Hypoxia-inducible factor 2α regulates key neutrophil functions in humans, mice, and zebrafish.

Neutrophil lifespan and function are regulated by hypoxia via components of the hypoxia inducible factor (HIF)/von Hippel Lindau/hydroxylase pathway, including specific roles for HIF-1α and prolyl hydroxylase-3. HIF-2α has both distinct and overlapping biological roles with HIF-1α and has not previously been studied in the context of neutrophil biology. We investigated the role of HIF-2α in regulating key neutrophil functions. Human and murine peripheral blood neutrophils expressed HIF-2α, with expression up-regulated by acute and chronic inflammatory stimuli and in disease-associated inflammatory neutrophil. HIF2A gain-of-function mutations resulted in a reduction in neutrophil apoptosis both ex vivo, through the study of patient cells, and in vivo in a zebrafish tail injury model. In contrast, HIF-2α-deficient murine inflammatory neutrophils displayed increased sensitivity to nitrosative stress induced apoptosis ex vivo and increased neutrophil apoptosis in vivo, resulting in a reduction in neutrophilic inflammation and reduced tissue injury. Expression of HIF-2α was temporally dissociated from HIF-1α in vivo and predominated in the resolution phase of inflammation. These data support a critical and selective role for HIF-2α in persistence of neutrophilic inflammation and provide a platform to dissect the therapeutic utility of targeting HIF-2α in chronic inflammatory diseases.

Differences in plasma and sputum biomarkers between COPD and COPD-asthma overlap.

The pathophysiological features of chronic obstructive pulmonary disease (COPD)-asthma overlap are poorly understood and there has been no study of plasma or sputum biomarkers in overlap patients. In order to clarify the similarity and differences between overlap and COPD or asthma, we have investigated four potential biomarkers of COPD: surfactant protein A (SP-A), soluble receptor for advanced glycation end-products (sRAGE), myeloperoxidase (MPO) and neutrophil gelatinase-associated lipocalin (NGAL). SP-A and sRAGE are pneumocyte-derived markers. MPO and NGAL are neutrophil-derived molecules, but NGAL can also be expressed by respiratory epithelial cells. Plasma levels of SP-A and sRAGE and induced sputum levels of MPO and NGAL were measured by enzyme immunoassay/ELISA in 134 subjects: nonsmokers (n=26), smokers (n=23), asthma (n=32), COPD (n=39) and COPD-asthma overlap patients (n=14). In patients with COPD-asthma overlap, sputum MPO and plasma SP-A were significantly elevated whereas plasma sRAGE levels were reduced compared with asthma patients. Only sputum NGAL was significantly elevated in COPD-asthma overlap compared with COPD (p=0.00016) and could be used to differentiate patients with overlap from those with COPD. Increased induced sputum levels of NGAL might be a characteristic feature of overlap, suggesting enhanced neutrophilic airway inflammation and/or airway epithelial injury in COPD-asthma overlap.

SIRT1 redresses the imbalance of tissue inhibitor of matrix metalloproteinase-1 and matrix metalloproteinase-9 in the development of mouse emphysema and human COPD.

