Ribosomal RNA­depleted RNA sequencing reveals the pathogenesis of refractory Mycoplasma pneumoniae pneumonia in children.

Pneumonia caused by Mycoplasma pneumoniae (M. pneumoniae) is a major cause of community­acquired pneumonia in children. In some cases, M. pneumoniae pneumonia (MPP) can develop into refractory MPP (RMPP), which shows no clinical or radiological response to macrolides, and can progress to severe and complicated pneumonia. However, the pathogenesis of RMPP remains poorly understood. The present study aimed to identify target genes that could be used as biomarkers for the clinical diagnosis of early­stage RMPP through high­throughput sequencing technology. The differences in long non­coding (lnc)RNAs, mRNAs and circular (circ)RNAs were examined between whole­blood samples from two patients with non­refractory MPP (NRMPP), two patients with RMPP and three healthy children using ribosomal (r)RNA­depleted RNA­sequencing techniques and an integrated mRNA/circRNA analysis. A total of 17 lncRNAs (four upregulated and 13 downregulated), 18 mRNAs (six upregulated and 12 downregulated) and 24 circRNAs (12 upregulated and 12 downregulated) were the most significantly differentially expressed (P<0.05) between the NRMPP and RMPP groups. Upon functional analysis, the significantly differentially expressed genes encoded by the targeting mRNAs (prostaglandin­endoperoxide synthase 2, IL­8 and fos­like antigen 1) were screened and identified to be enriched in the 'IL­17 signaling pathway'. Furthermore, the key circRNAs in the NRMPP and RMPP comparative groups were primarily enriched in 'herpes simplex virus 1 infection', 'viral carcinogenesis' and 'RNA transport'. In the present study, a comprehensive analysis of the differences between the NRMPP and RMPP cases was performed based on rRNA­depleted RNA­sequencing techniques, and the selected genes and circRNAs may be closely associated with the complex pathogenesis of RMPP.

Knockdown of circ-UQCRC2 ameliorated lipopolysaccharide-induced injury in MRC-5 cells by the miR-326/PDCD4/NF-κB pathway.

BACKGROUND: Circular RNAs (circRNAs) have been shown as important modulators in the pathogenesis of pediatric pneumonia. In this paper, we focused on the molecular basis of circRNA ubiquinol-cytochrome c reductase core protein 2 (circ-UQCRC2, circ_0038467) in lipopolysaccharide (LPS)-induced cell injury. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was used to gauge the levels of circ-UQCRC2, microRNA (miR)-326 and programmed cell death 4 (PDCD4) mRNA. PDCD4 protein expression and the activation of the NF-κB signaling pathway were evaluated by western blot. Ribonuclease R (RNase R) assay was performed to assess the stability of circ-UQCRC2. Cell viability and apoptosis were detected by the Cell Counting Kit-8 (CCK-8) and flow cytometry assays, respectively. The levels of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß) and IL-6 were measured by the enzyme-linked immunosorbent assay (ELISA). Targeted relationship between miR-326 and circ-UQCRC2 or PDCD4 was confirmed by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. RESULTS: Our data showed the up-regulation of circ-UQCRC2 level in pneumonia serum and LPS-treated MRC-5 cells. The silencing of circ-UQCRC2 attenuated LPS-induced MRC-5 cell injury. Mechanistically, circ-UQCRC2 directly targeted miR-326, and circ-UQCRC2 regulated PDCD4 expression through miR-326. MiR-326 was a downstream effector of circ-UQCRC2 function, and PDCD4 was a functional target of miR-326 in regulating LPS-induced MRC-5 cell injury. Additionally, circ-UQCRC2 knockdown inactivated the NF-κB signaling pathway by regulating the miR-326/PDCD4 axis. CONCLUSION: Our findings demonstrated a novel regulatory network, the miR-326/PDCD4/NF-κB pathway, for the function of circ-UQCRC2 in LPS-induced cell injury in MRC-5 cells.

Effects of age and comorbidities on serum levels of inflammatory markers in community-acquired pneumonia.

