Cytokines and chemokines as biomarkers of community-acquired bacterial infection

Effect of Periodontal Treatment on Reducing Chronic Inflammation in Systemically Healthy Patients With Periodontal Disease

BACKGROUND

We determined the effects and an accurate marker of periodontal treatment on serum interleukin (IL)-6 and high-sensitivity C-reactive protein (HsCRP) levels in systemically healthy individuals with periodontal disease.

METHODS

This multicenter study included systemically healthy individuals with periodontal disease who received initial periodontal treatment and had no periodontal treatment history. Periodontal parameters, including periodontal inflamed surface area, masticatory efficiency, and periodontal disease classification; serum IL-6 and HsCRP levels; and serum immunoglobulin (Ig)G titers against periodontal pathogens were evaluated at baseline and after treatment. Subjects were classified as low or high responders (group) based on periodontal inflamed surface area changes.

RESULTS

There were 153 participants. Only periodontal inflamed surface area changes were markedly different between low and high responders. Periodontal treatment (time point) decreased both serum IL-6 and HsCRP levels. The interaction between group and time point was remarkable only for serum IL-6 levels. Changes in serum immunoglobulin (Ig)G titers against periodontal pathogens were not associated with IL-6 changes in high responders. We analyzed the indirect effect of serum anti-Porphyromonas gingivalis type 2 IgG titer changes using mediation analysis and found no significance. However, the direct effect of group (low or high responder) on IL-6 changes was considerable.

CONCLUSIONS

Periodontal treatment effectively decreased serum IL-6 levels, independent of periodontal pathogen infection, in systemically healthy individuals with periodontal disease.

Cancer cachexia: biomarkers and the influence of age

Cancer cachexia (Ccx) is a complex metabolic condition characterized by pronounced muscle and fat wasting, systemic inflammation, weakness and fatigue. Up to 30% of cancer patients succumb directly to Ccx, yet therapies that effectively address this perturbed metabolic state are rare. In recent decades, several characteristics of Ccx have been established in mice and humans, of which we here highlight adipose tissue dysfunction, muscle wasting and systemic inflammation, as they are directly linked to biomarker discovery. To counteract cachexia pathogenesis as early as possible and mitigate its detrimental impact on anti-cancer treatments, identification and validation of clinically endorsed biomarkers assume paramount importance. Ageing was recently shown to affect both the validity of Ccx biomarkers and Ccx development, but the underlying mechanisms are still unknown. Thus, unravelling the intricate interplay between ageing and Ccx can help to counteract Ccx pathogenesis and tailor diagnostic and treatment strategies to individual needs.

Changes in chemokine and growth factor levels may be useful biomarkers for monitoring disease severity in COVID-19 patients; a pilot study

Aim

The aim of the present study was to assess differences in the serum levels of chemokines and growth factors (GFs) between COVID-19 patients and healthy controls. The diagnostic utility of the analyzed proteins for monitoring the severity of the SARS-CoV- 2 infection based on the patients' MEWS scores was also assessed.

Materials and methods

The serum levels of chemokines and growth factors were analyzed in hospitalized COVID-19 patients (50 women, 50 men) with the use of the Bio-Plex Pro™ Human Cytokine Screening Panel (Biorad) and the Bio-Plex Multiplex system.

Results

The study demonstrated that serum levels of MIP-1α, RANTES, Eotaxin, CTACK, GRO-α, IP-10, MIG, basic-FGF, HGF, SCGF-β, G-CSF, M-CSF, SCF, MIF, LIF, and TRAIL were significant higher in COVID-19 patients than in the control group. The concentrations of CTACK, GRO-α, IP-10, MIG, basic-FGF, HGF, PDGF- BB, GM-CSF, SCF, LIF, and TRAIL were higher in asymptomatic/mildly symptomatic COVID-19 patients (stage 1) and COVID-19 patients with pneumonia without respiratory failure (stage 2). The receiver operating characteristic (ROC) analysis revealed that IP-10, MIF, MIG, and basic-FGF differentiated patients with COVID-19 from healthy controls with the highest sensitivity and specificity, whereas GM-CSF, basic-FGF, and MIG differentiated asymptomatic/mildly symptomatic COVID-19 patients (stage 1) from COVID-19 patients with pneumonia without respiratory failure (stage 2) with the highest sensitivity and specificity.

Conclusions

MIG, basic-FGF, and GM-CSF can be useful biomarkers for monitoring disease severity in patients with COVID-19.

Maternal pre-pregnancy obesity affects the uncinate fasciculus white matter tract in preterm infants

Background

A growing body of evidence suggests an association between a higher maternal pre-pregnancy body mass index (BMI) and adverse long-term neurodevelopmental outcomes for their offspring. Despite recent attention to the effects of maternal obesity on fetal and neonatal brain development, changes in the brain microstructure of preterm infants born to mothers with pre-pregnancy obesity are still not well understood. This study aimed to detect the changes in the brain microstructure of obese mothers in pre-pregnancy and their offspring born as preterm infants using diffusion tensor imaging (DTI).

Methods

A total of 32 preterm infants (born to 16 mothers with normal BMI and 16 mothers with a high BMI) at <32 weeks of gestation without brain injury underwent brain magnetic resonance imaging at term-equivalent age (TEA). The BMI of all pregnant women was measured within approximately 12 weeks before pregnancy or the first 2 weeks of gestation. We analyzed the brain volume using a morphologically adaptive neonatal tissue segmentation toolbox and calculated the major white matter (WM) tracts using probabilistic maps of the Johns Hopkins University neonatal atlas. We investigated the differences in brain volume and WM microstructure between preterm infants of mothers with normal and high BMI. The DTI parameters were compared among groups using analysis of covariance adjusted for postmenstrual age at scan and multiple comparisons.

Results

Preterm infants born to mothers with a high BMI showed significantly increased cortical gray matter volume (p = 0.001) and decreased WM volume (p = 0.003) after controlling for postmenstrual age and multiple comparisons. We found a significantly lower axial diffusivity in the uncinate fasciculus (UNC) in mothers with high BMI than that in mothers with normal BMI (1.690 ± 0.066 vs. 1.762 ± 0.101, respectively; p = 0.005).

Conclusion

Our study is the first to demonstrate that maternal obesity impacts perinatal brain development patterns in preterm infants at TEA, even in the absence of apparent brain injury. These findings provide evidence for the detrimental effects of maternal obesity on brain developmental trajectories in offspring and suggest potential neurodevelopmental outcomes based on an altered UNC WM microstructure, which is known to be critical for language and social-emotional functions.

Epidemiologic, clinical, and serum markers may improve discrimination between bacterial and viral etiologies of childhood pneumonia

Background

Discrimination of bacterial and viral etiologies of childhood community-acquired pneumonia (CAP) is often challenging. Unnecessary antibiotic administration exposes patients to undue risks and may engender antimicrobial resistance. This study aimed to develop a prediction model using epidemiological, clinical and laboratory data to differentiate between bacterial and viral CAP.

Methods

Data from 155 children with confirmed bacterial or mixed bacterial and viral infection (N = 124) and viral infection (N = 31) were derived from a comprehensive assessment of causative pathogens [Partnerships for Enhanced Engagement in Research-Pneumonia in Pediatrics (PEER-PePPeS)] conducted in Indonesia. Epidemiologic, clinical and biomarker profiles (hematology and inflammatory markers) were compared between groups. The area under the receiver operating characteristic curve (AUROC) for varying biomarker levels was used to characterize performance and determine cut-off values for discrimination of bacterial and mixed CAP versus viral CAP. Diagnostic predictors of bacterial and mixed CAP were assessed by multivariate logistic regression.

