Influence of Age and Other Factors on Cytokine Expression Profiles in Healthy Children-A Systematic Review

Role of Genetic Polymorphisms -238 G>A and -308 G>A, and Serum TNF-α Levels in a Cohort of Mexican Pediatric Neuroblastoma Patients: Preliminary Study

The results of in vitro and in vivo studies have shown the pro-tumor effects of TNF-α, and this cytokine's increased expression is associated with poor prognosis in patients with some types of cancer. Our study objective was to evaluate the possible association of TNF-α genetic polymorphisms and serum levels with susceptibility and prognosis in a cohort of Mexican patients with NB. We performed PCR-RFLP and ELISA methods to analyze the genetics of these SNPs and determine serum concentrations, respectively. The distribution of the -308 G>A and -238 G>A polymorphisms TNFα genotypes was considerably different between patients with NB and the control group. The SNP rs1800629 GG/GA genotypes were associated with a decreased risk of NB (OR = 0.1, 95% CI = 0.03-0.393, p = 0.001) compared with the AA genotype, which was associated with susceptibility to NB (OR = 2.89, 95% CI = 1.45-5.76, p = 0.003) and related to unfavorable histology and high-risk NB. The rs361525 polymorphism GG genotype was associated with a lower risk of developing NB compared with the GA and AA genotypes (OR = 0.2, 95% CI = 0.068-0.63, p = 0.006). Circulating TNF-α serum concentrations were significantly different (p < 0.001) between patients with NB and healthy controls; however, we found no relationship between the analyzed TNF-α serum levels and SNP genotypes. We found associations between the rs1800629AA genotype and lower event-free survival (p = 0.026); SNP rs361525 and TNF-α levels were not associated with survival in patients with NB. Our results suggest the TNF-α SNP rs1800629 as a probable factor of NB susceptibility. The -308 G/A polymorphism AA genotype has a probable role in promoting NB development and poor prognosis associated with unfavorable histology, high-risk tumors, and lower EFS in Mexican patients with NB. It should be noted that it is important to conduct research on a larger scale, through inter-institutional studies, to further evaluate the contribution of TNF-α genetic polymorphisms to the risk and prognosis of NB.

Comparative analysis of changes in immune cell in the chicken spleen across different ages using flow cytometry

BACKGROUND

Concurrent emerging and reemerging avian infectious diseases cause multiple risk factors in poultry. A body amount studies attempted to understand pathogen-associated immunity in chickens. Recent research has made progress in identifying immune functions in chicken, there are still gaps in knowledge, especially regarding immune responses during infectious diseases. A deeper understanding in chicken immune system is critical for improving disease control strategies and vaccine development.

RESULTS

This study proposes analytical method for chicken splenocytes, enabling the tracking changes in T cells, monocytes, and B cells across three ages. Optimized lymphocyte-activating conditions were suggested using concanavalin A and chicken interleikin-2, which facilitate immune cell activation and proliferation. Next, splenocytes from embryonic day 18, day 5, and day 30 were compared using surface markers and flow cytometry analysis. We observed an increase in T cell subsets, including activated T cells (CD4+CD44+ and CD8+CD44+), and B cells, along with a reduced monocyte population after hatching. However, morphological changes and genetic expression of functional immune molecules were limited.

CONCLUSIONS

The present findings on chicken immune system development offer valuable insights into the avian immune system, including analytical methods and the phenotypic and functional changes in immune cells. Updated immune-boosting strategies during the early stages of life are crucial for developing preventive measures against major infectious diseases in the poultry industry.

Identification of State Markers in Anorexia Nervosa: Replication and Extension of Inflammation-Associated Biomarkers Using Multiplex Profiling

Background

Proteomics offers potential for detecting and monitoring anorexia nervosa (AN) and its variant, atypical AN (atyp-AN). However, research has been limited by small protein panels, a focus on adult AN, and lack of replication.

Methods

In this study, we performed Olink multiplex profiling of 92 inflammation-related proteins in females with AN/atyp-AN (n = 64), all of whom were ≤90% of expected body weight, and age-matched healthy control individuals (n = 44).

Results

Five proteins differed significantly between the primary AN/atyp-AN group and the healthy control group (lower levels: HGF, IL-18R1, TRANCE; higher levels: CCL23, LIF-R). The expression levels of 3 proteins (lower IL-18R1, TRANCE; higher LIF-R) were uniquely disrupted in participants with AN in our primary model. No unique expression levels emerged for atyp-AN. In the total sample, 12 proteins (ADA, CD5, CD6, CXCL1, FGF-21, HGF, IL-12B, IL18, IL-18R1, SIRT2, TNFSF14, TRANCE) were positively correlated with body mass index and 5 proteins (CCL11, FGF-19, IL8, LIF-R, OPG) were negatively correlated with body mass index in our primary models.

Conclusions

Our results replicate the results of a previous study that demonstrated a dysregulated inflammatory status in AN and extend those results to atyp-AN. Of the 17 proteins correlated with body mass index, 11 were replicated from a previous study that used similar methods, highlighting the promise of inflammatory protein expression levels as biomarkers of AN disease monitoring. Our findings underscore the complexity of AN and atyp-AN by highlighting the inability of the identified proteins to differentiate between these 2 subtypes, thereby emphasizing the heterogeneous nature of these disorders.

Bioenergetic and Inflammatory Alterations in Regressed and Non-Regressed Patients with Autism Spectrum Disorder

Autism spectrum disorder (ASD) is associated with multiple physiological abnormalities. Current laboratory and clinical evidence most commonly report mitochondrial dysfunction, oxidative stress, and immunological imbalance in almost every cell type of the body. The present work aims to evaluate oxygen consumption rate (OCR), extracellular acidification rate (ECAR), and inflammation-related molecules such as Cyclooxygenase-2 (COX-2), chitinase 3-like protein 1 (YKL-40), Interleukin-1 beta (IL-1β), Interleukin-9 (IL-9) in ASD children with and without regression compared to healthy controls. Children with ASD (n = 56) and typically developing children (TDC, n = 12) aged 1.11 to 11 years were studied. Mitochondrial activity was examined in peripheral blood mononuclear cells (PBMCs) isolated from children with ASD and from the control group, using a metabolic analyzer. Gene and protein levels of IL-1β, IL-9, COX-2, and YKL-40 were investigated in parallel. Our results showed that PBMCs of the ASD subgroup of regressed patients (ASD R(+), n = 21) had a specific pattern of mitochondrial activity with significantly increased maximal respiration, respiratory spare capacity, and proton leak compared to the non-regressed group (ASD R(-), n = 35) and TDC. Furthermore, we found an imbalance in the studied proinflammatory molecules and increased levels in ASD R(-) proving the involvement of inflammatory changes. The results of this study provide new evidence for specific bioenergetic profiles of immune cells and elevated inflammation-related molecules in ASD. For the first time, data on a unique metabolic profile in ASD R(+) and its comparison with a random group of children of similar age and sex are provided. Our data show that mitochondrial dysfunction is more significant in ASD R(+), while in ASD R(-) inflammation is more pronounced. Probably, in the group without regression, immune mechanisms (immune dysregulation, leading to inflammation) begin initially, and at a later stage mitochondrial activity is also affected under exogenous factors. On the other hand, in the regressed group, the initial damage is in the mitochondria, and perhaps at a later stage immune dysfunction is involved.

Prodromic Inflammatory-Oxidative Stress in Peritoneal Leukocytes of Triple-Transgenic Mice for Alzheimer's Disease

Inflammatory-oxidative stress is known to be pivotal in the pathobiology of Alzheimer's disease (AD), but the involvement of this stress at the peripheral level in the disease's onset has been scarcely studied. This study investigated the pro-inflammatory profile and oxidative stress parameters in peritoneal leukocytes from female triple-transgenic mice for AD (3xTgAD) and non-transgenic mice (NTg). Peritoneal leukocytes were obtained at 2, 4, 6, 12, and 15 months of age. The concentrations of TNFα, INFγ, IL-1β, IL-2, IL-6, IL-17, and IL-10 released in cultures without stimuli and mitogen concanavalin A and lipopolysaccharide presence were measured. The concentrations of reduced glutathione (GSH), oxidized glutathione (GSSG), lipid peroxidation, and Hsp70 were also analyzed in the peritoneal cells. Our results showed that although there was a lower release of pro-inflammatory cytokines by 3xTgAD mice, this response was uncontrolled and overstimulated, especially at a prodromal stage at 2 months of age. In addition, there were lower concentrations of GSH in leukocytes from 3xTgAD and higher amounts of lipid peroxides at 2 and 4 months, as well as, at 6 months, a lower concentration of Hsp70. In conclusion, 3xTgAD mice show a worse pro-inflammatory response and higher oxidative stress than NTg mice during the prodromal stages, potentially supporting the idea that Alzheimer's disease could be a consequence of peripheral alteration in the leukocyte inflammation-oxidation state.

Low unspliced cell-associated HIV RNA in early treated adolescents living with HIV on long suppressive ART

Introduction

Initiation of antiretroviral treatment (ART) in patients early after HIV-infection and long-term suppression leads to low or undetectable levels of HIV RNA and cell-associated (CA) HIV DNA and RNA. Both CA-DNA and CA-RNA, overestimate the size of the HIV reservoir but CA-RNA as well as p24/cell-free viral RNA can be indicators of residual viral replication. This study describes HIV RNA amounts and levels of cytokines/soluble markers in 40 well-suppressed adolescents who initiated ART early in life and investigated which viral markers may be informative as endpoints in cure clinical trials within this population.

