Measures of bronchodilator response of FEV1, FVC and SVC in a Swedish general population sample aged 50-64 years, the SCAPIS Pilot Study

BACKGROUND

Data are lacking from general population studies on how to define changes in lung function after bronchodilation. This study aimed to analyze different measures of bronchodilator response of forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC) and slow vital capacity (SVC).

MATERIALS AND METHODS

Data were derived from the Swedish Cardiopulmonary Bioimage Study (SCAPIS) Pilot study. This analysis comprised 1,050 participants aged 50-64 years from the general population. Participants were investigated using a questionnaire, and FEV1, FVC and SVC were recorded before and 15 minutes after inhalation of 400 µg of salbutamol. A bronchodilator response was defined as the relative change from baseline value expressed as the difference in units of percent predicted normal. Predictors of bronchodilator responses were assessed using multiple linear regression models. Airway obstruction was defined as FEV1/FVC ratio below lower limit of normal (LLN) before bronchodilation, and COPD was defined as an FEV1/FVC ratio below LLN after bronchodilation. Physician-diagnosed asthma was defined as an affirmative answer to "Have you ever had asthma diagnosed by a physician?". Asymptomatic never-smokers were defined as those not reporting physician-diagnosed asthma, physician-diagnosed COPD or emphysema, current wheeze or chronic bronchitis and being a lifelong never-smoker.

RESULTS

Among all subjects, the greatest bronchodilator responses (FEV1, FVC and SVC) were found in subjects with asthma or COPD. The upper 95th percentile of bronchodilator responses in asymptomatic never-smokers was 8.7% for FEV1, 4.2% for FVC and 5.0% for SVC. The bronchodilator responses were similar between men and women. In a multiple linear regression model comprising all asymptomatic never-smokers, the bronchodilator response of FEV1 was significantly associated with airway obstruction and height.

CONCLUSION

When the bronchodilator response in asymptomatic never-smokers is reported as the difference in units of predicted normal, significant reversibility of FEV1, FVC and SVC to bronchodilators is ~9%, 4% and 5%, respectively.

Treatment of idiopathic pulmonary fibrosis: a position paper from a Nordic expert group

Idiopathic pulmonary fibrosis (IPF) is a fatal progressive lung disease occurring in adults. In the last decade, the results of a number of clinical trials based on the updated disease classification have been published. The registration of pirfenidone and nintedanib, the first two pharmacological treatment options approved for IPF, marks a new chapter in the management of patients with this disease. Other nonpharmacological treatments such as lung transplantation, rehabilitation and palliation have also been shown to be beneficial for these patients. In this review, past and present management is discussed based on a comprehensive literature search. A treatment algorithm is presented based on available evidence and our overall clinical experience. In addition, unmet needs with regard to treatment are highlighted and discussed. We describe the development of various treatment options for IPF from the first consensus to recent guidelines based on evidence from large-scale, multinational, randomized clinical trials, which have led to registration of the first drugs for IPF.

Health effects of a subway environment in healthy volunteers

Environmental particle exposure, often estimated as the particulate mass of particles with a diameter <10 microm, <2.5 microm or <1 microm (PM(10), PM(2.5) or PM(1)), is known to have a negative impact on the health of the population. Little is known about how the size and origin of particles influence the effects. We have previously shown that exposure to a road tunnel environment causes a cellular inflammatory response in the airways of healthy individuals. In the present study, our aim was to investigate potential airway health effects from exposure to a subway environment. 20 healthy volunteers were exposed to a subway and a control environment for 2 h, followed by measurements of lung function and the inflammatory response in the lower airways (bronchoscopy) and in the peripheral blood. No cellular response was found in the airways after exposure to the subway environment. In the blood, we found a statistically significant increase in fibrinogen and regulatory T-cells expressing CD4/CD25/FOXP3. Subway and road tunnel environments have similar levels of PM(10) and PM(2.5), whilst the concentrations of ultrafine particles, nitrogen monoxide and dioxide are lower in the subway. Although no cellular response was detected, the findings indicate a biological response to the subway environment. Our studies show that using gravimetric estimates of ambient particulate air pollution alone may have clear limitations in health-risk assessment.