INTRODUCTION: Studies have suggested that an inappropriate inflammatory response is a major cause of treatment failure and mortality in patients with community-acquired pneumonia (CAP). We aimed to determine the effect of age and comorbidities on serum inflammatory markers in CAP. METHODS: We performed a prospective cohort study of adults hospitalized with CAP. For the purposes of this study, we compared patients according to comorbidities and age. Inflammatory markers were measured at hospital admission, focusing on acute phase proteins, cytokines and monocyte human leucocyte antigen DR (mHLA-DR) expression. RESULTS: In patients with chronic pulmonary disease (COPD), serum cytokines had significantly decreased levels of tumour necrosis factor (TNF)-α, interleukin (IL)-6 and mHLA-DR expression, as well as the C-reactive protein (CRP), compared with patients who had no comorbidities. Similarly, patients with chronic heart disease had a significantly reduced CRP levels and mHLA-DR expression, whereas patients with chronic kidney disease had significantly higher serum levels of procalcitonin and TNF-α. Lower procalcitonin, IL-6 and IL-10 levels, as well as mHLA-DR expression, were documented in older patients, but with no significant differences compared to younger patients. Multimorbidity in older patients was associated with significant lower levels of CRP and mHLA-DR expression. CONCLUSIONS: The circulating inflammatory markers to CAP have profiles that differ with age and underlying comorbidities. Multimorbidity in the elderly is also associated with lower serum levels of some inflammatory markers. Our findings suggest that inflammatory markers in CAP should be interpreted after considering age and comorbid conditions.

Activation and Functional Alteration of Mucosal-Associated Invariant T Cells in Adult Patients With Community-Acquired Pneumonia.

Community-acquired pneumonia (CAP) remains the significant infectious cause of morbidity and mortality worldwide. Although mucosal-associated invariant T cells (MAIT) play roles in the pathogenesis of children CAP and ICU-associated pneumonia, their roles in adult CAP are largely unexplored. In this study, we investigated the frequency, phenotype, and function of MAIT cells in peripheral blood and bronchoalveolar lavage fluid (BALF) of adult CAP patients. Our data indicate that MAIT-cell frequency is profoundly lower in the peripheral blood of CAP patients compared to that in healthy individuals. Furthermore, the circulatory MAIT cells express higher levels of CD69 and PD-1 compared to those in healthy individuals. In BALF of CAP patients, MAIT-cell frequency is higher and MAIT cells express higher levels of CD69 and PD-1 compared to their matched blood counterparts. Levels of IL-17A and IFN-γ are increased in BALF of CAP patients compared to those in BALF of patients with pulmonary small nodules. The IL-17A/IFN-γ ratio is significantly positively correlated with MAIT frequency in BALF of CAP patients, suggesting a pathogenic role of MAIT-17 cells in CAP. Of note, blood MAIT-cell frequency in CAP patients is strongly negatively correlated with high-sensitivity C-reactive protein (hsCRP) and neutrophil count percentage in blood. The ability of circulating MAIT cells in CAP patients to produce IFN-γ is significantly impaired compared to those in healthy individuals. In summary, our findings suggest the possible involvement of MAIT cells in the immunopathogenesis of adult CAP.

The Role of Streptococcus pneumoniae in Community-Acquired Pneumonia.

With the notable exceptions of the United States and Canada in particular, the global burden of disease in adults due to invasive infection with the dangerous respiratory, bacterial pathogen, Streptococcus pneumoniae (pneumococcus) remains. This situation prevails despite the major successes of inclusion of polysaccharide conjugate vaccines (PCVs) in many national childhood immunization programs and associated herd protection in adults, as well as the availability of effective antimicrobial agents. Accurate assessment of the geographic variations in the prevalence of invasive pneumococcal disease (IPD) has, however, been somewhat impeded by the limitations imposed on the acquisition of reliable epidemiological data due to reliance on often insensitive, laboratory-based, pathogen identification procedures. This, in turn, may result in underestimation of the true burden of IPD and represents a primary focus of this review. Other priority topics include the role of PCVs in the changing epidemiology of IPD in adults worldwide, smoking as a risk factor not only in respect of increasing susceptibility for development of IPD, but also in promoting pneumococcal antibiotic resistance. The theme of pneumococcal antibiotic resistance has been expanded to include mechanisms of resistance to commonly used classes of antibiotics, specifically ß-lactams, macrolides and fluoroquinolones, and, perhaps somewhat contentiously, the impact of resistance on treatment outcome. Finally, but no less importantly, the role of persistent antigenemia as a driver of a chronic, subclinical, systemic proinflammatory/procoagulant phenotype that may underpin the long-term sequelae and premature mortality of those adults who have recovered from an episode of IPD, is considered.

