IL-8 production in response to cigarette smoke is decreased in epithelial cells from COPD patients

Liquid Application Dosing Alters the Physiology of Air-Liquid Interface Primary Bronchial Epithelial Cultures and In vitro Testing Relevant Endpoints

Differentiated Primary human bronchial epithelial cell (dpHBEC) cultures grown under air-liquid interface (ALI) conditions exhibit key features of the human respiratory tract and are thus critical for respiratory research as well as efficacy and toxicity testing of inhaled substances (e.g., consumer products, industrial chemicals, and pharmaceuticals). Many inhalable substances (e.g., particles, aerosols, hydrophobic substances, reactive substances) have physiochemical properties that challenge their evaluation under ALI conditions in vitro. Evaluation of the effects of these methodologically challenging chemicals (MCCs) in vitro is typically conducted by "liquid application," involving the direct application of a solution containing the test substance to the apical, air-exposed surface of dpHBEC-ALI cultures. We report that the application of liquid to the apical surface of a dpHBEC-ALI co-culture model results in significant reprogramming of the dpHBEC transcriptome and biological pathway activity, alternative regulation of cellular signaling pathways, increased secretion of pro-inflammatory cytokines and growth factors, and decreased epithelial barrier integrity. Given the prevalence of liquid application in the delivery of test substances to ALI systems, understanding its effects provides critical infrastructure for the use of in vitro systems in respiratory research as well as in the safety and efficacy testing of inhalable substances.

Eurotium cristatum Fermented Loose Dark Tea Ameliorates Cigarette Smoke-Induced Lung Injury by MAPK Pathway and Enhances Hepatic Metabolic Detoxification by PXR/AhR Pathway in Mice

Cigarette smoke- (CS-) induced oxidative stress and inflammation in the lung are serious health problems. Primary and reprocessed tea products contain multiple antioxidants that have been reported to protect the lung against CS-induced injury. However, the beneficial effects of Eurotium cristatum fermented loose dark tea (ECT) and Eurotium cristatum particle metabolites (ECP) on CS-induced lung injury and its potential hepatic metabolic detoxification are still unclear. Therefore, sixty mice were randomly divided into six equal groups. CS-exposed mice were prevented or treated with ECP or ECT infusions for 12 or 8 weeks to determine the antioxidative stress, anti-inflammatory and potential metabolic detoxification of ECT and ECP. Thirty-six mice were randomly divided into six equal groups to observe the effects on hepatic metabolic detoxification by replacing daily drinking water with ECT. Results showed that CS significantly decreased the activities of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) and upregulated the expressions of malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), IL-8, and IL-1β in serum. These adverse effects were modulated by ECP and ECT. In addition, ECT upregulated the mRNA expression of pregnane X receptor (PXR) and cytochrome P450 (CYP450) in the liver on daily free drinking ECT mice group. Western blot analysis further revealed that in CS-exposed mice, ECP and ECT significantly decreased the phosphorylation of mitogen-activated protein kinase (MAPK) in the lung but upregulated the protein expressions of PXR and aryl hydrocarbon receptor (AhR) in the liver. Overall, our findings demonstrated that ECT and ECP protected against lung injury induced by CS via MAPK pathway and enhanced hepatic metabolic detoxification via PXR and AhR pathways. Therefore, daily intake of ECT and ECP can potentially protect against CS-induced oxidative and inflammatory injuries.

The inflammatory biomarker YKL-40 is elevated in the serum, but not the sputum, of E-cigarette users

METHODS

We conducted a cross-sectional study of adults between 18 and 55 years old. Inclusion criteria were: exclusive e-cigarette use or cigarette smoking for ≥ 1 year or no history of tobacco use. Participants with a history of pulmonary illness, atopy, medications (except birth control pills), marijuana, and illegal substance use were excluded. Custom Multiplex ELISA was used to measure YKL-40 and other biomarker levels in the serum and induced sputum of the participants. Multivariable linear regression was used to compare the levels of YLK-40 in healthy participants, e-cigarette, and cigarette users after adjusting for age, sex, and BMI.