Eosinophil cationic protein stimulates migration of human lung fibroblasts in vitro

Asthma is characterized by eosinophilic inflammation and remodelling of the airways. Eosinophil cationic protein (ECP) is a protein released by activated eosinophils and the hypothesis that ECP contributes to the development of structural changes in the airways of asthmatics has been posed. Fibroblast recruitment is an important step in the remodelling process, and we therefore put the question whether ECP stimulates migration of human lung fibroblasts. Human peripheral eosinophils isolated from buffycoats from healthy individuals were cultured and conditioned media (CM) were collected. Native ECP was extracted from human peripheral eosinophils by gel filtration, ion-exchange and chelating chromatography. The ability of eosinophil CM and ECP to stimulate fibroblast migration was determined using the 48-well Boyden chamber. ECP concentrations in CM were assayed by ECP-CAP-FEIA. Both CM and ECP significantly stimulated fibroblast migration (48.4+/-cells/field versus 33+/-2 and 36+/-6 versus 25+/-4; P<0.001 and 0.05 respectively) in a time- and concentration-dependent manner. Adding neutralizing ECP antibodies attenuated fibroblast migration induced by both ECP as well as CM. ECP stimulates migration of human lung fibroblasts, suggesting a potential mechanism for eosinophils in the fibrotic response. This may be an important mechanism by which ECP promotes remodelling of extracellular matrix leading to airway fibrosis in asthmatics.

Increased levels of nerve growth factor in the airways of patients with sarcoidosis

OBJECTIVES

Nerve growth factor (NGF) is a potent neuronal growth factor with inflammatory properties that recently has been proposed to be of importance in airway pathology. A role for NGF in the inflammatory granulomatous lung disease sarcoidosis is not well elucidated. The aims of this study were to investigate the secreted levels of NGF in bronchoalveolar lavage fluid (BALF) from sarcoidosis patients compared with patients with resolved disease, patients with another granulomatous disease--chronic beryllium disease (CBD)--and healthy subjects and also to investigate the relationship between NGF levels and markers of inflammation.

METHODS AND RESULTS

NGF levels in BALF from 56 patients with active sarcoidosis (22 with Löfgren's syndrome), nine subjects with resolved sarcoidosis, six patients with CBD, and 31 healthy subjects were compared. A 10-fold elevation of NGF levels was found in patients with active sarcoidosis compared with subjects with clinically resolved sarcoidosis, patients with CBD and healthy subjects. In sarcoidosis patients, positive correlations between concentrations of NGF and lymphocytes, eosinophils and interferon-gamma, interleukin (IL)-4, IL-10, IL-12 were found.

CONCLUSIONS

We demonstrate that secreted levels of NGF are markedly enhanced in the airways in active pulmonary sarcoidosis. Furthermore, a relationship between NGF and pulmonary inflammation in sarcoidosis is supported.

Human T cells stimulate fibroblast-mediated degradation of extracellular matrix in vitro

Several chronic diseases are characterized by inflammation, T cell recruitment and tissue remodelling. We hypothesized that activated T cells may stimulate remodelling of extracellular matrix (ECM) in vitro. Total T cells (CD3+) as well as CD4+ and CD8+ subsets were isolated from peripheral blood and stimulated, after which conditioned media (CM) were obtained. CM was added to human lung fibroblasts in three-dimensional collagen gels and the area of gels was measured daily. Hydroxyproline was determined as a measure of collagen degradation in the gels. Matrix metalloproteinase (MMP) activity in the culture media was analysed by gelatine zymography. Cytokine secretion of stimulated CD4+ and CD8+ T cells was analysed. CD3+ CM augmented collagen gel contraction in a time- and dose-dependent manner (P < 0.0001). CD4+ T cell CM was more potent than CD8+ T cell CM (P < 0.001). CD3+ CM and CD4+ T cell CM, but not CD8+ T cell CM, stimulated fibroblast-mediated collagen degradation and MMP-9 activity. A broad-spectrum MMP-inhibitor added to the culture system inhibited both gel contraction and MMP activity. Activated CD4+ T cells secreted significantly more tumour necrosis factor (TNF) and interleukin (IL)-6 compared to CD8+ T cells. CD3+ CM from patients with chronic obstructive pulmonary disease stimulated fibroblast-mediated collagen gel contraction to the same magnitude as CD3+ CM from healthy controls. In conclusion, activated CD4+ T cells can stimulate fibroblast-mediated degradation of ECM in vitro. This could be a mechanism by which activated T cells stimulate degradation of lung tissue leading to pulmonary emphysema.

Road tunnel air pollution induces bronchoalveolar inflammation in healthy subjects

Traffic-related air pollution is associated with adverse respiratory effects. The aim of the present study was to investigate whether exposure to air pollution in a road tunnel causes airway inflammatory and blood coagulation responses. A total of 16 healthy subjects underwent bronchoscopy with bronchial mucosal biopsies and bronchoalveolar lavage (BAL) on two occasions, in random order: once at 14 h after a 2-h exposure to air pollution in a busy road tunnel, and once after a control day with subjects exposed to urban air during normal activities. Peripheral blood was sampled prior to bronchoscopy. The road tunnel exposures included particulate matter with a 50% cut-off aerodynamic diameter of 2.5 microm, particulate matter with a 50% cut-off aerodynamic diameter of 10 mum and nitrogen dioxide which had median concentrations of 64, 176 and 230 microg.m(-3), respectively. Significantly higher numbers of BAL fluid total cell number, lymphocytes and alveolar macrophages were present after road tunnel exposure versus control. Significantly higher nuclear expression of the transcription factor component c-Jun was found in the bronchial epithelium after exposure. No upregulation of adhesion molecules or cellular infiltration was present and blood coagulation factors were unaffected. In conclusion, exposure of healthy subjects to traffic-related air pollution resulted in a lower airway inflammatory response with cell migration, together with signs of an initiated signal transduction in the bronchial epithelium.

