Bronchial epithelial cell transcriptome shows endotype heterogeneity of asthma in patients with NSAID-exacerbated respiratory disease.

BACKGROUND: Nonsteroidal anti-inflammatory drugs-exacerbated respiratory disease (N-ERD) is currently classified as a type-2 (T2) immune-mediated disease characterized by asthma, chronic rhinosinusitis, and hypersensitivity to cyclooxygenase-1 inhibitors. OBJECTIVES: The aim of this study was to characterize immunological endotypes of N-ERD based on the gene expression profile in the bronchial epithelium. METHODS: mRNA transcriptome (mRNA-sequencing) was analyzed in bronchial brushings from patients with N-ERD (n = 22), those with nonsteroidal anti-inflammatory drug-tolerant asthma (NTA, n = 21), and control subjects (n = 11). Additionally, lipid and protein mediators were measured in bronchoalveolar lavage fluid (BALF). RESULTS: Initial analysis of the entire asthma group revealed 2 distinct gene expression signatures: "T2-high" with increased expression of T2-related genes (eg, CLCA1, CST1), and "proinflammatory" characterized by the expression of innate immunity (eg, FOSB, EGR3) and IL-17A response genes. These endotypes showed similar prevalence in N-ERD and NTA (eg, T2-high: 33% and 32%, respectively). T2-high asthma was characterized by increased expression of mast cell and eosinophil markers, goblet cell hyperplasia, and elevated LTE4 and PGD2 in BALF. Patients with a proinflammatory endotype showed mainly neutrophilic inflammation and increased innate immunity mediators in BALF. Furthermore, the proinflammatory signature was associated with a more severe course of asthma and marked airway obstruction. These signatures could be recreated in vitro by exposure of bronchial epithelial cells to IL-13 (T2-high) and IL-17A (proinflammatory). CONCLUSIONS: T2-high signature was found only in one-third of patients with N-ERD, which was similar to what was found in patients with NTA. The proinflammatory endotype, which also occurred in N-ERD, suggests a novel mechanism of severe disease developing on a non-T2 background.

Machine learning in the diagnosis of asthma phenotypes during coronavirus disease 2019 pandemic.

Background: During the coronavirus disease 2019 (COVID-19) pandemic, it has become a pressing need to be able to diagnose aspirin hypersensitivity in patients with asthma without the need to use oral aspirin challenge (OAC) testing. OAC is time consuming and is associated with the risk of severe hypersensitive reactions. In this study, we sought to investigate whether machine learning (ML) based on some clinical and laboratory procedures performed during the pandemic might be used for discriminating between patients with aspirin hypersensitivity and those with aspirin-tolerant asthma. Methods: We used a prospective database of 135 patients with non-steroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (NERD) and 81 NSAID-tolerant (NTA) patients with asthma who underwent OAC. Clinical characteristics, inflammatory phenotypes based on sputum cells, as well as eicosanoid levels in induced sputum supernatant and urine were extracted for the purpose of applying ML techniques. Results: The overall best ML model, neural network (NN), trained on a set of best features, achieved a sensitivity of 95% and a specificity of 76% for diagnosing NERD. The 3 promising models (i.e., multiple logistic regression, support vector machine, and NN) trained on a set of easy-to-obtain features including only clinical characteristics and laboratory data achieved a sensitivity of 97% and a specificity of 67%. Conclusions: ML techniques are becoming a promising tool for discriminating between patients with NERD and NTA. The models are easy to use, safe, and achieve very good results, which is particularly important during the COVID-19 pandemic.

Eicosanoids and Eosinophilic Inflammation of Airways in Stable COPD.

PURPOSE: Lipid mediators, particularly eicosanoids, are associated with airway inflammation, especially with the eosinophilic influx. This study aimed to measure lipid mediators and cells in induced sputum, that could possibly reflect the inflammatory process in the bronchial tree of COPD subjects. PATIENTS AND METHODS: Eighty patients diagnosed with COPD and 37 healthy controls participated in the study. Induced sputum samples were ascertained for differential cell count and induced sputum supernatant concentrations of selected eicosanoids by the means of gas chromatography/mass spectrometry and high-performance liquid chromatography/tandem mass spectrometry. RESULTS: Increased sputum eosinophilia was associated with higher concentrations of selected proinflammatory eicosanoids. In COPD subjects prostaglandin D2 and 11-dehydro-thromboxane B2 correlated negatively with airway obstruction measured by FEV1 and FEV1/FVC values. COPD subjects with disease exacerbations during past 12 months had significantly higher concentrations of prostaglandin D2, 12-oxo-eicosatetraenoic acid and 5-oxo-eicosatetraenoic acid. CONCLUSION: Stable COPD is often associated with eosinophil influx in the lower airways and elevated concentrations of eicosanoids that is reflected by some disease characteristics.

