Innate immune and interferon-induced responses to in vivo nasal infection with rhinovirus (RV)16 in healthy subjects are accelerated by low-dose dietary supplementation with carrot-derived pectic polysaccharide rhamnogalacturonan-I (cRG-I), together with reduced duration and severity of symptoms. We aimed to further identify temporal mRNA responses by nasal epithelial cells (NEC) after RV16 infection, and to assess the effect of cRG-I supplementation. NECs were obtained prior to (day(d)-55) and after 8-weeks (d-1) of supplementation (0, 0.3, 1.5 g/d), and on d3, d6, d9 and d13 after exposure to 100 TCID50 RV16. Transcriptome data were generated and analysed with the R2: Genomics Analysis and Visualization platform (https://r2.amc.nl). RV16 infection reduced expression of genes related to oxidative phosphorylation (d3), induced gene expression by interferon (d6-9), and reduced expression of cilia-related genes (d13). cRG-I changed these responses. At low-dose, gene expression of important transcription factors and effector molecules (IRF4, IRF8, RFX3, IL-1B, CASP1) was enhanced markedly earlier (d3-6). At high-dose, cRG-I induced expression of inflammasome-related genes already after 8-weeks supplementation. cRG-I, in a dose-dependent manner, significantly affected the sequence and intensity of genes that regulate pathways involved in anti-viral responses and epithelial repair. This may underlie the reduced duration and severity of symptoms.

BACKGROUND:Bronchodilator response (BDR) is a key clinical feature in childhood asthma, but its relation to asthma pathophysiology is not fully understood. This study examines the associations between BDR, disease control, and serum cytokines/chemokines in children with moderate-to-severe asthma (MSA). METHODS:BDR was assessed in 140 children (aged 6-17 years, 41% females) from the SysPharmPediA cohort using the ERS/ATS 2022 guidelines (ΔFEV1 >10% predicted) and z-score (ΔFEV1-z-score >0.78) post-bronchodilator definitions. Risk of uncontrolled asthma in relation to BDR was estimated by a logistic regression model, adjusting for baseline lung function, age, sex, BMI z-score, ethnicity, country, season, GINA step, and smoking exposure. Thirty-nine serum proteins were measured using Luminex Multiplex Assay; levels below the detection limit (LOD) were imputed as LOD/√2, and proteins with >40% missing values across samples were excluded. Children with high and low BDR were compared for serum proteins by linear regression model, adjusting for covariates and applying false discovery rate correction. RESULTS:Children with high BDR (21%) had significantly higher odds of uncontrolled asthma (adjusted OR ≈ 3.22, 95% CIs: 1.07-11.3) and more frequent severe exacerbations in the past year compared with those with low BDR (70% vs. 46%, p < .05). High-BDR children showed elevated serum levels of IL-13, IL-4, TNF-α, IL-6, IL-7, IL-8, IL-1β, and MMP-1 (q < 0.05). CONCLUSION:In children with MSA, a high BDR is independently associated with poorer asthma control and a distinct systemic inflammatory profile involving T2 and non-T2 mediators. BDR may serve as a marker for asthma phenotyping.

Introduction Traditional sputum-based diagnostics often demonstrate sub-optimal diagnostic performance in people living with HIV (PWH) and children presenting with paucibacillary tuberculosis (TB). This study evaluated the diagnostic accuracy of circulating kynurenine-pathway metabolites against an authentic symptomatic control cohort in Uganda. Methods Tryptophan, kynurenine, and the kynurenine-to-tryptophan (Kyn/Trp) ratio were quantified via ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) in 70 adult PWH and 23 children presenting with presumptive TB. Results Median biomarker concentrations demonstrated no statistically significant differences between laboratory-confirmed TB cases and symptomatic controls. The Kyn/Trp ratio yielded an Area Under the Curve (AUC) of 0.51 (95% CI: 0.34–0.69) in adults and 0.62 (95% CI: 0.36–0.87) in children, indicating limited diagnostic discrimination with substantial uncertainty, particularly in the small paeditric cohort. At the evaluated cut-off points, none of the biomarkers met the minimum sensitivity and specificity requirements defined by the World Health Organisation Target Product Profiles (TPPs) for diagnostic and screening tests. Conclusion Blood kynurenine pathway metabolites demonstrated limited clinical utility as standalone diagnostic biomarkers for active TB in these vulnerable populations. In addition, larger diagnostic performance studies are needed to address the uncertainty associated with the small sample size and to further validate our findings.