Results

Diarrhea was more frequently reported in bacterial and mixed CAP, while viral infections more frequently occurred during Indonesia's rainy season. White blood cell counts (WBC), absolute neutrophil counts (ANC), neutrophil-lymphocyte ratio (NLR), C-reactive protein (CRP), and procalcitonin (PCT) were significantly higher in bacterial and mixed cases. After adjusting for covariates, the following were the most important predictors of bacterial or mixed CAP: rainy season (aOR 0.26; 95% CI 0.08-0.90; p = 0.033), CRP ≥5.70 mg/L (aOR 4.71; 95% CI 1.18-18.74; p = 0.028), and presence of fever (aOR 5.26; 95% CI 1.07-25.91; p = 0.041). The model assessed had a low R-squared (Nagelkerke R² = 0.490) but good calibration (p = 0.610 for Hosmer Lemeshow test). The combination of CRP and fever had moderate predictive value with sensitivity and specificity of 62.28 and 65.52%, respectively.

Conclusion

Combining clinical and laboratory profiles is potentially valuable for discriminating bacterial and mixed from viral pediatric CAP and may guide antibiotic use. Further studies with a larger sample size should be performed to validate this model.

Evaluation of Laboratory Results with Data from Bio-Speedy Respiratory Panel 2 in Nasopharyngeal Swab Specimens of COVID-19-Suspected Patients Having PCR(-) Results

Objective: The distinction between COVID-19 and other respiratory infections can be difficult during the flu and winter seasons. The aim of this study is to detect bacterial/viral microorganisms in nasopharyngeal swab samples and to evaluate routine laboratory results of patients with PCR (-) but suspected covid 19. Methods: Between 1 July 2021 and 31 December 2021, 78 patients who were hospitalized and followed up in the suspected Covid service were included in the study. The patients were divided into two groups as those with and without growth on the respiratory panel. Laboratory, demographic and radiological data were compared between groups. Results: C-reactive protein (CRP) and ferritin levels were found to be statistically significantly higher in the group with growth on the respiratory panel compared to the group without growth (p= .05, p= .041, respectively). Reproduction was detected in nasopharyngeal swab samples taken in 56.4% of the patients. More than half of the patients were radiologically defined as CO-RADS 3. Conclusion: It should not be forgotten that other respiratory viral and bacterial infections that mimic the COVID-19 clinic are also commonly observed during this period.

Electrochemiluminescence in paired signal electrode (ECLipse) enables modular and scalable biosensing

Electrochemiluminescence (ECL) has an inherently low background and enables precise chemical reactions through electrical control. Here, we report an advanced ECL system, termed ECLipse (ECL in paired signal electrode). We physically separated ECL generation from target detection: These two processes were carried out in isolated chambers and coupled through an electrode. The strategy allowed us to minimize cross-chemical reactions, design electrodes for high ECL signals, and integrate multiple sensors in a chip. As a proof of concept, we implemented an eight-plex ECLipse and applied it to detect host factors in human plasma. ECLipse achieved higher signal-to-noise ratio than conventional ECL assays and was >7000-fold more sensitive than enzyme-linked immunosorbent assay. In a pilot clinical study, we could detect septic conditions by measuring host factors [i.e., interleukin-3 (IL-3), IL-6, and procalcitonin (PCT)]. ECLipse assay further revealed distinct IL-3 and IL-6 patterns in patients with severe acute respiratory syndrome coronavirus 2 infection.

Biomarkers of sepsis in pigs, horses and cattle: from acute phase proteins to procalcitonin

Sepsis is a complex clinical syndrome triggered by an inflammatory host response to an infection. It is usually complicated to detect and diagnose, and has severe consequences in human and veterinary health, especially when treatment is not started early. Therefore, efforts to detect sepsis accurately are needed. In addition, its proper diagnosis could reduce the misuse of antibiotics, which is essential fighting against antimicrobial resistance. This case is a particular issue in farm animals, as antibiotics have been traditionally given massively, but now they are becoming increasingly restricted. When sepsis is suspected in animals, the most frequently used biomarkers are acute phase proteins such as C-reactive protein, serum amyloid A and haptoglobin, but their concentrations can increase in other inflammatory conditions. In human patients, the most promising biomarkers to detect sepsis are currently procalcitonin and presepsin, and there is a wide range of other biomarkers under study. However, there is little information on the application of these biomarkers in veterinary species. This review aims to describe the general concepts of sepsis and the current knowledge about the biomarkers of sepsis in pigs, horses, and cattle and to discuss possible advances in the field.

Soluble P2X7 Receptor Is Elevated in the Plasma of COVID-19 Patients and Correlates With Disease Severity

Inflammation is a tightly coordinated response against bacterial and viral infections, triggered by the production of pro-inflammatory cytokines. SARS-CoV-2 infection induces COVID-19 disease, characterized by an inflammatory response mediated through the activation of the NLRP3 inflammasome, which results in the production of IL-1β and IL-18 along with pyroptotic cell death. The NLRP3 inflammasome could be also activated by sterile danger signals such as extracellular ATP triggering the purinergic P2X7 receptor. Severe inflammation in the lungs of SARS-CoV-2-infected individuals is associated with pneumonia, hypoxia and acute respiratory distress syndrome, these being the causes of death associated with COVID-19. Both the P2X7 receptor and NLRP3 have been considered as potential pharmacological targets for treating inflammation in COVID-19. However, there is no experimental evidence of the involvement of the P2X7 receptor during COVID-19 disease. In the present study, we determined the concentration of different cytokines and the P2X7 receptor in the plasma of COVID-19 patients and found that along with the increase in IL-6, IL-18 and the IL-1 receptor antagonist in the plasma of COVID-19 patients, there was also an increase in the purinergic P2X7 receptor. The increase in COVID-19 severity and C-reactive protein concentration positively correlated with increased concentration of the P2X7 receptor in the plasma, but not with the IL-18 cytokine. The P2X7 receptor was found in the supernatant of human peripheral blood mononuclear cells after inflammasome activation. Therefore, our data suggest that determining the levels of the P2X7 receptor in the plasma could be a novel biomarker of COVID-19 severity.

A cytokine panel and procalcitonin in COVID-19, a comparison between intensive care and non-intensive care patients

OBJECTIVES

Procalcitonin (PCT) is an acute-phase reactant with concentrations ≥0.5 μg/L indicative of possible bacterial infection in patients with SARS-CoV-2 infection (COVID-19). Some with severe COVID-19 develop cytokine storm secondary to virally driven hyper-inflammation. However, increased pro-inflammatory cytokines are also seen in bacterial sepsis. This study aimed to assess the clinical utility of a cytokine panel in the assessment of COVID-19 with bacterial superinfections along with PCT and C-reactive protein (CRP).

METHODS

The retrospective analysis included serum cytokines (interleukins; IL-1β, IL-6, IL-8 and tumour necrosis factor (TNFα)) measured using Ella™ (Bio-Techne, Oxford, UK) and PCT measured by Roche Cobas (Burgess Hill, UK) in patients admitted with COVID-19 between March 2020 and January 2021. Patients enrolled into COVID-19 clinical trials, treated with Remdesivir/IL-6 inhibitors were excluded. The cytokine data was compared between intensive care unit (ICU) patients, age matched non-ICU patients and healthy volunteers as well as ICU patients with high and normal PCT (≥0.5 vs. <0.5 μg/L).

RESULTS

Cytokine concentrations and CRP were higher in COVID-19 patients (76; ICU & non-ICU) vs. healthy controls (n = 24), all p<0.0001. IL-6, IL-8, TNFα and were higher in ICU patients (n = 46) vs. non-ICU patients (n = 30) despite similar CRP. Among 46 ICU patients, the high PCT group (n = 26) had higher TNFα (p<0.01) and longer ICU stay (mean 47 vs. 25 days, p<0.05). There was no difference in CRP and blood/respiratory culture results between the groups.

CONCLUSIONS

Pro-inflammatory cytokines and PCT were higher in COVID-19 patients requiring ICU admission vs. non-ICU admissions despite no difference in CRP. Furthermore, TNFα was higher in those with high PCT and requiring longer ICU admission despite no difference in CRP or rate of bacterial superinfection.