The Associations of Perceived and Oxidative Stress with Hypertension in a Cohort of Police Officers.

PURPOSE: Associations between perceived stress and oxidative stress marker and metabolic syndrome (MetS) components were investigated in a cohort of police officers. METHODS: Cross-sectional data from a cohort of non-diabetic subjects (n=233; 19F), median [interquartile range] age 50 [37-44] years, were analysed. MetS was construed in line with International Diabetes Federation (IDF) criteria and perceived stress with Cohen's 10-item Perceived Stress Scale. Plasma oxidative stress marker (free 8-iso-prostaglandin F2α; 8-iso-PGF2α), presence of coronary plaque, carotid artery intima-media thickness (cIMT), and physical activity level were also determined. RESULTS: Obesity was established in 100 (42.92%), hypertension in 111 (47.64), whereas MetS was identified in 104 (44.63%) of the study subjects. A significant difference (p=0.003) in plasma 8-iso-PGF2α level, depending on the MetS components status, was noted. The associations of perceived stress with plasma 8-iso-PGF2α level and the select study variables were gender-specific. In multivariate analysis (adjusted for age and current smoking), positive associations of plasma 8-iso-PGF2α levels with PSS score (B=0.108, 95% CI [0.008, 0.209], p=0.03) and systolic blood pressure (B=0.029, 95% CI [0.003, 0.057], p=0.02) in men only were established. Both the perceived stress (OR 1.101, 95% CI [1.001-1.202], p=0.03) and plasma 8-iso-PGF2α levels (OR 1.223, 95% CI [1.046-1.432], p=0.01) impacted the prevalence of hypertension. Out of the MetS components, the effect of waist circumference (OR=1.138, 95% CI [1.064-1.218], p=0.0001) and glucose (B=2.696, 95% CI [1.081-6.725], p=0.03) were also encountered. No such associations were noted in women, though, neither in univariate nor in multivariate analyses. The prevalence of coronary plaque (0.001), obesity (p<0.001), hypertension (p<0.001) and median cIMT value (p=0.005), as well as leisure-time (p=0.04) and total walking physical activity (p=0.03), differed significantly between the subgroups stratified by MetS components status. CONCLUSION: Both the perceived and oxidative stress were found instrumental in promoting hypertension in a cohort of police officers under study, whereas all study outcomes were conclusively gender-related.

Heterogeneity of lower airway inflammation in patients with NSAID-exacerbated respiratory disease.

BACKGROUND: Nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (N-ERD) asthma is characterized by chronic rhinosinusitis and intolerance of aspirin and other COX1 inhibitors. Clinical data point to a heterogeneity within the N-ERD phenotype. OBJECTIVE: Our aim was to investigate immune mediator profiles in the lower airways of patients with N-ERD. METHODS: Levels of cytokines (determined by using Luminex assay) and eicosanoids (determined by using mass spectrometry) were measured in bronchoalveolar lavage fluid (BALF) from patients with N-ERD (n = 22), patients with NSAID-tolerant asthma (n = 21), and control subjects (n = 11). mRNA expression in BALF cells was quantified by using TaqMan low-density arrays. RESULTS: Lower airway eosinophilia was more frequent in N-ERD (54.5%) than in NSAID-tolerant asthma (9.5% [P = .009]). The type-2 (T2) immune signature of BALF cells was more pronounced in the eosinophilic subphenotype of N-ERD. Similarly, BALF concentrations of periostin and CCL26 were significantly increased in eosinophilic N-ERD and correlated with T2 signature in BALF cells. Multiparameter analysis of BALF mediators of all patients with asthma revealed the presence of 2 immune endotypes: T2-like (with an elevated level of periostin in BALF) and non-T2/proinflammatory (with higher levels of matrix metalloproteinases and inflammatory cytokines). Patients with N-ERD were classified mostly as having the T2 endotype (68%). Changes in eicosanoid profile (eg, increased leukotriene E4 level) were limited to patients with N-ERD with airway eosinophilia. Blood eosinophilia appeared to be a useful predictor of airway T2 signature (area under the curve [AUC] = 0.83); however, surrogate biomarkers had moderate performance in distinguishing eosinophilic N-ERD (for blood eosinophils, AUC = 0.72; for periostin, AUC = 0.75). CONCLUSIONS: Lower airway immune profiles show considerable heterogeneity of N-ERD, with skewing toward T2 response and eosinophilic inflammation. Increased production of leukotriene E4 was restricted to a subgroup of patients with eosinophilia in the lower airway.

