Local and systemic cytokine profiles in nonsevere and severe community-acquired pneumonia

Serum Interleukin-6 and Serum Ferritin Levels Are the Independent Risk Factors for Pneumonia in Elderly Patients

Pneumonia is a common infection in elderly patients. We explored the correlations of serum interleukin-6 (IL-6) and serum ferritin (SF) levels with immune function/disease severity in elderly pneumonia patients. Subjects were allocated into the mild pneumonia (MP), severe pneumonia (SP), and normal groups, with their age/sex/body mass index/ disease course and severity/blood pressure/comorbidities/medications/prealbumin (PA)/albumin (ALB)/C-reactive protein (CRP)/procalcitonin (PCT)/smoking status documented. The disease severity was evaluated by pneumonia severity index (PSI). T helper 17 (Th17)/regulatory T (Treg) cell ratios and IL-6/SF/immunoglobulin G (IgG)/Th17 cytokine (IL-21)/Treg cytokine (IL-10)/PA/ALB levels were assessed. The correlations between these indexes/independent risk factors in elderly patients with severe pneumonia were evaluated. There were differences in smoking and CRP/PCT/ALB/PA levels among the three groups, but only CRP/ALB were different between the MP/SP groups. Pneumonia patients exhibited up-regulated Th17 cell ratio and serum IL-6/SF/IL-21/IL-10/IgG levels, down-regulated Treg cell ratio, and greater differences were noted in severe cases. Serum IL-6/SF levels were positively correlated with disease severity, immune function, and IL-21/IL-10/IgG levels. Collectively, serum IL-6 and SF levels in elderly pneumonia patients were conspicuously positively correlated with disease severity and IL-21/IL-10/IgG levels. CRP, ALB, IL-6 and SF levels were independent risk factors for severe pneumonia in elderly patients.

Comparative analysis of immunological biomarkers in COVID-19 and bacterial pneumonia

Coronavirus disease 2019 (COVID-19) is a severe and infectious respiratory condition caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). This case-control study aimed to evaluate serum levels of various immunological markers in patients with COVID-19 compared to those with bacterial pneumonia and a healthy control group. Serum samples were collected from adult participants across various COVID-19 isolation centers, including Kassala State and Ahmed Gasim Hospital, between April and June 2021. The study included 70 patients diagnosed with COVID-19, 30 with bacterial pneumonia, and 50 healthy controls. Serum levels of C-reactive protein (CRP), complement components C3 and C4, and cytokines IL-8, IL-10, IL-12, TNF-α, and IFN-γ were measured using standard reagent kits. Serum level of CRP was significantly elevated in both bacterial pneumonia and COVID-19 but significantly higher among patients with bacterial pneumonia. C3 and C4 were also increased in both patient groups, with C3 significantly higher in bacterial pneumonia. IL-8, IL-10, IL-12, TNF-α, and IFN-γ were significantly increased in bacterial pneumonia and SARS-Cov-2 compared to healthy controls. However, IFN-γ was significantly increased among patients with COVID-19 than patients with bacterial pneumonia. This study highlights the potential significant impact of COVID-19 on the immunological biomarkers investigated.

RGS2 is an innate immune checkpoint for TLR4 and Gαq-mediated IFNγ generation and lung injury

IFNγ, a type II interferon secreted by immune cells, augments tissue responses to injury following pathogenic infections leading to lethal acute lung injury (ALI). Alveolar macrophages (AM) abundantly express Toll-like receptor-4 and represent the primary cell type of the innate immune system in the lungs. A fundamental question remains whether AM generation of IFNg leads to uncontrolled innate response and perpetuated lung injury. LPS induced a sustained increase in IFNg levels and unresolvable inflammatory lung injury in the mice lacking RGS2 but not in RGS2 null chimeric mice receiving WT bone marrow or receiving the RGS2 gene in AM. Thus, indicating RGS2 serves as a gatekeeper of IFNg levels in AM and thereby lung's innate immune response. RGS2 functioned by forming a complex with TLR4 shielding Gaq from inducing IFNg generation and AM inflammatory signaling. Thus, inhibition of Gaq blocked IFNg generation and subverted AM transcriptome from being inflammatory to reparative type in RGS2 null mice, resolving lung injury.

Highlights

RGS2 levels are inversely correlated with IFNγ in ARDS patient's AM.RGS2 in alveolar macrophages regulate the inflammatory lung injury.During pathogenic insult RGS2 functioned by forming a complex with TLR4 shielding Gαq from inducing IFNγ generation and AM inflammatory signaling.

eToc Blurb

Authors demonstrate an essential role of RGS2 in macrophages in airspace to promoting anti-inflammatory function of alveolar macrophages in lung injury. The authors provided new insight into the dynamic control of innate immune response by Gαq and RGS2 axis to prevent ALI.

Nausea Predicts Bacteremia in Immunocompetent Patients with Pneumococcal Community-Acquired Pneumonia: Secondary Data Analysis from a Prospective Cohort

BACKGROUND

In pneumococcal community-acquired pneumonia (CAP), bacteremia is associated with increased mortality, but initial clinical severity scores frequently fail to identify bacteremic patients at risk. We have previously shown that gastrointestinal symptoms are common among patients admitted to the hospital with pneumococcal bacteremia. The aim of this study was to examine gastrointestinal symptoms and inflammatory responses in bacteremic and non-bacteremic pneumococcal CAP in a prospective cohort of immunocompromised and immunocompetent patients hospitalized with CAP.

METHODS

Logistic regression analysis was used to estimate the predictive value of gastrointestinal symptoms for pneumococcal bacteremia in patients with CAP. The Mann-Whitney test was used to compare inflammatory responses in patients with bacteremic vs. non-bacteremic pneumococcal CAP.

RESULTS

Eighty-one patients with pneumococcal CAP were included, of whom 21 (26%) had bacteremia. Immunocompetent patients with pneumococcal CAP had an odds ratio of 16.5 (95% CI 3.0-90.9, p = 0.001) for bacteremia if nausea was present, whereas no such association was found in the immunocompromised patients (OR 0.22, 95% CI 0.02-2.05, p = 0.18). The serum levels of C-reactive protein, procalcitonin and interleukin 6 were significantly higher in the patients with bacteremic pneumococcal CAP compared to non-bacteremic pneumococcal CAP patients (p < 0.001, p = 0.005, and p = 0.019, respectively).

CONCLUSIONS

In immunocompetent patients hospitalized with pneumococcal CAP, nausea may be a predictor of bacteremia. Bacteremic pneumococcal CAP patients display an increased inflammatory response compared to non-bacteremic pneumococcal CAP patients.

Role of cellular senescence in inflammatory lung diseases

Cellular senescence, a characteristic sign of aging, classically refers to permanent cell proliferation arrest and is a vital contributor to the pathogenesis of cancer and age-related illnesses. A lot of imperative scientific research has shown that senescent cell aggregation and the release of senescence-associated secretory phenotype (SASP) components can cause lung inflammatory diseases as well. In this study, the most recent scientific progress on cellular senescence and phenotypes was reviewed, including their impact on lung inflammation and the contributions of these findings to understanding the underlying mechanisms and clinical relevance of cell and developmental biology. Within a dozen pro-senescent stimuli, the irreparable DNA damage, oxidative stress, and telomere erosion are all crucial in the long-term accumulation of senescent cells, resulting in sustained inflammatory stress activation in the respiratory system. An emerging role for cellular senescence in inflammatory lung diseases was proposed in this review, followed by the identification of the main ambiguities, thus further understanding this event and the potential to control cellular senescence and pro-inflammatory response activation. In addition, novel therapeutic strategies for the modulation of cellular senescence that might help to attenuate inflammatory lung conditions and improve disease outcomes were also presented in this research.