The Association between Inflammatory Biomarkers and Cardiovascular Autonomic Dysfunction after Bacterial Infection

Heart rate variability (HRV) is a known measure of cardiac autonomic function. A cardiovascular autonomic dysfunction (CAD), measured as changes in HRV, is usually presented after an infectious process. The aim of the present study is to assess the association between serum inflammatory markers and CAD. For this purpose, 50 volunteers (13 of them recovering from an infection) were recruited and followed-up for 6 weeks. Their serum inflammatory biomarkers (CRP, IL1, IL4, IL6, IL10, and TNFalpha) were quantified throughout those weeks, along with their HRV resting, in response to the Valsalva maneuver, metronome breathing, standing and sustained handgrip. The correlation of within-subject changes in both HRV and inflammatory biomarkers was assessed to evaluate the concurrent changes. An inverse within-subject correlation was found between CRP and HRV in response to the Valsalva maneuver (rho (95% CI): −0.517 (−0.877 to −0.001); p = 0.032) and HRV standing (rho (95% CI): −0.490 (−0.943 to −0.036); p = 0.034). At the beginning, increased values of CRP are found along with reduced levels of HRV. Then, the CRP was reduced, accompanied by an improvement (increase) in HRV. These results suggest that CRP is a potential marker of CAD. Whether it is the cause, the consequence or a risk indicator non-causally associated is still to be determined.

Interleukin 6 as a marker of severe bacterial infection in children with sickle cell disease and fever: a case-control study

Background

Etiological diagnosis of fever in children with sickle cell disease (SCD) is often challenging. The aim of this study was to analyze the pattern of inflammatory biomarkers in SCD febrile children and controls, in order to determine predictors of severe bacterial infection (SBI).

Methods

A prospective, case–control study was carried out during 3 years, including patients younger than 18 years with SCD and fever (cases) and asymptomatic steady-state SCD children (controls). Clinical characteristics and laboratory parameters, including 10 serum proinflammatory cytokines (IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-17a, IFN-γ and TNF-α) and comparisons among study subgroups were analyzed.

Results

A total of 137 patients (79 cases and 58 controls) were included in the study; 78.5% males, median age 4.1 (1.7–7.5) years. Four cases were diagnosed with SBI, 41 viral infection (VI), 33 no proven infection (NPI) and 1 bacterial-viral coinfection (the latter excluded from the subanalyses). IL-6 was significantly higher in patients with SBI than in patients with VI or NPI (163 vs 0.7 vs 0.7 pg/ml, p < 0.001), and undetectable in all controls. The rest of the cytokines analyzed did not show any significant difference. The optimal cut-off value of IL-6 for the diagnosis of SBI was 125 pg/mL, with high PPV and NPV (PPV of 100% for a prevalence rate of 5, 10 and 15% and NPV of 98.7%, 97.3% and 95.8% for those prevalences rates, respectively).

Conclusion

We found that IL-6 (with a cut-off value of 125 pg/ml) was an optimal marker for SBI in this cohort of febrile SCD children, with high PPV and NPV. Therefore, given its rapid elevation, IL-6 may be useful to early discriminate SCD children at risk of SBI, in order to guide their management.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06470-4.

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.

Discriminatory plasma biomarkers predict specific clinical phenotypes of necrotizing soft-tissue infections

BACKGROUNDNecrotizing soft-tissue infections (NSTIs) are rapidly progressing infections frequently complicated by septic shock and associated with high mortality. Early diagnosis is critical for patient outcome, but challenging due to vague initial symptoms. Here, we identified predictive biomarkers for NSTI clinical phenotypes and outcomes using a prospective multicenter NSTI patient cohort.METHODSLuminex multiplex assays were used to assess 36 soluble factors in plasma from NSTI patients with positive microbiological cultures (n = 251 and n = 60 in the discovery and validation cohorts, respectively). Control groups for comparative analyses included surgical controls (n = 20), non-NSTI controls (i.e., suspected NSTI with no necrosis detected upon exploratory surgery, n = 20), and sepsis patients (n = 24).RESULTSThrombomodulin was identified as a unique biomarker for detection of NSTI (AUC, 0.95). A distinct profile discriminating mono- (type II) versus polymicrobial (type I) NSTI types was identified based on differential expression of IL-2, IL-10, IL-22, CXCL10, Fas-ligand, and MMP9 (AUC >0.7). While each NSTI type displayed a distinct array of biomarkers predicting septic shock, granulocyte CSF (G-CSF), S100A8, and IL-6 were shared by both types (AUC >0.78). Finally, differential connectivity analysis revealed distinctive networks associated with specific clinical phenotypes.CONCLUSIONSThis study identifies predictive biomarkers for NSTI clinical phenotypes of potential value for diagnostic, prognostic, and therapeutic approaches in NSTIs.TRIAL REGISTRATIONClinicalTrials.gov NCT01790698.FUNDINGCenter for Innovative Medicine (CIMED); Region Stockholm; Swedish Research Council; European Union; Vinnova; Innovation Fund Denmark; Research Council of Norway; Netherlands Organisation for Health Research and Development; DLR Federal Ministry of Education and Research; and Swedish Children's Cancer Foundation.

Blood Genomics Identifies Three Subtypes of Systemic Lupus Erythematosus: "IFN-High," "NE-High," and "Mixed"

PURPOSE

Systemic lupus erythematosus (SLE) is a systemic and multifactorial autoimmune disease, and its diverse clinical manifestations affect molecular diagnosis and drug benefits. Our study was aimed at defining the SLE subtypes based on blood transcriptome data, analyzing functional patterns, and elucidating drug benefits.

METHODS

Three data sets were used in this paper that were collected from the Gene Expression Omnibus (GEO) database, which contained two published data sets of pediatric and adult SLE patients (GSE65391, GSE49454) and public longitudinal data (GSE72754) from a cohort of SLE patients treated with IFN-α Kinoid (IFN-K). Based on disease activity scores and gene expression data, we defined a global SLE signature and merged three clustering algorithms to develop a single-sample subtype classifier (SSC). Systematic analysis of coexpression networks based on modules revealed the molecular mechanism for each subtype.

RESULTS

We identified 92 genes as a signature of the SLE subtypes and three intrinsic subsets ("IFN-high," "NE-high," and "mixed"), which varied in disease severity. We speculated that IFN-high might be due to the overproduction of interferons (IFNs) caused by viral infection, leading to the formation of autoantibodies. NE-high might primarily result from bacterial and fungal infections that stimulated neutrophils (NE) to produce neutrophil extracellular traps (NETs) and induced individual autoimmune responses. The mixed type contained both of these molecular mechanisms and showed an intrinsic connection.

CONCLUSIONS

Our research results indicated that identifying the molecular mechanism associated with different SLE subtypes would benefit the molecular diagnosis and stratified therapy. Moreover, repositioning of IFN-K based on subtypes also revealed an improved therapeutic effect, providing a new direction for disease treatment and drug development.

Maternal obesity and developmental programming of neuropsychiatric disorders: An inflammatory hypothesis

Maternal obesity is associated with the development of a variety of neuropsychiatric disorders; however, the mechanisms behind this association are not fully understood. Comparison between maternal immune activation and maternal obesity reveals similarities in associated impairments and maternal cytokine profile. Here, we present a summary of recent evidence describing how inflammatory processes contribute towards the development of neuropsychiatric disorders in the offspring of obese mothers. This includes discussion on how maternal cytokine levels, fatty acids and placental inflammation may interact with foetal neurodevelopment through changes to microglial behaviour and epigenetic modification. We also propose an exosome-mediated mechanism for the disruption of brain development under maternal obesity and discuss potential intervention strategies.

Electrochemical Biosensors for Cytokine Profiling: Recent Advancements and Possibilities in the Near Future

Cytokines are soluble proteins secreted by immune cells that act as molecular messengers relaying instructions and mediating various functions performed by the cellular counterparts of the immune system, by means of a synchronized cascade of signaling pathways. Aberrant expression of cytokines can be indicative of anomalous behavior of the immunoregulatory system, as seen in various illnesses and conditions, such as cancer, autoimmunity, neurodegeneration and other physiological disorders. Cancer and autoimmune diseases are particularly adept at developing mechanisms to escape and modulate the immune system checkpoints, reflected by an altered cytokine profile. Cytokine profiling can provide valuable information for diagnosing such diseases and monitoring their progression, as well as assessing the efficacy of immunotherapeutic regiments. Toward this goal, there has been immense interest in the development of ultrasensitive quantitative detection techniques for cytokines, which involves technologies from various scientific disciplines, such as immunology, electrochemistry, photometry, nanotechnology and electronics. This review focusses on one aspect of this collective effort: electrochemical biosensors. Among the various types of biosensors available, electrochemical biosensors are one of the most reliable, user-friendly, easy to manufacture, cost-effective and versatile technologies that can yield results within a short period of time, making it extremely promising for routine clinical testing.