Methods

Forty adolescents perinatally infected with HIV on suppressive ART for >5 years were enrolled in the CARMA study. HIV DNA and total or unspliced CA-RNA in PBMCs were analyzed by qPCR/RT-qPCR and dPCR/RT-dPCR. Cell-free HIV was determined using an ultrasensitive viral load (US-VL) assay. Plasma markers and p24 were analyzed by digital ELISA and correlations between total and unspliced HIV RNA and clinical markers, including age at ART, Western Blot score, levels of cytokines/inflammation markers or HIV CA-DNA, were tested.

Results

CA-RNA was detected in two thirds of the participants and was comparable in RT-qPCR and RT-dPCR. Adolescents with undetectable CA-RNA showed significantly lower HIV DNA compared to individuals with detectable CA-RNA. Undetectable unspliced CA-RNA was positively associated with age at ART initiation and Western Blot score. We found that a higher concentration of TNF-α was predictive of higher CA-DNA and CA-RNA. Other clinical characteristics like US-VL, time to suppression, or percent CD4+ T-lymphocytes were not predictive of the CA-RNA in this cross-sectional study.

Conclusions

Low CA-DNA after long-term suppressive ART is associated with lower CA-RNA, in concordance with other reports. Patients with low CA-RNA levels in combination with low CA-DNA and low Western Blot scores should be further investigated to characterize candidates for treatment interruption trials. Unspliced CA-RNA warrants further investigation as a marker that can be prioritized in paediatric clinical trials where the sample volume can be a significant limitation.

Sex-specific inflammatory markers of risk and presence of depression in adolescents

BACKGROUND

Associations between inflammatory markers and depression are reported among adults; however, less is known in adolescent depression in particular whether these associations are sex-specific. We aimed to identify inflammatory markers of increased risk and presence of depression in adolescence and their association with severity of depressive symptoms in the entire cohort and separately in boys and girls.

METHODS

We measured serum cytokines using a Meso Scale Discovery electrochemiluminescence V-PLEX assay in a cohort of 150 adolescents stratified for risk/presence of depression. Risk group and sex-specific differences in inflammatory markers were assessed with 2-way mixed ANOVA, and sex-moderated associations between inflammatory markers and the severity of depressive symptoms were assessed with moderated multiple hierarchical regression analyses.

RESULTS

We found a significant interaction between biological sex and the risk group, where boys showed higher interleukin (IL)-2 levels among the depressed group compared with the low-risk group. The severity of depressive symptoms was associated with elevated levels of IL-2 in boys, and of IL-6 in girls. There was a significant moderating effect of sex on the relationship between IL-2 and the severity of depressive symptoms but not for IL-6.

LIMITATIONS

The cross-sectional design means that we cannot be certain about the direction of the associations.

CONCLUSIONS

Our findings suggest sex-specific associations between inflammatory markers and the development of adolescent depression, where IL-2 may increase risk for depression and severity of depressive symptoms in boys, but not in girls. However, IL-6 may increase risk for more severe depressive symptoms in girls.

Effective early antiretroviral therapy in perinatal-HIV infection reduces subsequent plasma inflammatory profile

BACKGROUND

The long-term immunologic effects of antiretroviral therapy (ART) in children with perinatally-acquired HIV (PHIV) have not been fully elucidated. Here, we investigated how the timing of ART initiation affects the long-term immune profile of children living with PHIV by measuring immunomodulatory plasma cytokines, chemokines, and adenosine deaminases (ADAs).

METHODS

40 PHIV participants initiated ART during infancy. 39 participant samples were available; 30 initiated ART ≤6 months (early-ART treatment); 9 initiated ART >6 months and <2 years (late-ART treatment). We compared plasma cytokine and chemokine concentrations and ADA enzymatic activities between early-ART and late-ART treatment 12.5 years later and measured correlation with clinical covariates.

RESULTS

Plasma concentrations of 10 cytokines and chemokines (IFNγ, IL-12p70, IL-13, IL-17A, IL-IRA, IL-5, IL-6, and IL-9 as well as CCL7, CXCL10), ADA1, and ADA total were significantly higher in late-ART compared to early-ART treatment. Furthermore, ADA1 was significantly positively correlated with IFNγ, IL-17A, and IL-12p70. Meanwhile, total ADA was positively correlated with IFNγ, IL-13, IL-17A, IL-1RA, IL-6, and IL-12p70 as well as CCL7.

CONCLUSIONS

Elevation of several pro-inflammatory plasma analytes in late-ART despite 12.5 years of virologic suppression compared to early-ART treatment suggests that early treatment dampens the long-term plasma inflammatory profile in PHIV participants.

IMPACT

This study examines differences in the plasma cytokine, chemokine, and ADA profiles 12.5 years after treatment between early (≤6months) and late (>6 months and <2 years) antiretroviral therapy (ART) treatment initiation in a cohort of European and UK study participants living with PHIV. Several cytokines and chemokines (e.g., IFNγ, IL-12p70, IL-6, and CXCL10) as well as ADA-1 are elevated in late-ART treatment in comparison to early-ART treatment. Our results suggest that effective ART treatment initiated within 6 months of life in PHIV participants dampens a long-term inflammatory plasma profile as compared to late-ART treatment.

Systemic inflammatory proteins in offspring following maternal probiotic supplementation for atopic dermatitis prevention

BACKGROUND

Maternal probiotic supplementation has a promising effect on atopic dermatitis (AD) prevention in infancy. In the randomised controlled study, Probiotics in the Prevention of Allergy among Children in Trondheim (ProPACT), maternal probiotics reduced the cumulative incidence of AD in their offspring by 40% at 2 years of age. However, our understanding on how probiotics prevented AD is still limited, and the role of inflammatory proteins in infants following maternal probiotic supplementation is unclear. We hypothesised that maternal probiotics lowered pro-inflammatory proteins and increased anti-inflammatory proteins in their 2-year-old children as a mechanism of AD prevention. We aimed to explore this hypothesis and the association between these proteins and the presence of AD, severity of AD, and the degree of preventive effect of probiotics.

METHODS

Plasma samples were collected from 2-year-old children (n = 202) during the ProPACT study, a randomised placebo-controlled trial of maternal probiotic supplementation. These samples were analysed for 92 inflammatory proteins using a multiplex proximity extension assay. Associations between inflammatory proteins and the presence and severity of AD, and the degree of preventive effect, was estimated individually using regression analysis and then collectively using unsupervised cluster analysis.

RESULTS

Several proteins were observed to differ between the groups. The probiotic group had lower CCL11 and IL-17C, while children with AD had higher IL-17C, MCP-4, uPA, and CD6. Cytokine CCL20 and IL-18 had moderate correlation (r = 0.35 and r = 0.46) with the severity of AD. The cluster analysis revealed that children in the cluster of samples with the highest value of immune checkpoint receptors and inflammatory suppressor enzymes showed the greatest AD preventive effect from probiotics.

CONCLUSIONS

The proteins associated with both maternal probiotic supplementation and the presence and severity of AD warrant attention because of their potential biological relevance. Cluster analysis may provide a new insight when considering which subgroups benefit from probiotic supplementation. Larger studies are needed to confirm the results.

TRIAL REGISTRATION NUMBER

The study was retrospectively registered at ClinicalTrials.gov (NCT00159523) on 12nd September 2005.

Identification of State Markers in Anorexia Nervosa: Replication and Extension of Inflammation Associated Biomarkers Using Multiplex Profiling in Anorexia Nervosa and Atypical Anorexia Nervosa

Proteomics provides an opportunity for detection and monitoring of anorexia nervosa (AN) and its related variant, atypical-AN (atyp-AN). However, research to date has been limited by the small number of proteins explored, exclusive focus on adults with AN, and lack of replication across studies. This study performed Olink Proseek Multiplex profiling of 92 proteins involved in inflammation among females with AN and atyp-AN (N = 64), all < 90% of expected body weight, and age-matched healthy controls (HC; N=44). After correction for multiple testing, nine proteins differed significantly in the AN/atyp-AN group relative to HC group ( lower levels: CXCL1, HGF, IL-18R1, TNFSF14, TRANCE; higher levels: CCL23, Flt3L, LIF-R, MMP-1). The expression levels of three proteins ( lower IL-18R1, TRANCE; higher LIF-R) were uniquely disrupted in females with AN. No unique expression levels emerged for atyp-AN. Across the whole sample, twenty-one proteins correlated positively with BMI (ADA, AXIN1, CD5, CD244, CD40, CD6, CXCL1, FGF-21, HGF, IL-10RB, IL-12B, IL18, IL-18R1, IL6, LAP TGF-beta-1, SIRT2, STAMBP, TNFRSF9, TNFSF14, TRAIL, TRANCE) and six (CCL11, CCL23, FGF-19, IL8, LIF-R, OPG) were negatively correlated with BMI. Overall, our results replicate the prior study demonstrating a dysregulated inflammatory status in AN, and extend these results to atyp-AN (AN/atyp-AN all < 90% of expected body weight). Of the 27 proteins correlated with BMI, 18 were replicated from a prior study using similar methods, highlighting the promise of inflammatory protein expression levels as biomarkers of disease monitoring. Additional studies of individuals across the entire weight spectrum are needed to understand the role of inflammation in atyp-AN.