Antibodies against atypical pathogens and respiratory viruses detected by Pneumoslide IgM test in adults with community-acquired pneumonia in Guangzhou City.

BACKGROUND: To detect the serum antibodies against respiratory viruses and atypical pathogens in adults with community-acquired pneumonia (CAP) in Guangzhou City (Guangdong province, China). METHODS: A retrospective study was carried out with samples from 685 adults who were admitted with CAP and 108 non-CAP control patients. Atypical pathogens and respiratory viruses in serum were detected using the Pneumoslide IgM test from Vircell, Spain. All patients were divided into 6 groups according to age: 18-24, 25-44, 45-59, 60-74, 75-89, and >90. RESULTS: The total positive rate of CAP was 35.4%, which was highest in the 18-24 age group (P < .05). The highest positive rate, 17.11%, was observed for Mycoplasma pneumoniae (MP). The mean age of MP-infected patients was higher than that of the controls (P < .05). The positive rates for influenza B (INFB), Legionella pneumophila (LP1), Coxiella burnetii (COX), influenza A (INFA), parainfluenza virus (PIV), respiratory syncytial virus (RSV), Chlamydophila pneumoniae (CP), and adenovirus (ADV) were 5.56%, 3.07%, 2.63%, 2.34%, 1.90%, 1.61, 0.88%, and 0.29%, respectively. There were 4.37% of patients with CAP having multiple infections. The main symptoms observed in the 685 CAP patients were cough and sputum production, in 78.4% and 67.4%. Fever was followed by 54% of CAP patients. Dyspnea (39.1%), anorexia (36.8%), increased thirst (26.7%), chills (18.7), headache (14.6%), and nausea (13.1%) were also frequently observed in the CAP patients. CONCLUSIONS: MP infection was the most common in adult CAP patients in Guangzhou City with the highest positive rate in the 18-24 age groups.

Concurrent Immune Suppression and Hyperinflammation in Patients With Community-Acquired Pneumonia.

Background: The nature and timing of the host immune response during infections remain uncertain and most knowledge is derived from critically ill sepsis patients. We aimed to test the hypothesis that community-acquired pneumonia (CAP) is associated with concurrent immune suppression and systemic inflammation. Methods: Blood was collected from 79 CAP patients within 24 h after hospitalization and 1 month after discharge; 42 age- and sex-matched subjects without acute infection served as controls. Blood leukocytes were stimulated with lipopolysaccharide (LPS) or Klebsiella pneumoniae, and cytokines were measured in supernatants. Fifteen plasma biomarkers reflective of key host response pathways were compared between CAP patients with the strongest immune suppression (lowest 25% blood leukocyte tumor necrosis factor (TNF)-α production in response to LPS) and those with the least immune suppression (highest 25% of LPS-induced TNF-α production). Results: Blood leukocytes of CAP patients (relative to control subjects) showed a reduced capacity to release TNF-α, interleukin (IL)-1ß, IL-6 and IL-10 upon stimulation with LPS or K. pneumoniae, with a concurrently enhanced ability to release the anti-inflammatory mediator IL-1 receptor antagonist, irrespective of the presence of sepsis (18.9% of cases). Low (relative to high) TNF-α producers displayed higher plasma levels of biomarkers reflecting systemic inflammation, neutrophil degranulation, endothelial cell activation, a disturbed vascular barrier function and coagulation activation. Conclusion: CAP replicates a common feature of immune suppression in sepsis. The coexistence of immune suppression and hyperinflammation in CAP argues against the theory of two distinct phases during the host response to sepsis.

Characterization of the Inflammatory Response to Severe COVID-19 Illness.

