Treatment of severe acute respiratory syndrome with glucosteroids: the Guangzhou experience

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.

Glucocorticosteroid in treatment of severe pneumonia

Airway diseases such as pneumonia constitute a major health burden on a global scale; untreated pneumonia may develop to severe pneumonia and consequently lead to to fatal episodes of mortality and morbidity. The balance between inflammatory mediators is key for the outcome of the pulmonary infection; elimination of invading pathogen was marked by the release of cytokines and other inflammatory mediators from alveolar macrophages and glucocorticoid steroids (GCs) acting on the inflammatory component. Treatments of severe pneumonia with GCs have been developing for years with inconclusive results. In many cases GCs have been administered empirically without clinical evidence. Recent studies assess beneficial impact on treatment of severe pneumonia by suggesting specific dosage, period of administration, and tapered dosage.

Clinical management and infection control of SARS: lessons learned

The outbreak of severe acute respiratory syndrome (SARS) in 2003 was the first emergence of an important human pathogen in the 21st century. Responding to the epidemic provided clinicians with extensive experience in diagnosing and treating a novel respiratory viral disease. In this article, we review the experience of the SARS epidemic, focusing on measures taken to identify and isolate patients, prevent the transmission of infection to healthcare workers and develop effective therapies. Lessons learned from the SARS epidemic will be especially important in responding to the current emergence of another highly pathogenic human coronavirus, the agent of Middle East respiratory syndrome (MERS), and to the recently emerging H7N9 influenza A virus in China. This paper forms part of a symposium in Antiviral Research on "From SARS to MERS: 10years of research on highly pathogenic human coronaviruses."

Other viral pneumonias: coronavirus, respiratory syncytial virus, adenovirus, hantavirus

Severe viral pneumonia is an increasing problem among adults. The incidence and number of viruses known to cause pneumonia and respiratory failure have also expanded in recent years. This article provides an overview of severe respiratory disease caused by coronavirus, respiratory syncytial virus, adenovirus, and hantavirus. These emerging pathogens are easily overlooked and timely diagnosis requires a high index of suspicion and confirmation by molecular testing. Management of individual cases is mainly supportive and requires institution of appropriate infection control measures. Vaccines and effective therapeutics for these potentially devastating respiratory viruses are urgently required.

A patient with severe respiratory failure caused by novel human coronavirus

We report a case of a 45-year-old patient who developed severe acute respiratory distress syndrome accompanied by renal failure. An infection with a novel human coronavirus was confirmed and found to be the reason for rapidly progressive respiratory failure of our patient.

Respiratory medicine in China: progress, challenges, and opportunities

The past century witnessed a rapid development of respiratory medicine in China. The major burden of respiratory disease has shifted from infectious diseases to chronic noninfectious diseases. Great achievements have been made in improving the national standard of clinical management of various respiratory diseases and in smoking control. The specialty of respiratory medicine is expanding into pulmonary and critical care medicine. Nevertheless, respiratory diseases remain a major public health problem, with new challenges such as air pollution and nosocomial infections. This review describes the history, accomplishments, new challenges, and opportunities in respiratory medicine in China.

Barrier stabilizing mediators in regulation of microvascular endothelial permeability

Increase of microvascular permeability is one of the most important pathological events in the pathogenesis of trauma and burn injury. Massive leakage of fluid from vascular space leads to lose of blood plasma and decrease of effective circulatory blood volume, resulting in formation of severe tissue edema, hypotension or even shock, especially in severe burn injury. Fluid resuscitation has been the only valid approach to sustain patient's blood volume for a long time, due to the lack of overall and profound understanding of the mechanisms of vascular hyperpermeability response. There is an emerging concept in recent years that some so-called barrier stabilizing mediators play a positive role in preventing the increase of vascular permeability. These mediators may be released in response to proinflammatory mediators and serve to restore endothelial barrier function. Some of these stabilizing mediators are important even in quiescent state because they preserve basal vascular permeability at low levels. This review introduces some of these mediators and reveals their underlying signaling mechanisms during endothelial barrier enhancing process.

Early corticosteroids in severe influenza A/H1N1 pneumonia and acute respiratory distress syndrome

RATIONALE

Despite their controversial role, corticosteroids are often administered to patients with adult respiratory distress syndrome (ARDS) secondary to viral pneumonia.

OBJECTIVES

To analyze the impact of corticosteroid therapy on outcomes of patients having ARDS associated with influenza A/H1N1 pneumonia.

METHODS

Patients from the French registry of critically ill patients with influenza A/H1N1v 2009 infection were selected if fulfilling criteria for ARDS, excluding patients having other indication for corticosteroids, or decompensated underlying disease as the primary cause for intensive care unit admission. Survival to hospital discharge was analyzed using Cox regression, accounting for the time to administration of steroids, and after adjustment on the propensity for receiving steroid therapy.

MEASUREMENTS AND MAIN RESULTS

Of 208 patients with ARDS, 83 (39.9%) received corticosteroids (median initial dose of 270 mg equivalent hydrocortisone per day for a median of 11 d). Steroid therapy was associated with death, both in crude analysis (33.7 vs. 16.8%; hazard ratio, 2.4; 95% CI, 1.3-4.3; P = 0.004) and after propensity score-adjusted analysis (adjusted hazard ratio, 2.82; 95% CI, 1.5-5.4; P = 0.002), controlling for an admission severity Simplified Acute Physiology Score, version 3, greater than 50, initial administration of vasopressors, and immunodepression. Early therapy (≤ 3 d of mechanical ventilation) appeared more strongly associated with mortality than late administration. Patients receiving steroids had more acquired pneumonia and a trend to a longer duration of ventilation.