Different inflammatory cell pattern and macrophage phenotype in chronic obstructive pulmonary disease patients, smokers and non-smokers

Smokers exhibit airway inflammation and increased number of alveolar macrophages (AM), but not all develop chronic obstructive pulmonary disease (COPD). We hypothesized that AMs in COPD patients have an altered functional capacity mirrored in a different phenotype. Sixteen steroid-naive COPD patients [forced expiratory volume in 1 s (FEV(1)) < 70% of predicted] underwent bronchoalveolar lavage (BAL). Age- and smoking-matched non-obstructive smokers (n = 10) and healthy non-smokers (n = 9) served as controls. Nine COPD patients had a BAL cell yield sufficient for flow cytometry analysis, where expression of AM cell surface markers reflecting various functions was determined. AMs from COPD patients showed decreased expression of CD86 (co-stimulation) and CD11a (adhesion) compared to smokers' AMs (P < 0.05). Furthermore, smokers' AMs showed lower (P < 0.05) expression of CD11a compared to non-smokers. AM expression of CD11c was higher in the COPD and smokers groups compared to non-smokers (P < 0.05). The expression of CD54 (adhesion) was lower in smokers' AMs compared to non-smokers (P < 0.05), whereas CD16 was lower (P < 0.05) in COPD patients compared to non-smokers. The AM expression of CD11b, CD14, CD58, CD71, CD80 and human leucocyte antigen (HLA) Class II did not differ between the three groups. The AM phenotype is altered in COPD and further research may develop disease markers. The lower AM expression of CD86 and CD11a in COPD implies a reduced antigen-presenting function. Some alterations were found in smokers compared to non-smokers, thus indicating that changes in AM phenotype may be associated with smoking per se. The functional relevance of our findings remains to be elucidated.

Bronchoalveolar lavage in COPD: fluid recovery correlates with the degree of emphysema

Bronchoscopy with bronchoalveolar lavage (BAL) is an important research tool for assessing airway inflammation in a variety of inflammatory lung diseases. In chronic obstructive pulmonary disease (COPD), BAL recovery is often low, making analysis of the recovered fluid difficult to interpret. The present authors hypothesised that the degree of emphysema may predict BAL recovery. A total of 20 COPD patients (mean age 57 yrs, range 49-69) with a median (interquartile range) forced expiratory volume in one second (FEV1) of 51 (33-69)% predicted underwent BAL. Matched "healthy" smokers and nonsmokers served as controls. Emphysema index in COPD patients was calculated on computed tomography scan as the percentage of the right lung with pixels <-950 Hounsfield units. The carbon monoxide diffusing capacity of the lung (DL,CO) was determined by the single-breath method. COPD patients had lower BAL recovery than controls. COPD patients with an emphysema index <1 had higher BAL recovery than patients with an emphysema index >1. BAL recovery correlated negatively to emphysema index and positively to DL,CO. However, no correlation was found between recovery and FEV1. In conclusion, the extent of emphysema evaluated by computed tomography-scan index and carbon monoxide diffusing capacity of the lung may predict a low bronchoalveolar lavage recovery in chronic obstructive pulmonary disease patients. These parameters may, therefore, be useful when chronic obstructive pulmonary disease patients are selected for bronchoscopy with bronchoalveloar lavage. The present study underlines the importance of careful phenotyping of chronic obstructive pulmonary disease patients.

The effect of eosinophils on collagen gel contraction and implications for tissue remodelling