Rationale: Coronavirus disease (COVID-19) is a global threat to health. Its inflammatory characteristics are incompletely understood.Objectives: To define the cytokine profile of COVID-19 and to identify evidence of immunometabolic alterations in those with severe illness.Methods: Levels of IL-1ß, IL-6, IL-8, IL-10, and sTNFR1 (soluble tumor necrosis factor receptor 1) were assessed in plasma from healthy volunteers, hospitalized but stable patients with COVID-19 (COVIDstable patients), patients with COVID-19 requiring ICU admission (COVIDICU patients), and patients with severe community-acquired pneumonia requiring ICU support (CAPICU patients). Immunometabolic markers were measured in circulating neutrophils from patients with severe COVID-19. The acute phase response of AAT (alpha-1 antitrypsin) to COVID-19 was also evaluated.Measurements and Main Results: IL-1ß, IL-6, IL-8, and sTNFR1 were all increased in patients with COVID-19. COVIDICU patients could be clearly differentiated from COVIDstable patients, and demonstrated higher levels of IL-1ß, IL-6, and sTNFR1 but lower IL-10 than CAPICU patients. COVID-19 neutrophils displayed altered immunometabolism, with increased cytosolic PKM2 (pyruvate kinase M2), phosphorylated PKM2, HIF-1α (hypoxia-inducible factor-1α), and lactate. The production and sialylation of AAT increased in COVID-19, but this antiinflammatory response was overwhelmed in severe illness, with the IL-6:AAT ratio markedly higher in patients requiring ICU admission (P < 0.0001). In critically unwell patients with COVID-19, increases in IL-6:AAT predicted prolonged ICU stay and mortality, whereas improvement in IL-6:AAT was associated with clinical resolution (P < 0.0001).Conclusions: The COVID-19 cytokinemia is distinct from that of other types of pneumonia, leading to organ failure and ICU need. Neutrophils undergo immunometabolic reprogramming in severe COVID-19 illness. Cytokine ratios may predict outcomes in this population.

Cytokine levels predict 30-day mortality in octogenarians and nonagenarians with community-acquired pneumonia: a retrospective observational study.

To analyze the value of cytokines (tumor necrosis factor [TNF]-α, interleukin [IL]-1ß, IL-6, IL-8, IL-10) as predictors of mortality at 30 days in octogenarians and nonagenarians hospitalized in an internal medicine unit for community-acquired pneumonia (CAP). An observational, analytical, retrospective cohort study was conducted in the Department of Internal Medicine at Alicante General University Hospital between January 2014 and December 2015. Blood samples were frozen at - 80 °C, and cytokines were measured by ELISA. We included 115 patients, of whom 54% were men, with a mean age of 86.4 (standard deviation 4.5) years. There is a moderate correlation between IL-10 levels and CURB-65 score (p < 0.001) and a weak correlation with creatinine levels (p = 0.012) and urea levels (p = 0.032). Forty-five (39.1%) patients died within 30 days. In a multivariate analysis, the variables associated with mortality at 30 days were the following: age (adjusted odds ratio [ORa] 1.134, 95% confidence interval [CI] 1.02, 1.26), male sex (ORa 2.85, 95% CI 1.14, 7.14), IL-8 of 19 pg/mL or more (ORa 4.09, 95% CI 1.67, 10.01), and IL-10 of 11.29 pg/mL or more (ORa 4.00, 95% CI 1.58, 10.12). High IL-8 and IL-10 levels were shown to predict 30-day mortality in elderly patients with CAP. The inflammatory response in these patients seems to condition their prognosis. Further research in this line would provide more understanding about the physiopathological mechanisms and potential therapeutic targets for improving survival.

Utilidad de la proteína C reactiva sérica en el diagnóstico y tratamiento del adulto inmunocompetente hospitalizado por neumonía adquirida en la comunidad / Immunocompetent adults hospitalized for a community-acquired pneumonia: Serum C-reactive protein as a prognostic marker

Background: C-reactive protein (CRP) is used to monitor patients' response during treatment of infectious diseases. Morbidity and mortality associated with community-acquired pneumonia (CAP) is high, particularly in hospitalized patients. Better risk prediction during hospitalization could improve management and ultimately reduce mortality rates. Aim: To evaluate CRP measured at admission and the third day of hospitalization as a predictor for adverse events in CAP. Material and Methods: A prospective cohort study of adult patients hospitalized with CAP at an academic hospital. Major adverse outcomes were admission to ICU, mechanical ventilation, prolonged hospital length of stay, hospital complications and 30-day mortality. Predictive associations between CRP (as absolute levels and relative decline at third day) and adverse events were analyzed. Results: Eight hundred and twenty-three patients were assessed, 19% were admitted to ICU and 10.6% required mechanical ventilation. The average hospital stay was 8.8 ± 8.2 days, 42% had nosocomial complications and 8.1% died within 30 days. Ninety eight percent of patients had elevated serum CRP on admission to the hospital (18.1 ± 14.1 mg/dL). C-reactive protein measured at admission was associated with the risk of bacterial pneumonia, bacteremic pneumonia, septic shock and use of mechanical ventilation. Lack of CRP decline within three days of hospitalization was associated with high risk of complications, septic shock, mechanical ventilation and prolonged hospital stay. Conclusions: CRP responses at third day of hospital admission was a valuable predictor of adverse events in hospitalized CAP adult patients.