Additive effectiveness of acrylonitrile-co-methallyl sulfonate surface-treated membranes in the treatment of pneumonia: A propensity score-matched retrospective cohort study

BACKGROUND

The acrylonitrile-co-methallyl sulfonate surface-treated (AN69ST) membrane has cytokine adsorption capacity and is used for treating sepsis. This study aimed to compare the effects of continuous renal replacement therapy (CRRT) using the AN69ST membrane with those of CRRT using other membranes for patients with pneumonia-associated sepsis.

METHODS

This retrospective, propensity score-matched, cohort study was based on a nationwide Japanese inpatient database. We included data from adults hospitalized with a primary diagnosis of pneumonia, who received CRRT using either the AN69ST membrane or another membrane within 2 days of admission, and who were discharged from the hospitals between September 2014, and March 2017. Propensity score matching was used to compare in-hospital mortality between the two groups.

RESULTS

Eligible patients (N = 2393) were categorized into an AN69ST group (N = 631) and a non-AN69ST group (N = 1762). The overall in-hospital mortality rate was 38.9%. Among the 545 propensity-matched patient pairs, the in-hospital mortality rate was significantly lower in the AN69ST group than in the non-AN69ST group (35.8 vs. 41.8%, p = 0.046).

CONCLUSIONS

Among patients with pneumonia-associated sepsis treated with CRRT, CRRT with the AN69ST membrane was associated with a significantly lower in-hospital mortality than CRRT with standard membranes.

Selective CB2 Receptor Agonist, HU-308, Reduces Systemic Inflammation in Endotoxin Model of Pneumonia-Induced Acute Lung Injury

Acute respiratory distress syndrome (ARDS) and sepsis are risk factors contributing to mortality in patients with pneumonia. In ARDS, also termed acute lung injury (ALI), pulmonary immune responses lead to excessive pro-inflammatory cytokine release and aberrant alveolar neutrophil infiltration. Systemic spread of cytokines is associated with systemic complications including sepsis, multi-organ failure, and death. Thus, dampening pro-inflammatory cytokine release is a viable strategy to improve outcome. Activation of cannabinoid type II receptor (CB₂) has been shown to reduce cytokine release in various in vivo and in vitro studies. Herein, we investigated the effect of HU-308, a specific CB₂ agonist, on systemic and pulmonary inflammation in a model of pneumonia-induced ALI. C57Bl/6 mice received intranasal endotoxin or saline, followed by intravenous HU-308, dexamethasone, or vehicle. ALI was scored by histology and plasma levels of select inflammatory mediators were assessed by Luminex assay. Intravital microscopy (IVM) was performed to assess leukocyte adhesion and capillary perfusion in intestinal and pulmonary microcirculation. HU-308 and dexamethasone attenuated LPS-induced cytokine release and intestinal microcirculatory impairment. HU-308 modestly reduced ALI score, while dexamethasone abolished it. These results suggest administration of HU-308 can reduce systemic inflammation without suppressing pulmonary immune response in pneumonia-induced ALI and systemic inflammation.

Low BALF CD4 T cells count is associated with extubation failure and mortality in critically ill covid-19 pneumonia

BACKGROUND

Critically ill COVID-19 pneumonia is one of the main causes of extubation failure and mortality. Understanding clinical characteristics, laboratory profiles and bronchoalveolar lavage fluid (BALF) immunopathology may help improve outcomes in critically ill COVID-19 pneumonia. We aimed to describe clinical characteristics, laboratory profiles and BALF immunopathology based on lung severity in critically ill COVID-19 pneumonia patients.

MATERIALS AND METHODS

Forty critically ill severe pneumonia patients requiring invasive mechanical ventilation in Cipto Mangunkusumo General (National Tertiary Referral Hospital), Indonesia within November 2020-January 2021 were enrolled in this study. Early BALF collection was performed after patients' intubation. Clinical characteristics, laboratory profiles and BALF biomarkers (sTREM-1, alveolar macrophage amount and function, IL-6, IL-17, CD4 T-cells, Tregs, SP-A and Caspase-3) were observed and analysed. Outcomes were measured based on extubation failure (within 19 days) and 28-days mortality. Univariate and bivariate analyses were performed.

RESULTS

Early bronchoscopy was performed in an average of 4 h (SD = 0.82) after patients' intubation. Twenty-three and twenty-two patients had extubation failure (within 19 days) and 28-days mortality, respectively. In the baseline clinical characteristics of critically ill COVID-19 patients, we found no significant differences in the extubation and mortality status groups. In the laboratory profiles of critically ill COVID-19 patients, we found no significant differences in the extubation status groups. In critically ill COVID-19 pneumonia patients, there was a significant high D-dimer levels in survived group (p = .027), a significant low BALF CD4 T-cells count in the right lung (p = .001) and a significant low BALF CD4 T-cells count (p = .010 and p = .018) in severely affected lung with extubation failure and mortality.

CONCLUSIONS

BALF CD4 T-cells count evaluation of severely affected lung is associated with early extubation failure and mortality in critically ill COVID-19 pneumonia patients. KEY MESSAGEFew studies have been conducted during the peak COVID-19 period analysing combined bronchoalveolar lavage fluid (BALF) immunopathology biomarkers within four hours of intubation to assess extubation failure and mortality. In this study, we reported eight BALF immunopathology biomarkers (sTREM-1, alveolar macrophage, IL-6, IL-17, CD4 T-cells, Tregs, SP-A and Caspase-3).We found significantly low BALF CD4 T-cells count in the right lung, and low BALF CD4 T-cells count in severely affected lung of critically ill COVID-19 pneumonia patients in extubation failure and mortality.

Rectal microbiota are coupled with altered cytokine production capacity following community-acquired pneumonia hospitalization

Human studies describing the immunomodulatory role of the intestinal microbiota in systemic infections are lacking. Here, we sought to relate microbiota profiles from 115 patients with community-acquired pneumonia (CAP), both on hospital admission and following discharge, to concurrent circulating monocyte and neutrophil function. Rectal microbiota composition did not explain variation in cytokine responses in acute CAP (median 0%, IQR 0.0%–1.9%), but did one month following hospitalization (median 4.1%, IQR 0.0%–6.6%, p = 0.0035). Gene expression analysis of monocytes showed that undisrupted microbiota profiles following hospitalization were associated with upregulated interferon, interleukin-10, and G-protein-coupled-receptor-ligand-binding pathways. While CAP is characterized by profoundly distorted gut microbiota, the effects of these disruptions on cytokine responses and transcriptional profiles during acute infection were absent or modest. However, rectal microbiota were related to altered cytokine responses one month following CAP hospitalization, which may provide insights into potential mechanisms contributing to the high risk of recurrent infections following hospitalization.

