Early dynamic changes to monocytes following major surgery are associated with subsequent infections.

Background: Post-operative infections are a common cause of morbidity following major surgery. Little is understood about how major surgery perturbs immune function leading to heightened risk of subsequent infection. Through analysis of paired blood samples obtained immediately before and 24 h following surgery, we evaluated changes in circulating immune cell phenotype and function across the first 24 h, to identify early immune changes associated with subsequent infection. Methods: We conducted a prospective observational study of adult patients undergoing major elective gastrointestinal, gynecological, or maxillofacial surgery requiring planned admission to the post-anesthetic care unit. Patients were followed up to hospital discharge or death. Outcome data collected included mortality, length of stay, unplanned intensive care unit admission, and post-operative infections (using the standardized endpoints in perioperative medicine-core outcome measures for perioperative and anesthetic care criteria). Peripheral blood mononuclear cells were isolated prior to and 24 h following surgery from which cellular immune traits including activation and functional status were assessed by multi-parameter flow cytometry and serum immune analytes compared by enzyme-linked immunosorbent assay (ELISA). Results: Forty-eight patients were recruited, 26 (54%) of whom developed a post-operative infection. We observed reduced baseline pre- and post-operative monocyte CXCR4 and CD80 expression (chemokine receptors and co-stimulation markers, respectively) in patients who subsequently developed an infection as well as a profound and selective post-operative increase in CD4+ lymphocyte IL-7 receptor expression in the infection group only. Higher post-operative monocyte count was significantly associated with the development of post-operative infection (false discovery rate < 1%; adjusted p-value = 0.001) with an area under the receiver operating characteristic curve of 0.84 (p < 0.0001). Conclusion: Lower monocyte chemotaxis markers, higher post-operative circulating monocyte counts, and reduced co-stimulatory signals are associated with subsequent post-operative infections. Identifying the underlying mechanisms and therapeutics to reverse defects in immune cell function requires further exploration.

Effect of dexamethasone dose on outcomes in acute COVID-19 disease: A systematic review and meta-analysis.

INTRODUCTION: The impact of different doses of dexamethasone on outcomes from acute COVID-19 pneumonia is unknown. METHODS: We performed a systematic review and meta-analysis of randomised control trials comparing different doses of dexamethasone in adult patients with COVID-19. High dose dexamethasone treatment was defined as 12-24 mg daily, whereas low-dose treatment was 6-8 mg daily. Primary outcome was 28-day mortality. RESULTS: Eight trials including 3469 patients were identified, with 1775 patients receiving high dose dexamethasone. There was no difference in mortality between patients receiving high dose or low-dose dexamethasone (22.0% vs. 20.2%; odds ratio 1.20 [95% confidence interval 0.86-1.67]; p = 0.29; I2 = 63%; TSA-adjusted CI [0.31-4.66]; very low QoE). Meta-regression did not demonstrate a dose-dependent effect of steroids on mortality. High dose dexamethasone was associated with an increased risk of hyperglycaemia (23.6% vs. 17.2%; 1.51 [1.19-1.92]; p = 0.0008; I2 = 0%; TSA-adjusted CI [0.90-2.54]; low QoE) but not secondary infections (14.3% vs. 15.0%; 0.87 [0.56-1.37]; p = 0.56; I2 = 72%; very low QoE). Risk of bias was low for seven of the eight studies. CONCLUSIONS: The mortality of patients with acute COVID-19 receiving high-dose dexamethasone is similar to patients receiving low-dose dexamethasone, although high-dose dexamethasone is associated with an increased risk of hyperglycaemia.