CONCLUSIONS

Our study provides no evidence of a beneficial effect of corticosteroids in patients with ARDS secondary to influenza pneumonia, but suggests that very early corticosteroid therapy may be harmful.

H1N1 influenza A virus-associated acute lung injury: response to combination oseltamivir and prolonged corticosteroid treatment

PURPOSE

During the 2009 H1N1 influenza A virus pandemic, a minority of patients developed rapidly progressive pneumonia leading to acute lung injury (ALI)-acute respiratory distress syndrome (ARDS). A recent meta-analysis provides support for prolonged corticosteroid treatment in ALI-ARDS. We prospectively evaluated the response to oseltamivir and prolonged corticosteroid treatment in patients with ALI-ARDS and suspected H1N1 influenza.

METHODS

From June 24 through 12 July 2009, 13 patients with suspected H1N1 pneumonia and ALI-ARDS were admitted to the intensive care unit (ICU) of a tertiary care hospital. H1N1 influenza was confirmed with real-time reverse transcriptase-polymerase chain reaction assay in eight patients. Oseltamivir and corticosteroid treatment were initiated concomitantly at ICU admission; those with severe ARDS received methylprednisolone (1 mg/kg/day), and others received hydrocortisone (300 mg/day) for a duration of 21 +/- 6 days.

RESULTS

Patients with and without confirmed H1N1 influenza had similar disease severity at presentation and a comparable response to treatment. By day 7 of treatment, patients experienced a significant improvement in lung injury and multiple organ dysfunction scores (P < 0.001). Twelve patients (92%) improved lung function, were extubated, and discharged alive from the ICU. Hospital length of stay and mortality were 18.7 +/- 9.6 days and 15%, respectively. Survivors were discharged home without oxygen supplementation.

CONCLUSIONS

In ARDS patients, with and without confirmed H1N1 influenza, prolonged low-to-moderate dose corticosteroid treatment was well tolerated and associated with significant improvement in lung injury and multiple organ dysfunction scores and a low hospital mortality. These findings provide the rationale for developing a randomized trial.

Rhesus theta-defensin prevents death in a mouse model of severe acute respiratory syndrome coronavirus pulmonary disease

We evaluated the efficacy of rhesus theta-defensin 1 (RTD-1), a novel cyclic antimicrobial peptide, as a prophylactic antiviral in a mouse model of severe acute respiratory syndrome (SARS) coronavirus (CoV) lung disease. BALB/c mice exposed to a mouse-adapted strain of SARS-CoV demonstrated 100% survival and modest reductions in lung pathology without reductions in virus titer when treated with two intranasal doses of RTD-1, while mortality in untreated mice was approximately 75%. RTD-1-treated, SARS-CoV-infected mice displayed altered lung tissue cytokine responses 2 and 4 days postinfection compared to those of untreated animals, suggesting that one possible mechanism of action for RTD-1 is immunomodulatory.

Corticosteroids for community-acquired pneumonia: time to act!

The use of corticosteroids for the treatment of community-acquired pneumonia has been reported for almost 50 years. A recent systematic analysis of the relevant literature suggested that corticosteroids reduce the critical illness associated with community-acquired pneumonia. There is little doubt that a prolonged administration of a moderate dose of corticosteroids may alleviate the systemic inflammatory response and subsequent organ dysfunction in severe infection. Whether these favorable effects on morbidity may translate into better survival and quality of life needs to be addressed in additional adequately powered randomized controlled trials.

Cytokine responses in porcine respiratory coronavirus-infected pigs treated with corticosteroids as a model for severe acute respiratory syndrome

The effectiveness and potential immunosuppressive effects of anti-inflammatory glucocorticoids in the lungs of severe acute respiratory syndrome (SARS) patients are undefined. We treated porcine respiratory coronavirus (PRCV)-infected conventional pigs with the corticosteroid dexamethasone (DEX) as a model for SARS. Innate and Th1 cytokines in bronchoalveolar lavage (BAL) and serum were elevated in PRCV-infected pigs compared to controls, but were decreased after DEX treatment in the PRCV-infected, DEX-treated (PRCV/DEX) pigs. Although decreased in BAL, Th2 cytokine levels were higher in serum after DEX treatment. Levels of the proinflammatory cytokine interleukin-6 in BAL and serum were decreased in PRCV/DEX pigs early but increased later compared to those in phosphate-buffered saline-treated, PRCV-infected pigs, corresponding to a similar trend for lung lesions. PRCV infection increased T-cell frequencies in BAL, but DEX treatment of PRCV-infected pigs reduced frequencies of T cells; interestingly B and SWC3a(+) (monocytes/macrophages/granulocytes) cell frequencies were increased. DEX reduced numbers of PRCV-stimulated Th1 gamma interferon-secreting cells in spleen, tracheobroncheolar lymph nodes, and blood. Our findings suggest that future glucocorticoid treatment of SARS patients should be reconsidered in the context of potential local immunosuppression of immune responses in lung and systemic Th1 cytokine-biased suppression.