Plasma cytokine profile on admission related to aetiology in community-acquired pneumonia.

BACKGROUND: Potentially unnecessary antibiotic use for community-acquired pneumonia (CAP) contributes to selection of antibiotic-resistant pathogens. Cytokine expression at the time that treatment is started may assist in identifying patients not requiring antibiotics. We determined plasma cytokine patterns in patients retrospectively categorized as strict viral, pneumococcal or combined viral-bacterial CAP. OBJECTIVE: To investigate whether cytokine-based prediction models can be used to differentiate strict viral CAP from other aetiologies at admission. METHODS: From 344 hospitalized CAP patients, 104 patients were categorized as viral CAP (n = 17), pneumococcal CAP (n = 48) and combined bacterial-viral CAP (n = 39). IL-6, IL-10, IL-27, IFN-γ and C-reactive protein (CRP) were determined on admission in plasma. Prediction of strict viral aetiology was explored with two multivariate regression models and ROC curves. RESULTS: Viral pneumonia was predicted by logistic regression using multiple cytokine levels (IL-6, IL-27 and CRP) with an AUC of 0.911 (95% CI: 0.852-0.971, P < .001). For the same patients the AUC of CRP was 0.813 (95% CI: 0.728-0.898, P < .001). CONCLUSIONS: This study demonstrated differences in cytokine expression in selected CAP patients between viral and bacterial aetiology. Prospective validation studies are warranted.

Impact of community respiratory viral infections in urban children with asthma.

BACKGROUND: Upper respiratory tract viral infections cause asthma exacerbations in children. However, the impact of natural colds on children with asthma in the community, particularly in the high-risk urban environment, is less well defined. OBJECTIVE: We hypothesized that children with high-symptom upper respiratory viral infections have reduced airway function and greater respiratory tract inflammation than children with virus-positive low-symptom illnesses or virus-negative upper respiratory tract symptoms. METHODS: We studied 53 children with asthma from Detroit, Michigan, during scheduled surveillance periods and self-reported respiratory illnesses for 1 year. Symptom score, spirometry, fraction of exhaled nitric oxide (FeNO), and nasal aspirate biomarkers, and viral nucleic acid and rhinovirus (RV) copy number were assessed. RESULTS: Of 658 aspirates collected, 22.9% of surveillance samples and 33.7% of respiratory illnesses were virus-positive. Compared with the virus-negative asymptomatic condition, children with severe colds (symptom score ≥5) showed reduced forced expiratory flow at 25% to 75% of the pulmonary volume (FEF25%-75%), higher nasal messenger RNA expression of C-X-C motif chemokine ligand (CXCL)-10 and melanoma differentiation-associated protein 5, and higher protein abundance of CXCL8, CXCL10 and C-C motif chemokine ligands (CCL)-2, CCL4, CCL20, and CCL24. Children with mild (symptom score, 1-4) and asymptomatic infections showed normal airway function and fewer biomarker elevations. Virus-negative cold-like illnesses demonstrated increased FeNO, minimal biomarker elevation, and normal airflow. The RV copy number was associated with nasal chemokine levels but not symptom score. CONCLUSION: Urban children with asthma with high-symptom respiratory viral infections have reduced FEF25%-75% and more elevations of nasal biomarkers than children with mild or symptomatic infections, or virus-negative illnesses.

Expression Levels of Interferon Regulatory Factor 5 (IRF5) and Related Inflammatory Cytokines Associated with Severity, Prognosis, and Causative Pathogen in Patients with Community-Acquired Pneumonia.