Potential roles of psychological and oxidative stress in insulin resistance: a cohort-based study.

BACKGROUND: The present study investigated the relationships between psychological stress indices and oxidative stress marker, also when combined with emergent insulin resistance (IR), in the non-diabetic, middle-aged subjects, exposed to frequent/chronic psychological stressors. METHODS: Cross-sectional data from a cohort of non-diabetic police officers (n = 234; 19F), aged 27-56 years, were used. Plasma inflammatory (CRP, TNF-α), oxidative stress (free 8-iso-prostaglandin F2α; 8-iso-PGF2α) markers, and insulin were measured. The value of homeostasis model assessment of IR index (HOMA-IR) was assumed the threshold value of IR, i.e. 2.04. Free cortisol in urine and perceived stress (psychological stress indices) were also measured. RESULTS: In the IR subjects, most biochemical variables, inflammatory markers and urine cortisol were significantly higher, as compared to the non-IR ones. Psychological stress indices were associated with plasma 8-iso-PGF2α [B = 0.139, 95% CI (0.048, 0.230), p = 0.002, and B = 0.007, 95% CI (0.0006, 0.014), p = 0.03; for perceived stress level and cortisol, respectively]. Positive associations were established between plasma 8-iso-PGF2α [B = 0.069, 95% CI (0.016-0.120), p = 0.01] and urine cortisol [B = 0.003, 95% CI (0.0003, 0.005), p = 0.02] with HOMA-IR. Metabolic syndrome, as defined by IDF criteria, was established in 110 study subjects, whereas 136 of them were hypertensive. Waist circumference [B = 0.056, 95% CI (0.039, 0.074), p < 0.0001], and systolic blood pressure [B = 0.009, 95% CI (0.00003, 0.018), p = 0.04] were positively associated with HOMA-IR, whereas the association of HDL cholesterol [B = - 0.597, 95% CI (- 1.139, - 0.055), p = 0.03] was a negative one. Cortisol [OR = 1.007, 95% CI (1.002, 1.012), p = 0.006], and 8-iso-PGF2α [OR = 1.103, 95% CI (1.010, 1.201), p = 0.02] affected the incidence of IR. After adjustment for metabolic syndrome (or its components), age, sex, and current smoking, the effects became non-significant. Out of metabolic syndrome components, waist circumference [OR 4.966, 95% CI (2.29, 10.751), p = 0.00004] and hypertriglyceridemia [OR 1.993, 95% CI (1.063, 3.736), p = 0.03] increased the chance of IR incidence. CONCLUSIONS: Both psychological stress indices were associated with oxidative stress, but only cortisol with HOMA-IR. In the subjects exposed to frequent/chronic psychological stressors, cortisol and oxidative stress marker affected IR incidence, being statistically attenuated, though, following adjustment for metabolic syndrome, or its components.

Concentration of meropenem in patients with sepsis and acute kidney injury before and after initiation of continuous renal replacement therapy: a prospective observational trial.