RESULTS

We recruited 20 healthy controls, 23 cigarette smokers, and 22 exclusive e-cigarette users. Serum YKL-40 (ng/ml) was significantly higher in e-cigarette users (Median 21.2 [IQR 12.1-24.0] ng/ml) when compared to controls (12.2 [IQR 8.7-18.1] ng/ml, p = 0.016) but comparable to cigarette smokers (21.6 [IQR 11.62-51.7] ng/ml, p = 0.31). No significant differences were found in the serum or sputum of the other biomarkers tested.

CONCLUSION

The inflammatory biomarker, YKL-40 is elevated in the serum but not the sputum of e-cigarette users with no reported pulmonary disease. Further research is necessary to characterize this association.

Establishment of rapid risk assessment model for cigarette smoke extract exposure in chronic obstructive pulmonary disease

Rapid risk assessment models for different types of cigarette smoke extract (CSE) exposure are critical to understanding the etiology of chronic obstructive pulmonary disease. The present study investigated inflammation of cultured tracheal tissues with CSE exposure. Rat trachea rings were isolated, cultured, then exposed to various concentrations of CSE from 3R4 F reference cigarettes for 4 h. Tissue/cellular morphology, ultrastructure, viability and damage, inflammatory cell infiltration, and inflammatory protein levels were measured and compared to untreated controls. Human bronchial epithelial cells (BEAS-2B) exposed to 0 or 300 μg/mL CSE were cocultured with macrophages to assess extent of mobilization and phagocytosis. Endotracheal epithelium cilia densities were significantly reduced with increasing CSE concentrations, while mucous membranes became increasingly disordered; both eventually disappeared. Macrophages became larger as the CSE concentration increased, with microvilli and extended pseudopodium covering their surface, and many primary and secondary lysosomes present in the cytoplasm. Inflammatory cell infiltration also increased with increasing CSE dose, as did intracellular adhesion molecule-1(ICAM-1), interleukin-6(IL-6). The method described here may be useful to qualitatively characterized the effects of the compound under study. Then, we use BEAS-2B cell line system to strength the observation made in the cultured tissues. Probably, an approach to integrate results from both experiments will facilitate its application. These results demonstrate that cultured rat tracheal rings have a whole-tissue structure that undergoes inflammatory processes similar to in vivo tissues upon CSE exposure.

An Insight into COPD Morphopathogenesis: Chronic Inflammation, Remodeling, and Antimicrobial Defense

Background and Objectives: Intercellular signaling networks with high complexity cause a spectrum of mechanisms achieving chronic obstructive pulmonary disease (COPD) that still question many uncertainties. Materials and Methods: Immunoreactive cells in bronchial tissue obtained from 40 COPD patients and 49 healthy control subjects were detected by biotin-streptavidin immunohistochemistry method for the following markers of IL-1α, IL-4, IL-6, IL-7, IL-8, IL-10, IL-12, TNF-α, MMP-2, TIMP-2, TGF-β1, Hsp−70, hBD−2, hBD−3, hBD−4. Results: Overall the highest numbers (from mostly moderate (++) to abundance (++++)) of IL-1α, IL-4, IL-7, IL-8, IL-10, IL-12, MMP-2, TIMP-2, TGF-β1 immunoreactive cells were marked increasingly in the blood vessel wall, connective tissue, and bronchial epithelium of COPD-affected lung, respectively. We found statistically significant (p < 0.05) higher numbers of immunoreactive cells positive for all of examined interleukins, TNF-α, MMP-2, TIMP-2, TGF-β1, hBD-2, and hBD-3 in the COPD-affected lung compared to the control group, but not for Hsp-70 and hBD-4. Conclusions: COPD-affected lung tissue exhibits mostly inflammatory response patterns of increased IL-1α, IL-4, IL-8, IL-12, and TNF-α, especially in the airway epithelium. Increased MMP-2 and TGF-β1, but decreased Hsp-70, proposes pronounced tissue damage and remodeling in COPD. High numbers of hBD-2 and hBD-3 immunoreactive cells may highlight antimicrobial activity in COPD within stable regulation of local immunity.

The evaluation of inflammatory, anti-inflammatory and regulatory factors contributing to the pathogenesis of COPD in airways

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a progressive chronic disease leading to obstructive lung airways and airflow limitations. The background of COPD is extensive cytopathology and histopathology orchestrated by mostly chronic inflammation with the local release of inflammatory, anti-inflammatory and regulatory mediators, as well as further remodeling and shaping of local architecture. Inflammatory mechanisms are provided by complex intercellular signalling networks and regulation of locally occurring immune responses.

