Percentage Of Neutrophils In Sputum Research Articles

Asthma and hypertension: the role of airway inflammation.

Asthma is a chronic inflammatory respiratory disease often associated with comorbidities. Among cardiovascular comorbidities, arterial hypertension seems to create an additional health burden in asthmatics. However, evidence on this relationship is lacking. Our study aims to evaluate the characteristics of hypertensive asthmatics, focusing on the role of inflammation as a possible link between these diseases. We conducted a monocentric retrospective analysis consecutively including asthmatics who underwent induced sputum (IS) at our asthma referral center. Patients were divided in two groups according to presence or absence of history of hypertension. Clinical, functional, and inflammatory (airway and systemic) data were collected. Data on two hundred and sixty asthmatic patients were analyzed. Seventy-nine (30.4%) of them had a diagnosis of hypertension requiring a specific pharmacological treatment. Asthmatics with hypertension were more frequently male (p = 0.047), older (p < 0.001), and with higher body max index (BMI) (p < 0.001) when compared to normotensive patients. No difference concerning asthma control, severity and pharmacological treatment was observed between the two groups (all p > 0.05); distribution of comorbidities and lung function impairment (forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC); all p < 0.05) were statistically different between groups. Mixed granulocytic airway inflammation was prevalent in the hypertensive asthmatics (p = 0.014). Interestingly, a multivariable analysis revealed that age ≥ 65 years and an increased percentage of sputum neutrophils (≥61%) were independent predictors of hypertensive status (p < 0.001). Our data suggest that neutrophilic airway inflammation (as evaluated by induced sputum) is strictly associated with hypertension. In clinical practice, phenotyping asthmatic patients with comorbidities like hypertension could be useful also from a therapeutic point of view. Additional studies are mandatory to further elucidate the role of neutrophilic airway inflammation in asthma with cardiovascular diseases.

The association between MUC5AC and MUC5B genes expression and remodeling progression in severe neutrophilic asthma: A direct relationship

BackgroundMUC5 dysregulation is a hallmark of severe neutrophilic asthmatic patients. This study investigates the expression of MUC5AC and MUC5B at mRNA levels on asthma severity and airway wall thickness in severe neutrophilic asthmatic patients. MethodIn this case-control clinical trial, twenty-five severe neutrophilic asthmatic patients and ten control subjects were enrolled. Subjects underwent ACT, pulmonary functions tests, and fractional exhaled nitric oxide (FENO). Also, induced sputum has been obtained to assess the expression of MUC5AC and MUC5B by the real-time PCR. In addition, the thickness of the airway wall was assessed by high-resolution computed tomography (HRCT), and bioinformatic analysis was implemented to approve the selection of the appropriate genes and for further investigations. ResultA significant difference was observed between the asthmatic and control in MUC5AC and MUC5B mRNA expression. Meanwhile, the expression of MUC5AC increased remarkably by asthma severity; also, it is associated with airway wall thickness (WT) (both P-value <0.05). The expression of MUC5B in asthmatic patients was lower than in control. There is no significant correlation between MUC5B mRNA level and WT and asthma severity. Notably, MUC5AC transcription level was correlated to sputum neutrophil percentage, while MUC5B transcription level had a positive correlation with sputum macrophages and a negative one with sputum neutrophils. ConclusionIn severe neutrophilic asthma, airway wall thickness increases with MUC5AC mRNA overexpression, which is probably related to asthma severity and the formation of mucus plugs. However, the expression of MUC5B was decreased, resulting in poor mucociliary clearance in the airways. Trial registrationIR.IAU.MSHD.REC.1400.124

Sputum Type 2 Markers Could Predict Remission in Severe Asthma Treated With Anti-IL-5

Biotherapies targeting IL-5 allow a tangible improvement of asthma. However, all patients do not respond the same way to these treatments. Even if high blood eosinophil counts seem to be associated with a reduction in exacerbations with treatment targeting IL-5, we lack biomarkers for the prediction of remission after these very expensive treatments. Are there biomarkers of remission after therapy targeting IL-5 in the sputum of patients with severe eosinophilic asthma? This observational study included 52 patients with severe asthma initiated with anti-IL-5 therapy and recruited from the asthma clinic of the Centre Hospitalier Universitaire of Liege, Belgium. Remission was defined as patients who combined the following at 1 year after therapy: no chronic treatment with oral corticosteroids; no exacerbation; asthma control questionnaire score< 1.5, asthma control test score > 19, or both; FEV1 of≥ 80%predicted, improvement of FEV1 of≥ 10%, or both; and a blood eosinophil count< 300 cells/μL. Eosinophil peroxidase (EPX), IgE, IL-3, IL-4, IL-5, IL-13, IL-25, IL-33, granulocyte-macrophage colony-stimulating factor, thymic stromal lymphopoietin (TSLP), and eotaxin-1 levels were measured in the sputum of these patients before anti-IL-5 treatment. Among the 52 patients, 11 were classified as being in remission. These patients were characterized by higher sputum eosinophil, macrophage, and lymphocyte counts, whereas the sputum neutrophil percentage was lower than in the nonremission group. In addition, the sputum eotaxin-1, TSLP, IL-5, EPX, and IgE protein levels were higher at baseline in the remission group compared with the nonremission group. Univariate regression analysis revealed that male vsfemale sex, sputum neutrophil percentage, eotaxin-1, IL-5, and EPX were potential predictors of remission. Sputum type 2 markers seemed to be potentially predictive of remission after anti-IL-5 therapy in a cohort of patients with severe eosinophilic asthma. These results need validation on a larger cohort.