Serum C-Reactive Protein Is Negatively Associated With Olfactory Identification Ability in Older Adults

IMPORTANCE

Olfactory deficits are common in aging and associated with several conditions linked to inflammation. A few studies suggest that increased concentration of pro-inflammatory biomarkers may be related to olfactory deficits, but these associations are understudied in population-based samples.

OBJECTIVE

To investigate the association between serum concentrations of C-reactive protein (CRP) and olfactory identification level as well as rate of change in aging.

METHODS

We included 1,721 participants (mean age 70.5 years; 61.9% female) with at least two olfactory assessments across the 12-year follow-up. Baseline level and change in odor identification were estimated with linear mixed models as a function of CRP levels, derived from blood plasma at baseline.

RESULTS

Results indicated a negative dose-response association between CRP level and odor identification scores at baseline, after adjustment for demographic, cognitive, health, and lifestyle factors. CRP levels ranging between 11 and 20 mg/L were significantly related to lower olfactory ability (β = -0.811, 95% confidence interval [CI] [-1.503 to -0.118]; p = .022). Likewise, CRP values above 20 mg/L were related to lower olfactory scores, an association that approached statistical significance (β = -0.996, 95% CI [-2.045 to 0.054]; p = .063). We found no associations between CRP and olfactory change (ps > .368). Sensitivity analyses showed that associations between CRP and olfaction were confined to younger participants (age ≤72 years) and men (ps < .034).

CONCLUSIONS

Our findings suggest a negative association between serum CRP levels and olfactory identification ability in aging that may be dependent on age and sex.

UvrY is required for the full virulence of Aeromonas dhakensis

Aeromonas dhakensis is an emerging human pathogen which causes fast and severe infections worldwide. Under the gradual pressure of lacking useful antibiotics, finding a new strategy against A. dhakensis infection is urgent. To understand its pathogenesis, we created an A. dhakensis AAK1 mini-Tn10 transposon library to study the mechanism of A. dhakensis infection. By using a Caenorhabditis elegans model, we established a screening platform for the purpose of identifying attenuated mutants. The uvrY mutant, which conferred the most attenuated toxicity toward C. elegans, was identified. The uvrY mutant was also less virulent in C2C12 fibroblast and mice models, in line with in vitro results. To further elucidate the mechanism of UvrY in controlling the toxicity in A. dhakensis, we conducted a transcriptomic analysis. The RNAseq results showed that the expression of a unique hemolysin ahh1 and other virulence factors were regulated by UvrY. Complementation of Ahh1, one of the most important virulence factors, rescued the pore-formation phenotype of uvrY mutant in C. elegans; however, complementation of ahh1 endogenous promoter-driven ahh1 could not produce Ahh1 and rescue the virulence in the uvrY mutant. These findings suggest that UvrY is required for the expression of Ahh1 in A. dhakensis. Taken together, our results suggested that UvrY controls several different virulence factors and is required for the full virulence of A. dhakensis. The two-component regulator UvrY therefore a potential therapeutic target which is worthy of further study.

Different Modulatory Effects of Four Methicillin-Resistant Staphylococcus aureus Clones on MG-63 Osteoblast-Like Cells

Staphylococcus aureus is a Gram-positive bacterium responsible for a variety of mild to life-threatening infections including bone infections such as osteomyelitis. This bacterium is able to invade and persist within non-professional phagocytic cells such as osteoblasts. In the present study, four different S. aureus strains, namely, 2SA-ST239-III (ST239), 5SA-ST5-II (ST5), 10SA-ST228-I (ST228), and 14SA-ST22-IVh (ST22), were tested for their ability to modulate cell viability in MG-63 osteoblast-like cells following successful invasion and persistence. Methicillin-sensitive S. aureus (MSSA) ATCC-12598-ST30 (ST30) was used as control strain. Despite being proven that ST30, ST239, and ST22 have a similar ability to internalize and persist in MG-63 osteoblast-like cells under our experimental conditions, we demonstrated that the observed decrease in cell viability was due to the different behavior of the considered strains, rather than the number of intracellular bacteria. We focused our attention on different biochemical cell functions related to inflammation, cell metabolism, and oxidative stress during osteoblast infections. We were able to show the following: (1) ST30 and ST239 were the only two clones able to persist and maintain their number in the hostile environment of the cell during the entire period of infection; (2) ST239 was the only clone able to significantly increase gene expression (3 and 24 h post-infection (p.i.)) and protein secretion (24 h p.i.) of both interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) in MG-63 osteoblast-like cells; (3) the same clone determined a significant up-regulation of the transforming growth factorbeta 1 (TGF-β1) and of the metabolic marker glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNAs at 24 h p.i.; and (4) neither the MSSA nor the four methicillin-resistant S. aureus (MRSA) strains induced oxidative stress phenomena in MG-63 cells, although a high degree of variability was observed for the different clones with regard to the expression pattern of nuclear factor E2-related factor 2 (Nrf2) and its downstream gene heme oxygenase 1 (HO-1) activation. Our results may pave the way for an approach to S. aureus-induced damage, moving towards individualized therapeutic strategies that take into account the differences between MSSA and MRSA as well as the distinctive features of the different clones. This approach is based on a change of paradigm in antibiotic therapy involving a case-based use of molecules able to counteract pro-inflammatory cytokines activity such as selective cytokine signaling inhibitors (IL-6, TNF-α).

A humoral solution: Autologous blood products and tissue repair

Autologous blood-derived products (ABP) are the focus of growing scientific interest and are investigated and used for multiple medical indications. ABPs hold promise thanks to their availability, ease of preparation, and low risk of adverse allogenic reaction, hypersensitivity, and contamination. Compositional analysis of ABPs reveals a diverse mixture of cellular components, cytokines and growth factors that play roles in healing processes such as tissue proliferation and angiogenesis, modulation of the local environment through chemotaxis and regulation of inflammation and the extracellular matrix, as well as several immunomodulatory actions. Thus, the administration of ABP induces supraphysiological levels of components necessary for orchestrating reparative efforts in currently difficult-to-treat medical conditions. In this article, we review the variety of autologous blood-derived products, their composition, current clinical uses, regulatory climate, and mechanisms of action.

Profile of common inflammatory markers in treatment-naïve patients with systemic rheumatic diseases

OBJECTIVES

To evaluate and compare the clinical implications of common inflammatory markers in systemic rheumatic diseases (SRDs).

METHOD

We investigated the profiles of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and white blood cell (WBC) count in treatment-naïve patients with SRDs, osteoarthritis and pneumonia diagnosed at Seoul National University Hospital during 2004-2016. SRDs included rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), ankylosing spondylitis (AS), systemic sclerosis (SSc), idiopathic inflammatory myopathy (IIM) and adult-onset Still's disease (AOSD). Associations between inflammatory markers were evaluated using Pearson's correlation and regression analysis. ROC curve analysis was performed to examine the predictive value of inflammatory markers for SRD diagnosis.

RESULTS

We identified a total of 1191 patients. Leukocytosis was present in < 20% SRD patients. There was marked variability in ESR and CRP levels among different SRDs. The highest mean CRP levels (mean ± SD, mg/dL) were observed in AOSD (11.3 ± 7.9), followed by RA (2.0 ± 3.3), IIM (1.8 ± 3.5), SLE (1.5 ± 3.1), SSc (0.6 ± 1.3) and AS (0.08 ± 0.1). Mean ESR (mm/h) was also highest in AOSD (71.2 ± 31.0), followed by SLE (47.3 ± 34.2), RA (45.5 ± 30.6), IIM (40.8 ± 24.8) and SSc (27.8 ± 26.0). All SRDs showed significant positive correlations between ESR and CRP: greatest in RA (r = 0.53, p < 0.001) and weakest in SLE (r = 0.20, p = 0.03). WBC correlated weakly with CRP but not with ESR in most SRDs. While the AUC for WBC count was less than that of ESR or CRP, the AUC for ESR and CRP were similar in SRD. The optimal cuff-off values for inflammatory markers predicting SRD were within or slightly above the normal limit.