BACKGROUND Community-acquired pneumonia (CAP) is a common disease with significant morbidity and mortality. Interferon regulatory factor 5 (IRF5), which induces type I interferons (IFNs) and cytokines such as interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-10, and interferon gamma-induced protein (IP)10, is a key transcription factor involved in controlling the expression of proinflammatory cytokines and responses to infection. Here, we carefully investigated the role of IRF5 in regulating immune responses to CAP. MATERIAL AND METHODS QRT-PCR was used to detect the mRNA levels of IRF5, IL-6, IL-10, IP10, TNF-α, and IFN-α in the peripheral blood of 71 CAP patients and 31 healthy controls, as well as in the bronchoalveolar lavage cells of 20 patients with CAP and 23 patients with lung cancer (using samples from the unaffected lung). Flow cytometry was performed to detect the protein level of IRF5, and a CBA flex set was used to detect the levels of these cytokines in the volunteers. RESULTS The expression levels of IRF5 and its related cytokines were significantly increased in CAP patients compared with the controls. Additionally, IRF5, IL-6, IL-10, and IP10 levels were found to be related with the severity of CAP. Furthermore, the levels of IRF5 and IFN-a increased significantly in the early phase of pneumonia caused by influenza virus infection. CONCLUSIONS IRF5 and its related inflammatory cytokines are associated with the severity, prognosis, and causative pathogen of CAP patients. This finding may provide new drug targets for the prevention and treatment of severe pneumonia caused by influenza virus.

Genetic variations in the fusion protein of respiratory syncytial virus isolated from children hospitalized with community-acquired pneumonia in China.

To identify the variations in fusion (F) protein gene of RSV in China, a molecular epidemiological study was conducted. A total of 553 RSV positive specimens were collected from 2338 pediatric patients hospitalized with community-acquired pneumonia during a multi-center study conducted during 2014-2016. A total of 252 samples (183 RSV A, 69 RSV B) were selected for F gene sequencing, and analyzed together with 142 F gene sequences downloaded from GenBank. The result showed that all the Chinese RSV A and RSV B strains could be divided respectively into three branches. Compared with RSV A/B prototype sequences respectively, there were significant amino acid (AA) mutations at multiple antigenic sites. For RSV A, changes were found at AA residues 122, 124, 125, 276 and 384, and for RSV B at AA residues 45, 116, 125, 172, 173 and 202. Variations in human histocompatibility leukocyte antigen-restricted CTL epitopes were also observed. In total, 56 amino acid differences for the complete F protein were found between the RSV A and B groups in China, while several mutations were only found in the RSV B strains during 2015-2016. The RSV F gene is relatively conserved in China, however, limited mutations are still occurring with time.

Microvesicle Subsets in Sepsis Due to Community Acquired Pneumonia Compared to Faecal Peritonitis.

RATIONALE: Microvesicles (MV) act as a nonsoluble means of intercellular communication, with effector roles in disease pathogenesis and potentially as biomarkers. Previously, we reported that neutrophil MV expressing alpha-2-macroglobulin (A2MG) are protective in experimental sepsis and associate with survival in a small cohort of patients with sepsis due to community acquired pneumonia (CAP). OBJECTIVES: To characterize MV profiles in sepsis due to CAP or fecal peritonitis (FP) and determine their relation to outcome. To investigate the effects of novel sepsis treatments (granulocyte-macrophage colony stimulating factor (GM-CSF) and interferon-υ (IFN-γ)) on MV production and functions in vitro. METHODS: Flow cytometry analysis of MV identified the cell of origin and the proportion of A2MG expression in the plasma of patients with sepsis secondary to CAP (n = 60) or FP (n = 40) and compared with healthy volunteers (HV, n = 10). The association between MV subsets and outcome was examined. The ability of GM-CSF and IFN-γ on A2MG MV production from whole blood was examined together with the assessment of their effect on neutrophil and endothelial functions. RESULTS: Circulating cell-derived and A2MG MV were higher in CAP compared with FP and HV. A2MG MV were higher in survivors of CAP, but not in FP. GM-CSF and IFN-γ enhanced A2MG MV production, with these MV eliciting pathogen clearance in vitro. CONCLUSIONS: Plasma MV profiles vary according to the source of infection. A2MG MV are associated with survival in CAP but not FP. We propose specific MV subsets as novel biomarkers in sepsis and potential effector for some of the actions of experimental therapeutic interventions.

Circulating level of high mobility group box­1 predicts the severity of community­acquired pneumonia: Regulation of inflammatory responses via the c­Jun N­terminal signaling pathway in macrophages.