MATERIAL AND METHODS

In this study, lung tissue specimens obtained from 33 COPD patients and 49 control patients were analysed. Tissue samples were examined by hematoxylin and eosin staining. Immunoreactive cells positive for interleukin (IL)-1α (IL-1α), IL-4, IL-6, IL-7, IL-8, IL-10, IL-12, and tumour necrosis factor-α (TNF-α) were detected by an immunohistochemistry (IHC) method.

RESULTS

We evaluated overall higher numbers of IL-7, IL-8 and IL-10 (mostly from few (0/+) to almost abundance (++++)) and overall less numbers of IL-1α and IL-6 (mostly from no positive (0) to numerous to abundance (+++/++++)) immunoreactive cells in airway epithelium and connective tissue of COPD affected lung. Furthermore, we evaluated statistically significant (P < 0.05) higher numbers of immunoreactive cells located in control group airway epithelium for IL-4, IL-6, IL-7, IL-10, and IL-12 compared to mucosal and submucosal connective tissue. Moreover, in COPD group airway epithelium for IL-1α, IL-4, IL-6, IL-7, IL-8, and IL-10. We found no statistically significant difference between the numbers of IL-12 and TNF-α immunoreactive cells in airway epithelium and connective tissue of COPD affected lung. In comparison with the control group, we found statistically significant (P < 0.05) higher numbers of immunoreactive cells positive for all examined markers in COPD group.

CONCLUSIONS

Increased numbers of IL-1α, IL-4, IL-6, IL-7, IL-8, IL-10, IL-12, and TNF-α immunoreactive cells highlight the local significance of these markers in COPD pathogenesis. Moreover, the pattern with dominance of immunoreactive cells in COPD affected airway epithelium over connective tissue is highlighting the essentials of epithelium in inflammatory signalling.

Circulating miR-146a/b correlates with inflammatory cytokines in COPD and could predict the risk of acute exacerbation COPD

The aim of this study was to investigate the predicting value of miR-146a/b for acute exacerbation chronic obstructive pulmonary disease (AECOPD) and COPD, and to explore their associations with inflammatory cytokines in AECOPD and stable COPD patients.One hundred six AECOPD, 122 stable COPD patients, and 110 health volunteers with age and sex matched to total COPD patients (AECOPD and stable COPD) were enrolled. Blood samples were collected from all participants. Relative expression of miR-146a/b was determined by real-time polymerase chain reaction. Tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), leukotriene B4 (LTB-4) expression in serum from AECOPD and stable COPD patients were assessed using commercial ELISA kit.Serum levels of miR-146a and miR-146b were down regulated in AECOPD patients compared with stable COPD patients and HCs. miR-146a and miR-146b are of good values for predicting the risk of AECOPD in HCs with AUC of 0.702 and 0.715. Additionally, miR-146a and miR-146b could distinguish AECOPD from stable COPD patients with AUC of 0.670 and 0.643. In AECOPD patients, levels of miR-146a in AECOPD patients were negatively associated with TNF-α, IL-6, IL-8, and LTE-4 expression. In stable COPD patients, miR-146a expressions were negatively correlated with TNF-α, IL-1β, IL-6, IL-8, and LTE-4 levels. And, the expressions of miR-146b in AECOPD patients were negatively associated with IL-1β and LTB-4 expression. While in stable COPD patients, miR-146b expressions were only negatively correlated with TNF-α level.In conclusion, miR-146a and miR-146b were negatively correlated with inflammatory cytokines, and could be promising biomarkers for predicting the risk of AECOPD in stable COPD patients and healthy individuals.

Sulforaphane increases Nrf2 expression and protects alveolar epithelial cells against injury caused by cigarette smoke extract