BACKGROUND: The effect of renal replacement therapy on drug concentrations in patients with sepsis has not been fully elucidated because the pharmacokinetic properties of many antimicrobials are influenced by both pathophysiological and treatment-related factors. The aim of this study was to determine meropenem concentrations in patients with sepsis before and after the initiation of continuous venovenous hemodialysis with regional citrate anticoagulation (RCA-CVVHD). METHODS: The study included 15 critically ill patients undergoing RCA-CVVHD due to sepsis-induced acute kidney injury. All participants received 2 g of meropenem every 8 h in a prolonged infusion lasting 3 h. Meropenem concentrations were measured in blood plasma using high-performance liquid chromatography coupled with tandem mass spectrometry. Blood samples were obtained at six-time points prior to and at six-time points after introducing RCA-CVVHD. RESULTS: The median APACHE IV and SOFA scores on admission were 118 points (interquartile range [IQR] 97-134 points) and 19.5 points (IQR 18-21 points), respectively. There were no significant differences in the plasma concentrations of meropenem measured directly before RCA-CVVHD and during the first 450 min of the procedure. The drug concentration reached its peak 2 h after initiating the infusion and then steadily declined. CONCLUSIONS: The concentration of high-dose meropenem (2 g every 8 h) administered in a prolonged infusion was similar before and after the introduction of RCA-CVVHD in patients with sepsis who developed acute kidney injury.

Subphenotypes of nonsteroidal antiinflammatory disease-exacerbated respiratory disease identified by latent class analysis.

BACKGROUND: Induced sputum (IS) allows to measure mediators of asthmatic inflammation in bronchial secretions. NSAID-exacerbated respiratory disease (NERD) is recognized as a distinct asthma phenotype, usually with a severe course, eosinophilic airway inflammation, and increased production of pro-inflammatory eicosanoids. A more insightful analysis of NERD patients has shown this phenotype to be nonhomogeneous. OBJECTIVE: We aimed to identify possible subphenotypes in a cohort of NERD patients with the means of latent class analysis (LCA). METHODS: A total of 95 asthma patients with aspirin hypersensitivity underwent sputum induction. High-performance liquid chromatography or gas chromatography coupled with mass spectrometry was used to profile eicosanoids in induced sputum supernatant (ISS). Sixteen variables covering clinical characteristics, IS inflammatory cells, and eicosanoids were considered in the LCA. RESULTS: Three classes (subphenotypes) were distinguished within the NERD cohort. Class 1 subjects had mild-to-moderate asthma, an almost equal distribution of inflammatory cell patterns, the lowest concentrations of eicosanoids, and logLTE4 /logPGE2 ratio. Class 2 represented severe asthma with impaired lung function despite high doses of steroids. High sputum eosinophilia was in line with higher pro-inflammatory LTE4 in ISS and the highest logLTE4 /logPGE2 ratio. Class 3 subjects had mild-to-moderate asthma and were also characterized by eosinophilic airway inflammation, yet increased production of pro- (LTE4 , PGD2 and 11-dehydro-TBX2 ) was balanced by anti-inflammatory PGE2 . The value of logLTE4 /logPGE2 was between values calculated for classes 1 and 3, similarly to disease control and severity. CONCLUSIONS: LCA revealed three distinct NERD subphenotypes. Our results support a more complex pathobiology of aspirin hypersensitivity. Considering NERD heterogeneity, the relationship between inflammatory pathways and clinical manifestations of asthma may lead to more individualized treatment in difficult to treat patients in the future.

LTB4 and 5-oxo-ETE from extracellular vesicles stimulate neutrophils in granulomatosis with polyangiitis.

Activation of neutrophils is an important mechanism in the pathology of granulomatosis with polyangiitis (GPA). In this study, we evaluated whether extracellular vesicles (EVs) circulating in the plasma of GPA patients could contribute to this process. EVs from the plasma of GPA patients in the active stage of the disease (n = 10) and healthy controls (n = 10) were isolated by ultracentrifugation and characterized by flow cytometry (CD63, CD8) and nanoparticle tracking analysis. Targeted oxylipin lipidomics of EVs was performed by HPLC-MS/MS. EV/oxylipin-induced neutrophil extracellular traps (NETs) were analyzed by confocal microscopy, and released double-stranded DNA (dsDNA) was quantified by PicoGreen fluorescent dye. Reactive oxygen species (ROS) production and neutrophils' EV binding/uptake were evaluated by flow cytometry. Brief priming with granulocyte-macrophage colony-stimulating factor was required for EV-mediated ROS production and dsDNA release. It was observed that priming also increased EV binding/uptake by neutrophils only for EVs from GPA patients. EVs from GPA patients had higher concentrations of leukotriene (LT)B4 and 5-oxo-eicosatetraenoic acid (5-oxo-ETE) as compared with EVs from healthy controls. Moreover, neutrophils stimulated with LTB4 or 5-oxo-ETE produced ROS and released dsDNA in a concentration-dependent manner. These results reveal the potential role of EVs containing oxylipin cargo on ROS production and NET formation by activated neutrophils.