Rationale Information is missing on the tissue cell expression patterns of interleukin 33 (IL-33) and splice variants of the IL-33 receptor ST2 in normal and chronic obstructive pulmonary disease (COPD) lungs.Objectives To characterize the expression patterns of IL-33, the soluble ST2 (sST2) and membrane-bound ST2 (ST2L) splice variants in the poorly studied small airway and distal lung compartments in COPD and controls.Methods Surgically excised lung tissue was collected from 38 COPD patients and 21 non-COPD controls. Lung compartment expression of IL-33 and ST2 and key expressing cell types were assessed histologically by combined in situ hybridization and multiplex immunohistochemistry. Expression dynamics of IL-33, ST2L, and sST2 were explored by spatially resolved single-cell analysis.Measurements and Main Results COPD lungs displayed increased IL-33 mRNA and IL-33 mRNA/protein ratios, suggesting increased IL-33 turnover. Total ST2/IL1RL1 mRNA levels were upregulated in COPD lungs. Mast cells constituted the major ST2-expressing immune cell population in controls and displayed a microenvironmental-specific upregulation of both ST2L and sST2 in COPD. In control alveolar regions, ST2Lhigh sST2high mast cells were present alongside IL-33-expressing general capillary (gCap) and sST2moderate ST2Llow aerocyte endothelial subsets. In COPD, patchy alveolar regions displayed markedly elevated capillary sST2 and numbers of ST2L+ and IL-33+ gCaps.Conclusions By unraveling the expression patterns of IL-33 and the biologically opposing ST2L and sST2 splice variants in control and COPD lungs, the present study provides novel insights into IL-33-mediated immunity in the distal lung, information that has bearing on treatment strategies targeting this pathway in lung diseases.

BACKGROUND:Early identification of children at risk of asthma attacks is important for optimizing treatment strategies. We aimed to integrate salivary microbiome and serum inflammatory mediator profiles with asthma attacks history to develop a comprehensive predictive model for future attacks. METHODS:This study contained a discovery (SysPharmPediA) and a replication phase (U-BIOPRED). School-aged children with asthma were classified into at risk and no-risk groups, based on the presence or absence of one or more severe attacks during one-year follow-up. Prediction models were developed using random forest on the training set (70%) with data on past asthma attacks, microbiome composition, serum inflammatory mediator levels, and their combinations and then tested on the rest of the population (30%). Outcomes were replicated in a subset of children with severe asthma from U-BIOPRED. RESULTS:Complete data were available for 154 children (SysPharmPediA = 121, U-BIOPRED = 33). In discovery, the model based on past attacks resulted in an area under the receiving characteristic curve (AUROCC) ~ 0.7. Models including six salivary bacteria or six inflammatory mediators achieved similar results. The combined model incorporating seven features, past asthma attacks, Capnocytophaga, Corynebacterium, and Cardiobacterium, TIMP-4, VEGF, and MIP-3β achieved the highest accuracy with AUROCC ~0.87. The combined model in the U-BIOPRED limited to available inflammatory mediators (VEGF), and incorporating past asthma attacks, Capnocytophaga, Corynebacterium, and Cardiobacterium, resulted in an AUROCC of 0.84. CONCLUSION:Serum inflammatory mediators and salivary microbiome complement asthma attacks history for predicting future attacks. These results highlight the imperative for continued investigation into oral microbiota and its interaction with the immune system.

BACKGROUND:Childhood asthma has been linked to distinct metabolomic profiles. OBJECTIVE:We sought to identify phenotypes (metabotypes) in children with moderate to severe asthma through integrative fecal and serum metabolome analysis. METHODS:Children from the Systems Pharmacology Approach to Uncontrolled Pediatric Asthma cohort with Global Initiative for Asthma treatment step 3 or higher were recruited. Asthma control was defined by the Asthma Control Test and annual exacerbation history. Targeted metabolomic profiling of feces and serum was performed using liquid chromatography and flow injection electrospray ionization-triple quadrupole mass spectrometry. Similarity network fusion integrated fecal and serum metabolome profiles, followed by spectral clustering. Clusters were analyzed for differences in asthma characteristics, food diaries, fecal microbiota composition, and levels of serum inflammatory markers and blood cells. RESULTS:Integrative fecal and serum metabolome analysis of 92 children with moderate to severe asthma (median age, 11.5 years, 34% female) revealed 3 metabotypes. Metabotype 1 had the lowest percentage of allergic rhinitis, with elevated serum ceramides and triglycerides. Metabotype 2 had higher odds of asthma control, the highest percentage of children with 4 or more months of breast-feeding, reduced sugar intake, lowest levels of blood neutrophils and serum inflammatory markers, and elevated serum acylcarnitines and ω-3 fatty acids. Metabotype 3 included the highest percentage of uncontrolled asthma patients, with decreased serum cholesteryl esters, phosphatidylcholines, and sphingomyelins, elevated fecal amino acids, and reduced fecal microbiota diversity. CONCLUSIONS:Metabotypes in children with moderate to severe asthma are linked to asthma control, distinct fecal microbiota, and systemic inflammatory patterns. The findings suggest that metabotyping can be valuable in precision medicine approaches for asthma.

