NETosis is critical in patients with severe community-acquired pneumonia

Pneumonia is the fourth leading cause of death globally, and the reason for the high mortality rate of patients with severe community-acquired pneumonia (SCAP) remains elusive. Corticosteroid treatment reduces mortality in adults with SCAP but can cause numerous adverse events. Therefore, novel therapeutic targets need to be explored and new adjunctive immune drugs are urgently required. We analyzed the transcriptome data of peripheral blood leukocytes from patients with SCAP and healthy controls from three perspectives: differentially expressed genes, predicted functions of differentially expressed long non-coding RNAs, and transcriptional read-through. We discovered that the NETosis pathway was top-ranked in patients with SCAP caused by diverse kinds of pathogens. This provides a potential therapeutic strategy for treating patients. Furthermore, we calculated the correlation between the expression of genes involved in NETosis and the ratio of arterial oxygen partial pressure to fractional inspired oxygen. We identified four novel potential therapeutic targets for NETosis in patients with SCAP, including H4C15, H3-5, DNASE1, and PRKCB. In addition, a higher occurrence of transcriptional read-through is associated with a worse outcome in patients with SCAP, which probably can explain the high mortality rate of patients with SCAP.

[Etiology of severe community - acquired pneumonia in adults: results of the first Russian multicenter study]

AIM

to study the etiology of severe community - acquired pneumonia (SCAP) in adults in Russian Federation. SCAP is distinguished by high mortality and socio - economic burden. Both etiology and antimicrobial resistance are essential for appropriate antibiotic choice.

MATERIALS AND METHODS

A prospective cohort study recruited adults with confirmed diagnosis of SCAP admitted to multi - word hospitals of six Russian cities in 2014-2018. Etiology was confirmed by routine culture of blood, respiratory (sputum, endotracheal aspirate or bronchoalveolar lavage) and when appropriate, autopsy samples, urinary antigen tests (L. pneumophila serogroup 1, S. pneumoniae); real - time PCR for identification of "atypical" bacterial pathogens (M. pneumoniae, C. pneumoniae, L. pneumophila) and respiratory viruses (influenza viruses A and B, parainfluenza, human metapneumovirus, etc.) was applied.

RESULTS

Altogether 109 patients (60.6% male; mean age 50.8±18.0 years old) with SCAP were enrolled. Etiological agent was identified in 65.1% of patients, S. pneumoniae, rhinovirus, S. aureus and K. pneumoniae were the most commonly isolated pathogens (found in 43.7, 15.5, 14.1 and 11.3% of patients with positive results of microbiological investigations, respectively). Bacteriemia was seen in 14.6% of patients and most commonly associated with S. pneumoniae. Co - infection with 2 or more causative agents was revealed in 36.6% of cases. Combination of bacterial pathogens (mainly S. pneumoniae with S. aureus or/and Enterobacterales) prevailed - 57.7% of cases; associations of bacteria and viruses were identified in 38.5% of patients, different viruses - in one case.

CONCLUSION

S. pneumoniae was the most common pathogen in adults with SCAP. A high rate of respiratory viruses (mainly rhinovirus and influenza viruses) identification both as mixt infection with bacteria and mono - infection should be taken into account.

Efficacy and safety of glucocorticoids in the treatment of severe community-acquired pneumonia: A meta-analysis

BACKGROUND

Recent clinical trials have shown that adjunctive glucocorticoids is associated with inhibiting excessive inflammatory response and modulating cytokines release offering several advantages over conventional therapy on relieving clinical symptoms, reducing mortality, and improving prognosis. However, given the severe complications triggered by glucocorticosteroid, whether similar benefits may be achieved by patients undergoing glucocorticosteroid intervention remains controversial. Our meta-analysis aimed to investigate the efficacy and safety of adjunctive glucocorticoids in the treatment of severe community acquired pneumonia.

METHODS

A search of PubMed, EMBASE, Cochrane Library, EBASO, Medline, Google Scholar, Science Dicet, CBM, and CNKI databases was performed to analyze all relevant randomized controlled trials (RCTs) of corticosteroids in patients with severe community acquired pneumonia (CAP) up to January 2018. All-cause mortality, C-reactive protein (CRP) level, incidence of septic shock, and requirement of mechanical ventilation were selected as efficacy outcomes. Major adverse events involving super infection, upper gastrointestinal bleeding, and hyperglycemia were safety outcomes. Meta-analysis was conducted with RevMan 5.3 software.