A Study on Cough Sensitivity and Airway Inflammation in Patients with Sinobronchial Syndrome.

Objective This study aimed to clarify the characteristics of cough-reflex sensitivity and airway inflammation in patients with sinobronchial syndrome (SBS). Methods 39 patients with SBS, 53 patients with upper airway cough syndrome (UACS) induced by rhinitis, 33 patients with chronic sinusitis without cough, and 39 healthy controls (HCs) were enrolled between January 2013 and December 2018. All participants underwent a capsaicin cough-sensitivity test and cytology of induced sputum. The concentration of calcitonin-gene-related peptide (CGPR), histamine, prostaglandin (PG) E2, and eosinophil cationic protein (ECP) in induced sputum were measured using enzyme-linked immunosorbent assays (ELISAs). Results The lowest concentration of capsaicin solution that induced ≥5 coughs (C5) was decreased markedly in patients with UACS induced by rhinitis compared with SBS patients (1.95 ± 2.92 vs. 31.2 ± 58.6 mol/L, P < 0.001), indicating higher cough-reflex sensitivity among UACS patients induced by rhinitis. However, there was no difference of these threshold between SBS patients and patients with sinusitis without cough and HCs. The percentage of neutrophils in sputum was increased remarkably in patients with SBS compared with HCs (40.0 ± 48.5% vs. 5.5 ± 9.0%, P < 0.001). A higher concentration of CGPR, histamine, and PGE2 was observed in induced sputum from patients with UACS induced by rhinitis than that in controls, and the ECP level was increased significantly in UACS induced by rhinitis compared with that in the other three groups. Conclusions Cough-reflex sensitivity and airway inflammation in patients with SBS were different in patients with UACS induced by rhinitis. Thus, the mechanism of cough in those two patient populations might differ. Our study is registered in the Chinese Clinical Trials Register (https://www.chictr.org.cn/) as ChiCTR-TRC-00000152.

Fish oil blunts lung function decrements induced by acute exposure to ozone in young healthy adults: A randomized trial.

Over one-third of the U.S. population is exposed to unsafe levels of ozone (O3). Dietary supplementation with fish oil (FO) or olive oil (OO) has shown protection against other air pollutants. This study evaluates potential cardiopulmonary benefits of FO or OO supplementation against acute O3 exposure in young healthy adults. Forty-three participants (26±4years old; 47% female) were randomized to receive 3g/day of FO, 3g/day OO, or no supplementation (CTL) for 4weeks prior to undergoing 2-hour exposures to filtered air and 300ppb O3 with intermittent exercise on two consecutive days. Outcome measurements included spirometry, sputum neutrophil percentage, blood markers of inflammation, tissue injury and coagulation, vascular function, and heart rate variability. The effects of dietary supplementation and O3 on these outcomes were evaluated with linear mixed-effect models. Compared with filtered air, O3 exposure decreased FVC, FEV1, and FEV1/FVC immediately post exposure regardless of supplementation status. Relative to that in the CTL group, the lung function response to O3 exposure in the FO group was blunted, as evidenced by O3-induced decreases in FEV1 (Normalized CTL -0.40±0.34 L, Normalized FO -0.21±0.27 L) and FEV1/FVC (Normalized CTL -4.67±5.0 %, Normalized FO -1.4±3.18 %) values that were on average 48% and 70% smaller, respectively. Inflammatory responses measured in the sputum immediately post O3 exposure were not different among the three supplementation groups. Systolic blood pressure elevations 20-h post O3 exposure were blunted by OO supplementation. FO supplementation appears to offer protective effects against lung function decrements caused by acute O3 exposure in healthy adults.

Validation of Sputum Biomarker Immunoassays and Cytokine Expression Profiles in COPD.