Cigarette smoking is a primary risk factor for chronic obstructive pulmonary disease (COPD), as it damages epithelial cells through a variety of mechanisms. Sulforaphane (SFN) is an antioxidant agent, which exerts protective effects against cell damage by activating the nuclear factor erythroid 2 like 2 (NFE2L2; Nrf2). The present study was undertaken to investigate the effects and underlying mechanisms of SFN in preventing cigarette smoke extract (CSE)‑induced oxidative damage to RLE‑6TN rat lung epithelial cells. MTT assay was used to determine the cytotoxicity of SFN and CSE. The effect of SFN and CSE on cell cycle progression, apoptosis and intracellular reactive oxygen species (ROS) levels were analyzed using flow cytometry. Reverse transcription‑quantitative polymerase chain reaction and western blotting were used to quantify mRNA and protein expression levels of Nrf2 respectively. SFN protected RLE‑6TN cells from oxidative damage, potentially via increasing Nrf2 expression and reducing ROS levels. In addition, SFN attenuated G1 phase cell cycle arrest and abrogated apoptosis. Therefore, SFN protected alveolar epithelial cells against CSE‑induced oxidative injury by upregulating Nrf2 expression. The results of the present study may provide theoretical support for the clinical use of SFN in patients with COPD.

MicroRNA Profiling Reveals a Role for MicroRNA-218-5p in the Pathogenesis of Chronic Obstructive Pulmonary Disease

RATIONALE

Aberrant expression of microRNAs (miRNAs) can have a detrimental role in disease pathogenesis.

OBJECTIVES

To identify dysregulated miRNAs in lung tissue of patients with chronic obstructive pulmonary disease (COPD).

METHODS

We performed miRNA and mRNA profiling using high throughput stem-loop reverse-transcriptase quantitative polymerase chain reaction and mRNA microarray, respectively, on lung tissue of 30 patients (screening cohort) encompassing 8 never-smokers, 10 smokers without airflow limitation, and 12 smokers with COPD. Differential expression of miRNA-218-5p (miR-218-5p) was validated by reverse-transcriptase quantitative polymerase chain reaction in an independent cohort of 71 patients, an in vivo murine model of COPD, and primary human bronchial epithelial cells. Localization of miR-218-5p was assessed by in situ hybridization. In vitro and in vivo perturbation of miR-218-5p combined with RNA sequencing and gene set enrichment analysis was used to elucidate its functional role in COPD pathogenesis.

MEASUREMENTS AND MAIN RESULTS

Several miRNAs were differentially expressed among the different patient groups. Interestingly, miR-218-5p was significantly down-regulated in smokers without airflow limitation and in patients with COPD compared with never-smokers. Decreased pulmonary expression of miR-218-5p was validated in an independent validation cohort, in cigarette smoke-exposed mice, and in human bronchial epithelial cells. Importantly, expression of miR-218-5p strongly correlated with airway obstruction. Furthermore, cellular localization of miR-218-5p in human and murine lung revealed highest expression of miR-218-5p in the bronchial airway epithelium. Perturbation experiments with a miR-218-5p mimic or inhibitor demonstrated a protective role of miR-218-5p in cigarette smoke-induced inflammation and COPD.

CONCLUSIONS

We highlight a role for miR-218-5p in the pathogenesis of COPD.

Protective effects of organic acid component from Taraxacum mongolicum Hand.-Mazz. against LPS-induced inflammation: Regulating the TLR4/IKK/NF-κB signal pathway

ETHNOPHARMACOLOGICAL RELEVANCE

TMHM is a type of Chinese medicine commonly used in medical practice and has multiple functions, including clearing heat, detoxification, reducing swelling, and tumor therapy. Previous research has demonstrated that the OAC of TMHM (TMHM-OAC) displays advantageous therapeutic action against respiratory inflammation. However, the effect of TMHM-OAC on inflammatory injury and its anti-inflammatory role requires further clarification.

MATERIALS AND METHODS

An in vitro inflammation damage model was employed using NHBE cells and 100ng/ml of (LPS). HPLC-DAD was conducted to analyze the components of TMHM-OAC. An ELISA was conducted to determine IL-1β, IL-6, TNF-α, and NO expression. An MTT assay was conducted to determine the cytotoxicity of TMHM-OAC. The levels of IL-1β, IL-6, TNF-α, caspase-3, caspase-8, iNOS, TLR4p-nuclear factor kappa-B kinase (p-IκκB), and p-NF-κB p65 in cellular protein, as well as the mRNA levels, were determined using WB, IF testing, and Q-PCR.

RESULTS

TMHM-OAC significantly reduced LPS-induced NHBE cell inflammation, which was reflected in the reduced expression of relevant cytokines such as TNF-α, IL-1β, IL-6 and NO, caspase-3, and caspase-8. In addition, this component suppressed TLR4, p-IKKβ, and p-NF-κB p65 levels in both mRNA and cellular protein.