Sirtuin1 (SIRT1), a protein/histone deacetylase, protects against the development of pulmonary emphysema. However, the molecular mechanisms underlying this observation remain elusive. The imbalance of tissue inhibitor of matrix metalloproteinases (TIMPs)/matrix metalloproteinases (MMPs) plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD)/emphysema. We hypothesized that SIRT1 protects against emphysema by redressing the imbalance between MMPs and TIMPs. To test this hypothesis, SIRT1-deficient and overexpressing/transgenic mice were exposed to cigarette smoke (CS). The protein level and activity of MMP-9 were increased in lungs of SIRT1-deficient mice exposed to CS compared with wild-type (WT) littermates, and these effects were attenuated by SIRT1 overexpression. SIRT1 deficiency decreased the level of TIMP-1, which was augmented in SIRT1 transgenic mice compared with WT littermates by CS. However, the level of MMP-2, MMP-12, TIMP-2, TIMP-3, or TIMP-4 was not altered by SIRT1 in response to CS exposure. SIRT1 reduction was associated with imbalance of TIMP-1 and MMP-9 in lungs of smokers and COPD patients. Mass spectrometry and immunoprecipitation analyses revealed that TIMP-1 acetylation on specific lysine residues was increased, whereas its interaction with SIRT1 and MMP-9 was reduced in mouse lungs with emphysema, as well as in lungs of smokers and COPD patients. SIRT1 deficiency increased CS-induced TIMP-1 acetylation, and these effects were attenuated by SIRT1 overexpression. These results suggest that SIRT1 protects against COPD/emphysema, in part, via redressing the TIMP-1/MMP-9 imbalance involving TIMP-1 deacetylation. Thus redressing the TIMP-1/MMP-9 imbalance by pharmacological activation of SIRT1 is an attractive approach in the intervention of COPD.

Chronic smoke exposure induces rheumatoid factor and anti-heat shock protein 70 autoantibodies in susceptible mice and humans with lung disease.

The impact of cigarette smoke (CS), a risk factor for rheumatoid arthritis (RA), on sauto-antibody production was studied in humans and mice with and without chronic lung disease (LD). Rheumatoid factor (RF), anti-cyclic citrullinated peptides (CCPs), and anti-HSP70 autoantibodies were measured in several mouse strains and in cohorts of smokers and nonsmokers with and without autoimmune disease. Chronic smoking-induced RFs in AKR/J mice, which are most susceptible to LD. RFs were identified in human smokers, preferentially in those with LD. Anti-HSP70 auto-antibodies were identified in CS-exposed AKR/J mice but not in ambient air exposed AKR/J controls. Whereas inflammation could induce anti-HSP70 IgM, smoke exposure promoted the switch to anti-HSP70 IgG autoantibodies. Elevated anti-CCP autoantibodies were not detected in CS-exposed mice or smokers. AKR/J splenocytes stimulated in vitro by immune complexes (ICs) of HSP70/anti-HSP70 antibodies produced RFs. The CD91 scavenger pathway was required as anti-CD91 blocked the HSP70-IC-induced RF response. Blocking Toll-like receptors did not influence the HSP70-IC-induced RFs. These studies identify both anti-HSP70 and RFs as serological markers of smoke-related LD in humans and mice. Identification of these autoantibodies could suggest a common environmental insult, namely CS, in a number of different disease settings.

FOXO3 deficiency leads to increased susceptibility to cigarette smoke-induced inflammation, airspace enlargement, and chronic obstructive pulmonary disease.

Forkhead box class O 3a (FOXO3) is a member of the FoxO transcription factor subfamily, which regulates the expression of target genes not only through DNA binding as a transcription factor, but also through protein-protein interaction. Although FoxO3 is a well-known transcription factor involved in diverse biological processes, the role of FoxO3 in cigarette smoke (CS)-induced lung inflammation and injury has not been studied. It is, therefore, hypothesized that deficiency of FoxO3 leads to increased susceptibility to CS-induced lung inflammatory response and airspace enlargement. In this article, we show that the levels of FOXO3 are significantly decreased in lungs of smokers and patients with chronic obstructive pulmonary disease, as well as in lungs of mice exposed to CS. Genetic ablation of FoxO3 led to pulmonary emphysema and exaggerated inflammatory response in lungs of mice exposed to CS. We further showed that CS induced the translocation of FoxO3 into the nucleus where FoxO3 interacted with NF-κB and disrupted NF-κB DNA-binding ability, leading to inhibition of its activity. Targeted disruption of FoxO3 also resulted in downregulation of antioxidant genes in mouse lungs in response to CS exposure. These results suggest that FoxO3 plays a pivotal role in regulation of lung inflammatory response and antioxidant genes, and deficiency of FoxO3 results in development of chronic obstructive pulmonary disease/emphysema.