Immunoassays are commonly used to assess airway inflammation in sputum samples from chronic obstructive pulmonary disease (COPD) patients. However, assay performance and validation in this complex matrix is inconsistently reported. The aim of this study was to assess the suitability of various immunoassays for use with sputum samples, followed by use of validated immunoassays to evaluate biomarker levels in COPD patients. Assays were assessed for recombinant reference standard suitability, optimal sample dilution, standard recovery in the biological matrix and reproducibility. Validated assays were used to assess sputum supernatants in Cohort A (n = 30 COPD, n = 10 smokers, n = 10 healthy) and Cohort B (n = 81 COPD, n = 15 smokers, n = 26 healthy). Paired baseline and exacerbation samples from 14 COPD patients were assessed in cohort A, and associations with sputum cell counts and bacterial colonisation investigated in cohort B. 25/32 assays passed validation; the primary reason for validation failure was recombinant reference standard suitability and sample dilution effects. Interleukin (IL-)6 and IL-8 were significantly increased in COPD patients compared to healthy subjects and smokers for both cohorts. Tumour necrosis factor (TNF)α and IL-1β were higher in COPD compared to smokers using one immunoassay but not another, partly explained by different absolute recovery rates. IL-1β, IL-2, IL-4, IL-8, IL-17A, Granulocyte colony stimulating factor (G-CSF), Interferon (IFN-)γ, Interferon gamma induced protein (IP-)10, Macrophage inflammatory protein (MIP)-1α, MIP-1β and TNF-α levels correlated with sputum neutrophil percentage in COPD patients. IL-1β, IL-4, IL-8, G-CSF and IFN-γ levels were associated with Haemophilus influenzae colonisation in COPD patients. Current smokers had lower levels of IL-1β, IL-4, IL-8, G-CSF, IFN-γ, IP-10, Monocyte chemoattractant protein (MCP)-1, MIP-1α, MIP-1β and TNF-α. Validated immunoassays applied to sputum supernatants demonstrated differences between COPD patients and controls, the effects of current smoking and associations between Haemophilus influenzae colonisation and higher levels of selected cytokines. Immunoassay validation enabled inflammatory mediators associated with different COPD characteristics to be determined.

Club cell 10-kDa protein (CC10) as a surrogate for identifying type 2 asthma phenotypes

Objective: Club cell 10-kDa protein (CC10) is a documented biomarker for airway obstructive diseases. Primarily produced by nonciliated club cells in the distal airway and in nasal epithelial cells, CC10 suppresses Th2 cell differentiation and Th2 cytokine production. In this study, we aimed to determine whether CC10 can also be used as an alternative biomarker for identifying Type 2 (T2) asthma. Methods: 74 patients with asthma, and 24 healthy controls were enrolled in the study. T2-high asthma was defined as elevation in two or more biomarkers, such as sputum eosinophilia ≥ 3%, high blood eosinophils ≥ 300/µL, or high FeNO ≥ 30 ppb. T2-low asthma was defined as no elevation in biomarkers. Enzyme-linked immunosorbent assay (ELISA) was used to assess the CC10 levels in plasma. Results: The plasma CC10 level in patients with T2-high asthma was lower than that of patients with T2-low asthma and healthy controls (P < 0.05). To distinguish between T2-high and T2-low phenotype in patients with asthma, a receiver-operating characteristic (ROC) analysis was performed. It showed a sensitivity of 58.1% and specificity of 78.0% when using 22.74 ng/ml of plasma CC10. Correlation analysis indicated that the plasma CC10 level was inversely correlated with sputum eosinophil, blood eosinophil, and FeNO, and positively correlated with log PD20. However, no correlation with sputum neutrophil percentages, macrophage percentages, IgE, or lung function was found. Conclusions: Plasma CC10 is potentially useful in predicting T2-high and T2-low asthma. Lower plasma CC10 was associated with enhanced airway hyperresponsiveness, and Type 2 inflammation.

Inflammatory Phenotypes of Cough Variant Asthma as Response Predictors to Anti-Asthmatic Therapy.

BackgroundEosinophilic inflammatory phenotype was thought to be the most common phenotype of cough variant asthma (CVA), nevertheless other phenotypes were also reported.PurposeThe study aimed to analyze the inflammatory phenotypes of CVA in relation to treatment response to the stepwise anti-asthmatic treatment.Patients and MethodsThe study included 45 patients with chronic cough (CC) and suspicion of CVA (normal chest X-ray, presence of bronchial hyperresponsiveness and no history of wheezing or dyspnea) in whom induced sputum was successfully collected. Based on the cellular composition of the sputum, patients were divided into major inflammatory phenotypes: eosinophilic, neutrophilic, paucigranulocytic or mixed granulocytic. A stepwise treatment, including inhaled corticosteroids with long-acting β2-agonist, montelukast and short-term therapy with prednisone was initiated. Good treatment response was defined as the reduction in cough severity at least 20 mm from the baseline in visual analogue scale and improvement in cough-related quality of life assessed by the Leicester cough questionnaire at least 1.3 points after any of three steps.ResultsFinally, 40/45 (88.9%) patients improved after therapy. Eosinophilic asthma was found in 13/40 (32.5%) patients, neutrophilic in 6/40 (15.0%) and paucigranulocytic pattern in 21/40 (52.5%) patients. No one demonstrated a mixed granulocytic phenotype. The response to the treatment was similar in all groups. However, the reduction in cough severity was inversely related to the percentage of sputum neutrophils (r = −0.44, P = 0.003). We showed that the percentage of neutrophils in sputum >46% may be considered as a predictor of poor response to anti-asthmatic therapy.ConclusionThe diversity of inflammatory phenotypes with paucigranulocytic preponderance was found in subjects with CVA. The response to anti-asthmatic treatment in patients with CVA was not related to the inflammatory phenotype. High neutrophil count in sputum may predict poor response to anti-asthmatic therapy in patients with CC and bronchial hyperresponsiveness.

