Corticosteroids as adjunctive therapy in the treatment of influenza

Severe acute respiratory infection risk following glucocorticosteroid treatment in uncomplicated influenza-like illness resulting from pH1N1 influenza infection: a case control study

Background

Current studies regarding glucocorticosteroid treatment of influenza have only estimated risk of critical illness or death which can be easily confounded by timing of treatment administration. We used severe acute respiratory infection (sARI) as an endpoint and investigated risk associated with receiving glucocorticosteroids before sARI onset.

Methods

sARI cases were defined as influenza-like illness (ILI) with pH1N1 infection and respiratory distress. Controls were defined as pH1N1 cases other than sARI and randomly selected from the community. We compared glucocorticosteroids and other medications used before sARI onset using a matched case control study adjusted for age group as well as underlying disease. Time-dependent risk and dose responses at different time periods over the course of sARI cases were also examined.

Results

Of the sARI cases, 34% received glucocorticosteroids before sARI onset compared to 3.8% of controls during equivalent days (OR_M-H = 17,95%CI = 2.1–135). Receiving glucocorticosteroids before sARI onset increased risk of developing subsequent critical illness or death (OR_M-H = 5.7,95%CI = 1.6–20.2), and the OR_M-H increased from 5.7 to 8.5 for continued glucocorticosteroid use after sARI onset. However, only receiving glucocorticosteroids after sARI onset did not increase risk of severe illness (OR_M-H = 1.1,95%CI = 0.3–4.6). Each increase in glucocorticosteroids dose of 1 mg/kg/day before sARI onset resulted in an increase of 0.62 (R² = 0.87) in the pMEWS score at the time of sARI onset.

Conclusions

Early glucocorticosteroid treatment increased risk of sARI and subsequent critical illness or death; however, only receiving glucocorticosteroids after sARI onset did not increase risk of severe illness.

Hot topics and current controversies in community-acquired pneumonia

Community-acquired pneumonia (CAP) is one of the most common infectious diseases, as well as a major cause of death both in developed and developing countries, and it remains a challenge for physicians around the world. Several guidelines have been published to guide clinicians in how to diagnose and take care of patients with CAP. However, there are still many areas of debate and uncertainty where research is needed to advance patient care and improve clinical outcomes. In this review we highlight current hot topics in CAP and present updated evidence around these areas of controversy.

Community-acquired pneumonia is the most frequent cause of infectious death worldwide; however, there are several areas of controversy that should be addressed to improve patient care. This review presents the available data on these topics.http://bit.ly/2ShnH7A

Use of antiviral drugs for seasonal influenza: Foundation document for practitioners-Update 2019

This document updates the previous AMMI Canada Foundation Guidance (2013) on the use of antiviral therapy for influenza.

Corticosteroids as adjunctive therapy in the treatment of influenza

BACKGROUND

Specific treatments for influenza are limited to neuraminidase inhibitors and adamantanes. Corticosteroids show evidence of benefit in sepsis and related conditions, most likely due to their anti-inflammatory and immunomodulatory properties. Although commonly prescribed for severe influenza, there is uncertainty over their potential benefits or harms. This is an update of a review first published in 2016.

OBJECTIVES

To systematically assess the effectiveness and potential adverse effects of corticosteroids as adjunctive therapy in the treatment of influenza, taking into account differences in timing and doses of corticosteroids.

SEARCH METHODS

We searched CENTRAL (2018, Issue 9), which includes the Cochrane Acute Respiratory infections Group's Specialised Register, MEDLINE (1946 to October week 1, 2018), Embase (1980 to 3 October 2018), CINAHL (1981 to 3 October 2018), LILACS (1982 to 3 October 2018), Web of Science (1985 to 3 October 2018), abstracts from the last three years of major infectious disease and microbiology conferences, and references of included articles. We also searched the World Health Organization International Clinical Trials Registry Platform, ClinicalTrials.gov, and the ISRCTN registry on 3 October 2018.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), quasi-RCTs, and observational studies that compared corticosteroid treatment with no corticosteroid treatment for influenza or influenza-like illness. We did not restrict studies by language of publication, influenza subtypes, clinical setting, or age of participants. We selected eligible studies in two stages: sequential examination of title and abstract, followed by full text.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias. We pooled estimates of effect using a random-effects model, where appropriate. We assessed heterogeneity using the I² statistic and assessed the certainty of the evidence using the GRADE framework.