Dual use of cigarettes and Swedish snuff (snus) among young adults in Northern Finland.

BACKGROUND: The sale of smokeless tobacco has been totally banned in Finland since the country joined the European Union in 1995. Adolescents have continued to use smokeless tobacco even after the sales ban. The objective was to describe dual use of Swedish snuff (snus) and cigarettes in young adults living in Northern Finland. METHODS: This study on male military recruits (n = 1151, mean age 19.4 years; response rate 80%) investigated association of snus use with self-reported tobacco use, nicotine dependence and attempts to quit smoking. RESULTS: Overall, 15.6% (n = 179) reported daily snus use, and almost half of them were dual users who used both products, i.e. cigarettes and snus, daily. Daily smokers were often occasional snus users (66.3%), and those with dual use smoked equal number of cigarettes per day as daily smokers who were not snus users. In addition, dual snus use seemed to increase the dependence to cigarettes, although this trend did not reach statistical significance. Dual users tried to quit less likely than exclusive smokers. Very few snus users were 'switchers' (ex-smokers) [3.2% (n = 22) of all snus users]. CONCLUSIONS: Dual use of snus and cigarettes is common among young in Finland, despite the sales ban on snus. The role of snus in reducing cigarette smoking is unclear, but it is likely that snus use complicates the attempts to quit smoking.

Extracellular superoxide dismutase protects against pulmonary emphysema by attenuating oxidative fragmentation of ECM.

Extracellular superoxide dismutase (ECSOD or SOD3) is highly expressed in lungs and functions as a scavenger of O(2)(*-). ECM fragmentation, which can be triggered by oxidative stress, participates in the pathogenesis of chronic obstructive pulmonary disease (COPD) through attracting inflammatory cells into the lungs. The level of SOD3 is significantly decreased in lungs of patients with COPD. However, the role of endogenous SOD3 in the development/progression of emphysema is unknown. We hypothesized that SOD3 protects against emphysema by attenuating oxidative fragmentation of ECM in mice. To test this hypothesis, SOD3-deficient, SOD3-transgenic, and WT C57BL/6J mice were exposed to cigarette smoke (CS) for 3 d (300 mg total particulate matter/m(3)) to 6 mo (100 mg/m(3) total particulate matter) or by intratracheal elastase injection. Airspace enlargement, lung inflammation, lung mechanical properties, and exercise tolerance were determined at different time points during CS exposure or after elastase administration. CS exposure and elastase administration caused airspace enlargement as well as impaired lung function and exercise capacity in SOD3-null mice, which were improved in mice overexpressing SOD3 and by pharmacological SOD mimetic. These phenomena were associated with SOD3-mediated protection against oxidative fragmentation of ECM, such as heparin sulfate and elastin, thereby attenuating lung inflammatory response. In conclusion, SOD3 attenuates emphysema and reduces oxidative fragmentation of ECM in mouse lung. Thus, pharmacological augmentation of SOD3 in the lung may have a therapeutic potential in the intervention of COPD/emphysema.

[Chronic obstructive pulmonary disease (COPD) phenotypes]. / Keuhkoahtaumataudin kliiniset alatyypit.

COPD--a progressive inflammatory disorder in the airways and lung parenchyma - is also associated with manifestations beyond the lungs. Although the diagnosis of COPD is based on spirometry, severity of airflow obstruction poorly predicts clinically important outcomes. Recently a COPD phenotype was defined as "a single or combination of disease attributes that describe differences between individuals with COPD as they relate to clinically meaningful outcomes". Four predominant clinical phenotypes were introduced. Awareness of them can lead to more accurate diagnostics and treatments specifically targeted for a specific subpopulation.

Sputum proteomics identifies elevated PIGR levels in smokers and mild-to-moderate COPD.