Airway hyperresponsiveness and inflammation in Japanese patients with human immunodeficiency virus 1 infection

IntroductionDespite the growing population of long-term survivors with human immunodeficiency virus 1 (HIV) exhibiting asthma-like features worldwide, the pathogenesis underlying airway hyperresponsiveness (AHR) and airway inflammation remains unclear. We aimed to investigate AHR and airway inflammation in an HIV-infected Japanese population. MethodsOf 94 Japanese participants, 10 HIV-infected participants with asthma were excluded from the study. We compared the characteristics of HIV-infected (n = 34) and non-HIV-infected participants (n = 50). Eosinophilic, neutrophilic, mixed (eosinophilic and neutrophilic), and paucigranulocytic airway inflammatory phenotypes were classified based on induced sputum characteristics. ResultsThe prevalence of AHR in HIV-infected participants (32.4%) was significantly higher than that in their non-HIV-infected counterparts (10.0%) (P = 0.0213). The multivariate nominal logistic regression analysis revealed HIV as an independent risk factor for AHR. HIV-infected participants were significantly more likely to have a neutrophilic airway inflammatory phenotype than non-HIV-infected participants (P = 0.0358). Furthermore, HIV-infected participants with AHR demonstrated a significant correlation between AHR levels and the percentage of sputum neutrophils (r = −0.65, P = 0.0316). The percentage of sputum neutrophils was negatively associated with the blood CD4 cell count (r = −0.66, P = 0.0266). ConclusionsWe observed the high prevalence of AHR and neutrophilic airway inflammatory phenotype in Japanese participants with stable HIV infection. Our findings provide insight into the mechanisms of AHR and may facilitate the development of novel treatment for individuals with AHR and HIV infection.

Distribution of inflammatory phenotypes among patients with asthma in Jilin Province, China: a cross-sectional study

BackgroundThe inflammatory phenotypes of asthma predict the treatment response and prognosis. The phenotype distributions differ depending on the geographical region. This study aimed to assess the distribution of different inflammatory phenotypes among asthma patients in Jilin Province, China.MethodsA total of 255 patients with asthma were recruited from Jilin Province, China for this cross-sectional study. Each patient underwent sputum induction following clinical assessment and peripheral blood collection. Inflammatory phenotypes were classified according to the inflammatory cell counts in the sputum.ResultsPaucigranulocytic asthma (PGA) was the most common inflammatory phenotype (52.2%), followed by eosinophilic asthma (EA, 38.3%), mixed granulocytic asthma (MGA, 5.2%), and neutrophilic asthma (NA, 4.3%). NA was more common among patients over 45 years old and those who were treated with higher doses of inhaled corticosteroids (ICS), but was less common following antibiotics treatment (p < 0.05). The proportion of patients with EA decreased as the ICS treatment dose and time increased (p = 0.038). Patients with uncontrolled asthma had higher numbers of sputum eosinophils and neutrophils (p < 0.05). Patients with severe asthma had a higher percentage of sputum neutrophils (p < 0.05). A greater proportion of patients with NA had severe asthma (60%) compared to those with EA (18.2%) (p = 0.016).ConclusionsThe most common asthma inflammatory cell phenotype in Jilin Province, China is PGA, followed by EA, MGA, and NA. The low prevalence of NA in Jilin Province compared to other countries and also other regions in China might be due to excessive antibiotic use and irregular ICS treatment in this region.