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Rectal microbiota are disrupted at hospitalization for CAP and one month thereafter

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No variation in cytokines is explained by gut microbiota in the acute phase of CAP

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Following recovery, gut microbiota are linked with variation in cytokine responses

Contribution of Puma to Inflammatory Resolution During Early Pneumococcal Pneumonia

Apoptosis of cells at the site of infection is a requirement for shutdown of inflammatory signaling, avoiding tissue damage, and preventing progression of sepsis. Puma^+/+ and Puma^-/- mice were challenged with TIGR4 strain pneumococcus and cytokines were quantitated from lungs and blood using a magnetic bead panel analysis. Puma^-/- mice exhibited higher lung and blood cytokine levels of several major inflammatory cytokines, including IL-6, G-CSF, RANTES, IL-12, IFN-ϒ, and IP-10. Puma^-/- mice were more susceptible to bacterial dissemination and exhibited more weight loss than their wild-type counterparts. RNA sequencing analysis of whole pulmonary tissue revealed Puma-dependent regulation of Nrxn2, Adam19, and Eln. Enrichment of gene ontology groups differentially expressed in Puma^-/- tissues were strongly correlated to IFN-β and -ϒ signaling. Here, we demonstrate for the first time the role of Puma in prohibition of the cytokine storm during bacterial pneumonia. These findings further suggest a role for targeting immunomodulation of IFN signaling during pulmonary inflammation. Additionally, our findings suggest previously undemonstrated roles for genes encoding regulatory and binding proteins during the early phase of the innate immune response of pneumococcal pneumonia.

Increased Cytokine Levels Assist in the Diagnosis of Respiratory Bacterial Infections or Concurrent Bacteremia in Patients With Non-Hodgkin’s Lymphoma

Non-Hodgkin’s lymphoma (NHL) is a form of tumor that originates in the lymphoid tissues. Bacterial infections are very common in NHL patients. Because most of the patients do not experience apparent symptoms during the initial stage of infection, it is difficult to detect the underlying condition before it progresses to a more critical level. The activation of the cytokines is a hallmark of inflammation. Due to the advantages of short detection time and high sensitivity of cytokines, many studies have focused on relationship between cytokines and infection. However, few studies have been conducted on NHL patients with infection. Therefore, we reviewed the cytokine profiles of 229 newly diagnosed NHL patients and 40 healthy adults to predict respiratory bacterial infection and bacteremia. Our findings revealed that IL-6(41.67 vs 9.50 pg/mL), IL-8(15.55 vs 6.61 pg/mL), IL-10(8.02 vs 4.52 pg/mL),TNF-β(3.82 vs 2.96 pg/mL), IFN- γ(4.76 vs 2.96 pg/mL), body temperature(37.6 vs 36.5°C), CRP(20.80 vs 4.37 mg/L), and PCT(0.10 vs 0.04 ng/mL) levels were considerably greater in NHL cases with respiratory bacterial infections relative to NHL cases without infection (P<0.05). Furthermore, IL-6(145.00 vs 41.67 pg/mL), IL-8(34.60 vs 15.55 pg/mL),temperature(38.4 vs 37.6°C), PCT(0.79 vs 0.10 ng/mL), and CRP(93.70 vs 20.80 mg/L) levels in respiratory infectious NHL patients with more severe bacteremia were considerably elevated than in patients with respiratory bacterial infections only (P<0.05). Remarkably, increased levels of IL-6 and IL-8 are effective in determining whether or not pulmonary bacterial infectious NHL patients have bacteremia. Temperature, PCT, and CRP all have lower sensitivity and specificity than IL-6. IL-6 ≥18.79pg/mL indicates the presence of pulmonary bacterial infection in newly diagnosed NHL patients, and IL-6 ≥102.6pg/mL may suggest pulmonary bacterial infection with bacteremia. In short, this study shows that cytokines can be advantageous in the diagnosis and differentiation of pulmonary bacterial infection and bacteremia in newly diagnosed NHL patients and may also guide for the use of clinical antibiotics.

Interleukin-6 and granulocyte colony-stimulating factor as predictors of the prognosis of influenza-associated pneumonia

Background

Pneumonia is a common complication of influenza and closely related to mortality in influenza patients. The present study examines cytokines as predictors of the prognosis of influenza-associated pneumonia.

Methods

This study included 101 inpatients with influenza (64 pneumonia and 37 non-pneumonia patients). 48 cytokines were detected in the serum samples of the patients and the clinical characteristics were analyzed. The correlation between them was analyzed to identify predictive biomarkers for the prognosis of influenza-associated pneumonia.

Results

Seventeen patients had poor prognosis and developed pneumonia. Among patients with influenza-associated pneumonia, the levels of 8 cytokines were significantly higher in those who had a poor prognosis: interleukin-6 (IL-6), interferon-γ (IFN-γ), granulocyte colony-stimulating factor (G-CSF), monocyte colony-stimulating factor (M-CSF), monocyte chemoattractant protein-1 (MCP-1), monocyte chemoattractant protein-3, Interleukin-2 receptor subunit alpha and Hepatocyte growth factor. Correlation analysis showed that the IL-6, G-CSF, M-CSF, IFN-γ, and MCP-1 levels had positive correlations with the severity of pneumonia. IL-6 and G-CSF showed a strong and positive correlation with poor prognosis in influenza-associated pneumonia patients. The combined effect of the two cytokines resulted in the largest area (0.926) under the receiver-operating characteristic curve.

Conclusion

The results indicate that the probability of poor prognosis in influenza patients with pneumonia is significantly increased. IL-6, G-CSF, M-CSF, IFN-γ, and MCP-1 levels had a positive correlation with the severity of pneumonia. Importantly, IL-6 and G-CSF were identified as significant predictors of the severity of influenza-associated pneumonia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07321-6.

Surfactant protein D: a predictor for severity of community-acquired pneumonia in children

BACKGROUND

Surfactant protein D (SP-D) is a promising biomarker proposed for the prediction of community-acquired pneumonia (CAP) severity. Therefore, we aimed to assess the role of SP-D in the prediction of CAP severity in pediatric patients.

METHODS

A prospective cohort study was carried out at the Pediatric Intensive Care Unit (PICU) and wards of Menoufia University Hospital. We recruited 112 children admitted into wards with pneumonia (simple pneumonia) and 68 children admitted into PICU with severe pneumonia (PICU admitted). World Health Organization (WHO) classification and mortality predictive scores were calculated to determine the severity of pneumonia for the two groups, including the Pediatric Respiratory Severity Score (PRESS) and the Predisposition, Insult, Response, and Organ dysfunction modified Score (PIROm). SP-D was measured at admission.

RESULTS

The SP-D level was significantly lower in patients with simple pneumonia than in patients with severe pneumonia (P < 0.001). SP-D was significantly higher among children with severe pneumonia, as determined by WHO, PRESS, and PIROm (P = 0.001). SP-D was significantly higher among children with mechanical ventilation, shock, hypoxia, sepsis, and mortality. Receiver operating characteristic curve analysis for SP-D showed that the area under the curve was 0.741 (P value < 0.001), with a sensitivity of 85.3% and a specificity of 44.6%.

CONCLUSIONS

Serum SP-D level has a predictive value for the detection of community-acquired pneumonia severity in children.