Asthma is characterized by an eosinophilic inflammation and a subepithelial fibrosis in the airways. Eosinophils contain several cytotoxic substances, such as eosinophil cationic protein (ECP), which can promote inflammation and cause tissue damage. This has generated the hypothesis that eosinophils may drive remodelling of extracellular matrix (ECM). To investigate the role of eosinophils we used an in vitro model for remodelling, the three-dimensional collagen gel contraction assay. Two sources of eosinophils were used in this study, isolated human peripheral eosinophils (purity > 95%) and stimulated [interleukin (IL)-5, IL-3 and granulocyte macrophage-colony stimulating factor (GM-CSF)] HL-60 clone 15 cells. Human eosinophils or HL-60 cells were cast together with human lung fibroblasts (HFL1) in type I collagen gels. Both types of eosinophils augmented fibroblast-mediated collagen gel contraction in a time and concentration-dependent manner. At 48 h, the gel area in HFL1/eosinophil co-culture was 46.5% +/- 0.5 (mean +/- s.e.m.) of initial area and in HFL1 culture 52.3% +/- 0.1 (P < 0.001). Respective figures for HFL1/stimulated HL-60 co-culture and HFL1 culture only were 44.1% +/- 0.5 and 52.4% +/- 0.4 (P < 0.001). The release of ECP was increased when fibroblasts were cultured with eosinophils compared to eosinophils cultured alone. In addition, native ECP added to fibroblast gel cultures also augmented contraction. Our results suggest that eosinophils may interact with mesenchymal cells, promoting remodelling of ECM and that ECP constitutes one potential eosinophil-derived mediator driving this process. We conclude that this may be one important mechanism by which eosinophil-ECM interactions will lead to airway tissue remodelling in asthma.

Determination of cardiac involvement in sarcoidosis by magnetic resonance imaging and Doppler echocardiography

OBJECTIVES

To elucidate whether cardiac magnetic resonance imaging (MRI) could be useful in disclosing structural changes in the myocardium in sarcoidosis patients and to relate echo-Doppler derived indices of left ventricular function to electrocardiogram (ECG) findings.

DESIGN

The MRI was performed in 18 consecutive patients with sarcoidosis. Left ventricular ejection fraction (LVEF), i.e. systolic function, was estimated echocardiographically by Simpson's two-dimensional method (n = 16). Diastolic function was estimated by age-corrected Doppler-derived indices: isovolumetric relaxation time (IVRT), deceleration time (DT) and early filling/atrial contraction ratio (E/A ratio).

RESULTS

Eleven patients had conduction defects or dysrhythmias (ECG+) whilst seven patients had a normal ECG (ECG-). In two patients, high signalling, contrast-enhanced, isolated regions, suggestive of deposits, were seen in the left ventricular myocardium on MRI. Both these patients had abnormal ECGs and signs of systolic and/or diastolic dysfunction on echocardiography. LVEF was subnormal in seven of 10 of the ECG+ patients and in two of six of the ECG-. Signs of diastolic dysfunction were found in 59% and 56% of the measurements in the ECG+ and ECG- patients, respectively.

CONCLUSION

We conclude (i) that myocardial deposits on MRI in sarcoidosis patients have a high specificity for cardiac involvement but a rather low sensitivity; (ii) that a substantial proportion of sarcoidosis patients with abnormal ECGs have echocardiographic signs of systolic and/or diastolic dysfunction.

Red blood cells stimulate fibroblast-mediated contraction of three dimensional collagen gels in co-culture

OBJECTIVE AND DESIGN

Following injury, red blood cells (RBC) may interact with extracellular matrix (ECM). In the present study we hypothesised that RBC, and soluble factors from RBC, might mediate remodelling of ECM by affecting fibroblast-mediated contraction of three dimensional collagen gels.

MATERIALS AND METHODS

Human lung fibroblasts (HFL-1), were cultured together with isolated RBC, conditioned medium from RBC (RBC-CM) and hemolysed RBC in type I collagen gels. Gel contraction was determined by an image analyser.

RESULTS

Both RBC, RBC-CM and hemolysed RBC stimulated gel contraction by fibroblasts (P < 0.001), compared to fibroblasts alone. The RBC-CM stimulated (P < 0.01) gel contraction in a time and concentration dependent manner. A similar effect was observed when supernatant from hemolysed RBC was tested. The production of fibronectin was increased (P < 0.01) in the co-culture system, compared to fibroblasts cultured alone.

CONCLUSIONS

The present study shows that RBC can interact with mesenchymal cells in vitro. The ability of RBC to modulate fibroblast-mediated contraction in vitro, might therefore be an important mechanism regulating repair processes after injury.

Interactions between monocytes and smooth-muscle cells can lead to extracellular matrix degradation

BACKGROUND

Chronic infiltration of the airway wall with inflammatory cells characterizes both asthma and chronic bronchitis. Remodeling of the airway wall is also a feature of both diseases.

OBJECTIVE

We hypothesized that collagen degradation may take place during coculture of monocytes with smooth-muscle cells (SMCs) and that this degradation might be altered by agents that modify the inflammatory regimen.

METHODS

Monocytes (4.5 x 10(5)/mL) were cast into collagen gels containing human airway SMCs (4.5 x 10(5)/mL) and released into serum-free Dulbecco's modified Eagle's medium containing neutrophil elastase. Collagen content was quantified as total insoluble hydroxyproline on day 5. Zymography and immunoblotting were used to detect matrix metalloproteinases.