Increased levels of serum IL-17 and induced sputum neutrophil percentage are associated with severe early-onset asthma in adults

BackgroundDifferences between adult patients with severe early-onset and late-onset asthma have not been well studied.ObjectivesTo determine the phenotypic distinction regarding age at onset in patients with severe asthma.MethodsThe present study enrolled thirty-two patients with severe early-onset (onset age < 12 years) asthma and thirty-two patients with severe late-onset (onset age > 12 years) asthma. Severe asthma was defined according to Global Initiative for Asthma criteria. The clinical, spirometric, and laboratory parameters were collected for group comparisons.ResultsAmong the 64 patients included (mean age, 46.22 ± 13.90 years; 53.1% male), the mean percent of predicted forced expiratory volume in 1 s (FEV1) was 68.43 ± 20.55%. Patients with severe early-onset asthma had a younger age, longer duration of asthma, higher rate of family history, and better small-airway function (MEF25% and MMEF75/25%) compared with severe late-onset asthma. Furthermore, levels of serum IL-17 and sputum neutrophil percentage were significantly higher for patients with severe early-onset asthma (P = 0.016, 0.033, respectively). Multiple logistic regression analysis revealed that increased serum IL-17 (odds ratio = 1.065, P = 0.016) was independently associated with severe early-onset asthma. The combination of serum IL-17 and sputum neutrophil percentage yielded a sensitivity of 80.0% and a specificity of 86.7% for identifying patients with severe early-onset asthma.ConclusionsPatients with severe early-onset asthma exhibit elevated levels of serum IL-17 and sputum neutrophil percentage, suggesting a potential role in the pathogenesis of severe early-onset phenotype.

Biomarkers for predicting response to aspirin therapy in aspirin‐exacerbated respiratory disease

BackgroundAspirin desensitization followed by daily aspirin use is an effective treatment for aspirin‐exacerbated respiratory disease (AERD).ObjectiveTo assess clinical features as well as genetic, immune, cytological and biochemical biomarkers that might predict a positive response to high‐dose aspirin therapy in AERD.MethodsWe enrolled 34 AERD patients with severe asthma who underwent aspirin desensitization followed by 52‐week aspirin treatment (650 mg/d). At baseline and at 52 weeks, clinical assessment was performed; phenotypes based on induced sputum cells were identified; eicosanoid, cytokine and chemokine levels in induced sputum supernatant were determined; and induced sputum expression of 94 genes was assessed. Responders to high‐dose aspirin were defined as patients with improvement in 5‐item Asthma Control Questionnaire score, 22‐item Sino‐Nasal Outcome Test (SNOT‐22) score and forced expiratory volume in 1 second at 52 weeks.ResultsThere were 28 responders (82%). Positive baseline predictors of response included female sex (p = .002), higher SNOT‐22 score (p = .03), higher blood eosinophil count (p = .01), lower neutrophil percentage in induced sputum (p = .003), higher expression of the hydroxyprostaglandin dehydrogenase gene, HPGD (p = .004) and lower expression of the proteoglycan 2 gene, PRG2 (p = .01). The best prediction model included Asthma Control Test and SNOT‐22 scores, blood eosinophils and total serum immunoglobulin E. Responders showed a marked decrease in sputum eosinophils but no changes in eicosanoid levels.Conclusions and Clinical RelevanceFemale sex, high blood eosinophil count, low sputum neutrophil percentage, severe nasal symptoms, high HPGD expression and low PRG2 expression may predict a positive response to long‐term high‐dose aspirin therapy in patients with AERD.

Relation of sputum neutrophilia to the development of chronic lung allograft dysfunction after lung transplantation.

Chronic lung allograft dysfunction (CLAD) is a serious complication after lung transplantation (LuTx) and is associated with elevated proportions of neutrophils in bronchoalveolar lavage (BAL). Induced sputum is a less-invasive sampling method than BAL and assesses markers of inflammation on the surfaces of large central airways. We wanted to examine whether % neutrophil levels in induced sputum were elevated prior to CLAD diagnosis among LuTx recipients, and whether sputum markers of inflammation can be used as a tool for predicting the development of CLAD. Induced sputum samples were collected at 1, 3, 6, 12, and 24months post-LuTx in 36 patients with a history of COPD or pulmonary fibrosis, and of these, 16 developed CLAD either during or after the sputum surveillance period. At 2years, median (IQR) % neutrophils in induced sputum were significantly higher among patients with CLAD compared with those without CLAD [73 (52-80) % vs 59 (41-76) %, p=.01]. Interestingly, we found a significant increase in the rate of change in % neutrophils beginning at 90days preceding the diagnosis of CLAD. This suggests using sputum neutrophil percentage as a surveillance modality for monitoring lung allograft function after LuTx.