Asthma, a chronic airway disease, is marked by allergic inflammation, hyperresponsiveness, and tissue remodeling. Influenza infections in asthma patients can cause severe exacerbations, though the underlying mechanisms remain unclear. This study investigated how pre-existing allergic inflammation affects immune responses to influenza infection in mice exposed to house dust mite (HDM). Mice were repeatedly exposed to HDM, followed by infection with the influenza A virus, and were sacrificed three days post-infection. Plasma was analyzed for HDM-specific immunoglobulins, while lung tissue was used for immune cell flow cytometry and RNA sequencing analysis. HDM exposure induced allergic inflammation, evidenced by more HDM-specific IgE, IgG1, IgG2, eosinophils, neutrophils, Th1, and Th17 cells compared to controls. Upon influenza infection, the effects of HDM and influenza co-infection interacted, showing fewer Th1 cells and regulatory T cells and more Th2 cells compared to mice exposed to the influenza virus alone. Interestingly, RNA-seq analysis revealed less upregulation of Th1-related genes and antiviral pathways in co-exposed mice, suggesting impaired Th1 immunity and antiviral responses. Pre-existing allergic inflammation significantly altered immune responses in mice co-infected with influenza, revealing underdeveloped antiviral responses as early as three days post-infection. These findings may explain the increased susceptibility of patients with asthma to severe viral diseases.

Background: Small airway dysfunction (SAD) is associated with impaired asthma control, but small airway physiology is not routinely assessed in clinical practice. Previously, we demonstrated impulse oscillometry (IOS)-defined small airway dysfunction (SAD) in dual responders (DRs) upon bronchoprovocation with various allergens. Aim: To compare lung physiology using spirometry and IOS following bronchoprovocation with methacholine (M) and inhaled house dust mite (HDM) extract in corticosteroid-naïve asthmatic subjects. Methods: Non-smoking, clinically stable HDM-allergic asthmatic subjects (18–55 years, FEV1 > 70% of pred.) underwent an M and inhaled HDM challenge on two separate days. Airway response was measured by IOS and spirometry, until a drop in FEV1 ≥ 20% (PC20) from post-diluent baseline (M), and up to 8 h post-allergen (HDM). Early (EAR) and late asthmatic response (LAR) to HDM were defined as ≥20% and ≥15% fall in FEV1 from post-diluent baseline during 0–3 h and 3–8 h post-challenge, respectively. IOS parameters (Rrs5, Rrs20, Rrs5-20, Xrs5, AX, Fres) were compared between mono-responders (MRs: EAR only) and dual responders (EAR + LAR). Correlations between maximal % change from baseline after the two airway challenges were calculated for both FEV1 and IOS parameters. Results: A total of 47 subjects were included (11 MRs; 36 DRs). FEV1 % predicted did not differ between MR and DR at baseline, but DR had lower median PC20M (0.84 (range 0.07–7.51) vs. MR (2.15 (0.53–11.29)); p = 0.036). During the LAR, DRs had higher IOS values than MRs. For IOS parameters (but not for FEV1), the maximal % change from baseline following M and HDM challenge were correlated. PC20M was inversely correlated with the % change in FEV1 and the % change in Xrs5 during the LAR (r= −0.443; p = 0.0018 and r= −0.389; p = 0.0075, respectively). Conclusions: During HDM-induced LAR, changes in small airway physiology can be non-invasively detected with IOS and are associated with increased airway hyperresponsiveness and changes in small airway physiology during methacholine challenge. DRs have a small airways phenotype, which reflects a more advanced airway disease.