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of morbidity and mortality around the world. However, the exact mechanisms leading to COPD and its progression are still poorly understood. In this study, induced sputum was analyzed by cysteine-specific two-dimensional difference gel electrophoresis (2D-DIGE) coupled with mass spectrometry to identify proteins involved in COPD pathogenesis. The comparison of nonsmokers, smokers, and smokers with moderate COPD revealed 15 changed proteins with the majority, including polymeric immunoglobulin receptor (PIGR), being elevated in smokers and subjects with COPD. PIGR, which is involved in specific immune defense and inflammation, was further studied in sputum, lung tissue, and plasma by Western blot, immunohistochemistry/image analysis, and/or ELISA. Sputum PIGR was characterized as glycosylated secretory component (SC). Lung PIGR was significantly elevated in the bronchial and alveolar epithelium of smokers and further increased in the alveolar area in mild to moderate COPD. Plasma PIGR was elevated in smokers and smokers with COPD compared to nonsmokers with significant correlation to obstruction. In conclusion, new proteins in smoking-related chronic inflammation and COPD could be identified, with SC/PIGR being one of the most prominent not only in the lung but also in circulating blood.

Regulation of TGF-ß storage and activation in the human idiopathic pulmonary fibrosis lung.

Idiopathic pulmonary fibrosis (IPF) is a progressive disease of unknown cause. The pathogenesis of the disease is characterized by fibroblast accumulation and excessive transforming growth factor-ß (TGF-ß) activation. Although TGF-ß activation is a complex process involving various protein interactions, little is known of the specific routes of TGF-ß storage and activation in human lung. Here, we have systematically analyzed the expression of specific proteins involved in extracellular matrix targeting and activation of TGF-ß. Latent TGF-ß-binding protein (LTBP)-1 was found to be significantly upregulated in IPF patient lungs. LTBP-1 expression was especially high in the fibroblastic foci, in which P-Smad2 immunoreactivity, indicative of TGF-ß signaling activity, was less prominent. In cultured primary lung fibroblasts and epithelial cells, short-interfering-RNA-mediated downregulation of LTBP-1 resulted in either increased or decreased TGF-ß signaling activity, respectively, suggesting that LTBP-1-mediated TGF-ß activation is dependent on the cellular context in the lung. Furthermore, LTBP-1 was shown to colocalize with fibronectin, fibrillin-1 and fibrillin-2 proteins in the IPF lung. Fibrillin-2, a developmental gene expressed only in blood vessels in normal adult lung, was found specifically upregulated in IPF fibroblastic foci. The TGF-ß-activating integrin ß8 subunit was expressed at low levels in both control and IPF lungs. Alterations in extracellular matrix composition, such as high levels of the TGF-ß storage protein LTBP-1 and the re-appearance of fibrillin-2, probably modulate TGF-ß availability and activation in different pulmonary compartments in the fibrotic lung.

Nitric oxide-induced eosinophil apoptosis is dependent on mitochondrial permeability transition (mPT), JNK and oxidative stress: apoptosis is preceded but not mediated by early mPT-dependent JNK activation.