Respiratory fluoroquinolone monotherapy vs. ß-lactam plus macrolide combination therapy for hospitalized adults with community-acquired pneumonia: A systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: Guidelines recommend respiratory fluoroquinolone monotherapy or ß-lactam plus macrolide combination therapy as first-line options for hospitalized adults with mild-to-moderate community-acquired pneumonia (CAP). Efficacy of these regimens has not been adequately evaluated. METHODS: A systematic review of randomized controlled trials (RCTs) comparing respiratory fluoroquinolone monotherapy and ß-lactam plus macrolide combination therapy in hospitalised adults with CAP was performed. A meta-analysis was performed using a random effects model. The primary outcome was clinical cure rate. Quality of evidence (QoE) was evaluated using GRADE methodology. RESULTS: A total of 4140 participants in 18 RCTs were included. Levofloxacin (11 trials) or moxifloxacin (6 trials) were the predominant respiratory fluoroquinolones evaluated, and the ß-lactam plus macrolide group used ceftriaxone plus a macrolide (10 trials), cefuroxime plus azithromycin (5 trials), and amoxicillin/clavulanate plus a macrolide (2 trials). Patients receiving respiratory fluoroquinolone monotherapy had a significantly higher clinical cure rate (86.5% vs. 81.5%; odds ratio [OR] 1.47; 95% confidence interval [95% CI: 1.17-1.83]; P = 0.0008; I2 = 0%; 17 RCTs; moderate QoE) and microbiological eradication rate (86.0% vs. 81.0%; OR 1.51 [95% CI: 1.00-2.26]; P = 0.05; I2 = 0%; 15 RCTs; moderate QoE) than patients receiving ß-lactam plus macrolide combination therapy. All-cause mortality (7.2% vs. 7.7%; OR 0.88 [95% CI: 0.67-1.17]; I2 = 0%; low QoE) and adverse events (24.8% vs. 28.1%; OR 0.87 [95% CI: 0.69-1.09]; I2 = 0%; low QoE] were similar in the two groups. CONCLUSION: Respiratory fluoroquinolone monotherapy demonstrated an advantage in clinical cure and microbiological eradication; however, it did not impact mortality.

Effect of Corticosteroids on Mortality and Clinical Cure in Community-Acquired Pneumonia: A Systematic Review, Meta-analysis, and Meta-regression of Randomized Control Trials.

BACKGROUND: Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality. Corticosteroids may be a beneficial adjunct in the treatment of bacterial pneumonia. RESEARCH QUESTION: Is there any benefit of corticosteroid therapy in the management of bacterial CAP among patients requiring hospitalization? STUDY DESIGN AND METHODS: PubMed, Cochrane Library, and Embase were searched to identify randomized controlled trials assessing the use of systemic corticosteroids compared with standard care in the management of CAP. A systematic review, meta-analysis, and Trial Sequential Analysis (TSA) were performed. The primary outcome was all-cause mortality. Secondary outcomes included ICU admission, mechanical ventilation, treatment failure, readmission, and adverse events. Data are presented as risk ratio (RR) with 95% CI, P value, heterogeneity (I2), and TSA-adjusted CIs. RESULTS: Sixteen trials met the eligibility criteria. All-cause mortality (16 studies [3,842 patients]; RR, 0.85 [95% CI, 0.67-1.07]; P = .17; I2 = 14%; TSA-adjusted CI, 0.61-1.09), ICU admission (six studies [2,619 patients]; RR, 0.66 [95% CI, 0.45-0.97]; P = .04; I2 = 0%; TSA-adjusted CI, 0.37-1.12), treatment failure (six studies [2,093 patients]; RR, 0.78 [95% CI, 0.37-1.67]; P = .52; I2 = 68%; TSA-adjusted CI, 0.02-25.5), and the incidence of adverse events (six studies [2,487 patients]; RR, 1.10 [95% CI, 0.97-1.25]; P = .14; I2 = 53%; TSA-adjusted CI, 0.82-2.41) were similar between patients receiving corticosteroids and patients assigned to the control group. The need for mechanical ventilation (eight studies [1,457 patients]; RR, 0.51 [95% CI, 0.33-0.77]; P = .001; I2 = 0%; TSA-adjusted CI, 0.20-0.85) was lower among patients receiving corticosteroids compared with those receiving standard care. However, corticosteroid use may be associated with higher rates of hospital readmission (five studies [2,853 patients]; RR, 1.20 [95% CI, 1.05-1.38]; P = .008; I2 = 0%; TSA-adjusted CI, 0.89-1.98). INTERPRETATION: Corticosteroid therapy is associated with a lower incidence of progression to requiring mechanical ventilation among patients hospitalized with CAP. No association was found between corticosteroid therapy and mortality, treatment failure, or adverse events. TRIAL REGISTRY: PROSPERO; No.: CRD42021279359; URL: https://www.crd.york.ac.uk/prospero/.