BACKGROUND:Peripheral biomarkers of inflammation and oxidative stress have previously been implicated in psychosis. However, many studies do not account for cigarette smoking, despite its known impact on these pathways. Moreover, heterogeneous patient samples and limited consideration of clinical characteristics have made it difficult to disentangle which factors are truly related to the disease process. This study aimed to compare selected biomarkers between patients with recent-onset psychosis and matched controls in a non-smoking sample, and to explore associations with clinical characteristics. METHODS:In this cross-sectional case-control study, 47 patients (mean age: 24.55 [3.80] years) with recent-onset psychosis (first episode less than 3 years ago) and 36 matched (on age, sex and ethnicity) controls were included. Plasma levels of free thiols, MMP-9, sCD163 and a panel of cytokines were measured. Group comparisons were conducted using the Wilcoxon rank-sum test. Associations with clinical and metabolic characteristics were examined using linear regression. Additional analyses were performed in the subgroup classified as having a schizophrenia spectrum disorder (SSD). RESULTS:Patients with psychosis exhibited significantly higher MMP-9 levels than controls (p = 0.029, r = 0.28). Across groups, free thiol levels were negatively associated with waist circumference. IP-10 levels were associated with alcohol consumption, educational level and PANSS total score. In the SSD subgroup, additional associations emerged between free thiols and educational level, IP-10 and age, and TNF-α and glucose. CONCLUSIONS:MMP-9 levels are elevated in recent-onset psychosis, independent of smoking. Our findings underscore the importance of accounting for clinical and metabolic heterogeneity when interpreting peripheral biomarkers in psychosis.

Rationale Biological processes continuously fluctuate due to non-linear interactions with other biological processes and external perturbations. A previous analysis showed that in patients with asthma physiological and inflammatory processes are regulated differently compared to healthy individuals, which leads to a loss of adaptive capacity in response to e.g. a viral challenge (PMID: 31687927). In this study we aimed to determine fluctuation patterns of metabolic pathways in patient with asthma and healthy individuals by analysis of the urine metabolome, both in stable phase and after a viral challenge. Methods Urine samples of 11 patients with asthma and 12 healthy individuals were collected 3 times a week for a duration of 7 weeks. Samples were analysed by ultra-high-performance liquid chromatography combined with tandem mass spectrometry, both in the positive and negative ion mode. The average fluctuation per metabolite was calculated as the mean squared difference in abundance between two consecutive measurements adjusted for the time interval. The difference between asthma and healthy were normalized based on the average abundance and the metabolites with the greatest difference were further analysed using metaboanalyst.ca to determine the most dominant metabolic pathways. Results As a first approach we selected the metabolites from the positive ion analysis that showed the largest fluctuations in urine from both asthma patients and healthy individuals. After that we determined which pathways were implicated most, thus being discriminatory between asthma and health. Table 1 shows the most discriminative metabolites and its pathways (mean A-H difference in all metabolites is -0.36). The fluctuations of the lysine degradation were the highest in patients with asthma. In healthy subject the fluctuations of the glyoxylate and dicarboxylate metabolism and tryptophan metabolism, glycine, serine and threonine metabolism and purine metabolism (all KEGG pathways) were highest. We have previously studied the tryptophan metabolism in asthma and healthy subjects in conjunction with a rhinovirus challenge (PMID: 23882022), showing that in asthma there was an enhanced systemic tryptophan metabolism, but a reduced metabolism in the airways. In the current analysis we found a larger fluctuation pattern for tryptophan in healthy individuals compared to patients with asthma. Conclusion Our fluctuation analysis of urine metabolites from asthma patients and healthy individuals showed marked differences in the fluctuation of metabolic pathways involving a number of amino acids and purines. The smaller fluctuation in tryptophan metabolism in asthma is consistent with the reduced capacity in controlling inflammation in response to a viral challenge.

Psychotic disorders are associated with systemic metabolic alterations, but these associations may be confounded by smoking. We investigated plasma metabolites in 47 non-smoking recent onset psychosis patients and 36 matched (on age, sex and ethnicity) healthy controls using untargeted LC MS metabolomics. We applied univariate, multivariate and pathway analyses, with subgroup exploration in patients that were diagnosed with schizophrenia spectrum disorder (SSD) specifically. We identified 28 significantly altered metabolites predominantly reflecting lipid metabolism (elevated saturated free fatty acids, glycerol 3 phosphate, conjugated bile acid), redox imbalances (decreased L cysteine, L cystine and taurine) and energy metabolism (reduced pyruvate). These alterations remained significant after adjusting for sex, antipsychotic treatment and metabolic syndrome parameters. Enrichment analyses highlighted taurine/hypotaurine metabolism, alanine/aspartate/glutamate pathways and fatty acid biosynthesis in psychosis. Within the SSD subgroup (n = 28), metabolic perturbations were more pronounced, showing stronger depletion of reducing equivalents and elevated free fatty acids. These findings indicate a specific systemic metabolic signature in psychosis independent of smoking, sex, antipsychotic medication or metabolic syndrome. The pattern suggests mitochondrial dysfunction and increased oxidative stress, accompanied by compensatory lipid mobilization. These findings identify redox and energy metabolism as promising targets for future pharmacological or metabolic interventions in SSD