Natural Microbial Exposure from the Earliest Natural Time Point Enhances Immune Development by Expanding Immune Cell Progenitors and Mature Immune Cells

Microbial experience fundamentally shapes immunity, particularly during the perinatal period when the immune system is underdeveloped, and novel microbial encounters are common. Most animal models are raised in specific pathogen-free (SPF) conditions with relatively uniform microbial communities. How SPF housing conditions alter early-life immune development relative to natural microbial exposure (NME) has not been thoroughly investigated. In this article, we compare immune development in SPF-raised mice with mice born from immunologically experienced mothers in microbially diverse environments. NME induced broad immune cell expansion, including naive cells, suggesting mechanisms besides activation-induced proliferation contribute to the increase in immune cell numbers. We found NME conditions also expanded immune cell progenitor cell populations in the bone marrow, suggesting microbial experience enhances immune development at the earliest stages of immune cell differentiation. Multiple immune functions characteristically impaired in infants were also enhanced by NME, including T cell memory and Th1 polarization, B cell class switching and Ab production, proinflammatory cytokine expression, and bacterial clearance after Listeria monocytogenes challenge. Collectively, our studies reveal numerous impairments in immune development in SPF conditions relative to natural immune development.

Circulating levels of cytokines and risk of cardiovascular disease: a Mendelian randomization study

Background

Epidemiological studies have linked various circulating cytokines to cardiovascular disease (CVD), which however remains uncertain whether these relationships represent causality or are due to bias. To address this question, we conducted a Mendelian randomization (MR) analysis to systematically investigate the causal effects of circulating cytokine levels on CVD development.

Methods

This study leveraged the summary statistic from respective genome-wide association study (GWAS) of 47 cytokines and four types of CVD. The cis-quantitative trait locus (cis-QTL) definition, derived from a GWAS meta-analysis comprising 31,112 participants of European descent, served as instruments for cytokines. A two-sample MR design was employed, followed by comprehensive sensitivity analyses to validate the robustness of results.

Results

The results of inverse-variance weighted method using cis-protein QTL (cis-pQTL) instruments, showed the causal effects of four cytokines (i.e., IL-1ra, MCSF, SeSelectin, SCF) on the risk of coronary artery disease (CAD). We also identified causal relationships between two cytokines (i.e., IL-2ra, IP-10) and heart failure (HF), as well as two cytokines (i.e., MCP-3, SeSelectin) and atrial fibrillation (AF), after controlling for false discovery rate (FDR). The use of cis-expression QTL (cis-eQTL) revealed additional causal associations between IL-1a, MIF and CAD, between IL-6, MIF, and HF, as well as between FGFBasic and AF. No significant sign was survived for stroke with FDR applied. Results were largely consistent across sensitivity analyses.

Conclusion

The present study provides supportive evidence that genetic predisposition to levels of certain cytokines causally affects the development of specific type of CVD. These findings have important implications for the creation of novel therapeutic strategies targeting these cytokines as a means of preventing and treating CVD.

The Common Cold and Influenza in Children: To Treat or Not to Treat?

The common cold, which is mostly caused by respiratory viruses and clinically represented by the symptoms of acute respiratory viral infections (ARVI) with mainly upper respiratory tract involvement, is an important problem in pediatric practice. Due to the high prevalence, socio-economic burden, and lack of effective prevention measures (except for influenza and, partially, RSV infection), ARVI require strong medical attention. The purpose of this descriptive literature review was to analyze the current practical approaches to the treatment of ARVI to facilitate the choice of therapy in routine practice. This descriptive overview includes information on the causative agents of ARVI. Special attention is paid to the role of interferon gamma as a cytokine with antiviral and immunomodulatory effects on the pathogenesis of ARVI. Modern approaches to the treatment of ARVI, including antiviral, pathogenesis-directed and symptomatic therapy are presented. The emphasis is on the use of antibody-based drugs in the immunoprophylaxis and immunotherapy of ARVI. The data presented in this review allow us to conclude that a modern, balanced and evidence-based approach to the choice of ARVI treatment in children should be used in clinical practice. The published results of clinical trials and systematic reviews with meta-analyses of ARVI in children allow us to conclude that it is possible and expedient to use broad-spectrum antiviral drugs in complex therapy. This approach can provide an adequate response of the child’s immune system to the virus without limiting the clinical possibilities of using only symptomatic therapy.

Maternal imprinting and determinants of neonates' immune function in the SEPAGES mother-child cohort

Introduction

Immune function in pregnancy is influenced by host-specific and environmental factors. This may impact fetal immune development, but the link between maternal and neonatal immune function is still poorly characterized. Here, we investigate the relationship between maternal and neonatal immune function, and identify factors affecting the association between maternal and child cytokine secretion.

Methods

In the French prospective cohort SEPAGES, blood samples were obtained from pregnant women (n=322) at gestational week 20 ± 4 and from their child at birth (n=156). Maternal and cord blood cytokine and chemokine (CK) levels were measured at baseline in all subjects and after T cell or dendritic cell activation with phytohemagglutinin or R848 (in total 29 and 27 measures in maternal and cord blood samples, respectively). Associations between environmental, individual factors and CK level were estimated by linear regression modeling. The maternal-cord blood CK relations were assessed by Pearson correlation and regression models.

Results

We observed that pregnant women and neonates displayed specific CK secretion profiles in the innate and adaptive compartments at baseline and upon activation. Activation of T cells in cord blood induced high levels of IL-2, but low levels of IFNγ, IL-13 or IL-10, in comparison to maternal blood samples. Elsewhere, neonatal innate immune responses were characterized by low production of IFNα, while productions of IL-1β, IL-6, IL-8, IL-10 and TNFα were higher than maternal responses. Strong correlations were observed between most CK after activation in maternal and cord blood samples. Strikingly, a statistical association between global mother and child cytokine profiles was evidenced. Correlations were observed between some individual CK of pregnant women and their children, both at baseline (MCP1, RANTES) and after activation with R848 (IL-6, IL-8 and IL-10). We looked for factors which could influence cytokine secretion in maternal or cord blood, and found that leucocyte counts, maternal age, pre-conception BMI, smoking and season were associated with the levels of several CK in mothers or children.

Discussion

Our study reveals in utero immune imprinting influencing immune responses in infants, opening the way to investigate the mechanisms responsible for this imprinting. Whether such influences have long lasting effects on children health warrants further investigation.

Chronic Home Radon Exposure Is Associated with Higher Inflammatory Biomarker Concentrations in Children and Adolescents

Children are particularly vulnerable to the deleterious impacts of toxic environmental exposures, though the effects of some rather ubiquitous toxins have yet to be characterized in youths. One such toxin, radon gas, is known to accumulate to hazardous levels in homes, and has been linked with the incidence of lung cancer in aging adults. However, the degree to which chronic home radon exposure may impact risk for health problems earlier in life is unknown. Herein, we explored the degree to which chronic home radon exposure relates to biomarkers of low-grade inflammation in 68 youths ages 6- to 14 years old residing in an area of the United States prone to high home radon concentrations. Parents completed a home radon test kit, and youths provided a saliva sample to assess concentrations of five biomarkers. Using a multiple regression approach, we found that greater radon exposure was specifically associated with higher levels of C-reactive protein (β = 0.31, p = 0.007) and interleukin-1β (β = 0.33, p = 0.016). The data suggested specificity in associations between chronic home radon exposure and different biomarkers of inflammatory activity and highlight a pathway which may confer risk for future mental and physical health maladies.

Host, technical, and environmental factors affecting QuantiFERON-TB Gold In-Tube performance in children below 5 years of age

Interferon-gamma release assays performance can be impaired by host-related, technical and environmental factors, but data in young children are limited. We performed a cross-sectional study of children < 5 years-of-age at risk of tuberculosis (TB), using QuantiFERON-TB Gold In-Tube (QFT-GIT) assays. The impact of the following was evaluated: (i) host-related [age; hematological parameters; erythrocyte sedimentation rate (ESR); C-reactive protein (CRP); and tobacco smoke exposure (TSE) based on serum cotinine concentrations], (ii) technical (pre-analytical delay) and (iii) environmental factors (annual season; monthly temperatures). Of 204 children, 35 (17.2%) were diagnosed with latent TB infection or TB disease. QFT-GIT results were indeterminate in 14 (6.9%) patients. In multivariate analysis, younger age and higher ESR were associated with lower positive control responses (beta: 0.247, p = 0.002 and - 0.204, p = 0.007, respectively), and increasing age was associated with lower rates of indeterminate QFT-GIT results [OR (95% CI) 0.948 (0.903-0.996) per month, p = 0.035]. In children with positive QFT-GIT results, average monthly temperatures correlated with antigen responses (r = 0.453, p = 0.020); also, antigen responses were lower in winter than in other seasons (p = 0.027). Serum cotinine concentrations determined in a subgroup of patients (n = 41) indicated TSE in 36 (88%), positive control responses being lower in children with TSE (p = 0.034). In children < 5 years-of-age, young age, elevated ESR, temperature, annual season and TSE can affect the performance of QFT-GIT assays.

Biomarkers Predictive of Metabolic Syndrome and Cardiovascular Disease in Childhood Cancer Survivors

The improvement in childhood cancer treatments resulted in a marked improvement in the survival of pediatric cancer patients. However, as survival increased, it was also possible to observe the long-term side effects of cancer therapies. Among these, metabolic syndrome is one of the most frequent long-term side effects, and causes high mortality and morbidity. Consequently, it is necessary to identify strategies that allow for early diagnosis. In this review, the pathogenetic mechanisms of metabolic syndrome and the potential new biomarkers that can facilitate its diagnosis in survivors of pediatric tumors are analyzed.