IMPACT

SP-D is a good predictor for the detection of CAP severity in hospitalized children. SP-D was correlated with severity scores and was associated with indicators of CAP severity, including mechanical ventilation, shock, hypoxia, sepsis, and mortality.

Soluble CD137 is a novel serum marker of liver cirrhosis in patients with hepatitis C and alcohol-associated disease etiology

Defective T-cell functions play a role in the persistence of HCV infection. Activated T cells express CD137, which costimulates antivirus T-cell responses, and this activity is antagonized by soluble CD137 (sCD137). Here, we show that in sera of 81 patients with chronic HCV, sCD137 levels did not correlate with measures of viral infection, and did not decline after virus eradication using direct-acting antivirals. Thus, serum sCD137 was similar in patients infected with HCV and in uninfected controls. Of note, in HCV patients with liver cirrhosis and patients with mostly alcohol-associated liver cirrhosis, sCD137 was increased. A negative association of sCD137 and albumin existed in both cohorts. sCD137 concentrations were similar in hepatic and portal vein blood excluding the liver as the origin of higher levels. Recombinant sCD137 reduced Th1 and Th2 but not Th17 cell polarization in vitro, and accordingly lowered IFN-γ, TNF, and IL-13 in cell media. Serum sCD137 is associated with inflammatory states, and positively correlated with serum TNF in cirrhotic HCV patients following virus eradication. Our study argues against a role of sCD137 in HCV infection and suggests a function of sCD137 in liver cirrhosis, which yet has to be defined.

Optimized detection of lung IL-6 via enzymatic liquefaction of low respiratory tract samples: application for managing ventilated patients

Lung IL-6 is a promising biomarker for predicting respiratory failure during pulmonary infections. This biomarker is found in respiratory samples which need to be liquefied prior to analysis. Traditional liquefying methods use reducing agents such as dithiothreitol (DTT). However, DTT impairs immunodetection and does not liquefy highly viscous samples. We propose an enzymatic method that liquefies samples by means of generating O₂ bubbles with endogenous catalase. Low respiratory tract specimens from 48 mechanically ventilated patients (38 with SARS-CoV-2 infection) were treated with DTT or with the enzymatic method. We used turbidimetry to compare the liquefaction degree and IL-6 was quantified with ELISA. Finally, we used AUC-ROC, time-to-event and principal component analysis to evaluate the association between respiratory compromise or local inflammation and IL-6 determined with both methods. Enzymatically treated samples were better liquefied than those reduced by DTT, which resulted in higher ELISA signals. Lung IL-6 levels obtained with the enzymatic procedure were negatively correlated with the oxygenation index (PaO₂/FiO₂) and the time of mechanical ventilation. The proposed enzymatic liquefaction method improves the sensitivity for lung IL-6 detection in respiratory samples, which increases its predictive power as a biomarker for evaluating respiratory compliance.

Potential of Point-of-Care and At-Home Assessment of Immune Status via Rapid Cytokine Detection and Questionnaire-Based Anamnesis

Monitoring the immune system's status has emerged as an urgent demand in critical health conditions. The circulating cytokine levels in the blood reflect a thorough insight into the immune system status. Indeed, measuring one cytokine may deliver more information equivalent to detecting multiple diseases at a time. However, if the reported cytokine levels are interpreted with considering lifestyle and any comorbid health conditions for the individual, this will promote a more precise assessment of the immune status. Therefore, this study addresses the most recent advanced assays that deliver rapid, accurate measuring of the cytokine levels in human blood, focusing on add-on potentials for point-of-care (PoC) or personal at-home usage, and investigates existing health questionnaires as supportive assessment tools that collect all necessary information for the concrete analysis of the measured cytokine levels. We introduced a ten-dimensional featuring of cytokine measurement assays. We found 15 rapid cytokine assays with assay time less than 1 h; some could operate on unprocessed blood samples, while others are mature commercial products available in the market. In addition, we retrieved several health questionnaires that addressed various health conditions such as chronic diseases and psychological issues. Then, we present a machine learning-based solution to determine what makes the immune system fit. To this end, we discuss how to employ topic modeling for deriving the definition of immune fitness automatically from literature. Finally, we propose a prototype model to assess the fitness of the immune system through leveraging the derived definition of the immune fitness, the cytokine measurements delivered by a rapid PoC immunoassay, and the complementary information collected by the health questionnaire about other health factors. In conclusion, we discovered various advanced rapid cytokine detection technologies that are promising candidates for point-of-care or at-home usage; if paired with a health status questionnaire, the assessment of the immune system status becomes solid and we demonstrated potentials for promoting the assessment tool with data mining techniques.

The impact of cytokine levels in young South African children with and without HIV-associated acute lower respiratory infections

Altered host immune responses are considered to play a key role in the pathogenesis of acute lower respiratory infections (ALRI). The existing literature on cytokine responses in ALRI is largely focussed on adults from developed countries and there are few reports describing the role of cytokines in childhood ALRI, particularly in African or human immunodeficiency virus (HIV)-infected populations. To measure systemic cytokine levels in blood plasma from young South African children with and without ALRI and with and without HIV to determine associations between cytokine responses and disease status and respiratory viral identification. Blood plasma samples were collected from 106 hospitalized ALRI cases and 54 non-ALRI controls less than 2 years of age. HIV status was determined. Blood plasma concentrations of 19 cytokines, 7 chemokines, and 4 growth factors (epidermal growth factor, fibroblast growth factor-basic, hepatocyte growth factor, and vascular endothelial) were measured using The Human Cytokine 30-Plex Panel. Common respiratory viruses were identified by PCR. Mean cytokine concentrations for G-CSF, interferon (IFN)-γ, interleukin (IL)-5, and MCP-1 were significantly higher in ALRI cases than in nonrespiratory controls. Within the ALRI cases, several cytokines were higher in children with a virus compared with children without a virus. Mean cytokine concentrations for IFN-α, IFN-γ, IL-4, IL-5, IL-13, tumour necrosis factor-α, and MIP-1α were significantly lower in HIV-infected cases than in HIV-uninfected cases, while IP-10 and monokine induced by interferon-γ were significantly higher in HIV-infected cases than in HIV-uninfected cases. Certain cytokines are likely to play an important role in the host immune response to ALRI. HIV-infected children have impaired inflammatory responses to respiratory infections compared with HIV-uninfected children.

The risk factors of children acquiring refractory mycoplasma pneumoniae pneumonia: A meta-analysis

OBJECTIVES

Refractory mycoplasma pneumoniae pneumonia (RMPP) in children has been increasing worldwide. In this study, we conducted a meta-analysis to generate large-scale evidence on the risk factors of RMPP to provide suggestions on prevention and controlling for children.

METHODS

Web of Science, PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, and Wanfang (Chinese) were searched to identify relevant articles. All analyses were performed using Stata 14.0.

RESULTS

We conducted a meta-analysis of 15 separate studies. Fever for more than 10 days (odds ratio [OR] 3.965, 95% confidence interval [CI] 2.109-7.456), pleural effusion (OR 6.922, 95% CI 2.058-23.282), extra-pulmonary complications (OR 17.762, 95% CI 11.146-28.305), pulmonary X-ray consolidation ≥2/3 (OR 8.245, 95% CI 1.990-34.153), CRP >40 mg/L (OR 4.975, 95% CI 2.116-11.697) were significantly related to the risk of RMPP. We did not find an association between male sex (OR 0.808, 95% CI 0.548-1.189), LDH >410IU/L (OR 1.033, 95% CI 0.979-1.091) and the risk of RMPP.