Pectin and its derivatives have been shown to modulate immune signaling as well as gut microbiota in preclinical studies, which may constitute the mechanisms by which supplementation of specific pectic polysaccharides confers protection against viral respiratory infections. In a double-blind, placebo-controlled rhinovirus (RV16) challenge study, healthy volunteers were randomized to consume placebo (0.0 g/day) (N = 46), low-dose (0.3 g/day) (N = 49) or high-dose (1.5 g/day) (N = 51) of carrot derived rhamnogalacturonan-I (cRG-I) for eight weeks and they were subsequently challenged with RV-16. Here, the effect of 8-week cRG-I supplementation on the gut microbiota was studied. While the overall gut microbiota composition in the population was generally unaltered by this very low dose of fibre, the relative abundance of Bifidobacterium spp. (mainly B. adolescentis and B. longum) was significantly increased by both doses of cRG-1. Moreover, daily supplementation of cRG-I led to a dose-dependent reduction in inter- and intra-individual microbiota heterogeneity, suggesting a stabilizing effect on the gut microbiota. The severity of respiratory symptoms did not directly correlate with the cRG-I-induced microbial changes, but several dominant groups of the Ruminococcaceae family and microbiota richness were positively associated with a reduced and hence desired post-infection response. Thus, the present results on the modulation of the gut microbiota composition support the previously demonstrated immunomodulatory and protective effect of cRG-I during a common cold infection.

Abstract Background Non-sputum-based tests are needed to predict or diagnose tuberculosis (TB) disease in people living with HIV (PWH). The enzyme indoleamine 2, 3-dioxygenase-1 (IDO1) is expressed in tuberculoid granuloma and catabolizes tryptophan (Trp) to kynurenine (Kyn). IDO1 activity compromises innate and adaptive immune responses, promoting mycobacterial survival. The plasma Kyn-to-Trp (K/T) ratio is a potential TB diagnostic and/or predictive biomarker in PWH on long-term antiretroviral therapy (ART). Methods We compared plasma K/T ratios in samples from PWH, who were followed up prospectively and developed TB disease after ART initiation. Controls were matched for age and duration of ART. Kyn and Trp were measured at 3 timepoints; at TB diagnosis, 6 months before TB diagnosis and 6 months after TB diagnosis, using ultra performance liquid chromatography combined with mass spectrometry. Results The K/T ratios were higher for patients with TB disease at time of diagnosis (median, 0.086; IQR, 0.069–0.123) compared to controls (0.055; IQR 0.045–0.064; p = 0.006), but not before or after TB diagnosis. K/T ratios significantly declined after successful TB treatment, but increased upon treatment failure. The K/T ratios showed a parabolic correlation with CD4 cell counts in participants with TB (p = 0.005), but there was no correlation in controls. Conclusions The plasma K/T ratio helped identify TB disease and may serve as an adjunctive biomarker for for monitoring TB treatment in PWH. Validation studies to ascertain these findings and evaluate the optimum cut-off for diagnosis of TB disease in PWH should be undertaken in well-designed prospective cohorts. Trial registration ClinicalTrials.gov Identifier: NCT00411983.

In about 1% of tuberculosis (TB) patients, Mycobacterium tuberculosis (M. tuberculosis) can disseminate to the meninges, causing tuberculous meningitis (TBM) with mortality rate up to 60%.Chronic granulomatous inflammation (non-necrotizing and necrotizing) in the brain is the histological hallmark of TBM. The tryptophan-catabolizing enzyme indoleamine 2,3-dioxygenase 1 (IDO1) and the generated kynurenine metabolites exert major effector functions relevant to TB granuloma functioning. Here we have assessed immunohistochemically IDO1 expression and activity and its effector function and that of its isoform, IDO2, in post-mortem brain tissue of patients that demised with neurotuberculosis. We also related these findings to brain tissue of fatal/severe COVID-19. In this study, IDO1 and IDO2 were abundantly expressed and active in tuberculoid granulomas and were associated with the presence of M. tuberculosis as well as markers of autophagy and apoptosis. Like in fatal/severe COVID-19, IDO2 was also prominent in specific brain regions, such as the inferior olivary nucleus of medulla oblongata and cerebellum, but not associated with granulomas or with M. tuberculosis. Spatially associated apoptosis was observed in TBM, whereas in fatal COVID-19 autophagy dominated. Together, our findings highlight IDO2 as a potentially relevant effector enzyme in TBM, which may relate to the symptomology of TBM.