RESULTS

A total of 10 RCTs comprising 665 patients were included for analysis. Regarding efficacy outcomes, adjunctive corticosteroid seemed to be superior compared with conventional treatment in terms of all-cause mortality (relative risk [RR]: 0.47, 95% confidence interval [CI], 0.3-0.74, P = .001), CRP level on day 8 after administration (standard mean difference [SMD]: -0.8, 95% CI, -1.11 to -0.5, P < .001), incidence of septic shock (odds ratio [OR] 0.15, 95% CI, 0.07-0.29, P < .001) and requirement for mechanical ventilation (OR: 0.32, 95% CI, 0.20-0.52, P < .001). Meanwhile, we found that low dose (≤86 mg) (RR: 0.41, 95% CI, 0.21-0.82, P = .01) and prolonged (>5 days) (RR: 0.35, 95% CI, 0.15-0.81, P = .01) use of corticosteroids in dosage modus of a maintenance dose after a bolus (RR: 0.28, 95% CI, 0.14-0.55, P = .002) obtained better results in death through subgroup analysis. Regarding safety outcomes, no difference was observed between 2 groups in terms of upper gastrointestinal bleeding (OR: 0.83, 95% CI, 0.27-2.52, P = .74), hyperglycemia (OR: 1.3, 95% CI, 0.68-2.49, P = .42), and super infection (OR: 1.11, 95% CI, 0.14-9.13, P = .92).

CONCLUSION

Adjunctive corticosteroid yielded favorable outcomes in the treatment of severe community acquired pneumonia (SCAP) as evidenced by decreased all-cause mortality, incidence of septic shock, and requirement for mechanical ventilation without increasing risk of adverse events. Low dose (≤86 mg/d), prolonged use (>5 days) of corticosteroid in dosage modus of a maintenance dose after a bolus can be recommended as preferred regimen to guard against SCAP.

Distribution of the atypical pathogens of community-acquired pneumonia to disease severity

Background

To investigate the epidemiological characteristics of 11 atypical pathogens of community-acquired pneumonia (CAP) among Chinese, and to determine whether or not there is an association between these pathogens and the severity of illness.

Methods

We conducted a surveillance study for CAP in 30 hospitals of Beijing. Epidemiological data and clinical specimens were systematically collected from enrolled CAP patients. The detection for 11 atypical pathogens [9 respiratory viruses, Mycoplasma pneumoniae (MP) and Chlamydophila pneumoniae (CP)] was performed. Risk factors of severe CAP and death in Hospital were evaluated.

Results

A total of 6,008 CAP patients [including 1,071 severe CAP (SCAP)] were enrolled. The overall detection rate of the 11 atypical pathogens was 42.4% among 1,925 child CAP (39.9% among 274 child SCAP), and 25.8% among 4,083 adult CAP (22.8% among 797 adult SCAP). The most frequent atypical pathogen among child SCAP was parainfluenza virus (10.2%) followed by respiratory syncytial virus (RSV) (8.4%). However, the most frequent atypical pathogen among adult SCAP was influenza virus (8.9%) followed by parainfluenza virus (3.8%). Multivariate analyses showed that the important predictors for SCAP were an age ≤9 years, an age ≥65 years and co-existing diseases. These factors, except an age ≤9 years, were also predictors of death in Hospital. None of these 11 atypical pathogens was included as the risk factors of SCAP or death in Hospital.

Conclusions

Although these 11 atypical pathogens were the common causes of CAP (including SCAP) among Chinese, they were not observed to increase risks for SCAP or death in Hospital.

The management of severe community acquired pneumonia in the intensive care unit

Severe CAP (SCAP), accounting for 6% of admissions to intensive care units (ICUs) needs early diagnosis and aggressive interventions at the most proximal point of disease presentation. The prognostic scores as the ATS/IDSA rule, the systolic blood pressure, multilobar infiltrates, albumin, respiratory rate, tachycardia, confusion, oxygen and pH or SCAP system are appropriate in early identification of eligible patients requiring admission to ICU. Then the recommended initial resuscitation in SCAP in the ICU consists of fluid volume intake titrated to specific goals after a fluid challenge and hemodynamic optimization. The first selection of antimicrobial therapy should be started in the first hour and would be broad enough to cover all likely pathogens. Combination therapy may be useful in patients with non refractory septic shock and severe sepsis pneumococcal bacteremia as well. After 6 hours the patient would be reevaluated in terms of hemodynamic stability and antibiotic and therapy. Future developments will focus on sepsis biomarkers, molecular diagnostic techniques and the development of novel therapeutic immunomodulaty agents.