CONCLUSIONS

ESR, CRP and WBC are not always elevated in treatment-naïve patients with SRD. Individual SRDs have a unique profile of inflammatory markers. However, routine inflammatory markers should still be interpreted with caution when diagnosing and assessing disease activity in those with SRD. Key Points •Leukocytosis and elevation of ESR and CRP are not always present in all systemic rheumatic diseases. •Inflammatory markers are often dissociated and they are not specific for disease diagnosis. •Better biomarkers, which measure disease-specific local and systemic inflammation, are needed.

Biomarkers of inflammation and the etiology of sepsis

Sepsis is characterized as a life-threatening organ dysfunction syndrome that is caused by a dysregulated host response to infection. The main etiological causes of sepsis are bacterial, fungal, and viral infections. Last decades clinical and preclinical research contributed to a better understanding of pathophysiology of sepsis. The dysregulated host response in sepsis is complex, with both pathogen-related factors contributing to disease, as well as immune-cell mediated inflammatory responses that can lead to adverse outcomes in early or advanced stages of disease. Due to its heterogenous nature, clinical diagnosis remains challenging and sepsis-specific treatment options are still lacking. Classification and early identification of patient subgroups may aid clinical decisions and improve outcome in sepsis patients. The initial clinical presentation is rather similar in sepsis of different etiologies, however, inflammatory profiles may be able to distinguish between different etiologies of infections. In this review, we summarize the role and the discriminating potency of host-derived inflammatory biomarkers in the context of the main etiological types of sepsis.

Cytokine concentrations are related to level of mental distress in inpatients not using anti-inflammatory drugs

OBJECTIVE

Cross-sectional data show elevated levels of circulating cytokines in psychiatric patients. The literature is divided concerning anti-inflammatory drugs' ability to relieve symptoms, questioning a causal link between inflammatory pathways and psychiatric conditions. We hypothesised that the development of circulating cytokine levels is related to mental distress, and that this relationship is affected by the use of anti-inflammatory drugs.

METHODS

The study was a longitudinal assessment of 12-week inpatient treatment at Modum Bad Psychiatric Center, Norway. Sera and self-reported Global Severity Index (GSI) scores, which measure psychological distress, were collected at admission (T0), halfway (T1) and before discharge (T2). Other variables known to distort the neuroimmune interplay were included. These were age, gender, diagnosis of PTSD, antidepressants and anti-inflammatory drugs. A total of 128 patients (92 women and 36 men) were included, and 28 were using anti-inflammatory medication. Multilevel modelling was used for data analysis.

RESULTS

Patients with higher levels of IL-1RA and MCP-1 had higher GSI scores (p = 0.005 and p = 0.020). PTSD patients scored higher on GSI than non-PTSD patients (p = 0.002). These relationships were mostly present among those not using anti-inflammatory drugs (n = 99), with higher levels of IL-1RA and MCP-1 being related to higher GSI score (p = 0.023 and 0.018, respectively). Again, PTSD patients showed higher GSI levels than non-PTSD patients (p = 0.014).

CONCLUSIONS

Cytokine levels were associated with level of mental distress as measured by the GSI scores, but this relationship was not present among those using anti-inflammatory drugs. We found no association between cytokine levels and development of GSI score over time.

Small intestinal transcriptome analysis revealed changes of genes involved in nutrition metabolism and immune responses in growth retardation piglets1

Postnatal growth retardation (PGR) is common in piglets. Abnormal development in small intestine was casually implicated in impaired growth, but the exact mechanism is still implausible. The present study unveiled transcriptome profile of jejunal mucosa, the major site of nutrient absorption, in PGR and healthy piglets using RNA-sequencing (RNA-seq). The middle segments of jejunum and ileum, and jejunal mucosa were obtained from healthy and PGR piglets at 42 d of age. Total RNA samples extracted from jejunal mucosa of healthy and PGR piglets were submitted for RNA-seq. Lower villus height was observed in both jejunum and ileum from PGR piglets suggesting structural impairment in small intestine (P < 0.05). RNA-seq libraries were constructed and sequenced, and produced average 4.8 × 107 clean reads. Analysis revealed a total of 499 differently expressed genes (DEGs), of which 320 DEGs were downregulated in PGR piglets as compared to healthy piglets. The functional annotation based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) highlighted that most DEGs were involved in nutrient metabolism and immune responses. Our results further indicated decreased gene expression associated with glucose, lipid, protein, mineral, and vitamin metabolic process, detoxication ability, oxidoreductase activity, and mucosal barrier function; as well as the increased insulin resistance and inflammatory response in the jejunal mucosa of PGR piglets. These results characterized the transcriptomic profile of the jejunal mucosa in PGR piglets, and could provide valuable information with respect to better understanding the nutrition metabolism and immune responses in the small intestine of piglets.

Plasma lipid profiles discriminate bacterial from viral infection in febrile children

Fever is the most common reason that children present to Emergency Departments. Clinical signs and symptoms suggestive of bacterial infection are often non-specific, and there is no definitive test for the accurate diagnosis of infection. The 'omics' approaches to identifying biomarkers from the host-response to bacterial infection are promising. In this study, lipidomic analysis was carried out with plasma samples obtained from febrile children with confirmed bacterial infection (n = 20) and confirmed viral infection (n = 20). We show for the first time that bacterial and viral infection produces distinct profile in the host lipidome. Some species of glycerophosphoinositol, sphingomyelin, lysophosphatidylcholine and cholesterol sulfate were higher in the confirmed virus infected group, while some species of fatty acids, glycerophosphocholine, glycerophosphoserine, lactosylceramide and bilirubin were lower in the confirmed virus infected group when compared with confirmed bacterial infected group. A combination of three lipids achieved an area under the receiver operating characteristic (ROC) curve of 0.911 (95% CI 0.81 to 0.98). This pilot study demonstrates the potential of metabolic biomarkers to assist clinicians in distinguishing bacterial from viral infection in febrile children, to facilitate effective clinical management and to the limit inappropriate use of antibiotics.

Balanced role of T3SS and T6SS in contribution to the full virulence of Edwardsiella piscicida

Edwardsiella piscicida is an important pathogen that infects a wide range of hosts, from fish to human. Its infection leads to extensive losses in a diverse array of commercially important fish, like Japanese flounder, turbot, and tilapia. During the infection, type III secretion system (T3SS) and type VI secretion system (T6SS) of E. piscicida play significant roles, but how T3SS and T6SS cooperatively contribute to its virulence is still unknown. In this study, we first examined the roles of T3SS and T6SS in different processes during E. piscicida infection of host cells, and revealed that T3SS of E. piscicida is responsible for promoting bacterial invasion, the following intracellular replication and inducing cell death in host cells, while T6SS restrains E. piscicida intracellular replication and cell death in J774A.1 cells, which suggested that T3SS and T6SS antagonistically concert E. piscicida infection. Furthermore, we found an significant decrease in transcription level of IL-1β in zebrafish kidney infected with T3SS mutant and an drastically increase in transcription level of TNF- α infected with T6SS mutant when compared with the wild-type. Interestingly, both T3SS and T6SS mutants showed significant attenuated virulence in the zebrafish infection model when compared with the wild-type. Finally, considering the cooperative role of T3SS and T6SS, we generated a mutant strain WEDΔT6SS based on the existing live attenuated vaccine (LAV) WED which showed improved vaccine safety and comparable immune protection. Therefore, WEDΔT6SS could be used as an optimized LAV in the future. Taken together, this work suggested a bilateral role of T3SS and T6SS which respectively act as spear and shield during E. piscicida infection, together contribute to E. piscicida virulence.