CONCLUSIONS

Fever for more than 10 days, pleural effusion, extra-pulmonary complications, pulmonary X-ray consolidation≥ 2/3 and CRP >40 mg/L are risk factors for early evaluation of RMPP.

Immunopathological Changes in SARS-CoV-2 Critical and Non-critical Pneumonia Patients: A Systematic Review to Determine the Cause of Co-infection

The ongoing COVID-19 pandemic originating from Wuhan, China is causing major fatalities across the world. Viral pneumonia is commonly observed in COVID-19 pandemic. The number of deaths caused by viral pneumonia is mainly due to secondary bacterial or fungal infection. The immunopathology of SARS-CoV-2 viral pneumonia is poorly understood with reference to human clinical data collected from patients infected by virus and secondary bacterial or fungal infection occurring simultaneously. The co-infection inside the lungs caused by pneumonia has direct impact on the changing lymphocyte and neutrophil counts. Understanding the attribution of these two immunological cells triggered by cytokines level change is of great importance to identify the progression of pneumonia from non-severe to severe state in hospitalized patients. This review elaborates the cytokines imbalance observed in SARS-CoV-1 (2003 epidemic), SARS-CoV-2 (2019 pandemic) viral pneumonia and community acquired pneumonia (CAP), respectively, in patients to determine the potential reason of co-infection. In this review the epidemiology, virology, clinical symptoms, and immunopathology of SARS-CoV-2 pneumonia are narrated. The immune activation during SARS-CoV-1 pneumonia, bacterial, and fungal pneumonia is discussed. Here it is further analyzed with the available literatures to predict the potential internal medicines, prognosis and monitoring suggesting better treatment strategy for SARS-CoV-2 pneumonia patients.

Role of the inflammatory response in community-acquired pneumonia: clinical implications

INTRODUCTION

Despite adequate antibiotic coverage, community-acquired pneumonia (CAP) remains a leading cause of hospitalization and mortality worldwide. It induces both a local pulmonary and a systemic inflammatory response, particularly significant in severe cases. The intensity of the dysregulated host response varies from patient to patient and has a negative impact on survival and other outcomes.

AREAS COVERED

This comprehensive review summarizes the pathophysiological aspects of the inflammatory response in CAP, briefly discusses the usefulness of biomarkers, and assesses the clinical evidence for modulating the inflammatory pathways. We searched PubMed for the most relevant studies, reviews, and meta-analysis until August 2020.

EXPERT OPINION

Notable efforts have been made to identify biomarkers that can accurately differentiate between viral and bacterial etiology, and indeed, to enhance risk stratification in CAP. However, none has proven ideal and no recommended biomarker-guided algorithms exist. Biomarker signatures from proteomic and metabolomic studies could be more useful for such assessments. To date, most studies have produced contradictory results concerning the role of immunomodulatory agents (e.g. corticosteroids, macrolides, and statins) in CAP. Adequately identifying the population who may benefit most from effective modulation of the inflammatory response remains a challenge.

Dynamics of cytokines, immune cell counts and disease severity in patients with community-acquired pneumonia - Unravelling potential causal relationships

BACKGROUND

Community acquired pneumonia (CAP) is a severe and often rapidly deteriorating disease. To better understand its dynamics and potential causal relationships, we analyzed time series data of cytokines, blood and clinical parameters in hospitalized CAP patients.

METHODS

Time series data of 10 circulating cytokines, blood counts and clinical parameters were related to baseline characteristics of 403 CAP patients using univariate mixed models. Bivariate mixed models were applied to analyze correlations between the time series. To identify potential causal relationships, we inferred cross-lagged relationships between pairs of parameters using latent curve models with structured residuals.

RESULTS

IL-6 levels decreased faster over time in younger patients (P_adj = 0.06). IL-8, VCAM-1, and IL-6 correlated strongly with disease severity as assessed by the sequential organ failure assessment (SOFA) score (r = 0.49, 0.48, 0.46, respectively; all P_adj < 0.001). IL-6 and bilirubin correlated with respect to their mean levels and slopes over time (r = 0.36 and r = 0.46, respectively; P_adj < 0.001). A number of potential causal relationships were identified, e.g., a negative effect of ICAM-1 on MCP-1, or a positive effect of the level of creatinine on the subsequent VCAM-1 concentration (P < 0.001).

CONCLUSIONS

These results suggest that IL-6 trajectories of CAP patients are associated with age and run parallel to bilirubin levels. The time series analysis also unraveled directed, potentially causal relationships between cytokines, blood parameters and clinical outcomes. This will facilitate the development of mechanistic models of CAP, and with it, improvements in treatment or surveillance strategies for this disease.

TRIAL REGISTRATION

clinicaltrials.gov NCT02782013, May 25, 2016, retrospectively registered.

The Clinical Presentation and Immunology of Viral Pneumonia and Implications for Management of Coronavirus Disease 2019

This review will briefly examine the clinical presentation and important immunology of viral pneumonia with a focus on severe acute respiratory syndrome coronavirus 2 (coronavirus disease 2019).

Isolated Pulmonary Embolism Is Associated With a High Risk of Arterial Thrombotic Disease: Results From the VTEval Study

BACKGROUND

Isolated PE is associated with a higher burden of atherosclerotic disease than other manifestations of VTE.

RESEARCH QUESTION

We hypothesized that the presence of isolated PE may signal a chronically elevated risk of arterial thrombotic disease.

STUDY DESIGN AND METHODS

Data from the VTEval Study, a prospective cohort study enrolling individuals with clinical suspicion and imaging-based diagnosis or exclusion of VTE, were analyzed. Patients with PE received whole-leg ultrasonography to assess presence of DVT. Regularized logistic regression identified features that discriminate between isolated PE and other VTE phenotypes at clinical presentation. Survival analyses were performed to evaluate the crude and adjusted 3-year risks of arterial thrombotic disease, recurrent VTE, and death.

RESULTS

The sample comprised 510 patients. Isolated PE patients (n = 63) had a distinct clinical profile from patients with other VTE phenotypes (n = 447). COPD, peripheral artery disease, atrial fibrillation, and coronary artery disease were significantly more prevalent among patients with isolated PE. Isolated PE patients had significantly higher risk (incidence rate ratio vs DVT-associated PE, 3.7 (95% CI, 1.3-10.8, P = .009); vs isolated DVT, 4.8 (1.7-14.3, P = .001) of arterial thrombotic events (ie, myocardial infarction, stroke/transient ischemic attack). After adjustment for clinical profile and medication intake, the risk of arterial thrombotic events for patients with isolated PE remained quadruple that of other VTE phenotypes (hazard ratio [HR], 3.8 [1.3-10.9], P = .01).

INTERPRETATION

Patients with isolated PE are at higher risk for arterial thrombosis and may require screening for arterial disease and development of novel therapeutic strategies.

CLINICAL TRIAL REGISTRATION

NCT02156401.