MAIN RESULTS

This updated review includes 30 studies (one RCT with two arms and 29 observational studies) with a total of 99,224 participants. We included 19 studies in the original review (n = 3459), all of which were observational, with 13 studies included in the meta-analysis for mortality. We included 12 new studies in this update (one RCT and 11 observational studies), and excluded one study in the original review as it has been superceded by a more recent analysis. Twenty-one studies were included in the meta-analysis (9536 individuals), of which 15 studied people infected with 2009 influenza A H1N1 virus (H1N1pdm09). Data specific to mortality were of very low quality, based predominantly on observational studies, with inconsistent reporting of variables potentially associated with the outcomes of interest, differences between studies in the way in which they were conducted, and with the likelihood of potential confounding by indication. Reported doses of corticosteroids used were high, and indications for their use were not well reported. On meta-analysis, corticosteroid therapy was associated with increased mortality (odds ratio (OR) 3.90, 95% confidence interval (CI) 2.31 to 6.60; I² = 68%; 15 studies). A similar increase in risk of mortality was seen in a stratified analysis of studies reporting adjusted estimates (OR 2.23, 95% CI 1.54 to 3.24; I² = 0%; 5 studies). An association between corticosteroid therapy and increased mortality was also seen on pooled analysis of six studies which reported adjusted hazard ratios (HRs) (HR 1.49, 95% CI 1.09 to 2.02; I² = 69%). Increased odds of hospital-acquired infection related to corticosteroid therapy were found on pooled analysis of seven studies (pooled OR 2.74, 95% CI 1.51 to 4.95; I² = 90%); all were unadjusted estimates, and we graded the data as of very low certainty.

AUTHORS' CONCLUSIONS

We found one RCT of adjunctive corticosteroid therapy for treating people with community-acquired pneumonia, but the number of people with laboratory-confirmed influenza in the treatment and placebo arms was too small to draw conclusions regarding the effect of corticosteroids in this group, and we did not include it in our meta-analyses of observational studies. The certainty of the available evidence from observational studies was very low, with confounding by indication a major potential concern. Although we found that adjunctive corticosteroid therapy is associated with increased mortality, this result should be interpreted with caution. In the context of clinical trials of adjunctive corticosteroid therapy in sepsis and pneumonia that report improved outcomes, including decreased mortality, more high-quality research is needed (both RCTs and observational studies that adjust for confounding by indication). The currently available evidence is insufficient to determine the effectiveness of corticosteroids for people with influenza.

Challenges in severe community-acquired pneumonia: a point-of-view review

Purpose

Severe community-acquired pneumonia (SCAP) is still associated with substantial morbidity and mortality. In this point-of-view review paper, a group of experts discuss the main controversies in SCAP: the role of severity scores to guide patient settings of care and empiric antibiotic therapy; the emergence of pathogens outside the core microorganisms of CAP; viral SCAP; the best empirical treatment; septic shock as the most lethal complication; and the need for new antibiotics.

Methods

For all topics, the authors describe current controversies and evidence and provide recommendations and suggestions for future research. Evidence was based on meta-analyses, most recent RCTs and recent interventional or observational studies. Recommendations were reached by consensus of all the authors.

Results and conclusions

The IDSA/ATS criteria remain the most pragmatic tool to predict ICU admission. The authors recommend a combination of a beta-lactam/beta-lactamase inhibitor or a third G cephalosporin plus a macrolide in most SCAP patients, and to empirically cover PES (P. aeruginosa, extended spectrum beta-lactamase producing Enterobacteriaceae, methicillin-resistant S. aureus) pathogens when at least two specific risk factors are present. In patients with influenza CAP, the authors recommend the use of oseltamivir and avoidance of the use of steroids. Corticosteroids can be used in case of refractory shock and high systemic inflammatory response.

Vogt-Koyanagi-Harada Disease Associated with Influenza A Virus Infection

We herein report a case of a 31-year-old Japanese man who simultaneously had a positive influenza A virus antigen test result and Vogt-Koyanagi-Harada disease (VKHD), demonstrated by both diffuse multiple early hyperfluorescent points on fluorescein fundus photography and serous retinal detachments on optical coherence tomography. He had meningitis. It was difficult to determine whether the main cause of meningitis was influenza A or VKHD. After initial treatment with peramivir for influenza A and then methylprednisolone pulse with subsequent corticosteroid therapy for VKHD, his symptoms improved gradually. These findings suggest that influenza A virus infection contributes to the onset or exacerbation of VKHD.