Probiotic Lactobacillus acidophilus bacteria or synthetic TLR2 agonist boost the growth of chicken embryo intestinal organoids in cultures comprising epithelial cells and myofibroblasts.

The intestinal epithelial cells reside in close proximity to myofibroblasts and microbiota, which are supposed to have an impact on intestinal stem cells fate and to influence processes of tissue maturation and regeneration. Mechanism underlying these phenomena and their diversity among vertebrates can be studied in 3D organoid cultures. We investigated the growth of chicken embryo intestinal epithelial organoids in Matrigel with and without Toll-like receptors (TLRs) stimulation. The organoid cultures contained also some myofibroblasts with potential to promote intestinal stem cell survival. Organoid cells, expressing TLR4, TLR2 type 1 and TLR2 type 2 were incubated with their agonists (lipopolysaccharide - LPS and Pam3CSK4) or co-cultured with Lactobacillus acidophilus bacteria (LA-5). Pam3CSK4 and LA-5 promoted organoid growth, which was demonstrated by comparing the morphological parameters (mean number and area of organoids). The profile of prostaglandins (PG), known to promote intestinal regeneration, in supernatants from organoid and fibroblast cultures were evaluated. Both PGE2 and PGD2 were detected. As compared to unstimulated controls, supernatants from the Pam3CSK4-stimulated organoids contained twice as much of PGE2 and PGD2. The changes in production of prostaglandins and the support of epithelial cell growth by myofibroblasts are factors potentially responsible for stimulatory effect of TLR2 activation.

Omega-3 fatty acid supplementation influences the whole blood transcriptome in women with obesity, associated with pro-resolving lipid mediator production.

The n-3 polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) may reduce low-grade inflammation associated with obesity. The relationship between therapeutic response to n-3 PUFAs and modification of the transcriptome in obesity or metabolic syndrome remains to be explored. Blood samples were obtained from women with obesity before and after three-months supplementation with a moderate dose of n-3 PUFAs (1.8g EPA+DHA per day) or from controls. n-3 PUFAs (GC) and plasma concentrations of lipoxins, resolvins, protectin X (GC-MS/MS) and inflammatory markers (ELISA) were measured. Whole blood transcriptome was assayed using microarray. Women supplemented with n-3 PUFAs for 3months had significantly higher levels of EPA and DHA in plasma phosphatidylcholine. n-3 PUFA supplementation, in contrast to placebo, significantly decreased the concentrations of several inflammatory markers (SELE, MCP-1, sVCAM-1, sPECAM-1, and hsCRP), fasting triglycerides and insulin and increased the concentrations of pro-resolving DHA derivatives in plasma. The microarray data demonstrated effects of n-3 PUFAs on PPAR-α, NRF2 and NF-κB target genes. N-3 PUFAs increased DHA-derived pro-resolving mediators in women with obesity. Elevated resolvins and up-regulation of the resolvin receptor occurred in parallel with activation of PPAR-α target genes related to lipid metabolism and of NRF2 up-regulated antioxidant enzymes.

Aspirin provocation increases 8-iso-PGE2 in exhaled breath condensate of aspirin-hypersensitive asthmatics.