Sputum microbiome profiles identify severe asthma phenotypes of relative stability at 12 to 18 months

Asthma is a heterogeneous disease characterized by distinct phenotypes with associated microbial dysbiosis. Our aim was to identify severe asthma phenotypes based on sputum microbiome profiles and assess their stability after 12 to 18 months. Afurther aim was to evaluate clusters' robustness after inclusion of an independent cohort of patients with mild-to-moderate asthma. In this longitudinal multicenter cohort study, sputum samples were collected for microbiome profiling from a subset of the Unbiased Biomarkers in Prediction of Respiratory Disease Outcomes adult patient cohort at baseline and after 12 to 18 months of follow-up. Unsupervised hierarchical clustering was performed by using the Bray-Curtis β-diversity measure of microbial profiles. For internal validation, partitioning around medoids, consensus cluster distribution, bootstrapping, and topological data analysis were applied. Follow-up samples were studied to evaluate within-patient clustering stability in patients with severe asthma. Cluster robustness was evaluated by using an independent cohort of patients with mild-to-moderate asthma. Data were available for 100 subjects with severe asthma (median age 55 years; 42% males). Two microbiome-driven clusters were identified; they were characterized by differences in asthma onset, smoking status, residential locations, percentage of blood and/or sputum neutrophils and macrophages, lung spirometry results, and concurrent asthma medications (all P values< .05). The cluster 2 patients displayed a commensal-deficient bacterial profile that was associated with worse asthma outcomes than those of the cluster 1 patients. Longitudinal clusters revealed high relative stability after 12 to 18 months in those with severe asthma. Further inclusion of an independent cohort of 24 patients with mild-to-moderate asthma was consistent with the clustering assignments. Unbiased microbiome-driven clustering revealed 2 distinct robust phenotypes of severe asthma that exhibited relative overtime stability. This suggests that the sputum microbiome may serve as a biomarker for better characterizing asthma phenotypes.

Noninvasive Monitoring of the Response of Human Lungs to Low-Dose Lipopolysaccharide Inhalation Challenge Using MRI: A Feasibility Study.

Development of antiinflammatory drugs for lung diseases demands novel methods for noninvasive assessment of inflammatory processes in the lung. To investigate the feasibility of hyperpolarized 129 Xe MRI, 1 H T1 time mapping, and dynamic contrast-enhanced (DCE) perfusion MRI for monitoring the response of human lungs to low-dose inhaled lipopolysaccharide (LPS) challenge compared to inflammatory cell counts from induced-sputum analysis. Prospective feasibility study. Ten healthy volunteers underwent MRI before and 6 hours after inhaled LPS challenge with subsequent induced-sputum collection. 1.5T/hyperpolarized 129 Xe MRI: Interleaved multiecho imaging of dissolved and gas phase, ventilation imaging, dissolved-phase spectroscopy, and chemical shift saturation recovery spectroscopy. 1 H MRI: Inversion recovery fast low-angle shot imaging for T1 mapping, time-resolved angiography with stochastic trajectories for DCE MRI. Dissolved-phase ratios of 129 Xe in red blood cells (RBC), tissue/plasma (TP) and gas phase (GP), ventilation defect percentage, septal wall thickness, surface-to-volume ratio, capillary transit time, lineshape parameters in dissolved-phase spectroscopy, 1 H T1 time, blood volume, flow, and mean transit time were determined and compared to cell counts. Wilcoxon signed-rank test, Pearson correlation. The percentage of neutrophils in sputum was markedly increased after LPS inhalation compared to baseline, P = 0.002. The group median RBC-TP ratio was significantly reduced from 0.40 to 0.31, P = 0.004, and 1 H T1 was significantly elevated from 1157.6 msec to 1187.8 msec after LPS challenge, P = 0.027. DCE MRI exhibited no significant changes in blood volume, P = 0.64, flow, P = 0.17, and mean transit time, P = 0.11. Hyperpolarized 129 Xe dissolved-phase MRI and 1 H T1 mapping may provide biomarkers for noninvasive assessment of the response of human lungs to LPS inhalation. By its specificity to the alveolar region, hyperpolarized 129 Xe MRI together with 1 H T1 mapping adds value to sputum analysis. 1 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;51:1669-1676.

Analysis of clinical features and inflammatory factors in induced sputum in common phenotypes of COPD with frequent exacerbations