CONCLUSION

TMHM-OAC can reduce LPS-induced inflammation in NHBE cells and this function could be linked to the regulation of the TLR4/IKK/NF-kB pathway.

Tollip SNP rs5743899 modulates human airway epithelial responses to rhinovirus infection

BACKGROUND

Rhinovirus (RV) infection in asthma induces varying degrees of airway inflammation (e.g. neutrophils), but the underlying mechanisms remain unclear.

OBJECTIVE

The major goal was to determine the role of genetic variation [e.g. single nucleotide polymorphisms (SNPs)] of Toll-interacting protein (Tollip) in airway epithelial responses to RV in a type 2 cytokine milieu.

METHODS

DNA from blood of asthmatic and normal subjects was genotyped for Tollip SNP rs5743899 AA, AG and GG genotypes. Human tracheobronchial epithelial (HTBE) cells from donors without lung disease were cultured to determine pro-inflammatory and antiviral responses to IL-13 and RV16. Tollip knockout and wild-type mice were challenged with house dust mite (HDM) and infected with RV1B to determine lung inflammation and antiviral response.

RESULTS

Asthmatic subjects carrying the AG or GG genotype (AG/GG) compared with the AA genotype demonstrated greater airflow limitation. HTBE cells with AG/GG expressed less Tollip. Upon IL-13 and RV16 treatment, cells with AG/GG (vs. AA) produced more IL-8 and expressed less antiviral genes, which was coupled with increased NF-κB activity and decreased expression of LC3, a hallmark of the autophagic pathway. Tollip co-localized and interacted with LC3. Inhibition of autophagy decreased antiviral genes in IL-13- and RV16-treated cells. Upon HDM and RV1B, Tollip knockout (vs. wild-type) mice demonstrated higher levels of lung neutrophilic inflammation and viral load, but lower levels of antiviral gene expression.

CONCLUSIONS AND CLINICAL RELEVANCE

Our data suggest that Tollip SNP rs5743899 may predict varying airway response to RV infection in asthma.

Reduced sputum expression of interferon-stimulated genes in severe COPD

BACKGROUND

Exacerbations of COPD are frequent and commonly triggered by respiratory tract infections. The purpose of our study was to investigate innate immunity in stable COPD patients.

METHODS

Induced sputum was collected from 51 stable consecutive COPD patients recruited from the COPD Clinic of CHU Liege and 35 healthy subjects. Expression of interferons beta (IFN-β) and lambda1 (IL-29), IFN-stimulated genes (ISGs) MxA, OAS, and viperin were measured in total sputum cells by reverse transcription quantitative polymerase chain reaction (RT-qPCR). The presence of Picornaviruses was assessed by RT-PCR, while potential pathogenic microorganisms (PPM) were identified by sputum bacteriology.

RESULTS

Expression of IL-29 was found in 16 of 51 COPD patients (31%) and in nine of 35 healthy subjects (26%), while IFN-β was detected in six of 51 COPD patients (12%) and in two of 35 healthy subjects (6%). ISGs were easily detectable in both groups. In the whole group of COPD patients, OAS expression was decreased (P<0.05), while that of viperin was increased (P<0.01) compared to healthy subjects. No difference was found with respect to MxA. COPD patients from group D of Global Initiative for Chronic Obstructive Lung Disease (GOLD) had reduced expression of all three ISGs (P<0.01 for MxA, P<0.05 for OAS, and P<0.01 for viperin) as compared to those of group B patients. Picornaviruses were detected in eight of 51 (16%) COPD patients vs four of 33 (12%) healthy subjects, while PPM were detected in seven of 39 (18%) COPD patients and associated with raised sputum neutrophil counts. IFN-β expression was raised when either picornavirus or PPM were detected (P=0.06), but no difference was seen regarding IL-29 or ISGs.

CONCLUSION

ISGs expression was reduced in severe COPD that may favor exacerbation and contribute to disease progress by altering response to infection.

Chronic Household Air Pollution Exposure Is Associated with Impaired Alveolar Macrophage Function in Malawian Non-Smokers

BACKGROUND

Household air pollution in low income countries is an important cause of mortality from respiratory infection. We hypothesised that chronic smoke exposure is detrimental to alveolar macrophage function, causing failure of innate immunity. We report the relationship between macrophage function and prior smoke exposure in healthy Malawians.