Increased risk of non-multiple sclerosis demyelinating syndromes in patients with preexisting septicaemia: a nationwide retrospective cohort study

Background

Growing evidence shows links between septicaemia and non-multiple sclerosis demyelinating syndromes (NMSDS); nevertheless, epidemiological data are still very limited. This study aimed to explore the relationship between septicaemia and NMSDS in a general population.

Methods

The study included 482 781 individuals diagnosed with septicaemia and 1 892 825 age/sex-matched non-septicaemia patients for the comparison. Data were drawn from a population-based nationwide National Health Insurance Research Database Taiwan, from 1 January 2002 to 31 December 2011. The two cohorts of patients with and without septicaemia were followed up for the occurrence of NMSDS. The Cox-proportional hazard regression model was performed to estimate adjusted HR after multivariate adjustment.

Results

Individuals with septicaemia had a 4.17-fold (95% CI 3.21 to 5.4, p < 0.001) higher risk to develop NMSDS compared with those without septicaemia. Patients aged <65 years had a greater NMSDS risk (<45 years: HR = 6.41, 95% CI 3.65 to 11.3, p < 0.001; 45–64 years: HR = 6.66, 95% CI 3.98 to 11.2, p < 0.001). Furthermore, females with septicaemia and individuals with higher severity of septicaemia were associated with increased risks of developing NMSDS.

Conclusions

Our results indicated that patients with septicaemia were likely to develop NMSDS. A possible contributing role of septicaemia in increasing the hazard of NMSDS is proposed, based on the outcome that individuals with higher severity of septicaemia carried elevated threat of encountering NMSDS.

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.

Salmonella enterica serotype typhimurium and S. Stanley differ in genomic evolutionary patterns and early immune responses in human THP-1 cell line and CD14+ monocytes

Salmonella Typhimurium and S. Stanley are the most prevalent serogroup B serovars to infect humans in Taiwan. The aim was to determine possible factors to influence the prevalence between S. Typhimurium and S. Stanley. Genotypes were determined by pulsed field gel electrophoresis (PFGE) analysis and the intracellular survival, phagocytosis, reactive oxygen species (ROS) production of human monocyte THP-1 cell and tumor necrosis factor-α(TNF-α), interleukin-6 (IL-6), and IL-1βexpression in peripheral blood CD14⁺ cells after infection were analyzed. 182 S. Stanley was clonal disseminated with main pulsotypes 2 from 2004 to 2007. Overall S. Typhimurium evolved more genotypes, while S. Stanley conserved in genotypes. Human blood CD14⁺ monocytes expressed TNF-α, IL-6 and IL-1β differently among serovars and bacterial conditions (live vs. killed). Live S. Stanley and S. Typhimurium suppressed the TNF-α and IL-6 expression compared to killed bacteria. However, live S. Typhimurium stimulated more IL-1β expression than the killed bacteria, but S. Stanley expressed similar IL-1β levels in both conditions. Furthermore, S. Stanley and S. Typhimurium differed in intracellular survival in the THP-1 cells, an early decrease for S. Stanley, not for S. Typhimurium. Additionally, higher reactive oxygen species (ROS) production in THP-1 cells was found agsinst S. Stanley infection, not found in S. Typhimurium. However, some isolates of S. Stanley could recover from early loss to become more in the monocytes than S. Typhimurium. Difference in phagocytized number, intracellular survival, ROS production and IL-1β expression may contribute to prevalence different between two serovars.

Neutrophil plays critical role during Edwardsiella piscicida immersion infection in zebrafish larvae

Edwardsiella piscicida is a facultative intracellular pathogen that causes hemorrhagic septicemia and haemolytic ascites disease in aquaculture fish. During bacterial infection, macrophages and neutrophils are the first line of host innate immune system. However, the role of neutrophils in response to E. piscicida infection in vivo remains poorly understood. Here, through developing an immersion infection model in the 5 day-post fertilization (dpf) zebrafish larvae, we found that E. piscicida was mainly colonized in intestine, and resulted into significant pathological changes in paraffin sections. Moreover, a dynamic up-regulation of inflammatory cytokines (TNF-α, IL-1β, GCSFb, CXCL8 and MMP9) was detected in zebrafish larvae during E. piscicida infection. Furthermore, a significant recruitment of neutrophils was observed during the E. piscicida infection in Tg(mpx:eGFP) zebrafish larvae. Thus, we utilized the CRISPR/Cas9 system to generate the neutrophil-knockdown (gcsfr^-/- crispants) larvae, and found a comparative higher mortality and bacterial colonization in gcsfr^-/- crispants, which reveals the critical role of fish neutrophils in bacterial clearance. Taken together, our results developed an effective E. piscicida immersion challenge model in zebrafish larvae to clarify the dynamic of bacterial infection in vivo, which would provide a better understanding of the action about innate immune cells during infection.

Tug of war between Acinetobacter baumannii and host immune responses

Acinetobacter baumannii is an emerging nosocomial, opportunistic pathogen with growing clinical significance. Acinetobacter baumannii has an exceptional ability to rapidly develop drug resistance and to adhere to abiotic surfaces, including medical equipment, significantly promoting bacterial spread and also limiting our ability to control A. baumannii infections. Consequently, A. baumannii is frequently responsible for ventilator-associated pneumonia in clinical settings. In order to develop an effective treatment strategy, understanding host-pathogen interactions during A. baumannii infection is crucial. Various A. baumannii virulence factors have been identified as targets of host innate pattern-recognition receptors, which leads to activation of downstream inflammasomes to develop inflammatory responses, and the recruitment of innate immune effectors against A. baumannii infection. To counteract host immune attack, A. baumannii regulates its expression of different virulence factors. This review summarizes the significance of mechanisms of host-bacteria interaction, as well as different bacteria and host defense mechanisms during A. baumannii infection.

Characterization of the plasma proteome of nonhuman primates during Ebola virus disease or melioidosis: a host response comparison

Background

In-depth examination of the plasma proteomic response to infection with a wide variety of pathogens can assist in the development of new diagnostic paradigms, while providing insight into the interdependent pathogenic processes which encompass a host’s immunological and physiological responses. Ebola virus (EBOV) causes a highly lethal infection termed Ebola virus disease (EVD) in primates and humans. The Gram negative non-spore forming bacillus Burkholderia pseudomallei (Bp) causes melioidosis in primates and humans, characterized by severe pneumonia with high mortality. We sought to examine the host response to infection with these two bio-threat pathogens using established animal models to provide information on the feasibility of pre-symptomatic diagnosis, since the induction of host molecular signaling networks can occur before clinical presentation and pathogen detection.

Methods

Herein we report the quantitative proteomic analysis of plasma collected at various times of disease progression from 10 EBOV-infected and 5 Bp-infected nonhuman primates (NHP). Our strategy employed high resolution LC–MS/MS and a peptide-tagging approach for relative protein quantitation. In each infection type, for all proteins with > 1.3 fold abundance change at any post-infection time point, a direct comparison was made with levels obtained from plasma collected daily from 5 naïve rhesus macaques, to determine the fold changes that were significant, and establish the natural variability of abundance for endogenous plasma proteins.

Results

A total of 41 plasma proteins displayed significant alterations in abundance during EBOV infection, and 28 proteins had altered levels during Bp infection, when compared to naïve NHPs. Many major acute phase proteins quantitated displayed similar fold-changes between the two infection types but exhibited different temporal dynamics. Proteins related to the clotting cascade, immune signaling and complement system exhibited significant differential abundance during infection with EBOV or Bp, indicating a specificity of the response.

Conclusions

These results advance our understanding of the global plasma proteomic response to EBOV and Bp infection in relevant primate models for human disease and provide insight into potential innate immune response differences between viral and bacterial infections.

Electronic supplementary material

The online version of this article (10.1186/s12014-019-9227-3) contains supplementary material, which is available to authorized users.

Association of Hospitalization, Critical Illness, and Infection with Brain Structure in Older Adults

OBJECTIVES

To examine the association between hospitalization, critical illness, and infection occurring during middle- and late-life and structural brain abnormalities in older adults.

DESIGN

Prospective cohort study.

SETTING

Atherosclerosis Risk in Communities (ARIC) Study.

PARTICIPANTS

A community sample of adults who were 44 to 66 years of age at study baseline.