BACKGROUND: Isoprostanes are bioactive compounds formed by non-enzymatic oxidation of polyunsaturated fatty acids, mostly arachidonic, and markers of free radical generation during inflammation. In aspirin exacerbated respiratory disease (AERD), asthmatic symptoms are precipitated by ingestion of non-steroid anti-inflammatory drugs capable for pharmacologic inhibition of cyclooxygenase-1 isoenzyme. We investigated whether aspirin-provoked bronchoconstriction is accompanied by changes of isoprostanes in exhaled breath condensate (EBC). METHODS: EBC was collected from 28 AERD subjects and 25 aspirin-tolerant asthmatics before and after inhalatory aspirin challenge. Concentrations of 8-iso-PGF2α, 8-iso-PGE2, and prostaglandin E2 were measured using gas chromatography/mass spectrometry. Leukotriene E4 was measured by immunoassay in urine samples collected before and after the challenge. RESULTS: Before the challenge, exhaled 8-iso-PGF2α, 8-iso-PGE2, and PGE2 levels did not differ between the study groups. 8-iso-PGE2 level increased in AERD group only (p=0.014) as a result of the aspirin challenge. Urinary LTE4 was elevated in AERD, both in baseline and post-challenge samples. Post-challenge airways 8-iso-PGE2 correlated positively with urinary LTE4 level (p=0.046), whereas it correlated negatively with the provocative dose of aspirin (p=0.027). CONCLUSION: A significant increase of exhaled 8-iso-PGE2 after inhalatory challenge with aspirin was selective and not present for the other isoprostane measured. This is a novel finding in AERD, suggesting that inhibition of cyclooxygenase may elicit 8-iso-PGE2 production in a specific mechanism, contributing to bronchoconstriction and systemic overproduction of cysteinyl leukotrienes.

Influence of dietary fatty acids on differentiation of human stromal vascular fraction preadipocytes.

Mediators such as cytokines, eicosanoids, nitric oxide and growth factors may regulate adipogenesis as well as inflammation. It is well documented that production of some form of eicosanoids activates lipid synthesis during adipogenesis but also contributes to the formation of factors maintaining low-level systemic inflammation. Developing nutrients for reduction of adipogenesis and inflammation can enhance preventive efficacy of daily diet. This study examined the effects of free fatty acid influence on changes in lipid biosynthesis and corresponding gene expression during differentiation of human subcutaneous adipose tissue stromal vascular fraction (SVF) cells. Proadipogenic conditions promoted SVF cell differentiation and lipid droplet (LD) formation up to 15 days. This correlated with gene expression of adipocyte differentiation markers as well as inflammatory cytokines and their receptors. Addition of free fatty acids to differentiation medium increased their incorporation during the first period of differentiation (48 h). Presence of eicosanoid acid (EPA) during the initial period of differentiation by elevation of Perilipin 3 protein (TIP47), may be responsible for smaller LD formation. Presence of arachidonic acid (AA) tends to deposit lipids in large form of LDs. Prolongation of differentiation up to 15 days decreased AA or EPA in cellular lipids. PUFA through up-regulation of both phospholipase 2 and enzymes related to eicosanoid production influenced type and quantity of eicosanoids which regulated the extent of SVF cell differentiation. Formation of small LDs and reduction of pro-inflammatory mediators in adipose tissue are the consequence of eicosanoid production with anti-inflammatory potential from EPA.

Aspirin desensitization in patients with aspirin-induced and aspirin-tolerant asthma: a double-blind study.

BACKGROUND: Numerous open trials have demonstrated the beneficial clinical effects of aspirin desensitization (AD) in patients with aspirin-induced asthma (AIA). These beneficial effects might be attributable to aspirin's potent anti-inflammatory properties, but that supposition requires further corroboration. OBJECTIVE: We sought to compare the clinical and biochemical responses to chronic oral AD in 20 patients with AIA and 14 patients with aspirin-tolerant asthma (ATA). All of the patients had chronic rhinosinusitis and nasal polyposis, and these responses were investigated in a pilot, double-blind, placebo-controlled study. METHODS: Twelve patients with AIA and 6 patients with ATA were randomly assigned to receive 624 mg of aspirin, and 8 patients with AIA and 8 patients with ATA received placebo. Both aspirin and placebo were administered once daily for 6 months. Nasal symptoms, Sino-Nasal Outcome Test (SNOT20) scores, peak nasal inspiratory flows, Asthma Control Questionnaire scores, spirometric parameters, peak expiratory flows, blood eosinophilia, and corticosteroid doses were assessed on a monthly basis. Levels of urinary leukotriene E4 and the stable plasma prostaglandin (PG) D2 metabolite 9α,11ß-PGF2 were evaluated at baseline and after 1, 3, 5, and 6 months. RESULTS: Only the patients with AIA subjected to AD reported improvements in smell and reductions in sneezing and nasal blockade. The SNOT20 and Asthma Control Questionnaire scores of these patients decreased, and their peak nasal inspiratory flows increased. The dosages of inhaled corticosteroids were reduced. There were no changes in leukotriene E(4) or 9α,11ß-PGF(2) levels after AD. CONCLUSION: The clinically beneficial effects of AD on nasal and bronchial symptoms occurred only in the patients with AIA.