Mucosal-associated invariant T cells and Vδ2+ γδ T cells in community acquired pneumonia: association of abundance in sputum with clinical severity and outcome

Mucosal-associated invariant T (MAIT) cells and Vδ2+ γδ T cells are anti-bacterial innate-like lymphocytes (ILLs) that are enriched in blood and mucosa. ILLs have been implicated in control of infection. However, the role of ILLs in community-acquired pneumonia (CAP) is unknown. Using sputum samples from a well-characterized CAP cohort, MAIT cell and Vδ2+ T cell abundance was determined by quantitative polymerase chain reaction (qPCR). Cytokine and chemokine concentrations in sputum were measured. The capacity of bacteria in sputum to produce activating ligands for MAIT cells and Vδ2+ T cells was inferred by 16S rRNA sequencing. MAIT cell abundance in sputum was higher in patients with less severe pneumonia; duration of hospital admission was inversely correlated with both MAIT and Vδ2+ T cell abundance. The abundance of both ILLs was higher in patients with a confirmed bacterial aetiology; however, there was no correlation with total bacterial load or the predicted capacity of bacteria to produce activating ligands. Sputum MAIT cell abundance was associated with interferon (IFN)-α, IFN-γ, and sputum neutrophil abundance, while Vδ2+ T cell abundance was associated with CXCL11 and IFN-γ. Therefore, MAIT and Vδ2+ T cells can be detected in sputum in CAP, where they may contribute to improved clinical outcome.

Inflammatory mediators and lung abnormalities in HIV: A systematic review

HIV and pneumonia infections have both been shown to negatively impact lung function. However, evidence of the role of inflammation on lung dysfunction in HIV and pneumonia co-infected individuals remains limited. We aimed to systematically review the association of inflammatory markers and lung abnormalities in HIV and pneumonia co-infected individuals. This systematic review was registered with the International Prospective Register of Systematic Reviews on August 15, 2017 (registration number CRD42017069254) and used 4 databases (Cochrane Central Register of Controlled Trials, PubMed Central, Clinical Trials.gov and Google Scholar). All clinical trial, observational, and comparative studies targeting adult (> 18 years old) populations with HIV, pneumonia, or both, that report on immune response (cytokine, chemokine, or biomarker), and lung abnormality as an outcome were eligible. Data selection, risk of bias and extraction were performed independently by 2 blinded reviewers. Due to heterogeneity among the articles, a qualitative synthesis was performed. Our search strategy identified 4454 articles of which, 7 met our inclusion criteria. All of the studies investigated the ability of circulating biomarkers to predict lung damage in HIV. None of the articles included patients with both HIV and pneumonia, nor pneumonia alone. Markers of inflammation (IL-6, TNF-α, CRP), innate defense (cathelicidin), monocyte and macrophage activation (sCD14, sCD163 and, IL-2sRα), endothelial dysfunction (ET-1) and general immune health (CD4/CD8 ratio) were associated with lung abnormalities in HIV. This review highlights the lack of available information regarding the impact of inflammatory mediators on lung function in HIV and pneumonia populations, therefore opportunities to prevent lung damage with available anti-inflammatory treatment or to investigate new ones still remain.

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.

Personalizing the Management of Pneumonia

Pneumonia is a highly prevalent disease with considerable morbidity and mortality. However, diagnosis and therapy still rely on antiquated methods, leading to the vast overuse of antimicrobials, which carries risks for both society and the individual. Furthermore, outcomes in severe pneumonia remain poor. Genomic techniques have the potential to transform the management of pneumonia through deep characterization of pathogens as well as the host response to infection. This characterization will enable the delivery of selective antimicrobials and immunomodulatory therapy that will help to offset the disorder associated with overexuberant immune responses.

Pathogenesis and prevention of risk of cardiovascular events in patients with pneumococcal community-acquired pneumonia

It is now well recognized that cardiovascular events (CVE) occur quite commonly, both in the acute phase and in the long-term, in patients with community-acquired pneumonia (CAP). CVE have been noted in up to 30% of patients hospitalized with all-cause CAP. One systematic review and meta-analysis of hospitalized patients with all-cause CAP noted that the incidence rates for overall cardiac events were 17.7%, for incident heart failure were 14.1%, for acute coronary syndromes were 5.3% and for incident cardiac arrhythmias were 4.7%. In the case of pneumococcal CAP, almost 20% of patients studied had one or more of these cardiac events. Recent research has provided insights into the pathogenesis of the acute cardiac events occurring in pneumococcal infections. With respect to the former, key involvements of the major pneumococcal protein virulence factor, pneumolysin, are now well documented, whilst systemic platelet-driven neutrophil activation may also contribute. However, events involved in the pathogenesis of the long-term cardiovascular sequelae remain largely unexplored. Emerging evidence suggests that persistent antigenaemia may predispose to the development of a systemic pro-inflammatory/prothrombotic phenotype underpinning the risk of future cardiovascular events. The current manuscript briefly reviews the occurrence of cardiovascular events in patients with all-cause CAP, as well as in pneumococcal and influenza infections. It highlights the close interaction between influenza and pneumococcal pneumonia. It also includes a brief discussion of mechanisms of the acute cardiac events in CAP. However, the primary focus is on the prevalence, pathogenesis and prevention of the longer-term cardiac sequelae of severe pneumococcal disease, particularly in the context of persistent antigenaemia and associated inflammation.

Systemic interleukins levels in community-acquired pneumonia and their association with adverse outcomes

Introduction: Community-acquired pneumonia (CAP) is still one of the major causes of morbidity and mortality worldwide. Pro-inflammatory and anti-inflammatory interleukins have been studied to elucidate the role that inflammation plays in its pathogenesis. The aim of this study is to investigate inflammation in CAP, by analyzing in dynamic, serum levels of six interleukins (IL) and their predictive value regarding adverse outcomes.

Materials and methods: Forty adult patients with CAP, admitted in the Teaching Hospital of Infectious Diseases, Cluj-Napoca, Romania from December 2015 to February 2017, were enrolled in this study. Serum levels of pro-inflammatory: IL1β, TNF-α, IL-6, anti-inflammatory: IL-10 and IL-4, along with IL-17A were analyzed in dynamic, on day 1 and day 4.The receiver – operator curves (ROC) were used to analyze the outcome prediction of IL.

Results: Serum levels of IL-1β, IL-6, TNF-α and IL-10 have decreased significantly in dynamic, while IL-4 increases. IL-17A has acted like a pro-inflammatory cytokine. We have found a correlation between IL-6 and IL-10 (r=0.429, p=0.000), IL-6 and IL-17A (r=0.295, p=0.008) and IL-10 and IL-17A (r=0.475, p=0.000). Out of 40 patients, 9 had adverse outcomes, consisting in 9 relapses from which 1 died. IL-6 discriminates alone between adverse and favorable outcomes. With multivariate analysis and multiple regression of all combined IL, we have found that there is a predictive model regarding adverse outcomes.

Conclusion: IL-10 and IL-17A behave like pro-inflammatory cytokines. IL-6 is a predictive marker for adverse outcomes alone. All IL studied together have an impact on adverse outcomes.