MEASUREMENTS

Active surveillance of local hospitals and annual participant contact were used to gather hospitalization information (including International Classification of Diseases, Ninth Revision, codes) on all participants over a 24-year surveillance period. Subsequently, a subset of participants underwent 3-Tesla brain magnetic resonance imaging (MRI) to quantify total and regional brain volumes, white matter hyperintensity (WMH) volume, and white matter microstructural integrity (fractional anisotropy (FA) and mean diffusivity (MD) as measured using diffusion tensor imaging (DTI)).

RESULTS

Of the 1,689 participants included (mean age at MRI 76±5), 72% were hospitalized, 14% had a major infection, and 4% had a critical illness during the surveillance period. Using covariate-adjusted regression, hospitalization was associated with 0.12-standard deviation (SD) greater WMH volume (95% confidence interval (CI)=0.00-0.24) and poorer white matter microstructural integrity (0.17-SD lower FA, 95% CI=-0.27 to -0.06; 0.16-SD greater MD, 95% CI=0.07-0.25) than no hospitalization. There was a dose-dependent relationship between number of hospitalizations, smaller brain volumes, and lower white matter integrity (p-trends ≤.048). In hospitalized participants, critical illness was associated with smaller Alzheimer's disease (AD) signature region (-1.64 cm3 , 95% CI=-3.16 to -0.12); major infection was associated with smaller AD signature region (-1.28 cm3 , 95% CI=-2.21 to -0.35) and larger ventricular volume (3.79 cm3 , 95% CI= 0.81-6.77).

CONCLUSIONS

Whereas all-cause hospitalization was primarily associated with lower white matter integrity, critical illness and major infection were associated with smaller brain volume, particularly within regions implicated in AD.

Interleukin 1 receptor antagonist (IL1RA) gene polymorphism and levels associated with adverse outcome in severe community-acquired pneumonia in children: A hospital-based study in India

BACKGROUND

High morbidity and mortality due to community-acquired pneumonia (CAP) is seen in children under 5 years of age in India. Besides identified risk factors for CAP, there may be a phenotype-genotype association with cytokines, resulting in enhanced inflammatory response resulting in the adverse outcome (AO), namely complications and death.

AIM

To assess the association of IL1RA gene polymorphism on serum levels of IL1RA and with AO in children under 5 years of age hospitalized with WHO-defined severe CAP.

METHOD

A prospective cohort study with nested case-control design conducted in a tertiary care teaching hospital after obtaining institutional ethical approval. Included were children between 2 and 59 months of age hospitalized with WHO-defined severe CAP with consistent radiological abnormalities. Excluded were those with suspected or proven cystic fibrosis, pulmonary tuberculosis, malignancy, immunodeficiency, and congenital heart disease. Polymerase chain reaction (PCR) was used to analyze the Variable Number of Tandem Repeats (VNTRs) of IL1RA gene polymorphism and ELISA test to detect serum levels of IL1RA.

RESULTS

From 2014 to 2016, of 420 screened cases, 350 were eligible and included, of which 132 (37.7%) had no complication and 218 (62.3%) had AO, which included complications like empyema, pyopneumothorax, acute respiratory distress syndrome (ARDS), and septic shock of these 24 (6.9%) expired. Higher risk of AO was seen in A2A2 genotype (OR 11.18, p 0.0001) and lower in A1A1 genotype (OR 0.18, P < 0.0001). Serum IL1RA (ng/mL) was statistically significantly elevated in CAP with AO (2.55 ± 1.44) versus uncomplicated (0.87 ± 0.52) (P < 0.0001).

CONCLUSION

In IL1RA gene, A1A1 genotype was associated with lower risk and A2A2 genotype with increased the risk of AO. Higher serum levels of IL1RA were found in A2A2 genotype indicating possibly enhanced inflammatory response resulting in AO of CAP.

Selected Biomarkers Correlate with the Origin and Severity of Sepsis

The microbial etiology and source of sepsis influence the inflammatory response. Therefore, the plasma levels of cytokines (IL-6, IL-8, and IL-10), chemokines (CCL2/MCP-1, MIP-1β), heparin-binding protein (HBP), soluble CD14 (sCD14), and cortisol were analyzed in blood from septic patients obtained during the first 96 hours of intensive care unit hospitalization. The etiology was established in 56 out of a total of 62 patients enrolled in the study. Plasma concentrations of MCP-1, sCD14, IL-6, and IL-10 were significantly higher in patients with community-acquired pneumonia (CAP; n = 10) and infective endocarditis (IE; n = 11) compared to those with bacterial meningitis (BM; n = 18). Next, cortisol levels were higher in IE patients than in those with BM and CAP, and at one time point, cortisol was also higher in patients with gram-negative sepsis when compared to those with gram-positive infections. Furthermore, cortisol and MCP-1 levels correlated positively with the daily measured SOFA score. In addition, HBP levels were significantly higher in patients with IE than in those with BM. Our findings suggest that MCP-1, sCD14, IL-6, IL-10, cortisol, and HBP are modulated by the source of sepsis and that elevated MCP-1 and cortisol plasma levels are associated with sepsis-induced organ dysfunction.

Cytokine kinetic profiles in children with acute lower respiratory tract infection: a post hoc descriptive analysis from a randomized control trial

OBJECTIVES

Standard inflammatory markers and chest radiography lack the ability to discriminate bacterial from non-bacterial lower respiratory tract infection (LRTI). Cytokine profiles may serve as biomarkers for LRTI, but their applicability to identify aetiology, severity of disease and need for antibiotic prescription in children remains poorly defined. Objectives were to determine the cytokine kinetic profiles over 5 days in paediatric patients with LRTI, to investigate the relationship between cytokine patterns, and clinical and laboratory variables.

METHODS

We included patients aged 1 month to 18 years, with febrile LRTI and three consecutive cytokines measurements on days 1, 3 and 5 of a randomized controlled trial (ProPAED study). We evaluated differences in cytokine concentrations between days and associations with clinical and laboratory variables.

RESULTS

A total of 181 patients (median age 4.1 years) were included; 72/181 (40%) received antibiotics. Serum concentrations of interferon (IFN)-γ, interleukin (IL)-1ra, IL-6, IL-10, IFN-γ-inducible protein (IP)-10 and tumor necrosis factor-α were elevated on day 1 and decreased subsequently, with the greatest decline between day 1 and 3 (by -8 to >-94%). Procalcitonin (PCT) and C-reactive protein (CRP) values showed a protracted decrease with the most prominent reduction in concentrations between days 3 and 5. Significantly elevated IL-6 concentrations were associated with hospital admission, antibiotic treatment, and prolonged antibiotic treatment. Bacteraemic LRTI patients had higher concentrations of IL-1ra (p <0.0055) and IL-6 (p <0.0055) on day 1.

CONCLUSIONS

We observed an earlier decrease of elevated cytokines compared to PCT or CRP. Both pro- and anti-inflammatory cytokines may serve as markers for severity of LRTI.

Interleukin-1β signaling in fenestrated capillaries is sufficient to trigger sickness responses in mice

BACKGROUND

The physiological and behavioral symptoms of sickness, including fever, anorexia, behavioral depression, and weight loss can be both beneficial and detrimental. These sickness responses are triggered by pro-inflammatory cytokines acting on cells within the brain. Previous research demonstrates that the febrile response to peripheral insults depends upon prostaglandin production by vascular endothelial cells, but the mechanisms and specific cell type(s) responsible for other sickness responses remain unknown. The purpose of the present study was to identify which cells within the brain are required for sickness responses triggered by central nervous system inflammation.

METHODS

Intracerebroventricular (ICV) administration of 10 ng of the potent pro-inflammatory cytokine interleukin-1β (IL-1β) was used as an experimental model of central nervous system cytokine production. We examined which cells respond to IL-1β in vivo via fluorescent immunohistochemistry. Using multiple transgenic mouse lines expressing Cre recombinase under the control of cell-specific promoters, we eliminated IL-1β signaling from different populations of cells. Food consumption, body weight, movement, and temperature were recorded in adult male mice and analyzed by two-factor ANOVA to determine where IL-1β signaling is essential for sickness responses.