Th2-type cytokine-induced mucus metaplasia decreases susceptibility of human bronchial epithelium to rhinovirus infection.

Human rhinoviruses (RVs) are a major cause of exacerbations in asthma and other chronic airway diseases. A characteristic feature of asthmatic epithelium is goblet cell metaplasia and mucus hypersecretion. Bronchial epithelium is also an important source of lipid mediators, including pro- and antiinflammatory eicosanoids. By using air-liquid interface cultures of airway epithelium from patients with asthma and nonasthmatic control subjects, we compared RV16 replication-induced changes in mRNA expression of asthma candidate genes and eicosanoid production in the epithelium with or without IL-13-induced mucus metaplasia. Mucus metaplastic epithelium was characterized by a 20-fold less effective replication of RV16 and blunted changes in gene expression; this effect was seen to the same extent in patients with asthma and control subjects. We identified ciliary cells as the main target for RV16 by immunofluorescence imaging and demonstrated that the numbers of ciliary cells decreased in RV16-infected epithelium. RV16 infection of mucociliary epithelium resulted in overexpression of genes associated with bronchial remodeling (e.g., MUC5AC, FGF2, and HBEGF), induction of cyclooxygenase-2, and increased secretion of prostaglandins. These responses were similar in both studied groups. These data indicate that structural changes associated with mucus metaplasia renders airway epithelium less susceptible to RV infection. Thus, exacerbations of the lung disease caused by RV may result from severe impairment in mucociliary clearance or activation of immune defense rather than from preferential infection of mucus metaplastic epithelium. Repeated rhinoviral infections of compromised epithelium may contribute to the remodeling of the airways.

Eicosanoid biosynthesis during mucociliary and mucous metaplastic differentiation of bronchial epithelial cells.

The purpose of this study was to examine the profile of eicosanoids secreted by human bronchial epithelial cells (HBEC) during their in vitro differentiation toward mucociliary or mucous metaplastic phenotype. Eicosanoids were measured in supernatants by mass spectrometry, and corresponding gene expression by real-time PCR. Primary HBEC produced mainly prostaglandins (PGE2, PGD2) and epoxides (e.g. 14,15-EET), but during further mucociliary differentiation we observed a gradual increase in secretion of lipoxygenase derived HETEs. Treatment with IL-13 and IL-4 induced mucous metaplasia and resulted in downregulation of PG pathway, and potent induction of 15-lipoxygenase (marked release of 15-HETE). The deficiency in PG production sustained during long term culture of mucous metaplastic epithelia. In conclusions, Th2-type cytokines induce changes in eicosanoid metabolism of airway epithelial cells, resulting in an immense induction of 15-lipoxygenase pathway, and inhibition of PG pathways. Deficient production of immunomodulatory PGs may promote chronic inflammation and airway remodeling.

Targeted eicosanoid lipidomics of exhaled breath condensate provide a distinct pattern in the aspirin-intolerant asthma phenotype.

BACKGROUND: Eicosanoids, important signaling and inflammatory molecules, are present in exhaled breath condensate (EBC) in very low concentrations, requiring highly sensitive analytic methods for their quantification. OBJECTIVE: We sought to assess a vast platform of eicosanoids in different asthma phenotypes, including aspirin-intolerant asthma, by means of a recently developed analytic approach based on mass spectrometry. METHODS: EBC from 115 adult asthmatic subjects (62 with aspirin intolerance) and 38 healthy control subjects were assessed quantitatively for 19 eicosanoids by using complementary HPLC, gas chromatography-mass spectrometry, or both. Palmitic acid concentrations were used as a marker for dilution of condensate samples. RESULTS: Asthma was characterized by an increase in arachidonate lipoxygenase products and cysteinyl leukotrienes. The COX pathway was also significantly upregulated in asthmatic subjects. Subjects with aspirin-intolerant asthma were distinguished by a sharp increase in the level of prostaglandin D(2) and E(2) metabolites; their 5- and 15-hydroxyeicosateraenoic acid levels were also higher than in aspirin-tolerant subjects. A classical discriminant analysis permitted us to classify correctly 99% of asthmatic subjects within the study population; the specificity of the analysis was 97%. The eicosanoid profiling allowed for 92% correct classification of aspirin-intolerant subjects. CONCLUSIONS: The highly sensitive eicosanoid profiling in EBC makes it possible to detect alterations in asthma, especially in its distinct phenotype characterized by hypersensitivity to aspirin and other nonsteroidal anti-inflammatory drugs. This permits us to discriminate asthmatic subjects from healthy subjects, as well as to distinguish the 2 asthma phenotypes based on the presence or absence of aspirin hypersensitivity.