Alteration in cerebral blood flow, kynurenines with respect to mood profile in freshly recruited armed forces personnel

The present study is conducted to understand the association of mood profile with the kynurenine pathway (KP) metabolites, and cerebral hemodynamics in freshly recruited central armed forces personnel. Profile of Mood States questionnaire was utilized to assess mood profile, and Total Mood Disturbance (TMD) score was calculated. Transcranial Doppler was used to record blood flow velocity bilaterally of the middle cerebral artery. Chromatographic profile of the kynurenine metabolites was obtained in serum. Further, personnel were stratified according to sociodemographic variables (gender, age and diet) to observe the changes in their KP metabolic status. An activation of the kynurenic acid branch of the KP and the reduction in the mean blood flow velocity, and an increase in Gosling pulsatility index (PI) were observed in females having high TMD score. On gender comparative analysis, kynurenine metabolites of quinolinic acid branch and serotonin were significantly high in males. In males, with increase in age, a significant increase in the quinolinic acid branch of the KP was observed. Furthermore, a significant difference in level metabolites of the KP among the vegetarian and non-vegetarian groups was also observed. In conclusion we observed that increased TMD score was associated with cerebral hypoperfusion and higher vascular resistance along with activation of the KP. Our findings highlighted the importance of multi-facet brain function to showcase the close interaction of various dimensionalities and true picture of the assessee.

Cell saver blood transfusions may be associated with a decrease in inflammation and improved outcome measures in pediatric cardiac surgery patients

OBJECTIVE

Cardiopulmonary bypass (CPB) is a requisite for correction of congenital heart disease by open-heart surgery and induces a systemic inflammatory response that can lead to complications such as acute lung injury and acute kidney injury. In addition, blood transfusions are commonly required for this type of surgery, and they may further exacerbate this inflammatory response and increase morbidity and mortality. We hypothesized that, in contrast to red blood cells, intraoperative cell saver (CS) blood transfusions attenuate the post-CPB proinflammatory cytokine response.

METHODS

Serum cytokine concentrations of IL-10, IL-1RA, IL-6, IL-8, and TNF-α were measured at four time points (preoperatively and postoperatively on postoperative days 0, 1, and 2).

RESULTS

Anti-inflammatory IL-10 levels were significantly lower in the CS group on POD 0 than in the control group (mean 1083.2 pg/mL vs 2080.2 pg/mL, 95%CI 357.4-1636.6, p = .0026). Of the clinical parameters measured, mean BUN and creatinine levels on POD 2 were significantly lower in the CS group (13.79 vs 21.88, p = .004 and 0.45 vs 0.55, p = .055, respectively). In addition, the duration of milrinone use decreased by 80% in the CS group (0.20, 95%CI 0.04, 0.94; p = .048), the median time to extubation in hours was significantly lower in the CS group (3.5 vs 6.5; 95%CI -38.00, -0.50; p = .026), and hospital length of stay was decreased by 60% in the CS group (p = .003).

CONCLUSIONS

CS transfusions in children may lower postoperative anti-inflammatory IL-10 levels, possibly due to an overall decrease in proinflammatory state, and may be associated with improvements in renal and pulmonary functions.

Fluctuations of aeroallergen-specific immunoglobulins and children's allergic profiles: Japan Environment & Children's Study of a pilot cohort

BACKGROUND

Allergen-specific immunoglobulins have a crucial role in allergic diseases. Most wheeze episodes develop before school age, and allergic rhinitis later develops during early elementary school years. However, the clinical background and cytokine/chemokine profiles associated with changes in immunoglobulins during early school-age are poorly understood.

METHODS

This study used blood samples from children participating in the JECS Pilot Study. We examined nineteen kinds of aeroallergen-specific immunoglobulins (IgE, IgG1, IgG4, and IgA) levels in patients at age 6 and age 8. Fluctuations of Der f 1- and Cry j 1-specific immunoglobulins levels during the two periods were compared to assess the frequency of allergic statuses and clusters of cytokine/chemokine profiles.

RESULTS

The medians of aeroallergen-specific IgE levels did not fluctuate, and almost all IgG1 and IgG4 decreased. In IgA, four (e.g., Der f 1) increased, whereas the other four (e.g., Cry j 1) decreased. The ratio of the Der f 1-specific IgG1 level at age 8 to that at age 6 was higher in children with poor asthma control than in children with better asthma control. Moreover, the cytokine/chemokine cluster with relatively lower IL-33 and higher CXCL7/NAP2 was associated with lower Der f 1- and Cry j 1-specific IgG4 levels, but not IgE levels.

CONCLUSIONS

The cluster of cytokine/chemokine profiles characterized by lower IL-33 and higher CXCL7/NAP2 was associated with the maintenance of aeroallergen-specific IgG4 levels. This result provides a basis for considering the control of aeroallergen-specific immunoglobulins.

Inflammation and depression in young people: a systematic review and proposed inflammatory pathways

Depression onset peaks during adolescence and young adulthood. Current treatments are only moderately effective, driving the search for novel pathophysiological mechanisms underlying youth depression. Inflammatory dysregulation has been shown in adults with depression, however, less is known about inflammation in youth depression. This systematic review identified 109 studies examining the association between inflammation and youth depression and showed subtle evidence for inflammatory dysregulation in youth depression. Longitudinal studies support the bidirectional association between inflammation and depression in youth. We hypothesise multiple inflammatory pathways contributing to depression. More research is needed on anti-inflammatory treatments, potentially tailored to individual symptom profiles.

Perforin, COVID-19 and a possible pathogenic auto-inflammatory feedback loop

During COVID‐19 infection, reduced function of natural killer (NK) cells can lead to both compromised viral clearance and dysregulation of the immune response. Such dysregulation leads to overproduction of cytokines, a raised neutrophil/lymphocyte ratio and monocytosis. This in turn increases IL‐6 expression, which promotes scar and thrombus formation. Excess IL‐6 also leads to a further reduction in NK function through downregulation of perforin expression, therefore forming a pathogenic auto‐inflammatory feedback loop. The perforin/granzyme system of cytotoxicity is the main mechanism through which NK cells and cytotoxic T lymphocytes eliminate virally infected host cells, as well as being central to their role in regulating immune responses to microbial infection. Here, we present epidemiological evidence suggesting an association between perforin expression and resistance to COVID‐19. In addition, we outline the manner in which a pathogenic auto‐inflammatory feedback loop could operate and the relationship of this loop to genes associated with severe COVID‐19. Such an auto‐inflammatory loop may be amenable to synergistic multimodal therapy.

Robust innate responses to SARS-CoV-2 in children resolve faster than in adults without compromising adaptive immunity

SARS-CoV-2 infection in children is less severe than it is in adults. We perform a longitudinal analysis of the early innate responses in children and adults with mild infection within household clusters. Children display fewer symptoms than adults do, despite similar initial viral load, and mount a robust anti-viral immune signature typical of the SARS-CoV-2 infection and characterized by early interferon gene responses; increases in cytokines, such as CXCL10 and GM-CSF; and changes in blood cell numbers. When compared with adults, the antiviral response resolves faster (within a week of symptoms), monocytes and dendritic cells are more transiently activated, and genes associated with B cell activation appear earlier in children. Nonetheless, these differences do not have major effects on the quality of SARS-CoV-2-specific antibody responses. Our findings reveal that better early control of inflammation as observed in children may be key for rapidly controlling infection and limiting the disease course.

Ontogeny of plasma cytokine and chemokine concentrations across the first week of human life

Introduction/background & aims:

Early life is marked by distinct and rapidly evolving immunity and increased susceptibility to infection. The vulnerability of the newborn reflects development of a complex immune system in the face of rapidly changing demands during the transition to extra-uterine life. Cytokines and chemokines contribute to this dynamic immune signaling network and can be altered by many factors, such as infection. Newborns undergo dynamic changes important to health and disease, yet there is limited information regarding human neonatal plasma cytokine and chemokine concentrations over the first week of life. The few available studies are limited by small sample size, cross-sectional study design, or focus on perturbed host states like severe infection or prematurity. To characterize immune ontogeny among healthy full-term newborns, we assessed plasma cytokine and chemokine concentrations across the first week of life in a robust longitudinal cohort of healthy, full-term African newborns.

Methods:

We analyzed a subgroup of a cohort of healthy newborns at the Medical Research Council Unit in The Gambia (West Africa; N = 608). Peripheral blood plasma was collected from all study participants at birth (day of life (DOL) 0) and at one follow-up time point at DOL 1, 3, or 7. Plasma cytokine and chemokine concentrations were measured by bead-based cytokine multiplex assay. Unsupervised clustering was used to identify patterns in plasma cytokine and chemokine ontogeny during early life.

Results:

We observed an increase across the first week of life in plasma Th1 cytokines such as IFNγ and CXCL10 and a decrease in Th2 and anti-inflammatory cytokines such as IL-6 and IL-10, and chemokines such as CXCL8. In contrast, other cytokines and chemokines (e.g. IL-4 and CCL5, respectively) remained unchanged during the first week of life. This robust ontogenetic pattern did not appear to be affected by gestational age or sex.

Conclusions:

Ontogeny is a strong driver of newborn plasma-based levels of cytokines and chemokines throughout the first week of life with a rising IFNγ axis suggesting post-natal upregulation of host defense pathways. Our study will prove useful to the design and interpretation of future studies aimed at understanding the neonatal immune system during health and disease.

Non-IFNγ Whole Blood Cytokine Responses to Mycobacterium tuberculosis Antigens in HIV-exposed Infants

BACKGROUND

HIV-exposed uninfected (HEU) infants have increased risk of tuberculosis (TB). Testing for Mycobacterium tuberculosis (Mtb) infection is limited by reduced Quantiferon (QFT) sensitivity in infants and tuberculin skin test (TST) cross-reactivity with Bacillus Calmette-Guérin vaccine. Our objective is to assess if non-IFNγ cytokine responses to Mtb-specific antigens have improved sensitivity in detecting Mtb infection in HEU infants compared with QFT.