High mobility group box­1 (HMGB­1) has been reported to serve significant roles in various inflammatory diseases. However, the correlation between the circulating level of HMGB­1 and severity of community­acquired pneumonia (CAP) remains unclear. The present study investigated differential alterations in plasma HMGB­1 levels of patients with CAP prior to and following antibiotic treatment, and further analyzed the association between CAP severity and HMGB­1 levels. Furthermore, lipopolysaccharide (LPS)­induced HMGB­1 expression in RAW264.7 macrophages and the relevant signaling pathways were examined. Plasma HMGB­1 levels of 90 patients with CAP and 52 healthy controls were measured using a commercial ELISA. The levels of plasma HMGB­1 were significantly elevated in CAP patients compared with the controls, and antibiotic treatment was effective in reducing HMGB­1 levels. Plasma HMGB­1 correlated with the pneumonia severity index score (r=0.566, P<0.001). Furthermore, LPS­stimulation significantly upregulated HMGB­1 secretion via the c­Jun N­terminal kinase (JNK) signaling pathway in RAW264.7 macrophages, whereas pretreatment with the JNK inhibitor SP600125 markedly downregulated LPS­induced HMGB­1 levels. In conclusion, plasma HMGB­1 levels may serve a role in the diagnosis and clinical assessment of CAP severity. These findings may provide information on novel targets for the treatment of CAP.

Evaluación de los índices predictores de eventos adversos en el adulto inmunocompetente hospitalizado por neumonía adquirida en la comunidad / Adverse event prediction in immunocompetent adult patients hospitalized with community-acquired pneumonia

Background: Community-acquired pneumonia (CAP) causes significant morbidity and mortality in adults. Aim: To compare the accuracy of four validated rules for predicting adverse outcomes in patients hospitalized with CAP. Patients and Methods: We compared the pneumonia severity index (PSI), British Thoracic Society score (CURB-65), SMART-COP and severe CAP score (SCAP) in 659 immunocompetent adult patients aged 18 to 101 years, 52% male, hospitalized with CAP. Major adverse outcomes were: admission to ICU, need for mechanical ventilation (MV), in-hospital complications and 30-day mortality. Mean hospital length of stay (LOS) was also evaluated. The predictive indexes were compared based on sensitivity, specificity, and area under the curve of the receiver operating characteristic curve. Results: Of the studied patients, 77% had comorbidities, 23% were admitted to the intensive care unit and 12% needed mechanical ventilation. The rate of all adverse outcomes and hospital LOS increased directly with increasing PSI, CURB-65, SMART-COP and SCAP scores. The sensitivity, specificity and area under the curve of the prognostic indexes to predict adverse events were: Admission to ICU (PSI: 0.48, 0.84 and 0.73; SMART-COP: 0.97, 0.23 and 0.75; SCAP: 0.57, 0.81 and 0.76); use of MV (PSI: 0.44, 0.84 and 0.75; SMART-COP: 0.96, 0.35 and 0.84; SCAP: 0.53, 0.87 and 0.78); 30-days mortality (PSI: 0.45, 0.97 and 0.83; SMART-COP: 0.94, 0.29 and 0.77; SCAP: 0.53, 0.95 and 0.81). CURB-65 had a lower discriminatory power compared to the other indices. Conclusions: PSI score and SCAP were more accurate and specific and SMART-COP was more sensitive to predict the risk of death. SMART-COP was more sensitive and SCAP was more specific in predicting the use of mechanical ventilation.

Post-hoc analysis of a randomized controlled trial: Diabetes mellitus modifies the efficacy of the 13-valent pneumococcal conjugate vaccine in elderly.

BACKGROUND: The 13-valent pneumococcal conjugate-vaccine (PCV13) was effective in preventing vaccine-type Community-Acquired Pneumonia (VT-CAP) and Invasive Pneumococcal Disease (VT-IPD) in elderly subjects, but vaccine efficacy (VE) in patients with comorbidities at time of vaccination is unknown. METHODS: This is a post hoc analysis of the CAPiTA study, a double blind, randomized controlled trial with 84,496 immunocompetent participants aged ⩾65years, receiving PCV13 or placebo vaccination. Presence of diabetes mellitus (DM), heart disease, respiratory disease, liver disease, asplenia, and smoking at the time of immunization was verified on medical records in 139 subjects developing the primary endpoint of VT-CAP. Presence of DM and respiratory disease based on International Classification of Primary Care (ICPC) coding was also determined in 40,427 subjects. FINDINGS: In the 139 subjects developing VT-CAP, DM caused significant effect modification (p-value 0.002), yielding VE of 89.5% (95%CI, 65.5-96.8) and 24.7% (95%CI, -10.4 to 48.7) for those with and without DM, respectively. Comparable effect modification (p-value 0.020) was found in the 40,427 subjects with and without ICPC-based classification of DM with VE of 85.6% (95%CI, 36.7-96.7) and of 7.0% (95%CI, -58.5 to 45.5) respectively. Effect modification through respiratory disease was not statistically significant, although the point estimate of VE was lower for those with respiratory disease in both analyses. There was no evidence of effect modification in subjects stratified by heart disease, smoking, and presence of any comorbidity. CONCLUSIONS: Among immunocompetent elderly, VE of PCV13 was modified by DM with higher VE among subjects with DM. Significant effect modification was not observed for subjects with heart disease, respiratory disease, smoking, or presence of any comorbidity. CAPiTA trial registration number: www.ClinicalTrials.gov; trial number NCT00744263.