Biomarkers of Community-Acquired Pneumonia: A Key to Disease Diagnosis and Management

Community-acquired pneumonia (CAP) is a dangerous disease caused by a spectrum of bacterial and viral pathogens. The choice of specific therapy and the need for hospitalization or transfer to the intensive care unit are determined by the causative agent and disease severity. The microbiological analysis of sputum largely depends on the quality of the material obtained. The prediction of severity and the duration of therapy are determined individually, and existing prognostic scales are used generally. This review examines the possibilities of using specific serological biomarkers to detect the bacterial or viral aetiology of CAP and to assess disease severity. Particular emphasis is placed on the use of biomarker signatures and the discovery of biomarker candidates for a single multiplex analysis.

Interleukin-5, interleukin-6, interferon induced protein-10, procalcitonin and C-reactive protein among mechanically ventilated severe community-acquired viral and bacterial pneumonia patients

BACKGROUND

The serum cytokine levels among 45 mechanically ventilated, intensive care unit (ICU)-treated severe community-acquired pneumonia (SCAP) patients with known microbial etiology in three different etiology groups were assessed.

METHODS

Blood samples for C-reactive protein (CRP), procalcitonin (PCT), interleukin (IL)-5, IL-6, IL-10, human interferon gamma induced protein (IP)-10, and TNF-α (tumor necrosis factor alpha) were collected at time points 0, 12, 24, 48, 72 and 96 h after study inclusion.

RESULTS

There were 21 (43%) pure bacterial infections (bacterial group, BG), 5 (10%) pure viral infections (viral group, VG), and 19 (39%) mixed bacterial-viral infections (mixed group, MG) among 45 mechanically ventilated SCAP patients. CRP and PCT levels were significantly higher in the MG and values decreased with time in all groups. PCT differed also in time and group analysis (P = 0.001), the highest being in the MG. IL-5 levels were significantly higher in the VG compared to others (Ptime = 0.001, Pgroup = 0.051 and Ptimexgroup = 0.016). IL-6 and IP-10 levels decreased over time (Ptime = 0.003 and Ptime = 0.021), but there were no differences between groups.

CONCLUSION

SCAP patients with viral etiology have higher IL-5 levels. Patients with mixed viral and bacterial group have higher PCT compared to other etiologies.

The Influence of Acanthamoeba-Legionella Interaction in the Virulence of Two Different Legionella Species

The genus Legionella comprises more than 60 species, and about half are associated with infection. Legionella pneumophila is the most commonly associated with these infections and by far the most studied, but L. non-pneumophila species, such as L. feeleii, L. anisa, etc., may also present clinical importance. Free-living amoebae are their preferred environmental host, where these bacteria not only survive but also succeed in multiplying, and this relationship can lead to an increase in bacterial virulence. The goal of this study was to evaluate the alterations of Legionella pathogenicity due to its interaction with Acanthamoeba. For this, the expression of protein effectors SdhA, LegK2, and SidK were evaluated in L. pneumophila and L. feeleii, before and after infecting Acanthamoeba. Additionally, the host response was evaluated by measuring the production of IL-6, IL-8, and IFN-γ in infected macrophages. Regarding the virulence factors, an increase in SdhA expression was observed after these bacteria infected Acanthamoeba, with a higher increase in the macrophage cultures infected with L. feeleii. Also, an increase in the expression of LegK2 was observed after infecting Acanthamoeba, but it was more intense in the cultures infected with L. pneumophila. With regard to SidK, it was increased in L. feeleii after infecting Acanthamoeba, however the same effect was not observed for L. pneumophila. In cytokine production, the effect on IL-6 and IL-8 was similar for both cytokines, increasing their concentration, but higher production was observed in the cultures infected with L. feeleii, even though it demonstrated slightly lower production with the inoculum obtained from Acanthamoeba. Concerning IFN-γ, induction was observed in both species but higher in the infection by L. pneumophila. Nevertheless, it is not known if this induction is enough to promote an efficient immune response against either L. pneumophila or L. feeleii. Altogether, these alterations seem to increase L. feeleii virulence after infecting Acanthamoeba. However, this increase does not seem to turn L. feeleii as virulent as L. pneumophila. More studies are necessary to understand the aspects influenced in these bacteria by their interaction with Acanthamoeba and, thus, identify targets to be used in future therapeutic approaches.

Cytokine responses, microbial aetiology and short-term outcome in community-acquired pneumonia

BACKGROUND

The inflammatory response to community-acquired pneumonia (CAP) is orchestrated through activation of cytokine networks and the complement system. We examined the association of multiple cytokines and the terminal complement complex (TCC) with microbial aetiology, disease severity and short-term outcome.

MATERIALS AND METHODS

Plasma levels of 27 cytokines and TCC were analysed in blood samples obtained at hospital admission, clinical stabilization and 6-week follow-up from 247 hospitalized adults with CAP. Fourteen mediators were included in final analyses. Adverse short-term outcome was defined as intensive care unit (ICU) admission and 30-day mortality.

RESULTS

Cytokine and TCC levels were dynamic in the clinical course of CAP, with highest levels seen at admission for most mediators. Admission levels of cytokines and TCC did not differ between groups of microbial aetiology. High admission levels of IL-6 (odds ratio [OR] 1.47, 95% confidence interval [CI] 1.18-1.84, P = .001), IL-8 (OR 1.79, 95% CI 1.26-2.55, P = .001) and MIP-1β (OR 2.28, 95% CI 1.36-3.81, P = .002) were associated with a CURB-65 severity score of ≥3, while IL-6 (OR 1.37, 95% CI 1.07-1.74, P = .011) and MIP-1β (OR 1.86, 95% CI 1.03-3.36, P = .040) were associated with a high risk of an adverse short-term outcome.

CONCLUSIONS

In this CAP cohort, admission levels of IL-6, IL-8 and MIP-1β were associated with disease severity and/or adverse short-term outcome. Still, for most mediators, only nonsignificant variations in inflammatory responses were observed for groups of microbial aetiology, disease severity and short-term outcome.

Assessment of Cytokine and Chemokine Signatures as Potential Biomarkers of Childhood Community-acquired Pneumonia Severity: A Nested Cohort Study in India

BACKGROUND

Pediatric community-acquired pneumonia (CAP) is a leading cause of childhood mortality in developing countries. In resource-poor settings, pneumonia diagnosis is commonly made clinically, based on World Health Organization guidelines, where breathing difficulty or cough and age-adjusted tachypnea suffice to establish diagnosis. Also, the severity of CAP is generally based on clinical features and existing biomarkers do not reliably correlate to either clinical severity or outcome. Here, we asked whether systemic immune and inflammatory mediators could act as biomarkers predicting CAP severity or outcome.

METHODS

Serum from a subset of a CAP cohort (n = 196), enrolled in India, classified according to World Health Organization criteria as having pneumonia or severe pneumonia, was used for simultaneous measurement of 21 systemic cytokines and chemokines.

RESULTS

We found significantly higher IL-6, IL-8, IL-13, IFN-γ and lower CCL22 concentrations in patients with severe compared with mild CAP (P values: 0.019, 0.036, 0.006, 0.016 and 0.003, respectively). Based on higher MIP-1α, IL-8, IL-17 or lower CCL22 response pattern at the time of enrolment, children with fatal outcome showed markedly different pattern of inflammatory response compared with children classified with the same disease severity, but with nonfatal outcome (P values: 0.043, 0.017, 0.008 and 0.020, respectively).