METHODS

HEU infants were enrolled in a randomized clinical trial of isoniazid preventive therapy (IPT) to prevent Mtb infection in Kenya (N = 300) and assessed at 12 months postrandomization (14 months of age) by TST and QFT-Plus. Non-IFNγ cytokine secretion (IL2, TNF, IP10, N = 229) in QFT-Plus supernatants was measured using Luminex assay. Logistic regression was used to assess the effect of IPT on Mtb infection outcomes in HEU infants.

RESULTS

Three of 251 (1.2%) infants were QFT-Plus positive. Non-IFNγ Mtb antigen-specific responses were detected in 12 additional infants (12/229, 5.2%), all TST negative. IPT was not associated with Mtb infection defined as any Mtb antigen-specific cytokine response (odds ratio = 0.7, P = 0.54). Mtb antigen-specific IL2/IP10 responses had fair correlation (τ = 0.25). Otherwise, non-IFNγ cytokine responses had minimal correlation with QFT-Plus and no correlation with TST size.

CONCLUSIONS

We detected non-IFNg Mtb antigen-specific T-cell responses in 14-month HEU infants. Non-IFNg cytokines may be more sensitive than IFNg in detecting infant Mtb infection. IPT during the first year of life was not associated with Mtb infection measured by IFNg, IL2, IP10 and TNF Mtb-specific responses.

Complex biological patterns of soluble cytokines and CD163 in childhood necessitating age-specific reference intervals for evidence-based clinical interpretation

BACKGROUND

Cytokine measurements to support clinical laboratory and research investigations have become increasingly common in pediatrics. However, there is a paucity of accurate pediatric reference intervals (RIs) essential to the interpretation of cytokine results. To address this gap, here, we establish age- and sex-specific pediatric reference values for clinically relevant inflammatory markers including CD163, and the cytokines IL-1β, IL-6, IL-10, IL-18, TNF-α, IFN-γ, and CXCL-9.

METHODS

Healthy children and adolescents (n = 311, 1-19 years) were recruited as part of the Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER) study. Multi-analyte measurements in plasma and analytical performance verification were conducted on the ProteinSimple® Ella™ automated immunoassay platform (Bio-Techne, MN, USA). Age- and sex-specific RIs were calculated based on Clinical and Laboratory Standards Institute guidelines. Additionally, 75th and 95th percentile cut-offs were determined.

RESULTS

Three types of reference value distributions were observed: (a) consistent levels throughout age and sex: IL-6, and IFN-γ, (b) gradual decline in concentration with age: CD163, TNF-α, CXCL-9, and IL-10, (c) significantly higher concentrations during ages 4-14 years than earlier and later ages: IL-1β and IL-18. Reference values for CXCL-9, IL-10, and TNF-α under 8 years of age differed significantly from older children. CD163, IL-18 and IL-1β required three age partitions. CD163 demonstrated significant sex differences in ages 8-13 years.

CONCLUSION

The circulating profile of cytokines in children is complex and can vary by age and sex. This necessitates careful interpretation of test results based on age and/or sex specific RIs facilitating more accurate clinical decision making.

Neonatal BCG vaccination and infections in the first year of life: the MIS BAIR randomised controlled trial

BACKGROUND

Bacille Calmette-Guérin (BCG) vaccination has beneficial off-target effects that may include protecting against non-mycobacterial infectious diseases. We aimed to determine whether neonatal BCG vaccination reduces lower respiratory tract infections (LRTI) in infants in the MIS BAIR trial.

METHODS

In this investigator-blinded trial, neonates in Australia were randomised to receive BCG-Denmark vaccination or no BCG at birth. Episodes of LRTI were determined by symptoms reported in parent-completed 3-monthly questionnaires over the first year of life. Data were analysed by intention-to-treat using binary regression. Clinicaltrials.gov (NCT01906853).

RESULTS

From August 2013 to September 2016, 1272 neonates were randomised to the BCG vaccination (n=637) or control (n=635) group. The proportion of participants with an episode of LRTI in the first year of life among BCG-vaccinated infants was 54.8% compared to 58.0% in the control group, resulting in a risk difference of -3.2 (95% CI -9.0 to 2.6) after multiple imputation. There was no interaction observed between the primary outcome and sex, maternal BCG or the other pre-specified effect modifiers.

CONCLUSIONS

Based on the findings of this trial, there is insufficient evidence to support the use of neonatal BCG vaccination to prevent LRTI in the first year of life in high-income settings.

dmLT Adjuvant Enhances Cytokine Responses to T Cell Stimuli, Whole Cell Vaccine Antigens and Lipopolysaccharide in Both Adults and Infants

Enhancement of mucosal immune responses in children and infants using novel adjuvants such as double mutant heat labile toxin (dmLT) is an important goal in the enteric vaccine field. dmLT has been shown to enhance mucosal IgA responses to the oral inactivated enterotoxigenic Escherichia coli (ETEC) vaccine ETVAX. dmLT can enhance IL-17A production from adult T cells, which may increase the production and secretion of mucosal IgA antibodies. However, the adjuvant mechanism remains to be fully elucidated and might differ between infants and adults due to age-related differences in the development of the immune system. The main objective of this study was to determine how dmLT influences antigen presenting cells and T cells from infants compared to adults, and the role of IL-1β for mediating the adjuvant activity. Peripheral blood mononuclear cells (PBMCs) from Bangladeshi infants (6-11 months) and adults (18-40 years) were stimulated with the mitogen phytohaemagglutinin (PHA), the superantigen Staphylococcal enterotoxin B (SEB), ETVAX whole cell component (WCC) or E. coli lipopolysaccharide (LPS) ± dmLT, and cytokine production was measured using ELISA and electrochemiluminescence assays. The adjuvant dmLT significantly enhanced SEB- and PHA-induced IL-17A, but not IFN-γ responses, in PBMCs from both infants and adults. Blocking experiments using an IL-1 receptor antagonist demonstrated the importance of IL-1 signaling for the adjuvant effect. dmLT, ETVAX WCC and LPS induced dose-dependent IL-1β responses of comparable magnitudes in infant and adult cells. Depletion experiments suggested that IL-1β was mainly produced by monocytes. dmLT enhanced IL-1β responses to low doses of WCC and LPS, and the adjuvant effect appeared over a wider dose-range of WCC in infants. dmLT and WCC also induced IL-6, IL-23 and IL-12p70 production in both age groups and dmLT tended to particularly enhance IL-23 responses to WCC. Our results show that dmLT can induce IL-1β as well as other cytokines, which in turn may enhance IL-17A and potentially modulate other immunological responses in both infants and adults. Thus, dmLT may have an important function in promoting immune responses to the ETVAX vaccine, as well as other whole cell- or LPS-based vaccines in infants in low- and middle-income countries.

Geriatrics and COVID-19

Since December 2019, a novel coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has begun to infect people. The virus first occurred in Wuhan, China, but the whole world is now struggling with the pandemic. Over 13 million confirmed cases and 571,000 deaths have been reported so far, and this number is growing. Older people, who constitute a notable proportion of the world population, are at an increased risk of infection because of altered immunity and chronic comorbidities. Thus, appropriate health care is necessary to control fatalities and spread of the disease in this specific population. The chapter provides an overview of diagnostic methods, laboratory and imaging findings, clinical features, and management of COVID-19 in aged people. Possible mechanisms behind the behavior of SARS-CoV-2 in the elderly include immunosenescence and related impaired antiviral immunity, mature immunity and related hyper-inflammatory responses, comorbidities and their effects on the functioning of critical organs/systems, and the altered expression of angiotensin-converting enzyme 2 (ACE2) that acts as an entry receptor for SARS-CoV-2. This evidence defines the herding behavior of COVID-19 in relation to ACE2 under the influence of immune dysregulation. Then, identifying the immunogenetic factors that affect the disease susceptibility and severity and as well as key inflammatory pathways that have the potential to serve as therapeutic targets needs to remain an active area of research.

Cytokines in saliva as biomarkers of oral and systemic oncological or infectious diseases: A systematic review

Recent evidence suggests that salivary cytokines provide information about both oral conditions and systemic diseases. This review summarizes evidence for the use of salivary cytokines as biomarkers for oral and systemic diseases. We included studies in adults and children with a focus on the latter, due to the importance of non-invasive diagnostic methods in the paediatric age group. A systematic review was performed using Medline and Web of Science covering the period of January 1996 to December 2019 according to the preferred reporting items for systematic reviews. Thirty-four studies were included in the final analysis, for a total of 2407 patients and healthy controls. Pro-inflammatory cytokines including interleukin (IL)-1β, IL-2, IL-6 and tumor necrosis factor (TNF)-α were associated with the severity of oral mucosal tissue damage in patients with cancer, and IL-1β may be an early marker of graft-versus-host disease. Salivary interferon-γ levels were correlated with oral complications and the presence of the underlying disease in HIV-infected individuals, and salivary cytokine patterns may be useful for diagnosing tuberculosis. In summary, current data illustrate that salivary cytokines are associated with oral inflammation, making them potential biomarkers for disease diagnosis and treatment efficacy. Because of the simplicity of saliva collection, this method may be useful in pediatric studies and in resource-limited settings.