Objective To compare the clinical characteristics of chronic bronchitis (CB), emphysema (EM), asthma - chronic obstructive pulmonary disease overlapping syndrome (ACOS) with frequent exacerbations (FE) or infrequent exacerbations (iFE)and induced sputum inflammatory cells and the heterogeneity of the transmitter. Methods Ninety-one cases of chronic obstructive pulmonary disease(COPD)with acute exacerbation were divided into CB, EM or ACOS phenotype, among which 44 were frequent, and 47 were non frequent.The clinical data, induced sputum inflammatory cells, interferon-γ(IFN-γ), tumor necrosis factor-α(TNF-α), interleukin(IL)-4, IL-13 were analyzed. Results The FEV1% was (47±13.1)%, significantly lower than that of non frequent episodes ((56.2±10.2)%), and the difference was statistically significant(P=0.049). The FEV1/FVC% was (54.3±9.3)%, significantly lower than that of non frequent episodes (60.1±7.3)%, and there was a significant difference between them (P=0.001). The proportion of patients with GOLD III and IV, the percentage of neutrophils in induced sputum, tumor necrosis factor -α(TNF-α) and interferon -γin the patients with frequent episodes were significantly higher than those with non frequent episodes (P<0.05). Among them, FEV1/FVC% and TNF-αwere independent risk factors for COPD patients (P=0.032, 0.021). The FEV1% of patients with CB phenotypic frequent episodes were (47.9±14.9)%, significantly lower than that of non frequent episodes ((57.2±10.9)% )(P=0.000), and FEV1/FVC% was (53.4±9.5)% in patients with CB frequent episodes, significantly lower than that of non frequent episodes ((60.3±6.9)%), and the difference was statistically significant (P=0.022), while the level of N%, TNF-α in induced sputum were significantly higher in CB phenotype subjects with FE than those in subjects with iFE(P<0.01). Patients with frequent episodes of emphysema had longer duration of disease (P<0.05), lower FEV1% and FEV1/FVC%(P<0.05), the proportion of GOLD III patients and the induced sputum TNF-αwere higher, but there was no significant difference in the number and proportion of phlegm inflammatory cells, interferon -γ, interleukin 4 and interleukin 3.The level of GOLD III and the IL-13 level of induced sputum in patients with frequent ACOS phenotype were significantly higher than those in patients with non frequent episodes (P<0.05). Conclusion The lung function, the severity of the disease, the course of the disease, and the percentage of sputum neutrophils, tumor necrosis factor -α, or interleukin 13 are helpful in diagnosing patients with high risk of frequent episodes. Key words: Chronic obstructive pulmonary disease; chronic bronchitis; emphysema; asthma-COPD overlap syndrome

Neutrophilic Asthma Is Associated with Increased Airway Bacterial Burden and Disordered Community Composition.

Neutrophilic asthma (NA) is an important asthma inflammatory phenotype associated with disease severity, airflow limitation, and steroid resistance, and its mechanism is still uncertain. Evidences suggest a potential role for bacteria in its pathogenesis, but, so far, this remains poorly understood. We sought to investigate airway bacterial burden, community composition, and inflammatory response in NA. Fifty-four stable asthmatics without infection were enrolled and separated into either NA group (n = 20) or non-NA group (n = 34). Subject demographics, Asthma Control Test (ACT) scores, medications, and pulmonary functions were documented. Sputum cytology, airway bacterial burden, microbial community composition, and inflammatory cytokines were assessed. The total airway bacterial burden was significantly increased in subjects with NA versus non-NA and was positively correlated with the sputum neutrophil percentage. Airway neutrophilia was associated with less airway bacterial community richness and diversity, along with a distinct community composition. In patients with NA, bacteria in phylum Proteobacteria, especially Haemophilus spp. and Moraxella spp., showed significant increases in both actual loads and relative abundances, while bacteria in phyla Firmicutes, Actinobacteria, and Saccharibacteria showed decreased relative abundances compared with non-NA. Patients with NA demonstrated higher levels of interleukin-1β (IL-1β), IL-6, IL-8, IL-12, IL-17A, and tumor necrosis factor-α (TNF-α) in sputum samples compared with non-NA. Increased bacterial burden and distinct microbiota composition were the key characters of neutrophilic phenotype in asthma, accompanied by excessive airway inflammation. Understanding the relationship between airway microbiota and neutrophilic inflammation may help in treatment and management of asthma, such as targeting airway microbiota.

Can inflammatory markers in induced sputum be used to detect phenotypes and endotypes of pediatric severe therapy-resistant asthma?

The phenotypes and endotypes of severe therapy-resistant asthma (STRA) have not been fully elucidated in children. The aim of the present study was to investigate inflammatory markers in the induced sputum of children with STRA and to compare them with those present in a group of children who achieved control. A prospective cohort of children (6-18 years of age) diagnosed with severe asthma (GINA criteria) who had undergone treatment for at least 6 months was comprehensively followed for 3 months. Inhalation technique, adherence to treatment, ACT score, and main comorbidities were assessed. Induced sputum samples were collected for cytology analysis and quantitative assessment of cytokines; the participants also underwent spirometry, plethysmography, and fractional exhaled nitric oxide (FeNO) measurement. Forty patients were included (average age 12.8 years; 62.5% male); of these, 13 (32.5%) were classified as STRA at the end of follow-up. There were no significant differences between the STRA and control groups in demographic data, functional test results, or FeNO levels. The eosinophilic inflammatory pattern predominated in both groups; however, the STRA group showed a proportionally higher percentage of sputum neutrophils (P < 0.05). The median sputum levels of the cytokines IL-10, GM-CSF, IFN-γ, and TNF-α were significantly higher in the STRA group (P < 0.05). GM-CSF and TNF-α levels showed inverse correlations with ACT scores. The presence of neutrophils, the cytokines IL-10, and IFN-γ and, more particularly, TNF-α, and GM-CSF in the sputum may play an important role in the pathophysiological mechanism of STRA in children and adolescents. Specific antagonists for these cytokines may represent a future therapeutic strategy.