RESULTS

Monocytes cocultured with SMCs in 3-dimensional native type I collagen gels produced TNF-alpha and IL-1beta and resulted in collagen degradation (30.5 vs 17.9 mg per gel) through inducing matrix metalloproteinase 1, 2, and 9 by means of SMCs. PGE(2) was significantly increased in coculture (0.9 vs 10.5 ng/mL). Indomethacin (1 micromol/L) completely inhibited PGE(2) production but augmented collagen degradation (17.9 vs 2.3 microg per gel), and this was blocked by the addition of exogenous PGE(2). Dexamethasone also inhibited collagen degradation in coculture.

CONCLUSION

The current study supports the concept that interactions among cells present in the airway inflammatory milieu that characterize airway disease can lead to alterations in tissue structure and suggests mechanisms by which therapeutic strategies can be designed to modify tissue remodeling.

Cigarette smoke inhibits human bronchial epithelial cell repair processes

By interfering with the ability of airway epithelial cells to support repair processes, cigarette smoke could contribute to alterations of airway structures and functions that characterize chronic obstructive pulmonary disease (COPD). The current study assessed the ability of cigarette smoke extract (CSE) to alter human airway epithelial cell chemotaxis, proliferation, and contraction of three-dimensional collagen gels, a model of extracellular matrix remodeling. The volatile components contained in cigarette smoke, acetaldehyde and acrolein, were able to inhibit all three processes. Nonvolatile components contained within lyophilized CSE also inhibited chemotaxis but displayed no activity in the other two bioassays. CSE also inhibited the ability of airway epithelial cells to release transforming growth factor (TGF)-beta and fibronectin. Exogenous fibronectin was unable to restore epithelial cell contraction of collagen gels. Exogenous TGF-beta partially restored the ability of airway epithelial cells to contract collagen gels and to produce fibronectin. This supports a role for inhibition of TGF-beta release in mediating the inhibitory effects of cigarette smoke. Taken together, the results of the current study suggest that epithelial cells present in the airways of smokers may be altered in their ability to support repair responses, which may contribute to architectural disruptions present in the airways in COPD associated with cigarette smoking.

ECG-abnormalities in Japanese and Swedish patients with sarcoidosis. A comparison

BACKGROUND AND AIM OF THE WORK

ECG abnormalities are more common in patients with sarcoidosis than in controls. The incidence of cardiac sarcoid granulomas in the Japanese population has been found to be higher than that seen in Caucasians. We compared the prevalence of ECG abnormalities in Japanese and Swedish patients with sarcoidosis.

METHODS

Twelve-lead routine ECG's were compared between consecutive patients (134 Japanese and 149 Swedish) of similar age with histologically verified sarcoidosis or a high clinical probability of the disease and a history of no more than 12 months before the ECG.

RESULTS

There was no statistically significant difference in the prevalence of first degree AV block, ST-T-segment abnormalities, right bundle branch block (RBBB) and left anterior block (LAH) in Japanese and Swedish patients. Among the Swedes, the results were compared with those of a smaller group (n = 29) of older patients with a longer disease course. In these few patients LAH and RBBB occurred more frequently than in patients with a recent diagnosis.

CONCLUSIONS

ECG abnormalities in patients with sarcoidosis seem to be of similar frequency in Japan and Sweden. ST-T changes and first degree AV block would appear early in the course of the disease, whereas more pronounced conduction defects may appear later.

Synergistic neutrophil elastase-cytokine interaction degrades collagen in three-dimensional culture

Proteolytic degradation of extracellular matrix is thought to play an important role in many lung disorders. In the current study, human lung fibroblasts were cast into type I collagen gels and floated in medium containing elastase, cytomix (combination of tumor necrosis factor-alpha, interleukin-1beta, and interferon-gamma), or both. After 5 days, gel collagen content was determined by measuring hydroxyproline. Elastase alone did not result in collagen degradation, but in the presence of fibroblasts, elastase reduced hydroxyproline content to 75.2% (P < 0.01), whereas cytomix alone resulted in reduction of hydroxyproline content to 93% (P < 0.05). The combination of elastase and cytomix reduced hydroxyproline content to 5.2% (P < 0.01). alpha(1)-Proteinase inhibitor blocked this synergy. Gelatin zymography and Western blot revealed that matrix metalloproteinase (MMP)-1, -3, and -9 were induced by cytomix and activated in the presence of elastase. Tissue inhibitor of metalloproteinase (TIMP)-1 and -2 were also induced by cytomix but were cleaved by elastase. We conclude that a synergistic interaction between cytomix and elastase, mediated through cytokine induction of MMP production and elastase-induced activation of latent MMPs and degradation of TIMPs, can result in a dramatic augmentation of collagen degradation. These findings support the notion that interaction among inflammatory mediators secreted by mononuclear cells and neutrophils can induce tissue cells to degrade extracellular matrix. Such a mechanism may contribute to the protease-anti-protease imbalance in emphysema.