METHODS

Healthy subjects exposed daily to cooking smoke at home volunteered for bronchoalveolar lavage. Alveolar macrophage particulate content was measured as a known correlate of smoke exposure. Phagocytosis and intraphagosomal function (oxidative burst and proteolysis) were measured by a flow cytometric assay. Cytokine responses in macrophages were compared following re-exposure in vitro to wood smoke, before and after glutathione depletion.

RESULTS

Volunteers had a range of alveolar macrophage particulate loading. The macrophage capacity for phagosomal oxidative burst was negatively associated with alveolar macrophage particulate content (n = 29, r2 = 0.16, p = 0.033), but phagocytosis per se and proteolytic function were unaffected. High particulate content was associated with lower baseline CXCL8 release (ratio 0.51, CI 0.29-0.89) and lower final concentrations on re-exposure to smoke in vitro (ratio 0.58, CI 0.34-0.97). Glutathione depletion augmented CXCL8 responses by 1.49x (CI 1.02-2.17) compared with wood smoke alone. This response was specific to smoke as macrophages response to LPS were not modulated by glutathione.

CONCLUSION

Chronic smoke exposure is associated with reduced human macrophage oxidative burst, and dampened inflammatory cytokine responses. These are critical processes in lung defence against infection and likely to underpin the relationship between air pollution and pneumonia.

Genetic variants in ADAM33 are associated with airway inflammation and lung function in COPD

BACKGROUND

Genetic factors play a role in the development and severity of chronic obstructive pulmonary disease (COPD). The pathogenesis of COPD is a multifactorial process including an inflammatory cell profile. Recent studies revealed that single nucleotide polymorphisms (SNPs) within ADAM33 increased the susceptibility to COPD through changing the airway inflammatory process and lung function.

METHODS

In this paper, we investigated associations of four polymorphisms (T1, T2, S2 and Q-1) of ADAM33 as well as their haplotypes with pulmonary function and airway inflammatory process in an East Asian population of patients with COPD.

RESULTS

We found that T1, T2 and Q-1 were significantly associated with the changes of pulmonary function and components of cells in sputum of COPD, and T1 and Q-1 were significantly associated with cytokines and mediators of inflammation in airway of COPD in recessive models. 10 haplotypes were significantly associated with transfer factor of the lung for carbon monoxide in the disease state, 4 haplotypes were significantly associated with forced expiratory volume in one second, and other haplotypes were associated with airway inflammation.

CONCLUSIONS

We confirmed for the first time that ADAM33 was involved in the pathogenesis of COPD by affecting airway inflammation and immune response in an East Asian population. Our results made the genetic background of COPD, a common and disabling disease, more apparent, which would supply genetic support for the study of the mechanism, classification and treatment for this disease.

Sputum neutrophil count after bronchial allergen challenge is related to peripheral blood neutrophil chemotaxis in asthma patients

OBJECTIVE

The aim of this study was to estimate relations between sputum neutrophilia and the chemotactic activity of peripheral blood neutrophils after the bronchial allergen challenge in asthma patients.

MATERIALS AND METHODS

Fifteen patients with allergic asthma (AA), 13 patients with allergic rhinitis (AR), all sensitized to Dermatophagoides pteronyssinus, and 8 healthy subjects (HS) underwent bronchial challenge with D. pteronyssinus. Sputum and peripheral blood collection were performed 24 h before, 7 and 24 h after the bronchial challenge. Cell counts were determined by the May-Grünwald-Giemsa method. Neutrophil chemotaxis was analyzed by a flow cytometer; IL-8 levels were measured by ELISA.

RESULTS

Sputum neutrophil count and peripheral blood neutrophil chemotaxis of patients with AA were greater 7 and 24 h after the challenge compared with the baseline values and patients with AR and HS (P < 0.05). Moreover, a significant correlation was found between the neutrophil count in sputum and IL-8 levels, and the chemotactic activity of peripheral blood neutrophils 24 h after the bronchial challenge only the patients with AA (P < 0.05).

CONCLUSIONS

Increased sputum neutrophil count was found to be associated with an enhanced chemotactic activity of peripheral blood neutrophils during allergen-induced late-phase airway inflammation in patients with allergic asthma.