Clinical features of community acquired adenovirus pneumonia during the 2011 community outbreak in Southern Taiwan: role of host immune response.

BACKGROUND: Human adenovirus 7 (HAdV-7) was responsible for a significant number of fatalities during the 2011 community outbreak in Taiwan. The mechanisms underlying the pathogenesis of severe adenovirus infections in non-immunocompromised individuals remain unclear. Adenovirus pneumonia was associated with pleural effusion in a number of patients from the 2011 outbreak suggesting that similar to bacterial pneumonia, patients diagnosed with adenovirus pneumonia who have pleural effusion are more severely and systemically infected, and may have a more protracted disease course. We hypothesized that the host immunological response determines the severity of adenoviral infection. METHODS: This retrospective case series study included patients diagnosed with severe lower respiratory tract infections at the National Cheng Kung University Hospital in southern Taiwan between December 2010 and October 2011. The main inclusion criteria were 1) presence of multifocal patchy infiltrates, lobar consolidation or reticular interstitial opacities in chest X-rays, and 2) presence of adenovirus isolated from respiratory specimens. All patients had adenovirus isolated from respiratory specimens, and were negative for other viruses. Pleural effusion was confirmed in all patients using chest echography. Clinical features and laboratory data were compared in patients with (n = 12) and without (n = 15) parapneumonic effusion. RESULTS: Presence of parapneumonic effusion was significantly associated with a longer febrile duration, more complicated clinical management, and a greater risk of extrapulmonary involvement, notably hepatitis. Patients without pleural effusion had significantly higher numbers of WBCs, platelets, and absolute segment cell counts (ASCs) compared to patients with pleural effusion (all p < 0.05). Patients without pleural effusion had significantly higher counts of CD4+, CD8+, and CD20+ T cells (all p < 0.05) compared to patients with pleural effusion. CONCLUSION: Our data indicated that presence of parapneumonic effusion in adenoviral pneumonia was associated with longer febrile duration, more complicated clinical management, a greater risk of hepatitis, and suppression of host cellular immunity. Further prospective, large-scale studies are needed to validate our results.

Immunomodulatory effects of pidotimod in adults with community-acquired pneumonia undergoing standard antibiotic therapy.

The morbidity and mortality of community-acquired pneumonia (CAP) are still elevated and two aspects seem to contribute to a worse outcome: an uncontrolled inflammatory reaction and an inadequate immune response. Adjuvants, including corticosteroids and intravenous immunoglobulins, have been proposed to counterbalance these effects but their efficacy is only partial. We examined the immunomodulatory activity of Pidotimod (PDT), a synthetic dipeptide molecule in adult patients hospitalized for CAP. Sixteen patients with a diagnosis of CAP and a PSI score III or IV and/or a CURB-65 0-2 were randomized to receive either levofloxacin 500 mg b.i.d. alone or levofloxacin plus PDT (800mg, 2 daily doses). Blood samples were drawn at baseline (T0), before initiation of therapy, as well as 3 (T3), and 5 (T5) days after initiation of therapy. Immunologic and clinical parameters were analyzed at each time point. Supplementation of antibiotic therapy with PDT resulted in an upregulation of antimicrobial and of immunomodulatory proteins as well as in an increased percentage of Toll like receptor (TLR)2- and TLR4, and of CD80- and CD86-expressing immune cells. Notably, Pidotimod supplementation was also associated with a robust reduction of TNFα-producing immune cells. No significant differences were observed in clinical parameters. These results confirm that supplementation of antibiotic therapy with Pidotimod in patients with CAP results in a potentially beneficial modulation of innate immunity.