Glucocorticoids and TGF-beta1 synergize in augmenting fibroblast mediated contraction of collagen gels

TGF-beta plays a central role in the initiation and progression of pulmonary fibrosis. Glucocorticoids are frequently used to treat fibrotic diseases, but beneficial effects are often modest. Both TGF-beta and glucocorticoids have been reported to increase fibroblast contraction of native collagen gels, a model of fibrotic tissue remodeling. Therefore, we sought to determine how glucocorticoids interact with TGF-beta in this system. In this study, human fetal lung fibroblasts (HFL-1) were pretreated with or without TGF-beta for 72 h before they were cast into type I collagen gels. Various concentrations of glucocorticoids (budesonide or hydrocortisone) were added at the time of casting. Gel size was then monitored at different times after gel release. The surrounding media were collected for the assay of prostaglandin E2 (PGE2) and the cell lysates were analyzed for cyclooxygenase (COX) expression by immunoblot. Glucocorticoids alone significantly enhanced fibroblast-mediated contraction of collagen gels (P < 0.01) and dose-dependently inhibited PGE2 release by HFL-1 fibroblasts. TGF-beta significantly augmented gel contraction but also induced a 30% increase in PGE2 release and increased the expression of COX-1. Glucocorticoids inhibited TGF-beta1 induced-PGE2 release, and enhanced TGF-beta augmented gel contraction without significantly affecting TGF-beta augmented COX-1 expression. Indomethacin, a COX inhibitor, increased TGF-beta augmented gel contraction but had no further effect when added together with glucocorticoids. Thus, glucocorticoids can synergize with TGF-beta in augmenting fibroblast mediated collagen gel contraction through the inhibition of PGE2 production. Such interactions between glucocorticoids and TGF-beta may account, in part, for the lack of response of fibrotic diseases to glucocorticoids.

Functional and morphological differences between human alveolar and interstitial macrophages

Macrophages play an essential role in pulmonary host defense. They are, however, a heterogeneous cell population located in different lung compartments. This study was designed to elucidate differences between two macrophage populations obtained from the human lung, i.e., alveolar macrophages (AM) and interstitial macrophages (IM). Macroscopically tumor-free lung segments from nine patients undergoing lobectomy or pulmectomy were studied. All patients had a diagnosis of primary lung cancer. AM were recovered by bronchoalveolar lavage and IM were isolated by mechanical fragmentation of the lavaged lung segments followed by enzymatic treatment. The cell fractions were analyzed with respect to morphology (transmission electron microscopy) and function (phagocytosis). The cells in the IM fraction were smaller (7.6 +/- 1.8 microm (mean +/- SD) compared with 16.0 +/- 4.1 microm) and morphologically more heterogeneous than those in the AM fraction. Interestingly, a considerable portion of the cells in the IM fraction had a typical AM-like appearance. Despite this, the AM fraction had a higher phagocytic activity compared to IM, with faster attachment and ingestion processes (P <0.001 for both). We conclude that the heterogeneity of human lung macrophages must be taken into consideration when their role in the inflammatory response is studied.

Co-cultured human mast cells stimulate fibroblast-mediated contraction of collagen gels

In the current study, we asked whether mast cells might modulate remodeling of extracellular matrix by affecting fibroblast-mediated contraction of three-dimensional collagen gels. Mast cells and human lung fibroblasts were co-cultured in floating type I collagen gels. The area of the gels was measured by an image analyzer. Mast cells in co-culture augmented fibroblast contractility (P < 0.001) in a time- and concentration dependent manner. The tryptase inhibitor bis(5-amidino-2-benzimidazo-lyl)methane (BABIM) were unable to block the augmented fibroblast contractility induced by co-cultured mast cells and tryptase added alone in the culture system had no effect on contractility, suggesting that other mediators besides tryptase might be involved. The amount of collagen in dissolved gels, measured as hydroxyproline, did not change after co-culture indicating that degradation of collagen may not be a major mechanism. Our findings support the hypothesis that the activity of mast cells may drive rearrangement of extracellular matrix and this and could subsequently lead to fibrosis and tissue dysfunction.