Low-dose steroids are associated with indeterminate QuantiFERON-TB Gold In-Tube assay results in immunocompetent children

Immunocompromised status can result in indeterminate QuantiFERON-TB Gold In-Tube (QFT-GIT) results, but the association of indeterminate results with immunocompetent status in children is unknown. Therefore, we aimed to identify factors associated with indeterminate QFT-GIT results for immunocompetent children. We conducted a retrospective chart review of children (aged ≤ 18 years) who underwent QFT-GIT between September 2006 and July 2017 at the Severance Hospital, Seoul, South Korea. Of the 2037 QFT-GIT assays included in the present study, 7.7% yielded indeterminate QFT-GIT results. Multivariable logistic regression analysis identified younger age (OR 0.88; 95% CI 0.836–0.927; P < 0.001), elevated white blood cell (WBC) count (OR 1.066; 95% CI 1.020–1.115; P = 0.005), decreased albumin levels (OR 0.505; 95% CI 0.316–0.807; P = 0.004), and low-dose steroid therapy (< 1 mg/kg per day of prednisone or equivalent for < 2 weeks) (OR 76.146; 95% CI 8.940–648.569; P < 0.001) as significant factors influencing indeterminate results. Younger age, high WBC count, low albumin levels, and low-dose steroid therapy were associated with indeterminate QFT-GIT results. Low-dose steroid therapy had the highest OR for the indeterminate results compared to other significant risk factors. Our study suggests that screening for steroid doses is important prior to performing interferon-gamma release assays for immunocompetent children.

Silence of the Lambs: The Immunological and Molecular Mechanisms of COVID-19 in Children in Comparison with Adults

Children infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can suffer from severe coronavirus disease 2019 (COVID-19). However, compared to adults and the elderly, susceptibility to SARS-CoV-2 infection in children seems to be lower; when infection does develop, most infected children remain asymptomatic or develop a mild disease. Understanding why children seem generally protected from severe COVID-19 and only rarely develop clinical conditions that can cause hospitalization, admission to the pediatric intensive care unit and death can be important. More details on the mechanism of action of SARS-CoV-2 could be defined. Moreover, the role played by children in virus diffusion should be better analyzed, and the development of effective preventive and therapeutic measures against COVID-19 could be favored. The main aim of this paper is to discuss the present knowledge on immunological and molecular mechanisms that could explain differences in COVID-19 clinical manifestations between children and adults. Literature analysis showed that although most children are clearly protected from the development of severe COVID-19, the reasons for this peculiarity are not fully understood. Developmental variations in immune system function together with the potential role of repeated antigen stimulation in the first periods of life on innate immunity are widely studied. As the few children who develop the most severe form of pediatric COVID-19 have certain alterations in the immune system response to SARS-CoV-2 infection, studies about the relationships between SARS-CoV-2 and the immune system of the host are essential to understand the reasons for the age-related differences in the severity of COVID-19.

The safety and efficacy of BCG encapsulated alginate particle (BEAP) against M.tb H37Rv infection in Macaca mulatta : A pilot study

Due to the limited utility of Bacillus Calmette–Guérin (BCG), the only approved vaccine available for tuberculosis, there is a need to develop a more effective and safe vaccine. We evaluated the safety and efficacy of a dry powder aerosol (DPA) formulation of BCG encapsulated alginate particle (BEAP) and the conventional intradermal BCG immunization in infant rhesus macaques (Macaca mulatta). The infant macaques were immunized intratracheally with DPA of BEAP into the lungs. Animals were monitored for their growth, behaviour, any adverse and allergic response. The protective efficacy of BEAP was estimated by the ex-vivo H37Rv infection method. Post-immunization with BEAP, granulocytes count, weight gain, chest radiography, levels of liver secreted enzymes, cytokines associated with inflammation like TNF and IL-6 established that BEAP is non-toxic and it does not elicit an allergic response. The T cells isolated from BEAP immunized animals’ blood, upon stimulation with M.tb antigen, secreted high levels of IFN-γ, TNF, IL-6 and IL-2. The activated T cells from BEAP group, when co-cultured with M.tb infected macrophages, eliminated largest number of infected macrophages compared to the BCG and control group. This study suggests the safety and efficacy of BEAP in Non-human primate model.

RAISE study protocol: a cross-sectional, multilevel, neurobiological study of resilience after individual stress exposure

INTRODUCTION

This paper describes the protocol for an ongoing project funded by the Royal Society, the Resilience After Individual Stress Exposure (RAISE) study; which aims to examine the factors and mechanisms that facilitate resilient functioning after childhood adversity (CA).

METHODS AND ANALYSIS

We aim to recruit up to 200 participants. We will use dimension reduction techniques (principal component analysis) on standard-normally transformed individual parameters of mental health, social functioning and CA to calculate a composite measure of adaptive (ie, 'resilient') psychosocial functioning. To examine the neuroimmune responses to stress and their relationship with the brain and social environment, we will use a well validated functional MRI task; the Montreal imaging stress task and venepuncture. We will run group or dimensional comparisons in multiple levels of biological and psychological outcomes, as well as mediation and moderation analyses to study how key biological systems (ie, the hypothalamic-pituitary-adrenal axis and the immune system) interrelate and interact with brain function and social influences in order to facilitate resilient functioning after CA. We hypothesise that resilient functioning will be facilitated by reduced morning cortisol and cytokine levels before and after the stressor and improved neural responses to such stress, as well as increased gray matter volume in the hippocampus and prefrontal cortex, enhanced inhibitory control and emotion regulation, and more friendship and family support.

ETHICS AND DISSEMINATION

This study has been reviewed and given favourable opinion by the National Research Ethics Service, NRES Committee East of England-Cambridge Central and external reviewers from the Royal Society (RGF\R1\180064 and RGF\EA\180029). The results of the RAISE study will be disseminated through (1) publications in scientific peer reviewed journals, (2) presentations on relevant scientific conferences and meetings, (3) publications and presentations for the general public and (4) through social media.

Plasma Cytokine Profiling to Predict Steroid Resistance in Pediatric Nephrotic Syndrome

Introduction

Glucocorticoids (GCs) are the primary treatment for nephrotic syndrome (NS), although ∼10% to 20% of children develop steroid-resistant NS (SRNS). Unfortunately, there are no validated biomarkers able to predict SRNS at initial disease presentation. We hypothesized that a plasma cytokine panel could predict SRNS at disease presentation, and identify potential pathways regulating SRNS pathogenesis.

Methods

Paired plasma samples were collected from 26 children with steroid-sensitive NS (SSNS) and 14 with SRNS at NS presentation and after ∼7 weeks of GC therapy, when SSNS versus SRNS was clinically determined. Plasma cytokine profiling was performed with a panel of 27 cytokines.

Results

We identified 13 cytokines significantly different in Pretreatment SSNS versus SRNS samples. Statistical modeling identified a cytokine panel (interleukin [IL]-7, IL-9, monocyte chemoattractant protein–1 [MCP-1]) able to discriminate between SSNS and SRNS at disease presentation (receiver operating characteristic [ROC] value = 0.846; sensitivity = 0.643; specificity = 0.846). Furthermore, GC treatment resulted in significant decreases in plasma interferon-γ (IFN-γ), tumor necrosis factor–α (TNF-α), IL-7, IL-13, and IL-5 in both SSNS and SRNS patients.

Conclusions

These studies suggest that initial GC treatment of NS reduces the plasma cytokines secreted by both CD4⁺ T_H1 cells and T_H2 cells, as well as CD8⁺ T cells. Importantly, a panel of 3 cytokines (IL-7, IL-9, and MCP-1) was able to predict SRNS prior to GC treatment at disease presentation. Although these findings will benefit from validation in a larger cohort, the ability to identify SRNS at disease presentation could greatly benefit patients by enabling both avoidance of unnecessary GC-induced toxicity and earlier transition to more effective alternative treatments.

Targeting the eCIRP/TREM-1 interaction with a small molecule inhibitor improves cardiac dysfunction in neonatal sepsis

Background

Neonatal sepsis and the associated myocardial dysfunction remain a leading cause of infant mortality. Extracellular cold-inducible RNA-binding protein (eCIRP) acts as a ligand of triggering receptor expressed on myeloid cells-1 (TREM-1). M3 is a small CIRP-derived peptide that inhibits the eCIRP/TREM-1 interaction. We hypothesize that the eCIRP/TREM-1 interaction in cardiomyocytes contributes to sepsis-induced cardiac dysfunction in neonatal sepsis, while M3 is cardioprotective.

Methods

Serum was collected from neonates in the Neonatal Intensive Care Unit (NICU). 5–7-day old C57BL/6 mouse pups were used in this study. Primary murine neonatal cardiomyocytes were stimulated with recombinant murine (rm) CIRP with M3. TREM-1 mRNA and supernatant cytokine levels were assayed. Mitochondrial oxidative stress, ROS, and membrane potential were assayed. Neonatal mice were injected with rmCIRP and speckle-tracking echocardiography was conducted to measure cardiac strain. Sepsis was induced by i.p. cecal slurry. Mouse pups were treated with M3 or vehicle. After 16 h, echocardiography was performed followed by euthanasia for tissue analysis. A 7-day survival study was conducted.

Results

Serum eCIRP levels were elevated in septic human neonates. rmCIRP stimulation of cardiomyocytes increased TREM-1 gene expression. Stimulation of cardiomyocytes with rmCIRP upregulated TNF-α and IL-6 in the supernatants, while this upregulation was inhibited by M3. Stimulation of cardiomyocytes with rmCIRP resulted in a reduction in mitochondrial membrane potential (MMP) while M3 treatment returned MMP to near baseline. rmCIRP caused mitochondrial calcium overload; this was inhibited by M3. rmCIRP injection impaired longitudinal and radial cardiac strain. Sepsis resulted in cardiac dysfunction with a reduction in cardiac output and left ventricular end diastolic diameter. Both were improved by M3 treatment. Treatment with M3 attenuated serum, cardiac, and pulmonary levels of pro-inflammatory cytokines compared to vehicle-treated septic neonates. M3 dramatically increased sepsis survival.