Saturated fatty acids, obesity, and the nucleotide oligomerization domain–like receptor protein 3 (NLRP3) inflammasome in asthmatic patients

Both obesity and high dietary fat intake activate the nucleotide oligomerization domain-like receptor protein 3 (NLRP3) inflammasome. We aimed to examine NLRP3 inflammasome activity in the airways of obese asthmatic patients after macronutrient overload and in immune cells challenged by inflammasome triggers. Study 1 was a cross-sectional observational study of nonobese (n=51) and obese (n=76) asthmatic adults. Study 2 was a randomized, crossover, acute feeding study in 23 asthmatic adults (n=12 nonobese and n=11 obese subjects). Subjects consumed 3 isocaloric meals on 3 separate occasions (ie, saturated fatty acid, n-6 polyunsaturated fatty acid, and carbohydrate) and were assessed at 0 and 4hours. For Studies 1 and 2, airway inflammation was measured based on sputum differential cell counts, IL-1β protein levels (ELISA), and sputum cell gene expression (Nanostring nCounter). In Study 3 peripheral blood neutrophils and monocytes were isolated by using Ficoll density gradient and magnetic bead separation and incubated with or without palmitic acid, LPS, or TNF-α for 24hours, and IL-1β release was measured (ELISA). In Study 1 NLRP3 and nucleotide oligomerization domain 1 (NOD1) gene expression was upregulated, and sputum IL-1β protein levels were greater in obese versus nonobese asthmatic patients. In Study 2 the saturated fatty acid meal led to increases in sputum neutrophil percentages and sputum cell gene expression of Toll-like receptor 4 (TLR4) and NLRP3 at 4hours in nonobese asthmatic patients. In Study 3 neutrophils and monocytes released IL-1β when challenged with a combination of palmitic acid and LPS or TNF-α. The NLRP3 inflammasome is a potential therapeutic target in asthmatic patients. Behavioral interventions that reduce fatty acid exposure, such as weight loss and dietary saturated fat restriction, warrant further exploration.

Association between fractional exhaled nitric oxide, sputum induction and peripheral blood eosinophil in uncontrolled asthma

BackgroundThe fractional exhaled nitric oxide (FeNO) and blood eosinophils are biomarkers of eosinophilic airway inflammation used in the diagnosis and management of asthma, although induced sputum is the gold standard test for phenotypic asthma. Nevertheless, the clinical application of the correlation between sputum eosinophils, FeNO and blood eosinophils is controversial.ObjectiveTo investigate the clinical application of the correlation between sputum eosinophils, FeNO and blood eosinophils with uncontrolled asthmatic patients. It also examined the relationships between these biomarkers in bronchial reversibility and bronchial hyper-responsiveness (BHR).MethodsThis study evaluated 75 uncontrolled asthmatic patients (symptom control and future risk of adverse outcomes). All patients underwent the following on the same day: FeNO, spirometry, BHR or bronchodilator reversibility, sputum induction and blood collection. Eosinophilic airway inflammation was defined as sputum eosinophils ≥ 2.5% or FeNO levels ≥ 32 parts per billion (ppb).ResultsA significant positive relationship was between percentage of sputum eosinophils and FeNO (r = 0.4556; p < 0.0001) and percentage of blood eosinophils (r = 0.3647; p = 0.0013), and a significant negative correlation was between percentage of sputum neutrophils and FeNO (r = − 0.3653; p = 0.0013). No relationship between FeNO and percentage of blood eosinophils (p = 0.5801). ROC curve analysis identified FeNO was predictive of sputum eosinophilia [area under the curve (AUC) 0.707, p = 0.004] at a cutoff point of 35.5 ppb (sensitivity = 67.3%, specificity = 73.9%). Percentage of blood eosinophils was also highly predictive with an AUC of 0.73 (p = 0.002) at a cut-off point of 1.5%, sensitivity and specificity were 61.5 and 78.3%, respectively. Although the sputum neutrophil percentage was correlated with FeNO, ROC curve of these parameters did not show useful values (AUC = 0.297, p = 0.003; AUC = 0.295, p = 0.021).Conclusions and clinical relevanceBlood eosinophils and FeNO can accurately predict eosinophilic airway inflammation in uncontrolled asthmatic patients. FeNO is poor surrogates for sputum neutrophils and blood eosinophils. The FeNO level and blood eosinophils, which determine an optimal cutoff for sputum eosinophilia, need more studies.