Efficacy of Doxycycline for Mild-to-Moderate Community-Acquired Pneumonia in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Doxycycline has been recommended as a treatment option for non-severe community-acquired pneumonia (CAP) in adults. We sought to review the evidence for the efficacy of doxycycline in adult patients with mild-to-moderate CAP. METHODS: We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) of doxycycline versus comparator to assess the clinical efficacy. The primary outcome was the clinical cure rate. Random effects model meta-analyses were used to generate pooled odds ratio (OR) and evaluate heterogeneity (I2). Risk of bias (RoB) and quality of evidence (QoE) were evaluated using the Cochrane Risk of Bias 2.0 tool and GRADE methods, respectively. RESULTS: We included 6 RCTs with 834 clinically evaluable patients. The trials were performed between 1984 and 2004. Comparators were 3 macrolides (roxithromycin, spiramycin, and erythromycin) and 3 fluoroquinolones (ofloxacin, fleroxacin, and levofloxacin). Four trials had an overall high RoB. The clinical cure rate was similar between the doxycycline and comparator groups (87.2% [381/437] vs 82.6% [328/397]; OR 1.29 [95% confidence interval {CI}: .73-2.28]; I2 = 30%; low QoE). Subgroup analysis of two studies with a low RoB showed significantly higher clinical cure rates in the doxycyline group (87.1% [196/225] vs 77.8% [165/212]; OR 1.92 [95% CI: 1.15-3.21]; P = .01; I2 = 0%). Adverse event rates were comparable between the doxycycline and comparator groups. CONCLUSIONS: The efficacy of doxycycline was comparable to macrolides or fluoroquinolones in mild-to-moderate CAP and thus represents a viable treatment option. Considering the lack of recent trials, it warrants large-scale clinical trials.

Beneficial ex vivo immunomodulatory and clinical effects of clarithromycin in COVID-19.

INTRODUCTION: Macrolide antibiotics have immunomodulatory properties which may be beneficial in viral infections. However, the precise effects of macrolides on T cell responses to COVID, differences between different macrolides, and synergistic effects with other antibiotics have not been explored. METHODS: We investigated the effect of antibiotics (amoxicillin, azithromycin, clarithromycin, and combined amoxicillin with clarithromycin) on lymphocyte intracellular cytokine levels and monocyte phagocytosis in healthy volunteer PBMCs stimulated ex vivo with SARS-CoV-2 S1+2 spike protein. A retrospective cohort study was performed on intensive care COVID-19 patients. RESULTS: Co-incubation of clarithromycin with spike protein-stimulated healthy volunteer PBMCs ex vivo resulted in an increase in CD8+ (p = 0.004) and CD4+ (p = 0.007) IL-2, with a decrease in CD8+ (p = 0.032) and CD4+ (p = 0.007) IL-10. The addition of amoxicillin to clarithromycin resulted in an increase in CD8+ IL-6 (p = 0.010), decrease in CD8+ (p = 0.014) and CD4+ (p = 0.022) TNF-alpha, and decrease in CD8+ IFN-alpha (p = 0.038). Amoxicillin alone had no effect on CD4+ or CD8+ cytokines. Co-incubation of azithromycin resulted in increased CD8+ (p = 0.007) and CD4+ (p = 0.011) IL-2. There were no effects on monocyte phagocytosis. 102 COVID-19 ICU patients received antibiotics on hospital admission; 62 (61%) received clarithromycin. Clarithromycin use was associated with reduction in mortality on univariate analysis (p = 0.023), but not following adjustment for confounders (HR = 0.540; p = 0.076). CONCLUSIONS: Clarithromycin has immunomodulatory properties over and above azithromycin. Amoxicillin in addition to clarithromycin is associated with synergistic ex vivo immunomodulatory properties. The potential benefit of clarithromycin in critically ill patients with COVID-19 and other viral pneumonitis merits further exploration.