Conclusions

Inhibition of eCIRP/TREM-1 interaction with M3 is cardioprotective, decreases inflammation, and improves survival in neonatal sepsis.

Trial registration Retrospectively registered.

Reduced development of COVID-19 in children reveals molecular checkpoints gating pathogenesis illuminating potential therapeutics

The reduced development of COVID-19 for children compared to adults provides some tantalizing clues on the pathogenesis and transmissibility of this pandemic virus. First, ACE2, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor, is reduced in the respiratory tract in children. Second, coronavirus associated with common colds in children may offer some protection, due to cross-reactive humoral immunity and T cell immunity between common coronaviruses and SARS-CoV-2. Third, T helper 2 immune responses are protective in children. Fourth, surprisingly, eosinophilia, associated with T helper 2, may be protective. Fifth, children generally produce lower levels of inflammatory cytokines. Finally, the influence of the downturn in the global economy, the impact of living in quarters among families who are the most at risk, and factors including the openings of some schools, are considered. Those most disadvantaged socioeconomically may suffer disproportionately with COVID-19.

Questioning Cause and Effect: Children with Severe Asthma Exhibit High Levels of Inflammatory Biomarkers Including Beta-Hexosaminidase, but Low Levels of Vitamin A and Immunoglobulins

Asthma affects over 8% of the pediatric population in the United States, and Memphis, Tennessee has been labeled an asthma capital. Plasma samples were analyzed for biomarker profiles from 95 children with severe asthma and 47 age-matched, hospitalized nonasthmatic controls at Le Bonheur Children's Hospital in Memphis, where over 4000 asthmatics are cared for annually. Asthmatics exhibited significantly higher levels of periostin, surfactant protein D, receptor for advanced glycation end products and β-hexosaminidase compared to controls. Children with severe asthma had lower levels of IgG1, IgG2 and IgA, and higher levels of IgE compared to controls, and approximately half of asthmatics exhibited IgG1 levels that were below age-specific norms. Vitamin A levels, measured by the surrogate retinol-binding protein, were insufficient or deficient in most asthmatic children, and correlated positively with IgG1. Which came first, asthma status or low levels of vitamin A and immunoglobulins? It is likely that inflammatory disease and immunosuppressive drugs contributed to a reduction in vitamin A and immunoglobulin levels. However, a nonmutually exclusive hypothesis is that low dietary vitamin A caused reductions in immune function and rendered children vulnerable to respiratory disease and consequent asthma pathogenesis. Continued attention to nutrition in combination with the biomarker profile is recommended to prevent and treat asthma in vulnerable children.

Umbilical cord interleukin-6 predicts outcome in very low birthweight infants in a high HIV-burden setting: a prospective cohort study

OBJECTIVES

South Africa has a double burden of high neonatal mortality and maternal HIV prevalence. Common to both is a proinflammatory in utero and perinatal milieu. The aim of this study was to determine cytokine profiles in HIV exposed (HE) and HIV unexposed (HU) very low birthweight (VLBW) infants and to determine whether these were associated with predischarge outcomes.

DESIGN

Single-centre, prospective cohort study conducted from 1 June 2017 to 31 January 2019.

PATIENTS

Inborn infants with birth weight of <1500 g were enrolled and cord blood was collected for interleukin (IL)-6 and tumour necrosis factor alpha (TNF-α) assays. Participants provided informed consent and ethics approval was obtained.

OUTCOME MEASURES

The primary outcome was umbilical cord cytokine levels according to maternal HIV status. Secondary outcomes included death and/or serious neonatal infection, necrotising enterocolitis, intraventricular haemorrhage, periventricular leucomalacia, chronic lung disease and haemodynamically significant patent ductus arteriosus before discharge.

RESULTS

A total of 279 cases were included with 269 cytokine assays performed on 122 HEs and 147 HUs. Median IL-6 levels were 53.0 pg/mL in HEs and 21.0 pg/mL in HUs (p=0.07). Median TNF-α levels were 7.2 pg/mL in HEs and 6.5 pg/mL in HUs (p=0.6). There was significantly more late-onset sepsis in the HE group compared with the HU group (41.2% vs 27.9%) (p=0.03). IL-6 levels were significantly higher for those with any adverse outcome (p=0.006) and death and/or any adverse outcome (p=0.0001). TNF-α levels did not differ according to predischarge outcomes.

CONCLUSION

There is no significant difference in IL-6 and TNF-α levels in cord blood of HE compared with HU VLBWs. However, IL-6 levels are significantly higher in VLBWs with adverse predischarge outcomes, and VLBW HEs are at increased risk of adverse predischarge outcomes compared with HUs, particularly late-onset sepsis.

Salivary Cytokine Profile as a Possible Predictor of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is characterized by neurodevelopmental disorders and alterations in immune function and cytokine levels. The aim of this study is to determine the salivary levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor α (TNFα), monocyte chemoattractant protein-1 (MCP-1), Regulated on Activation, Normal T-cell Expressed and Secreted (RANTES), and Eotaxin in children with ASD and in healthy controlsto assess their predictive potential. We explored correlations between the cytokine levels and the neurodevelopmental disorders related to ASD. The study comprised 19 children with ASD and 19 typically developing (TD) ones. We analyzed salivary levels of IL-1β, IL-6, IL-8, TNFα, MCP-1, RANTES, and eotaxin on Luminex with custom-designed 7-plex kits. The level of RANTES in ASD children was significantly lower than those of TD. In TDs, the salivary levels of IL-1β, MCP-1, and TNFα correlated positively with age. In ASD, the cytokine levels did not correlate with age. There were statistically significant differences between the RANTES level and aggression and gait disturbances, between IL-8 level and fixations/stimulations, and between IL-1β level and no active speech. The levels of the cytokine detected can manifest both systemic and local changes related to ASD. The cytokine pattern cannot be used as a sole ASD predictor, but the salivary levels may be helpful in categorizing the ASD subtype.

Cytokine changes during treatment of anti-Caspr2 encephalitis: a case report

BACKGROUND

Cytokines are effective molecules of immune reactions. They work in inflammatory sites as well as circulate in the blood. Cytokines in the cerebrospinal fluid have been suggested to be markers of autoimmune encephalitis and reflect disease progression. However, studies on blood cytokines in autoimmune encephalitis are scarce. We report a case presenting with serial changes in blood cytokine levels in a male patient with anti-contactin-associated protein 2 (Caspr2) encephalitis.

CASE PRESENTATION

A 61-year-old man without systemic disease presented with ataxia and speech disturbance 1 week. After admission, he further developed visual hallucinations, psychosis, and consciousness deterioration. Brain magnetic resonance imaging and infection and tumor surveillances were negative. 18F-fluorodeoxyglucose positron emission tomography of brain revealed frontal and occipital hypometabolism and anterior cingulate gyrus and mesial temporal hypermetabolism. Autoimmune studies confirmed Caspr2 antibodies in his blood. After receiving a diagnosis of anti-Caspr2 encephalitis, the patient received steroids, plasmapheresis, and zonisamide. He recovered well and was totally independent 6 months after disease onset. A cytokine profiler array kit was used to investigate neuroimmune mechanisms during the disease course. Several cytokines showed significant changes in plasma levels, such as B cell activating factor for B cell proliferation; thymus and activation-regulated chemokine for T cell chemoattraction; soluble CD40 ligand for Th2 cell mediation; C5/C5a for complement activation; brain-derived neurotrophic factor for neuronal survival response; and dipeptidyl peptidase 4, retinol binding protein, dickkopf-related protein, and epidermal growth factor for response to environmental provocation. The concentration of cytokines was verified using Luminex multiplexing assay.

CONCLUSIONS

Due to their easy accessibility, blood cytokines are potential biomarkers of autoimmune encephalitis. Based on the investigating platform of this single case study, future larger scale studies are warranted.

A Novel Utility to Correct for Plate/Batch/Lot and Nonspecific Binding Artifacts in Luminex Data

Cytokines and other secreted soluble proteins are routinely assayed as fluorescence intensities on the Luminex (Luminex, Austin, TX) platform. As with any immunoassay, a portion of the measured Ab binding can be nonspecific. Use of spiked-in microbead controls (e.g., AssayChex Process, Control Panel; Radix Biosolutions, Georgetown, TX) can determine the level of nonspecific binding on a per specimen basis. A statistical approach for correction of this assay's nonspecific binding artifact was first described in earlier work. The current paper describes a novel utility written in the R language (https://www.r-project.org), that refines correction for nonspecific binding in three important ways: 1) via local polynomial regression, the utility allows for curvature in relationships between soluble protein median fluorescence intensities and nonspecific binding median fluorescence intensities; 2) to stabilize correction, the fit of the nonlinear regression function is obtained via repeated cross-validation; and 3) the utility addresses possible bias due to technical error in measured nonspecific binding. The utility first logarithm transforms and then removes plate/batch/lot artifacts from median fluorescence intensities prior to correction for nonspecific binding, even when plates/batches/lots are unbalanced with respect to experimental factors of interest. Continuous (e.g., age) and categorical (e.g., diagnosis) covariates are accommodated in plate/batch/lot artifact correction. We present application of the utility to a panel of 62 cytokines in a sample of human patients diagnosed with systemic sclerosis and to an experiment that examined multiple lots of a human 51-cytokine panel. The R script for our new utility is publicly available for download from the web.