BACKGROUND: Eosinophils are critically involved in the pathogenesis of asthma. Nitric oxide (NO) is produced in high amounts in asthmatic lungs and has an important role as a regulator of lung inflammation. NO was previously shown to induce eosinophil apoptosis mediated via c-jun N-terminal kinase (JNK) and caspases. Our aim was to clarify the cascade of events leading to NO-induced apoptosis in granulocyte macrophage-colony stimulating factor (GM-CSF)-treated human eosinophils concentrating on the role of mitochondria, reactive oxygen species (ROS) and JNK. METHODS: Apoptosis was determined by flow cytometric analysis of relative DNA content, by Annexin-V labelling and/or morphological analysis. Immunoblotting was used to study phospho-JNK (pJNK) expression. Mitochondrial membrane potential was assessed by JC-1-staining and mitochondrial permeability transition (mPT) by loading cells with calcein acetoxymethyl ester (AM) and CoCl2 after which flow cytometric analysis was conducted. Statistical significance was calculated by repeated measures analysis of variance (ANOVA) or paired t-test. RESULTS: NO-donor S-nitroso-N-acetyl-D,L-penicillamine (SNAP) induced late apoptosis in GM-CSF-treated eosinophils. SNAP-induced apoptosis was suppressed by inhibitor of mPT bongkrekic acid (BA), inhibitor of JNK SP600125 and superoxide dismutase-mimetic AEOL 10150. Treatment with SNAP led to late loss of mitochondrial membrane potential. Additionally, we found that SNAP induces early partial mPT (1 h) that was followed by a strong increase in pJNK levels (2 h). Both events were prevented by BA. However, these events were not related to apoptosis because SNAP-induced apoptosis was prevented as efficiently when BA was added 16 h after SNAP. In addition to the early and strong rise, pJNK levels were less prominently increased at 20-30 h. CONCLUSIONS: Here we demonstrated that NO-induced eosinophil apoptosis is mediated via ROS, JNK and late mPT. Additionally, our results suggest that NO induces early transient mPT (flickerings) that leads to JNK activation but is not significant for apoptosis. Thereby, we showed some interesting early events in NO-stimulated eosinophils that may take place even if the threshold for irreversible mPT and apoptosis is not crossed. This study also revealed a previously unknown physiological function for transient mPT by showing that it may function as initiator of non-apoptotic JNK signalling.

SIRT1 as a therapeutic target in inflammaging of the pulmonary disease.

OBJECTIVE: Chronic inflammation and cellular senescence are intertwined in the pathogenesis of premature aging, which is considered as an important contributing factor in driving chronic obstructive pulmonary disease (COPD). Sirtuin1 (SIRT1), a nicotinamide adenine dinucleotide (NAD(+))-dependent protein/histone deacetylase, regulates inflammation, senescence/aging, stress resistance, and deoxyribonucleic acid (DNA) damage repair via deacetylating intracellular signaling molecules and chromatin histones. The present review describes the mechanism and regulation of SIRT1 by environmental agents/oxidants/reactive aldehydes and pro-inflammatory stimuli in lung inflammation and aging. The role of dietary polyphenols in regulation of SIRT1 in inflammaging is also discussed. METHODS: Analysis of current research findings on the mechanism of inflammation and senescence/aging (i.e., inflammaging) and their regulation by SIRT1 in premature aging of the lung. RESULTS: COPD is a disease of the lung inflammaging, which is associated with the DNA damage response, transcription activation and chromatin modifications. SIRT1 regulates inflammaging via regulating forkhead box class O 3, p53, nuclear factor kappa B, histones and various proteins involved in DNA damage and repair. Polyphenols and its analogs have been shown to activate SIRT1 although they have anti-inflammatory and antioxidant properties. CONCLUSIONS: Targeting lung inflammation and cellular senescence as well as premature lung aging using pharmacological SIRT1 activators or polyphenols would be a promising therapeutic intervention for COPD/emphysema.

Young male daily smokers are nicotine dependent and experience several unsuccessful quit attempts.

OBJECTIVE: Previous studies on smoking cessation have generally been conducted with adolescents or adults. Very little is known about the cessation attempts, their success, and/or use of pharmacological aids in young adult smokers who want to quit. The present study aimed to investigate quitting attempts in a group of both young male daily and occasional smokers. DESIGN AND SUBJECTS: 614 male smokers aged 18-26 years completed a standardized questionnaire about their smoking habits, quit attempts, and aids used in smoking cessation. RESULTS: Nearly all daily smokers (95.3%, 95% CI 93.1-96.8) were nicotine addicted to some extend according to the standardized questionnaire, and the more addicted they were, the more often they had tried to quit (p = 0.025). Of the daily smokers, 55.6% (95% CI 51.3-59.9) had made quit attempts and 36.2% (95% CI 32.1-40.4) had used nicotine replacement therapy (NRT). In all, 34.1% (95% CI 25.2-44.3) of all occasional smokers reported having intended to quit but they had seldom made more than one attempt whereas 20.2% of daily smokers had made at least three attempts. The stronger the nicotine dependence in daily smokers was, the more likely the subject was to have attempted to use NRT (quite dependent 23.8% vs. totally dependent 48.9%) (p < 0.001). CONCLUSIONS: A high proportion of young male daily smokers were nicotine addicted. Young smokers make many unsuccessful attempts to stop smoking using nicotine replacement therapy (NRT) on their own. A better availability of professional cessation services directed to young adult smokers is needed.