Mortality and clinical cure rates for pneumonia: a systematic review, meta-analysis, and trial sequential analysis of randomized control trials comparing bactericidal and bacteriostatic antibiotic treatments.

BACKGROUND: Bactericidal antibiotics are generally assumed to be superior to bacteriostatic antibiotics as first-line treatment for pneumonia. OBJECTIVES: We performed a systematic review, meta-analysis, and trial sequential analysis (TSA) of randomized controlled trials (RCTs) of bactericidal versus bacteriostatic antibiotics to ascertain clinical superiority. Clinical cure rate was the primary outcome. Secondary outcomes included all-cause mortality, microbiological eradication, treatment failure, and relapse rates. DATA SOURCES: PubMed, Cochrane Library, Embase, and MedRxiv STUDY ELIGIBILITY CRITERIA: Randomized control trials. PARTICIAPANTS: Adult patients with bacterial pneumonia treated with antibiotics in the community or in-hospital. INTERVENTIONS: Bacteriostatic versus bactericidal antibiotics. ASSESSMENT OF RISK OF BIAS: The Cochrane Collaboration assessing risk of bias 2 tool. METHODS OF DATA SYNTHESIS: Data on dichotomous outcomes are presented as risk ratio (RR). A random-effects model with the generic Mantel-Haenszel method was used for integrating RRs for generalizability of findings. The I2 method was used to assess the magnitude of variation secondary to heterogeneity. RESULTS: Forty-three RCTs involving 10 752 patients met the eligibility criteria. The clinical cure rate (42 studies, 10 312 patients; RR: 1.02; 95% CI, 0.99-1.05; I2: 37%; TSA-adjusted CI, 0.99-1.05), all-cause mortality (25 studies, 8302 patients; RR: 1.07; 95% CI, 0.81-1.42; I2: 57%), microbiological eradication (24 studies, 2776 patients; RR: 1.00; 95% CI, 0.97-1.03; I2: 0%), treatment failure (31 studies, 7296 patients; RR: 0.96; 95% CI, 0.83-1.11; I2: 42%), and relapse rate (5 studies, 1111 patients; RR: 1.15; 95% CI, 0.50-2.63; I2: 0%) were similar between bactericidal and bacteriostatic antibiotic treatments. CONCLUSIONS: Bactericidal agents are not associated with any statistical difference in clinical cure rates, mortality, microbiological eradication, treatment failure, or relapse rates compared with bacteriostatic antibiotics in the treatment of pneumonia.

Defining Potential Therapeutic Targets in Coronavirus Disease 2019: A Cross-Sectional Analysis of a Single-Center Cohort.

