bacteria. Polymyxin B-immobilized cartridge has been successfully used to treat patients with sepsis of abdominal origin. Although this cartridge was conceived to adsorb endotoxin, several other immunological mechanisms have been elucidated, and this device has also yielded promising results in patients with nonseptic respiratory failure. In this paper, we summarize the immune modulation actions of Polymyxin B-immobilized cartridge to explore its potential usefulness beyond endotoxin elimination.

Adjunctive therapies and immunomodulatory agents in the management of severe influenza

In addition to neuraminidase inhibitors and other drugs that directly target viral replication, a number of adjunctive and immunomodulatory therapies are currently under evaluation for the treatment of influenza. These novel treatments, which focus either on pathophysiological aspects of influenza virus infection or the neutralization of virus with antibodies, are the subject of this review. Cytokine dysregulation has been observed in patients with severe influenza, such as avian influenza A (H5N1) and pandemic 2009 influenza A (H1N1pdm09) virus infections, but the role of immunomodulatory therapy is unclear, due to lack of data from randomized controlled trials (RCTs). Convalescent plasma appears to be useful as an adjunctive therapy for the treatment of H5N1 and H1N1pdm09 infections. Until lately, data interpretation was limited to case reports and studies of non-randomized design, but a recent RCT found that patients with severe influenza A (H1N1pdm09) who were treated with hyperimmune immunoglobulin from persons who had survived the same disease had a lower peak viral load and lower mortality than controls, providing treatment was begun within 5 days of symptom onset. The efficacy of agents with potential immunomodulating effects, including intravenous immunoglobulin, N-acetylcysteine, acute use of statins, macrolides, peroxisome proliferator-activated receptors agonists, celecoxib and mesalazine, and the role of plasmapheresis and hemoperfusion as rescue therapy, deserve more investigation and where feasible, studies by RCTs. Prospective observational studies have shown that systemic corticosteroids increase morbidity (e.g., secondary infections) and mortality in H1N1pdm09 influenza. This article forms part of a symposium in Antiviral Research on "Treatment of influenza: targeting the virus or the host."

Clinical preparedness for severe pneumonia with highly pathogenic avian influenza A (H5N1): experiences with cases in Vietnam

BACKGROUND

Avian influenza A (H5N1) in human presents a global pandemic threat, and preparedness is urgently required in high-risk countries.

METHODS

A retrospective chart review was conducted on 8 patients with H5N1 infection (aged 2-30 years; 3 fatal) who were hospitalized in Bach Mai Hospital (BMH), Vietnam, or in affiliated hospitals with consultation by physicians in BMH between 2007 and 2010. Demographic background, chest radiographs, and clinical and laboratory data were evaluated to determine the critical issues in relation to clinical outcomes. Treatment of 4 patients with acute respiratory distress syndrome (ARDS) (2 fatal) was assessed for renal replacement therapy using continuous hemodiafiltration (CHDF), polymyxin B-immobilized (PMX) hemoperfusion, or their combination.

RESULTS

Patients had direct contact with dead/sick poultry infected with H5N1 virus or lived in areas where H5N1 poultry outbreaks had been reported at the same time as their illness. Time to initiation of oseltamivir from symptom onset was 2-6 days for survivors and 7-9 days for non-survivors. All patients except one had infiltrative shadows on chest radiographs on admission. Patients with delayed treatment developed ARDS. Renal replacement therapy contributed to patient survival, with improvement of oxygenation and a dramatic decrease in serum cytokine levels if initiated earlier.

CONCLUSIONS

Understanding local H5N1 poultry outbreaks and chest radiography assist early diagnosis and initiation of antiviral treatment. Developing a network among local and tertiary care hospitals can reduce the time to initiation of treatment. CHDF and PMX hemoperfusion are possible candidates for effective treatment of ARDS with H5N1 if applied earlier.

Removal of increased circulating CD4+CD25+Foxp3+ regulatory T cells in patients with septic shock using hemoperfusion with polymyxin B-immobilized fibers

BACKGROUND

Although sepsis-induced immunosuppression has long been considered to be a factor in the late mortality of patients with sepsis, little is known about regulatory T cell (Treg)-mediated immunosuppression and the effect of polymyxin B-immobilized fiber (PMX-F) on sepsis-induced immunosuppression. We sought to investigate the role of CD4(+)CD25(+)Foxp3(+) Tregs in septic patients, and to evaluate the effect of hemoperfusion with PMX-F on the recovery from immunosuppression owing to septic shock.

METHODS

Thirty-two septic patients who had an identified focus of infection in the abdominal cavity were enrolled in this study. Peripheral blood mononuclear cells in the septic patients were examined to evaluate the roles of Tregs and the serum cytokine levels. We also examined the effects of PMX-F therapy on CD4(+) T cells, especially Tregs and serum cytokine levels in patients with septic shock.

RESULTS

The percentage of Tregs in the CD4(+) T-cell population, and the serum IL-6 and IL-10 levels, were significantly higher among patients with septic shock compared with those without septic shock, and PMX-F therapy significantly decreased the number of Tregs, as well as the serum IL-6 and IL-10 levels. Furthermore, a significant increase in the number of CD4(+) T cells, a significant decrease in the percentage of Tregs in the CD4(+) T-cell population, and a significant decrease in the serum IL-6 and IL-10 levels 24 hours after PMX-F therapy were observed in septic shock survivors compared with nonsurvivors.

CONCLUSION

We found a major increase in the percentage of Tregs in peripheral blood circulating CD4(+) T cells from patients with septic shock, and observed that the removal of Tregs by hemoperfusion with PMX-F might represent a novel strategy for inducing recovery from the immunosuppression associated with sepsis.

Staphylococcal enterotoxin B toxic shock syndrome induced by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA)

We herein report a case of toxic shock syndrome (TSS) associated with the 2009 pandemic H1N1 (pH1N1) influenza virus and a community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infection in a 16-year-old Vietnamese girl. Staphylococcal enterotoxin B (SEB) was detected in the patient's serum, and the level of anti-SEB antibodies was found to be elevated. A flow cytometric analysis showed evidence of activated SEB-reactive Vβ3+ and Vβ12+ T cells. These data suggest that the CA-MRSA-induced activation of SEB-reactive T cells may cause TSS in patients with pH1N1 virus infection. Moreover, this is the first report describing immunological confirmation of SEB contributing directly to TSS in a patient fulfilling the diagnostic criteria of TSS.

A case of successful treatment with polymyxin B-immobilized fiber column direct hemoperfusion in acute respiratory distress syndrome after influenza A infection

We report a case of acute respiratory distress syndrome (ARDS) after influenza A infection who was successfully treated with combined treatment including direct hemoperfusion with polymyxin B-immobilized fiber (PMX-DHP) column. A 56-year-old Japanese man was admitted to our hospital in January 2010 because of progressive dyspnea, hypoxemia, fever and bilateral diffuse infiltration on chest radiograph after pandemic influenza A infection. His chest computed tomography showed diffuse and patchy bilateral ground-glass opacities, and we diagnosed ARDS after influenza A infection. The patient was successfully treated with PMX-DHP in addition to the treatment with oseltamivir, corticosteroid, sivelestat and antibiotics with mechanical ventilation, and the patient recovered with only minor pulmonary fibrotic change. Although the efficacy of PMX-DHP treatment in patients with acute lung injury (ALI)/ARDS after influenza virus infection is not well established, this treatment could be a possible therapeutic modality in treating the patients with this disease.