Blood monocytes attenuate lung fibroblast contraction of three-dimensional collagen gels in coculture

Mononuclear phagocytes can interact with mesenchymal cells and extracellular matrix components that are crucial for connective tissue rearrangement. We asked whether blood monocytes can alter matrix remodeling mediated by human lung fibroblasts cultured in a three-dimensional collagen gel. Blood monocytes from healthy donors (>95% pure) were cast into type I collagen gels that contained lung fibroblasts. Monocytes in coculture inhibited the fibroblast-mediated gel contractility in a time- and concentration-dependent manner. The concentration of PGE(2), a well-known inhibitor of gel contraction, was higher (P < 0.01) in media from coculture; this media attenuated fibroblast gel contraction, whereas conditioned media from either cell type cultured alone did not. Three-dimensional cultured monocytes responded to conditioned media from cocultures by producing interleukin-1beta and tumor necrosis factor-alpha, whereas fibroblasts increased synthesis of PGE(2). Antibodies to interleukin-1beta and tumor necrosis factor-alpha blocked the monocyte inhibitory effect and reduced the amount of PGE(2) produced. The ability of monocytes to block the fibroblast contraction of matrix may be an important mechanism in regulating tissue remodeling.

Rat alveolar and interstitial macrophages in the fibrosing stage following quartz exposure

Exposure to quartz induces pulmonary inflammation and development of fibrosis. In order to study the fibrosing process, we investigated morphology, function and phenotype of alveolar (AMs) and interstitial (IMs) macrophages at an early stage of fibrosis in rats. Rats were exposed by intratracheal instillations of 10 mg quartz (n=8) or saline (n=8) and studied 3 months later. AMs were obtained by bronchoalveolar lavage and IMs by mechanical fragmentation, followed by enzymatic digestion of lung tissue. Histology revealed subacute silicosis, with early focal fibrosis and alveolar lipoproteinosis. AM quartz exposure increased phagocytic activity and expression of major histocompatibility complex (MHC) Ia antigens, the latter being associated with cellular antigen presenting capacity. IM had an even more pronounced expression of MHC than AM after quartz exposure. Both macrophage fractions had a higher expression of OX-42 (complement receptor 3, CR3) than controls, but the increase in the IM fraction might be explained by the remaining AM in the IM fraction. Exposed AM adhered less to extracellular matrix components (vitronectin and fibronectin) than controls. In contrast, the adhesion of IM to vitronectin increased after exposure. Besides increased adhesion, the effects on IM were scarce. Our results therefore do not support the hypothesis that IM has a key role in the process of inflammation, including fibrosis.

Clara cell secretory protein. Levels in BAL fluid after smoking cessation

STUDY OBJECTIVES

The bronchiolar Clara cell is a major target for tobacco smoke exposure. To improve our understanding of the putative regenerative/repair mechanism(s) in the bronchiolar epithelium, we measured the levels of the Clara cell secretory protein (CCSP) in BAL fluid in healthy volunteers following smoking cessation.

DESIGN

BAL was performed before smoking cessation, and at 1, 3, 6, 9, and 15 months following smoking cessation, in eight healthy volunteers with a previous mean cigarette consumption of 19 pack-years. The levels of CCSP in BAL fluid were assessed in immunoblotting experiments using an antibody against human CCSP.

RESULTS

Significantly (p < 0.05) higher levels of CCSP in BAL fluid were observed at 3, 6, and 9 months after smoking cessation, while the levels of CCSP in BAL fluid at 15 months after smoking cessation were the same as those before smoking cessation.

CONCLUSIONS

Despite the long history of smoking among patients in the present study group, signs of early regeneration in the bronchiolar epithelium were noted, in that the levels of CCSP in BAL fluid were elevated at the indicated time points following smoking cessation. Furthermore, we propose that the insult to the bronchiolar epithelium made by cigarette smoking caused the levels of CCSP in the BAL fluid at 15 months after smoking cessation to return to the levels noted before smoking cessation. The present study suggests a role for CCSP as a marker for nonciliated bronchiolar cell function.

Modulation of elastase binding to elastin by human alveolar macrophage-derived lipids

Human neutrophil elastase (HNE), an enzyme secreted by activated neutrophils, can bind to and degrade extracellular matrix including human lung elastin. This protease is believed to play an important role in several destructive processes including pulmonary emphysema. In this study, we hypothesized that an alveolar macrophage (AM) product or products may interact with neutrophil elastase (NE) and modulate its binding to elastin. Elastase binding to elastase was evaluated by a modified elastase functional assay using a synthetic substrate. Supernatants from cultured AM inhibited elastase binding to elastin at a dose-dependent manner without inhibiting functional elastase activity. The AM products had a heterogeneous molecular weight ranging from 440,000 to 54,000. The activity was heat-stable, but was lost after ultracentrifugation. After lipid fractionation, neither the aqueous nor the lipid fractions contained activity, suggesting that the factor may be a lipid complex. Culture supernatants from smokers' AM released significantly higher amounts of the factor than nonsmokers. In addition, high-molecular-weight elastase was present in bronchoalveolar lavage fluid (BALF) obtained from patients with pneumonia. Most of the in vivo high-molecular-weight elastase was lost after lipid extraction. In conclusion, macrophages release a factor or factors, probably lipid, which can interact with NE and inhibit its binding to human lung elastin without inhibiting elastase activity. This macrophage-derived factor may play a role in protecting the lung from NE by partitioning elastase into the airspace and thus protecting the interstitial connective tissue matrix from elastase degradation.