CONCLUSIONS

Our results suggest a relation between an elevated mixed cytokine response and CAP severity on one hand, and a bias toward uncontrolled neutrophilic inflammation in subjects with fatal outcome on the other. Collectively our findings contribute to increased knowledge on new biomarkers that can potentially predict severity and outcome of childhood CAP in the future.

Plasma cytokines eotaxin, MIP-1α, MCP-4, and vascular endothelial growth factor in acute lower respiratory tract infection

Major overlaps of clinical characteristics and the limitations of conventional diagnostic tests render the initial diagnosis and clinical management of pulmonary disorders difficult. In this pilot study, we analyzed the predictive value of eotaxin, macrophage inflammatory protein 1 alpha (MIP-1α), monocyte chemoattractant protein 4 (MCP-4), and vascular endothelial growth factor (VEGF) in 40 patients hospitalized with acute lower respiratory tract infections (LRTI). The cytokines contribute to the pathogenesis of several inflammatory respiratory diseases, indicating a potential as markers for LRTI. Patients were stratified according to etiology and severity of LRTI, based on baseline C-reactive protein and CURB-65 scores. Using a multiplex immunoassay of plasma, levels of eotaxin and MCP-4 were shown to increase from baseline until day 6 after admission to hospital. The four cytokines were unable to predict the etiology and severity. Eotaxin and MCP-4 were significantly lower in patients with C-reactive protein ≥100, and MIP-1α was significantly higher in the patients with CURB-65 > 3, but the predictive power was low. In conclusion, further evaluation, including more patients, is required to assess the full potential of eotaxin, MCP-4, MIP-1α, and VEGF as biomarkers for LRTI because of their low predictive power and a high interindividual variation of cytokine levels.

Interleukin-22 is elevated in lavage from patients with lung cancer and other pulmonary diseases

BACKGROUND

Interleukin-22 (IL-22) is involved in lung diseases such as pneumonia, asthma and lung cancer. Lavage mirrors the local environment, and may provide insights into the presence and role of IL-22 in patients.

METHODS

Bronchoscopic lavage (BL) samples (n = 195, including bronchoalveolar lavage and bronchial washings) were analysed for IL-22 using an enzyme-linked immunosorbent assay. Clinical characteristics and parameters from lavage and serum were correlated with lavage IL-22 concentrations.

RESULTS

IL-22 was higher in lavage from patients with lung disease than in controls (38.0 vs 15.3 pg/ml, p < 0.001). Patients with pneumonia and lung cancer had the highest concentrations (48.9 and 33.0 pg/ml, p = 0.009 and p < 0.001, respectively). IL-22 concentration did not correlate with systemic inflammation. IL-22 concentrations did not relate to any of the analysed cell types in BL indicating a potential mixed contribution of different cell populations to IL-22 production.

CONCLUSIONS

Lavage IL-22 concentrations are high in patients with lung cancer but do not correlate with systemic inflammation, thus suggesting that lavage IL-22 may be related to the underlying malignancy. Our results suggest that lavage may represent a distinct compartment where the role of IL-22 in thoracic malignancies can be studied.

Serum and exhaled breath condensate inflammatory cytokines in community-acquired pneumonia: a prospective cohort study

Background

The role and relationship between pro- and anti-inflammatory cytokines represents one of the least studied aspects of the pathogenesis of community-acquired pneumonia (CAP). The aim of the present study was to evaluate pro- and anti-inflammatory cytokines at both local (lung) and systemic (blood) levels and their relationship with the severity of the disease on admission and time for a patient to reach clinical stability during hospitalisation.

Methods

This was an observational, prospective, cohort study of hospitalised patients with a diagnosis of CAP at the IRCCS Policlinico Hospital, Milan, Italy, between April 2010 and January 2012. Ten pro-inflammatory cytokines (interleukin [IL]-1, IL-1α, IL-1β, IL-2, IL-6, IL-8, tumor necrosis factor [TNF]α and interferon [IFN]γ) and anti-inflammatory cytokines (IL-4 and IL-10) were measured in both serum and exhaled breath condensate within 24 h after hospital admission.

Results

A total of 74 patients (median age: 76 years; gender: 61 % male) were enrolled. The anti- to pro-inflammatory cytokine ratio was reduced in patients with severe disease on admission and prolonged time to reach clinical stability. This was due to lower levels of anti-inflammatory cytokines in the exhaled breath condensate and higher levels of pro-inflammatory cytokines in serum.

Conclusions

Dis-regulation between pro- and anti-inflammatory pathways might be a part of the pathogenic mechanisms that lead to severe infection and worse early clinical outcomes in CAP patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s41479-016-0009-7) contains supplementary material, which is available to authorized users.

Effects of different anaesthetics on cytokine levels in children with community-acquired pneumonia undergoing flexible fibreoptic bronchoscopy

Objective

To determine the effects of propofol and sevoflurane on cytokine levels in children with community-acquired pneumonia undergoing flexible fibreoptic bronchoscopy (FFB).

Method

Children with community-acquired pneumonia were randomly assigned to receive 3–5 mg/kg propofol i.v. or 8% inhaled sevoflurane. Haemodynamic variables, stress hormone responses and serum cytokines were compared between the two groups.

Results

Out of 50 children aged 2–12 years (propofol, n = 25; sevoflurane, n = 25), there were no significant between-group differences in haemodynamic variables and stress hormones. Interleukin (IL)-6 and IL-10 decreased significantly following FFB in both groups. IL-6 levels were significantly lower in the sevoflurane group than propofol group at 4 h and 1 d following FFB (61.3 ± 11.9 versus 82.6 ± 19.7 pg/ml; 52.8 ± 9.7 versus 75.4 ± 13.6 pg/ml, respectively). IL-10 levels in the sevoflurane group were significantly lower than in the propofol group at 1 d following FFB.

Conclusions

In children with community-acquired pneumonia, use of sevoflurane was associated with lower circulating IL-6 and IL-10 levels compared with propofol, following FFB. Pneumonia severity is reflected by higher blood cytokine levels, thus, sevoflurane may be more beneficial to recovery from community-acquired pneumonia than propofol, however further studies are required to test this hypothesis.

Multiplex single molecule counting technology used to generate interleukin 4, interleukin 6, and interleukin 10 reference limits

Detecting biomarkers at pg/ml concentrations or below is, in many situations, critical for quantifying levels in healthy individuals as well as the changes that can occur in the progression of disease states. The ability to detect multiple biomarkers from the same sample allows for better diagnoses, more efficient testing, and lower volumes of sample required. Based on single molecule counting technology, a multiplex instrument was designed and built that is capable of detecting cytokines and other low-abundance proteins at sub-pg/ml quantities in human plasma samples. The multiplex single molecule counting instrument was used to generate 95% reference limits for interleukin 4 (IL-4, <0.61 pg/ml), interleukin 6 (IL-6, <6.53 pg/ml), and interleukin 10 (IL-10, <1.08 pg/ml) from 100 healthy human donor plasma samples, with more than 90% of IL-4 concentrations and 100% of IL-6 and IL-10 concentrations above the limit of detection.