A combined pulmonary-radiology workshop for visual evaluation of COPD: study design, chest CT findings and concordance with quantitative evaluation.

UNLABELLED: The purposes of this study were: to describe chest CT findings in normal non-smoking controls and cigarette smokers with and without COPD; to compare the prevalence of CT abnormalities with severity of COPD; and to evaluate concordance between visual and quantitative chest CT (QCT) scoring. METHODS: Volumetric inspiratory and expiratory CT scans of 294 subjects, including normal non-smokers, smokers without COPD, and smokers with GOLD Stage I-IV COPD, were scored at a multi-reader workshop using a standardized worksheet. There were 58 observers (33 pulmonologists, 25 radiologists); each scan was scored by 9-11 observers. Interobserver agreement was calculated using kappa statistic. Median score of visual observations was compared with QCT measurements. RESULTS: Interobserver agreement was moderate for the presence or absence of emphysema and for the presence of panlobular emphysema; fair for the presence of centrilobular, paraseptal, and bullous emphysema subtypes and for the presence of bronchial wall thickening; and poor for gas trapping, centrilobular nodularity, mosaic attenuation, and bronchial dilation. Agreement was similar for radiologists and pulmonologists. The prevalence on CT readings of most abnormalities (e.g. emphysema, bronchial wall thickening, mosaic attenuation, expiratory gas trapping) increased significantly with greater COPD severity, while the prevalence of centrilobular nodularity decreased. Concordances between visual scoring and quantitative scoring of emphysema, gas trapping and airway wall thickening were 75%, 87% and 65%, respectively. CONCLUSIONS: Despite substantial inter-observer variation, visual assessment of chest CT scans in cigarette smokers provides information regarding lung disease severity; visual scoring may be complementary to quantitative evaluation.

ELMOD2, a candidate gene for idiopathic pulmonary fibrosis, regulates antiviral responses.

Viral infections and abnormal host response are thought to cause epithelial injury in idiopathic pulmonary fibrosis (IPF). To understand IPF pathogenesis, we have used overexpression cell models and expression microarrays to discover genes networked with ELMO domain containing 2 (ELMOD2) gene genetically implicated in IPF. The identified pathways were confirmed in vitro, and ELMOD2 protein expression was characterized in tissue samples. Here 303 genes were significantly altered after ELMOD2 transfection of human alveolar epithelial A549 cell line. The enriched pathways were interferon induction, viral response, antigen processing and presentation, and I-/nuclear factor-kappaB signaling. ELMOD2 showed immunoreactivity in macrophages and type II alveolar epithelial cells in normal human lung. In A549 cells, forced expression of ELMOD2 increased type I and type III interferon mRNA expression, and ELMOD2-specific siRNA molecules inhibited expression of these antiviral cytokines in response to Toll-like receptor three (TLR3) activation. In human macrophages silencing of ELMOD2 inhibited TLR3-dependent expression of type I and type III interferon genes. Influenza A virus infection decreased ELMOD2 mRNA expression in A549 cells and macrophages suggesting negative regulation in viral infections. In summary, our results show that TLR3 pathway is dependent on ELMOD2.-Pulkkinen, V., Bruce, S., Rintahaka, J., Hodgson, U., Laitinen, T., Alenius, H., Kinnula, V. L., Myllärniemi, M., Matikainen, S., Kere, J. ELMOD2, a candidate gene for idiopathic pulmonary fibrosis, regulates antiviral responses.

Comparison between the disease-specific Airways Questionnaire 20 and the generic 15D instruments in COPD.