Variability of ex-vivo stimulated T-cells secretory profile in healthy subjects

Peripheral blood lymphocytes (PBL) are able to synthesize various cytokines that play key roles in the immune response and intercellular signaling. Since alterations in cytokine production and/or activity occur in many pathological processes, the study of cytokine synthetic capacity of PBL is a valuable tool for assessing the immune profile. In this paper, we aimed to investigate the variability of interleukin-2 (IL-2), tumor necrosis factor-alpha (TNF-α) and interferon gamma (IFN-γ) synthetic capacity of CD4+/CD8+ T-cells stimulated ex-vivo in healthy subjects, by means of a commercial intracellular cytokine staining (ICS) protocol. Peripheral blood mononuclear cells were isolated from 16 healthy subjects by Ficoll gradient centrifugation and activated ex-vivo with PMA/Ionomycin/Brefeldin-A for 4 hours. Activated PBL were surface-stained for CD3/CD4/CD8, fixed and permeabilized. ICS was performed using anti-human IL-2/TNF-α/IFN-γ and samples were analyzed on a BD-FACSAria-III flow cytometer. We recorded high post-isolation and post-activation mean viabilities: 82.1% and 82.4% respectively, p=0.84. Both CD4+/CD8+ subpopulations were found to partially produce each of the three cytokines, but in different proportions. On average, a significantly greater percentage of CD4+ cells was shown to produce IL-2 and TNF-α, compared with CD8+ cells (61.5%+/-5.8 vs. 25%+/-5.6 and 26.9%+/-11 vs. 7.5%+/-3.3 respectively, p---lt---0.0001 for both). Contrarily, IFN-γ was produced by a higher proportion of CD8+ cells (8.4%+/-3.9 vs. 6.8%+/-3.2, p=0.01). These results show that the employed ICS protocol elicits a satisfactory and consistent cytokine response from PBL of healthy subjects. The collected data may be used to outline a preliminary reference range for future studies on both healthy/pathological subjects.

Ontogeny of cytokine responses to PHA from birth to adulthood

BACKGROUND

Altered production of cytokines is believed to contribute to early childhood susceptibility to infection. The aim of this study was to get further insight into the developmental patterns of cytokine responses from birth to adulthood.

METHODS

The expression levels of 13 cytokines were compared in the supernatants of phytohemaggluttinin (PHA)-stimulated whole blood from healthy neonates (cord blood, n = 8), infants ( < 1-year-old, n = 20), and school-aged children (3-15 y; n = 20). Five adults were used as reference.

RESULTS

While Th1, Th2, and Th17 cytokine levels increased progressively from birth to childhood (Mann-Whitney, p < 0.003), high IL-10 secretion at birth dropped to low adult levels in infants (p < 0.004) such that a negative correlation between IL-10 and Th1, Th2, and Th17 cytokine levels at birth (Spearman's correlation, r < -0.70, p < 0.01) converted to a positive correlation in infants (r > 0.60, p < 0.001). Finally, high IL-2, IL-7, and Granulocyte-Colony Stimulating factor (G-CSF) cytokine levels at birth decreased steadily over the first year of life (Mann-Whitney, p ≤ 0.001).

CONCLUSION

The most noticeable result of the study is the rapid shift from enhanced IL-10 secretion capacity at birth toward balanced IL-10/Th1/Th2/Th17 cytokine levels early in life. This change appears an essential precondition to fight pathogens and at the same time to avoid overwhelming inflammatory reactions.

QuantiFERON®-TB Gold In-Tube reliability for immigrants with parasitic infections in Boston, USA

SETTING

Accurate testing and treatment for latent tuberculous infection is necessary for tuberculosis elimination. Certain parasite infections are associated with increased tuberculin skin test positivity; species-specific effects on QuantiFERON®-TB Gold In-Tube (QGIT) have not been described.

OBJECTIVE

To determine whether infection with helminths or protozoa affects QGIT results.

DESIGN

We retrospectively analyzed QGIT and parasite testing results for immigrants screened in Boston, MA, USA, from 2012 to 2017. We also prospectively measured cytokines in QGIT supernatants for a subset (n = 68) with 1) helminths, 2) Blastocystis hominis, 3) other protozoa, and 4) no parasites.

RESULTS

Of 527 immigrants screened, 141 (26.8%) were QGIT-positive and 229 (43.4%) had parasites detected: 27/527 (5.1%) had helminths and 202/527 (38.3%) protozoa. Cytokine analysis revealed increased interleukin-10 concentrations with protozoa (P = 0.04), and non-significantly higher T-helper 2 concentrations with helminths compared with no parasites. No significant differences emerged in QGIT positivity or interferon-gamma concentrations in any group.

CONCLUSION

Study results support the use of QGIT in parasite-endemic settings. .

Advances in Research on Immunoregulation of Macrophages by Plant Polysaccharides

Polysaccharides are among the most important members of the biopolymer family. They are natural macromolecules composed of monosaccharides. To date, more than 300 kinds of natural polysaccharide compounds have been identified. They are present in plants, animals, and microorganisms, and they engage in a variety of physiological functions. In the 1950s, due to the discovery of their immunoregulatory and anti-tumor activities, polysaccharides became a popular topic of research in pharmacology, especially in immunopharmacology. Plants are an important source of natural polysaccharides. Pharmacological and clinical studies have shown that plant polysaccharides have many functions, such as immune regulation, anti-tumor activity, anti-inflammatory activity, anti-viral functions, anti-radiation functions, and a hypoglycaemic effect. The immunomodulatory effects of plant polysaccharides have received much attention. Polysaccharides with these effects are also referred to as biological response modifiers (BRMs), and research on them is one of the most active areas of polysaccharide research. Thus, we summarize immunomodulatory effects of botanical polysaccharides isolated from different species of plants on the macrophage. The primary effect of botanical polysaccharides is to enhance and/or activate macrophage immune responses, including increasing reactive oxygen species (ROS) production, and enhancing secretion of cytokines and chemokines. Therefore, it is believed that botanical polysaccharides have significant therapeutic potential, and represent a new method for discovery and development of novel immunomodulatory medicine.

Risk Factors for Indeterminate Interferon-Gamma Release Assay for the Diagnosis of Tuberculosis in Children-A Systematic Review and Meta-Analysis

Background: Interferon-gamma release assays (IGRA) are well-established immunodiagnostic tests for tuberculosis (TB) in adults. In children these tests are associated with higher rates of false-negative and indeterminate results. Age is presumed to be one factor influencing cytokine release and therefore test performance. The aim of this study was to systematically review factors associated with indeterminate IGRA results in pediatric patients. Methods: Systematic literature review guided by the preferred reporting items for systematic reviews and meta-analyses (PRISMA) searching PubMed, EMBASE, and Web of Science. Studies reporting results of at least one commercially available IGRA (QuantiFERON-TB, T-SPOT.TB) in pediatric patient groups were included. Random effects meta-analysis was used to assess proportions of indeterminate IGRA results. Heterogeneity was assessed using the I² value. Risk differences were calculated for studies comparing QuantiFERON-TB and T-SPOT.TB in the same study. Meta-regression was used to further explore the influence of study level variables on heterogeneity. Results: Of 1,293 articles screened, 133 studies were included in the final analysis. These assessed QuantiFERON-TB only in 77.4% (103/133), QuantiFERON-TB and T-SPOT.TB in 15.8% (21/133), and T-SPOT.TB only in 6.8% (9/133) resulting in 155 datasets including 107,418 participants. Overall 4% of IGRA results were indeterminate, and T-SPOT.TB (0.03, 95% CI 0.02-0.05) and QuantiFERON-TB assays (0.05, 95% CI 0.04-0.06) showed similar proportions of indeterminate results; pooled risk difference was-0.01 (95% CI -0.03 to 0.00). Significant differences with lower proportions of indeterminate assays with T-SPOT.TB compared to QuantiFERON-TB were only seen in subgroup analyses of studies performed in Africa and in non-HIV-infected immunocompromised patients. Meta-regression confirmed lower proportions of indeterminate results for T-SPOT.TB compared to QuantiFERON-TB only among studies that reported results from non-HIV-infected immunocompromised patients (p < 0.001). Conclusion: On average indeterminate IGRA results occur in 1 in 25 tests performed. Overall, there was no difference in the proportion of indeterminate results between both commercial assays. However, our findings suggest that in patients in Africa and/or patients with immunocompromising conditions other than HIV infection the T-SPOT.TB assay appears to produce fewer indeterminate results.

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.

Cytokine profiling in healthy children shows association of age with cytokine concentrations

Cytokine-based diagnostic assays are increasingly used in research and clinical practice. Assays developed for adults such as the interferon-gamma release assay for tuberculosis show inferior performance in children. Limited evidence suggests that release of cytokines is influenced by age but normal ranges of cytokines in children are lacking. Whole blood of healthy children (0-12 years) undergoing elective/diagnostic procedures was stimulated with SEB, PHA, Candida albicans for 24 hours or left unstimulated. Concentrations of eight cytokines were measured by multiplex bead-based immunoassays and associations with age and other factors quantified by regression analysis. 271 children (median age 5.2 years) were included. In unstimulated samples IL-1ra, IP-10 and TNF-α concentrations decreased by up to -60% with age. Following antigen stimulation, an age-associated increase (ranging from +90% to +500%) was observed for all cytokines except IL-1ra (significant for IL-4, IFN-γ and TNF-α). Inter-individual variability in cytokine concentrations was large with a coefficient of variation ranging from 42% to 1412%. Despite inter-individual variation age was identified as a strong influencing factor of cytokine concentrations. Age-specific normal values need to be considered for cytokine-based diagnostic purposes. These results are relevant for development of novel cytokine-based diagnostic assays and for optimal dosing of therapeutic agents targeting cytokines.