OBJECTIVES: Multiple mechanisms have been proposed to explain disease severity in coronavirus disease 2019. Therapeutic approaches need to be underpinned by sound biological rationale. We evaluated whether serum levels of a range of proposed coronavirus disease 2019 therapeutic targets discriminated between patients with mild or severe disease. DESIGN: A search of ClinicalTrials.gov identified coronavirus disease 2019 immunological drug targets. We subsequently conducted a retrospective observational cohort study investigating the association of serum biomarkers within the first 5 days of hospital admission relating to putative therapeutic biomarkers with illness severity and outcome. SETTING: University College London, a tertiary academic medical center in the United Kingdom. PATIENTS: Patients admitted to hospital with a diagnosis of coronavirus disease 2019. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Eighty-six patients were recruited, 44 (51%) with mild disease and 42 (49%) with severe disease. We measured levels of 10 cytokines/signaling proteins related to the most common therapeutic targets (granulocyte-macrophage colony-stimulating factor, interferon-α2a, interferon-ß, interferon-γ, interleukin-1ß, interleukin-1 receptor antagonist, interleukin-6, interleukin-7, interleukin-8, tumor necrosis factor-α), immunoglobulin G antibodies directed against either coronavirus disease 2019 spike protein or nucleocapsid protein, and neutralization titers of antibodies. Four-hundred seventy-seven randomized trials, including 168 different therapies against 83 different pathways, were identified. Six of the 10 markers (interleukin-6, interleukin-7, interleukin-8, interferon-α2a, interferon-ß, interleukin-1 receptor antagonist) discriminated between patients with mild and severe disease, although most were similar or only modestly raised above that seen in healthy volunteers. A similar proportion of patients with mild or severe disease had detectable spike protein or nucleocapsid protein immunoglobulin G antibodies with equivalent levels between groups. Neutralization titers were higher among patients with severe disease. CONCLUSIONS: Some therapeutic and prognostic biomarkers may be useful in identifying coronavirus disease 2019 patients who may benefit from specific immunomodulatory therapies, particularly interleukin-6. However, biomarker absolute values often did not discriminate between patients with mild and severe disease or death, implying that these immunomodulatory treatments may be of limited benefit.

Tocilizumab in COVID-19: a meta-analysis, trial sequential analysis, and meta-regression of randomized-controlled trials.

PURPOSE: Interleukin-6 (IL-6) levels discriminate between patients with mild and severe COVID-19, making IL-6 inhibition an attractive therapeutic strategy. We conducted a systematic review, meta-analysis, trial sequential analysis (TSA), and meta-regression of randomized-controlled trials to ascertain the benefit of IL-6 blockade with tocilizumab for COVID-19. METHODS: We included randomized-controlled trials (RCTs) allocating patients with COVID-19 to tocilizumab. Our control group included standard care or placebo. Trials co-administering other pharmacological interventions for COVID-19 were not excluded. Primary outcome was 28-30 day mortality. Secondary outcomes included progression-to-severe disease defined as need for mechanical ventilation, intensive-care unit (ICU) admission, or a composite. RESULTS: We identified 10 RCTs using tocilizumab, 9 of which reported primary outcome data (mortality), recruiting 6493 patients with 3358 (52.2%) allocated to tocilizumab. Tocilizumab may be associated with an improvement in mortality (24.4% vs. 29.0%; OR 0.87 [0.74-1.01]; p = 0.07; I2 = 10%; TSA adjusted CI 0.66-1.14). Meta-regression suggested a relationship between treatment effect and mortality risk, with benefit at higher levels of risk (logOR vs %risk beta = -0.018 [-0.037 to -0.002]; p = 0.07). Tocilizumab did reduce the need for mechanical ventilation and was associated with a benefit in the composite secondary outcome but did not reduce ICU admission. CONCLUSIONS: For hospitalized COVID-19 patients, there is some evidence that tocilizumab use may be associated with a short-term mortality benefit, but further high-quality data are required. Its benefits may also lie in reducing the need for mechanical ventilation.

COVID-19 and non-COVID ARDS patients demonstrate a distinct response to low dose steroids- A retrospective observational study.

Patients with COVID-19 ARDS have distinct physiological and immunological phenotypes compared to patients with non-COVID ARDS. Patients with COVID-19 ARDS (n = 32) had a significant improvement in PaO2: FiO2 ratio (p = 0.046) following low-dose steroid treatment, unlike patients with non-COVID ARDS (n = 16) (p = 0.529). Patients with COVID-19 ARDS had a greater fall in CRP compared to patients with non-COVID ARDS, albeit not statistically significant (p = 0.07). Our novel findings highlight differences in the underlying physiological and immunological phenotypes between COVID-19 and non-COVID ARDS, with implications for future ARDS studies.