BACKGROUND: Given that the assessment of health-related quality of life (HRQoL) is an essential outcome measure to optimize chronic obstructive pulmonary disease (COPD) patient management, there is a need for a short and fast, reliable and valid instrument for routine use in clinical practice. The objective of this study was to analyse the relationship between the disease-specific Airways questionnaire (AQ20) and the generic 15D health-related quality of life (HRQoL) instrument simultaneously in a large cohort of patients with COPD. We also compare the HRQoL of COPD patients with that of the general population. METHODS: The AQ20 and 15D were administered to 739 COPD patients representing an unselected hospital-based COPD population. The completion rates and validity of, and correlations among the questions and dimension scores were examined. A factor analysis with varimax rotation was performed in order to find subsets of highly correlating items of the questionnaires. RESULTS: The summary scores of AQ20 and 15D were highly correlated (r = - 0.71, p < 0.01). In AQ20 over 50% of patients reported frequent cough, breathlessness during domestic work, and chest problem limiting their full enjoyment of life. 15D results showed a noteworthy decrease of HRQoL in breathing, mobility, sleeping, usual activities, discomfort and symptoms, vitality, and sexual activity (scores ≤ 0.75). Compared to the age- and gender-standardized Finnish general population, the COPD patients were statistically significantly worse off on 13 of 15 dimensions. CONCLUSIONS: The AQ20 and 15D summary scores are comparable in terms of measuring HRQoL in COPD patients. The data support the validity of 15D to measure the quality of life in COPD. COPD compromises the HRQoL broadly, as reflected by the generic instrument. Both questionnaires are simple and short, and could easily be used in clinical practice with high completion rates.

Overlap syndrome of asthma and COPD predicts low quality of life.

BACKGROUND: In clinical practice, patients whose airway disease shares features of both asthma and chronic obstructive pulmonary disease (COPD) remain poorly recognized. MATERIAL AND METHODS: The study population consisted of 1546 patients with a diagnosis of asthma or COPD or both. Based on patient-reported outcomes and retrospective medical record data, the study population was divided into three groups: ( 1 ) asthma only, ( 2 ) COPD only, and ( 3 ) both asthma and COPD (overlap syndrome group). We evaluated patient characteristics associated with health-related quality of life (HRQoL). RESULTS: In many respects, the overlap group fell between the asthma and COPD groups. In the overlap group, however, HRQoL was the poorest of all. In the logistic regression model, with the asthma group as the reference, both the overlap and the COPD group showed higher risk for low HRQoL [odd ratio (OR): 1.9; 95% confidence interval (CI): 1.2-3.2; and OR: 1.8, 95% CI: 1.0-3.2; respectively]. In addition, female gender, obesity, duration of disease, disability pension, and coexisting cardiovascular disease were associated with low HRQoL across the study population. CONCLUSIONS: Patients with overlapping asthma and COPD differed from those patients with asthma or COPD only. Overlap syndrome was associated with low HRQoL.

Levels of surfactant proteins A and D and KL-6 are elevated in the induced sputum of chronic obstructive pulmonary disease patients: a sequential sputum analysis.

BACKGROUND: Recent clinical studies have suggested that serum surfactant protein (SP) A, SP-D and Krebs von den Lungen-6 (KL-6) are potential biomarkers for interstitial lung diseases. Serum levels of SP-A and SP-D have also been found to be elevated in chronic obstructive pulmonary disease (COPD), but their significance has not been evaluated or compared in induced sputum samples obtained directly from the airways. OBJECTIVE: A sequential sputum analysis was conducted to assess the value of SP-A, SP-D and KL-6 levels in COPD. METHODS: The study material consisted of induced sputum samples from 61 subjects, 28 with COPD and 33 with prolonged cough (cough lasting >3 weeks and normal spirometry). Sputum was collected in 3 fractions (3 periods of 5 min each). Sputum levels of these proteins were measured, and receiver operating characteristic curve analysis was carried out to evaluate the sensitivity, specificity and area under the curve (AUC) for each fraction. RESULTS: The levels of SP-A, SP-D and KL-6 were higher in patients with COPD than in those with prolonged cough in each of the fractions. Sputum levels of these proteins correlated inversely with obstruction and positively with ageing, smoking history, sputum macrophages and eosinophils. Sputum fractionation had a relatively minor effect on the levels and AUC of these proteins. CONCLUSION: Sequential sputum analysis from 3 consecutive fractions indicated a significant difference in the levels of SP-A, SP-D and KL-6 between COPD and prolonged cough. However, sputum fractionation itself had a relatively minor effect on the levels of these proteins.