Triple combination of FDA-approved drugs including flufenamic acid, clarithromycin and zanamivir improves survival of severe influenza in mice

Seasonal influenza virus remains a common cause of mortality despite the use of neuraminidase inhibitors. This study evaluated the efficacy of a triple combination of zanamivir, clarithromycin and flufenamic acid (FFA) in the treatment of influenza virus A(H1N1) infection. An in vitro cell protection assay and a multiple-cycle growth assay showed that the antiviral activity of zanamivir was enhanced when combined with clarithromycin or FFA. A mouse challenge model was used here for the evaluation of the in vivo efficacy of the triple combination treatment. We found that mice receiving the triple combination of FFA, zanamivir, and clarithromycin had a significantly better survival rate than those receiving the double combination of zanamivir and clarithromycin (88% versus 44%, P = 0.0083) or zanamivir monotherapy (88% versus 26%, P = 0.0002). Mice in the FFA-zanamivir-clarithromycin triple combination group also exhibited significantly less body weight loss than those in the zanamivir-clarithromycin double combination group. There was no significant difference in the lung viral titers among the different groups from day 2 to day 6 postinfection. However, the levels of IL-1β, TNF-α and RANTES in the FFA-zanamivir-clarithromycin triple combination group were significantly lower than those in the zanamivir-clarithromycin double combination group, zanamivir monotherapy group, or solvent group on day 2 postinfection. Our findings showed that the FFA-zanamivir-clarithromycin triple combination improved the inflammatory markers and survival of severe influenza A(H1N1) infection in mice.

A clinical approach to the threat of emerging influenza viruses in the Asia-Pacific region

Seasonal influenza epidemics and periodic pandemics are important causes of morbidity and mortality. Patients with chronic co‐morbid illness, those at the extremes of age and pregnant women are at higher risks of complications requiring hospitalization, whereas young adults and obese individuals were also at increased risk during the A(H1N1) pandemic in 2009. Avian influenza A(H5N1) and A(H7N9) viruses have continued to circulate widely in some poultry populations and infect humans sporadically since 1997 and 2013, respectively. The recent upsurge in human cases of A(H7N9) infections in Mainland China is of great concern. Sporadic human cases of avian A(H5N6), A(H10N8) and A(H6N1) have also emerged in recent years while there are also widespread poultry outbreaks due to A(H5N8) in many countries. Observational studies have shown that treatment with a neuraminidase inhibitor (NAI) for adults hospitalized with severe influenza is associated with lower mortality and better clinical outcomes, especially when administered early in the course of illness. Whether higher than standard doses of NAI would provide greater antiviral effects in such patients will require further investigation. High‐dose systemic corticosteroids were associated with worse outcomes in patients with severe influenza. There is an urgent need for developing more effective antiviral therapies for treatment of influenza infections.

Safety and efficacy of anti-influenza drugs, intravenous peramivir against influenza virus infection in elderly patients with underlying disease

We retrospectively analyzed data of 38 elderly patients, each with an underlying disease, to evaluate peramivir safety and efficacy. Six patients (15.8%) experienced adverse events, all tolerated. Median time from administration until the return to normal temperatures was 31.5 h (95% CI: 22.4-40.6). Results confirm intravenous peramivir's usefulness.

Rapamycin adjuvant and exacerbation of severe influenza in an experimental mouse model

Influenza virus infection often causes severe disease and acute respiratory distress syndrome. It is a common belief that overwhelming immune response contributes to the severe illness. Physicians and researchers have put forth immune modulation as salvage therapy for better recovery. However, empiric corticosteroid failed in both humans and animal models. Reported success with Rapamycin in humans prompted a comprehensive animal study and mechanistic dissection. Here we report the effect of Rapamycin alone or in combination with Oseltamivir for severe influenza in BALB/c mice. We found that Rapamycin had no antiviral effect against H1N1, H3N2 and novel-H1N1 influenza viruses in vitro. Rapamycin alone aggravated the severe disease of PR8 H1N1 influenza virus infection in mice. Timely Oseltamivir anti-viral therapy abolished the disease. Delayed Oseltamivir treatment could not prevent severe illness and Rapamycin adjuvant was associated with exacerbated disease. Rapamycin adjuvant suppressed influenza hemagglutinin antigen-specific T cell immunity and impaired virus clearance from the lungs. It also resulted in intensified lung pathology with increased intra-alveolar edema and hyaline deposition. Rapamycin may work as the salvage therapy for severe influenza but it is very difficult to define the appropriate window for such treatment to take effect.

Treatable traits and therapeutic targets: Goals for systems biology in infectious disease

Among the many medical applications of systems biology, we contend that infectious disease is one of the most important and tractable targets. We take the view that the complexity of the immune system is an inevitable consequence of its evolution, and this complexity has frustrated reductionist efforts to develop host-directed therapies for infection. However, since hosts vary widely in susceptibility and tolerance to infection, host-directed therapies are likely to be effective, by altering the biology of a susceptible host to induce a response more similar to a host who survives. Such therapies should exert minimal selection pressure on organisms, thus greatly decreasing the probability of pathogen resistance developing.