RESULTS

Endothelial cells, microglia, ependymal cells, and astrocytes exhibit nuclear translocation of NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) in response to IL-1β. Interfering with IL-1β signaling in microglia, endothelial cells within the parenchyma of the brain, or both did not affect sickness responses. Only mice that lacked IL-1β signaling in all endothelium including fenestrated capillaries lacked sickness responses.

CONCLUSIONS

These experiments show that IL-1β-induced sickness responses depend on intact IL-1β signaling in blood vessels and suggest that fenestrated capillaries act as a critical signaling relay between the immune and nervous systems.

TRIAL REGISTRATION

Not applicable.

Transcriptomic Analysis on Responses of Murine Lungs to Pasteurella multocida Infection

Pasteurella multocida infection in cattle causes serious epidemic diseases and leads to great economic losses in livestock industry; however, little is known about the interaction between host and P. multocida in the lungs. To explore a fully insight into the host responses in the lungs during P. multocida infection, a mouse model of Pasteurella pneumonia was established by intraperitoneal infection, and then transcriptomic analysis of infected lungs was performed. P. multocida localized and grew in murine lungs, and induced inflammation in the lungs, as well as mice death. With transcriptomic analysis, approximately 10⁷ clean reads were acquired. 4236 differently expressed genes (DEGs) were detected during P. multocida infection, of which 1924 DEGs were up-regulated. By gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichments, 5,303 GO enrichments and 116 KEGG pathways were significantly enriched in the context of P. multocida infection. Interestingly, genes related to immune responses, such as pattern recognition receptors (PRRs), chemokines and inflammatory cytokines, were significantly up-regulated, suggesting the key roles of these genes in P. multocida infection. Transcriptomic data showed that IFN-γ/IL-17-related genes were increased, which were validated by qRT-PCR, ELISA, and immunoblotting. Our study characterized the transcriptomic profile of the lungs in mice upon Pasteurella infection, and our findings could provide valuable information with respect to better understanding the responses in mice during P. multocida infection.

IL-1β/IL-6/CRP and IL-18/ferritin: Distinct Inflammatory Programs in Infections

The host inflammatory response against infections is characterized by the release of pro-inflammatory cytokines and acute-phase proteins, driving both innate and adaptive arms of the immune response. Distinct patterns of circulating cytokines and acute-phase responses have proven indispensable for guiding the diagnosis and management of infectious diseases. This review discusses the profiles of acute-phase proteins and circulating cytokines encountered in viral and bacterial infections. We also propose a model in which the inflammatory response to viral (IL-18/ferritin) and bacterial (IL-6/CRP) infections presents with specific plasma patterns of immune biomarkers.

Systemic and localized extra-central nervous system bacterial infections and the risk of dementia among US veterans: A retrospective cohort study

INTRODUCTION

Emerging evidence indicates associations between extra-central nervous system (CNS) bacterial infections and an increased risk for dementia; however, epidemiological evidence is still very limited.

METHODS

This study involved a retrospective cohort of a national sample of US veterans (N = 417,172) aged ≥56 years. Extended Cox proportional hazard models adjusted for demographic characteristics and medical and psychiatric comorbidities determined the associations between systemic and localized extra-CNS bacterial infections occurring >2 years before the initial dementia diagnosis and the risk for dementia.

RESULTS

Exposure to any extra-CNS bacterial infection was associated with a significantly increased risk for dementia (hazard ratio [HR] = 1.20 [95% confidence interval = 1.16-1.24]). Independently, septicemia (HR = 1.39 [1.16-1.66]), bacteremia (HR = 1.22 [1.00-1.49]), osteomyelitis (HR = 1.20 [1.06-1.37]), pneumonia (HR = 1.10 [1.02-1.19]), urinary tract infections (HR = 1.13 [1.08-1.18]), and cellulitis (HR = 1.14 [1.09-1.20]) were associated with a significantly increased risk for dementia.

DISCUSSION

Both systemic and localized extra-CNS bacterial infections are associated with an increased risk for developing dementia.

Multiplexed femtomolar quantitation of human cytokines in a fluoropolymer microcapillary film

Sensitive quantitation of multiple cytokines can provide important diagnostic information during infection, inflammation and immunopathology. In this study sensitive immunoassay detection of human cytokines IL-1β, IL-6, IL-12p70 and TNFα is shown for singleplex and multiplex formats using a novel miniaturized ELISA platform. The platform uses a disposable plastic multi-syringe aspirator (MSA) integrating 8 disposable fluoropolymer microfluidic test strips, each containing an array of ten 200 μm mean i.d. microcapillaries coated with a set of monoclonal antibodies. Each MSA device thus performs 10 tests on 8 samples, delivering 80 measurements. Unprecedented levels of sensitivity were obtained with the novel fluoropolymer microfluidic material and simple colorimetric detection in a flatbed scanner. The limit of detection for singleplex detection ranged from 2.0 to 15.0 pg ml(-1), i.e. 35 and 713 femtomolar for singleplex cytokine detection, and the intra- and inter-assay coefficient of variation (CV) remained within 10%. In addition, a triplex immunoassay was developed for measuring IL-1β, IL-12p70 and TNFα simultaneously from a given sample in the pg ml(-1) range. These assays permit high sensitivity measurement with rapid <15 min assay or detection from undiluted blood serum. The portability, speed and low-cost of this system are highly suited to point-of-care testing and field diagnostics applications.

Plasma Monocyte Chemoattractant Protein-1 Level as a Predictor of the Severity of Community-Acquired Pneumonia

Monocyte chemoattractant protein (MCP)-1 increases in the serum of immunocompetent patients with community-acquired pneumonia (CAP). However, the correlation between the circulating level of MCP-1 and severity of CAP remains unclear. This study investigated differential changes in the plasma MCP-1 levels of patients with CAP before and after an antibiotic treatment and further analyzes the association between the CAP severity and MCP-1 levels. We measured the plasma MCP-1 levels of 137 patients with CAP and 74 healthy controls by using a commercial enzyme-linked immunosorbent assay. Upon initial hospitalization, Acute Physiology and Chronic Health Evaluation II (APACHE II); confusion, urea level, respiratory rate, blood pressure, and age of >64 years (CURB-65); and pneumonia severity index (PSI) scores were determined for assessing the CAP severity in these patients. The antibiotic treatment reduced the number of white blood cells (WBCs) and neutrophils as well as the level of C-reactive protein (CRP) and MCP-1. The plasma MCP-1 level, but not the CRP level or WBC count, correlated with the CAP severity according to the PSI (r = 0.509, p < 0.001), CURB-65 (r = 0.468, p < 0.001), and APACHE II (r = 0.360, p < 0.001) scores. We concluded that MCP-1 levels act in the development of CAP and are involved in the severity of CAP.

Antibody arrays in biomarker discovery

All of life is regulated by complex and organized chemical reactions that help dictate when to grow, to move, to reproduce, and to die. When these processes go awry, or are interrupted by pathological agents, diseases such as cancer, autoimmunity, or infections can result. Cytokines, chemokines, growth factors, adipokines, and other chemical moieties make up a vast subset of these chemical reactions that are altered in disease states, and monitoring changes in these molecules could provide for the identification of disease biomarkers. From the first identification of carcinoembryonic antigen, to the discovery of prostate-specific antigen, to numerous others described within, biomarkers of disease are detectable in a plethora of sample types. The growing number of biomarkers for infection, autoimmunity, and cancer allow for increasingly early detection, to identification of novel drug targets, to prognostic indicators of disease outcome. However, more and more studies are finding that a single cytokine or growth factor is insufficient as a true disease biomarker and that a more global perspective is needed to understand true disease biology. Such a broad view requires a multiplexed platform for chemical detection, and antibody arrays meet and exceed this need by performing this detection in a high-throughput fashion. Herein, we will discuss how antibody arrays have evolved, and how they have helped direct new drug target design, helped identify therapeutic disease markers, and helped in earlier disease detection. From asthma to renal disease, and neurological dysfunction to immunologic disorders, antibody arrays afford a bright future for new biomarkers discovery.