Ageing and long-term smoking affects KL-6 levels in the lung, induced sputum and plasma.

BACKGROUND: KL-6 is a high-molecular-weight glycoprotein classified as a human MUC1 mucin. It was hypothesized that KL-6 could be detectable in the circulating blood and especially in airway secretions in lung diseases associated with mucus production such as chronic obstructive pulmonary disease (COPD). Additional aims of this study were to investigate whether the levels of KL-6 in plasma and sputum are related to ageing and smoking history. METHODS: The concentrations of KL-6 in plasma and induced sputum supernatants from young and/or middle aged/elderly non-smokers, smokers and patients with COPD were assayed by ELISA (n = 201). The subjects were classified into five groups according to age, smoking status and presence of COPD. In addition, KL-6 expression in control and diseased lung i.e. samples from patients with COPD (n = 28), were analyzed by immunohistochemistry and digital image analysis. RESULTS: The plasma levels of KL-6 increased with age both in non-smokers and smokers. Among middle aged/elderly subjects, plasma KL-6 levels in all smokers regardless of COPD were significantly higher than in non-smokers, whereas sputum levels of KL-6 were significantly higher in COPD compared not only to non-smokers but also to smokers. KL-6 was more prominently expressed in the bronchiolar/alveolar epithelium in COPD than in the control lungs. Plasma and sputum KL-6 levels correlated inversely with obstruction and positively with smoking history and ageing. The linear multiple regression analysis confirmed that age and cigarette smoking had independent effects on plasma KL-6. CONCLUSIONS: KL-6 increases with ageing and chronic smoking history, but prospective studies will be needed to elucidate the significance of KL-6 in chronic airway diseases.

Ageing and smoking contribute to plasma surfactant proteins and protease imbalance with correlations to airway obstruction.

BACKGROUND: A significant number of young people start smoking at an age of 13-15, which means that serious smoking-evoked changes may have been occurred by their twenties. Surfactant proteins (SP) and matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) have been linked to cigarette smoke induced lung remodelling and chronic obstructive pulmonary disease (COPD). However, the level of these proteins has not been examined during ageing or in young individuals with short smoking histories. METHODS: Plasma levels of SP-A, SP-D, MMP-9, and TIMP-1 were measured by EIA/ELISA from young (18-23 years) non-smoking controls (YNS) (n = 36), smokers (YS) (n = 51), middle aged/elderly (37-77 years) non-smoking controls (ONS) (n = 40), smokers (OS) (n = 64) (FEV1/FVC >0.7 in all subjects) and patients with COPD (n = 44, 35-79 years). RESULTS: Plasma levels of SP-A increased with age and in the older group in relation to smoking and COPD. Plasma SP-D and MMP-9 levels did not change with age but were elevated in OS and COPD as compared to ONS. The TIMP-1 level declined with age but increased in chronic smokers when compared to ONS. The clearest correlations could be detected between plasma SP-A vs. age, pack years and FEV1/FVC. The receiver operating characteristic (ROC) curve analysis revealed SP-A to be the best marker for discriminating between patients with COPD and the controls (area under ROC curve of 0.842; 95% confidence interval, 0.785-0.899; p < 0.001). CONCLUSIONS: Age has a significant contribution to potential markers related to smoking and COPD; SP-A seems to be the best factor in differentiating COPD from the controls.