A systems medicine approach to infection has the potential to provide new solutions to old problems: to identify host traits that are potentially amenable to therapeutic intervention, and the host immune factors that could be targeted by host-directed therapies. Furthermore, undiscovered sub-groups with different responses to treatment are almost certain to exist among patients presenting with life-threatening infection, since this population is markedly clinically heterogeneous. A major driving force behind high-throughput clinical phenotyping studies is the aspiration that these subgroups, hitherto opaque to observation, may be observed in the data generated by new technologies. Subgroups of patients are unlikely to be static – serial clinical and biological phenotyping may reveal different trajectories through the pathophysiology of disease, in which different therapeutic approaches are required.

We suggest there are two major goals for systems biology in infection medicine: (1) to identify subgroups of patients that share treatable features; and, (2) to integrate high-throughput data from clinical and in vitro sources in order to predict tractable therapeutic targets with the potential to alter disease trajectories for individual patients.

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High throughput technologies can reveal clinical patterns in infection that were previously opaque.

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Host-targeted therapies have conceptual advantages but are difficult to develop.

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Key clinically-relevant objectives are identification of disease endotypes and treatable traits.

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Mechanistic understanding will reveal opportunities for drug design, repurposing and better targeting.

Influenza A Virus Infection Predisposes Hosts to Secondary Infection with Different Streptococcus pneumoniae Serotypes with Similar Outcome but Serotype-Specific Manifestation

Influenza A virus (IAV) and Streptococcus pneumoniae are major causes of respiratory tract infections, particularly during coinfection. The synergism between these two pathogens is characterized by a complex network of dysregulated immune responses, some of which last until recovery following IAV infection. Despite the high serotype diversity of S. pneumoniae and the serotype replacement observed since the introduction of conjugate vaccines, little is known about pneumococcal strain dependency in the enhanced susceptibility to severe secondary S. pneumoniae infection following IAV infection. Thus, we studied how preinfection with IAV alters host susceptibility to different S. pneumoniae strains with various degrees of invasiveness using a highly invasive serotype 4 strain, an invasive serotype 7F strain, and a carrier serotype 19F strain. A murine model of pneumococcal coinfection during the acute phase of IAV infection showed a significantly increased degree of pneumonia and mortality for all tested pneumococcal strains at otherwise sublethal doses. The incidence and kinetics of systemic dissemination, however, remained bacterial strain dependent. Furthermore, we observed strain-specific alterations in the pulmonary levels of alveolar macrophages, neutrophils, and inflammatory mediators ultimately affecting immunopathology. During the recovery phase following IAV infection, bacterial growth in the lungs and systemic dissemination were enhanced in a strain-dependent manner. Altogether, this study shows that acute IAV infection predisposes the host to lethal S. pneumoniae infection irrespective of the pneumococcal serotype, while the long-lasting synergism between IAV and S. pneumoniae is bacterial strain dependent. These results hold implications for developing tailored therapeutic treatment regimens for dual infections during future IAV outbreaks.

New aspects in the management of pneumonia

Despite improvements in the management of community-acquired pneumonia (CAP), morbidity and mortality are still high, especially in patients with more severe disease. Early and appropriate antibiotics remain the cornerstone in the treatment of CAP. However, two aspects seem to contribute to a worse outcome: an uncontrolled inflammatory reaction and an inadequate immune response. Adjuvant treatments, such as corticosteroids and intravenous immunoglobulins, have been proposed to counterbalance these effects. The use of corticosteroids in patients with severe CAP and a strong inflammatory reaction can reduce the time to clinical stability, the risk of treatment failure, and the risk of progression to acute respiratory distress syndrome. The administration of intravenous immunoglobulins seems to reinforce the immune response to the infection in particular in patients with inadequate levels of antibodies and when an enriched IgM preparation has been used; however, more studies are needed to determinate their impact on outcome and to define the population that will receive more benefit.

Argument against the Routine Use of Steroids for Pediatric Acute Respiratory Distress Syndrome

Steroids have a plausible mechanism of action of reducing severity of lung disease in acute respiratory distress syndrome (ARDS) but have failed to show consistent benefits in patient-centered outcomes. Many studies have confounding from the likely presence of ventilator-induced lung injury and steroids may have shown benefit because administration minimized ongoing inflammation incited by injurious ventilator settings. If steroids have benefit, it is likely for specific populations that fall within the heterogeneous diagnosis of ARDS. Those pediatric patients with concurrent active asthma or reactive airway disease of prematurity, in addition to ARDS, are the most common group likely to derive benefit from steroids, but are poorly studied. With the information currently available, it does not appear that the typical adult or pediatric patient with ARDS derives benefit from steroids and steroids should not be given on a routine basis.