Eoxins: a new inflammatory pathway in childhood asthma.

BACKGROUND: Increased levels of leukotrienes (LTs) in exhaled breath condensate (EBC) are associated with asthma and bronchial hyperresponsiveness (BHR), whereas eicosanoids generated through the 15-lipoxygenase (LO) pathway (15-hydroxyeicosatetraenoic acid [HETE] and eoxins) have been less studied. OBJECTIVE: We investigated whether metabolites of the 5- and 15-LO pathways in EBC are associated with childhood asthma, asthma severity, and clinical parameters. METHODS: The present study included 131 school-aged children (27 children with problematic severe asthma, 80 children with mild-to-moderate asthma, and 24 healthy children) from the Severe Asthma Recognized in Childhood study and 19 children with other nonasthmatic chronic lung diseases. Clinical work-up included spirometry, fractional exhaled nitric oxide measurements, skin prick testing, and methacholine challenge. Eicosanoids were analyzed in EBC by using mass spectrometry and are reported as concentrations (in picograms per milliliter) and eicosanoid/palmitic acid (PA) ratios. RESULTS: Eoxin C4/PA, eoxin D4/PA, eoxin E4/PA, 15-HETE/PA, and LTC4/PA ratios were significantly increased in asthmatic versus healthy children. Eoxin D4/PA and LTE4/PA ratios were also significantly higher in children with BHR. A nonsignificant trend was observed toward higher eoxin/PA ratios with increasing asthma severity. In contrast to asthma, children with chronic lung disease had the highest 15-HETE/PA, LTC4/PA, LTE4/PA, and LTB4/PA ratios. CONCLUSION: The results point to increased activity of the 15-LO inflammatory pathway in childhood asthma. Mass spectrometric analyses of EBC demonstrate that increased eoxin levels not only accompany the increased 5-LO product LTC4 but are also associated with BHR. These markers might represent a new therapeutic target for asthma treatment.

Targeted eicosanoids lipidomics of exhaled breath condensate in healthy subjects.

BACKGROUND: Exhaled breath condensate collection is a non-invasive method of sampling the respiratory tract that can be repeated several times in a wide range of clinical settings. Quantitation of non-volatile compounds in the condensate requires highly sensitive analytical methods, e.g. mass spectrometry. OBJECTIVE: To validate cross-platform measurements of eicosanoids using high performance liquid chromatography or gas chromatography coupled with mass spectrometry in exhaled breath condensate sampled from 58 healthy individuals. METHODS: Twenty different eicosanoid compounds, representing major arachidonic acid lipoxygenation and cyclooxygenation pathways were measured using a stable isotope dilution method. We applied a free palmitic acid concentration as a surrogate marker for the condensate dilution factor. RESULTS: Eicosanoids concentrations in the condensates were consistent with their content in other biological fluids. Prostaglandin E(2) was the most abundant mediator, represented by its stable metabolite tetranor-PGEM. Prostaglandin D(2) products were at low concentration, while hydroxyacids derived from lipoxygenation were abundant. 5-HETE was elevated in current tobacco smokers. Leukotriene B(4) has the highest concentration of all 5-LO products. 15-LO analogues of cysteinyl leukotrienes-eoxins were detectable and metabolized to eoxin E(4). Two main vascular prostanoids: prostacyclin and thromboxane B(2) were present as metabolites. A marker for non-enzymatic lipid peroxidation, 8-iso-PGF(2alpha) isoprostane was increased in smokers. CONCLUSION: Presented targeted lipidomics analysis of exhaled breath condensate in healthy subjects justifies its application to investigation of inflammatory lung diseases. Measurements of non-volatile mediators of inflammation in the condensates might characterize disease-specific pathological mechanisms and responses to treatment.