Glucocorticoids augment fibroblast-mediated contraction of collagen gels by inhibition of endogenous PGE production

Glucocorticoids are currently regarded as the drug of choice in the treatment of inflammatory airway and lung diseases, however, they are not routinely effective in fibrotic phases of inflammation. In the current study, glucocorticoids were investigated for their ability to affect fibroblast mediated contraction of a three dimensional collagen gel, a measure of one aspect of tissue remodeling. Dexamethasone, budesonide, hydrocortisone and fluticasone propionate were all able to significantly augment fibroblast contractility in a concentration dependent manner. Glucocorticoids also had an augmentative effect on collagen gel contraction mediated by fibroblasts from bronchi, skin and bone marrow. The increased contractility was not due to cell proliferation or to collagen degradation, since the glucocorticoids did not alter the amounts of DNA and hydroxyproline in the gels. The concentration of prostaglandin E2 (PGE2) in supernatant media was lower from glucocorticoid-treated gels compared to control gels. Consistent with this, addition of exogenous PGE2 to the culture system restored the contractile properties and indomethacin augmented contraction similar to the glucocorticoids suggesting that inhibition of prostaglandins or related eicosanoids may be the mechanism by which the increased contractility occurs. DBcAMP, forskolin and the long lasting beta2-agonist formoterol were able to reverse the effect of the glucocorticoids on fibroblast mediated collagen gel contraction suggesting that enhancers of cAMP can counteract the effect of glucocorticoids. Thus, we provide evidence that glucocorticoids have the ability to directly augment fibroblast contractility by inhibiting fibroblast endogenous PGE synthesis. The findings could be one possible mechanism to explain the poor therapeutic response to glucocorticoids on the later stages of fibrotic diseases.

Human neutrophil elastase augments fibroblast-mediated contraction of released collagen gels

In the present study, we tested the hypothesis that neutrophil elastase (NE) might mediate remodeling of extracellular matrix by affecting fibroblast-mediated contraction of three-dimensional collagen gels. Human lung fibroblasts were cast into type I collagen gels containing NE. After gelation, the gels were released into medium and the area was measured by image analyzer. NE augmented gel contraction (p < 0.001). This was not due to cell proliferation or to degradation to soluble collagen fragments because the amounts of DNA and hydroxyproline were not altered. alpha1-Protease inhibitor and the synthetic inhibitor of NE, L-680,833, when added in sufficient amount to inhibit free elastase activity, blocked the contraction induced by NE. Furthermore, neutrophil granulocytes (PMN) in coculture, as well as conditioned media from PMN, resulted in an increased contractility (p < 0.001 for both). Bronchoalveolar lavage fluid (BALF) from patients with increased PMN in their lower respiratory tract and free elastase activity had augmentive activity for gel contraction which could be partially blocked by the inhibitors. We conclude that NE augments fibroblast-mediated contraction of collagen gels. The findings support the notion that products secreted by PMN in inflammatory disorders may lead to rearrangement of extracellular matrix and could subsequently lead to tissue dysfunction.

Phenotypic analysis of lymphocytes and monocytes/macrophages in peripheral blood and bronchoalveolar lavage fluid from patients with pulmonary sarcoidosis

BACKGROUND

The granulomatous inflammation in sarcoidosis is driven by the interplay between T cells and macrophages. To gain a better understanding of this process the expression by these cells of cell surface activation markers, co-stimulatory molecules, and adhesion molecules was analysed.

METHODS

CD4+ and CD8+ T lymphocytes from peripheral blood (PBL) or bronchoalveolar lavage (BAL) fluid, as well as paired peripheral blood monocytes and alveolar macrophages from 27 patients with sarcoidosis were analysed by flow cytometry.

RESULTS

CD26, CD54, CD69, CD95, and gp240 were all overexpressed in T cells from BAL fluid compared with those from PBL in both the CD4+ and CD8+ subsets, while CD57 was overexpressed only in BAL CD4+ cells. In contrast, CD28 tended to be underexpressed in the BAL T cells. Monocyte/macrophage markers included CD11a, CD11b, CD11c, CD14, CD16, CD54, CD71, CD80 and CD86 and HLA class II. CD11a expression in alveolar macrophages (and peripheral blood monocytes) was increased in patients with active disease and correlated positively with the percentage of BAL lymphocytes. Expression of CD80 in macrophages correlated with the BAL CD4/CD8 ratio.

CONCLUSIONS

Our data indicate substantial activation of both CD4+ and CD8+ lung T cells in sarcoidosis. There were also increased numbers of BAL lymphocytes whose phenotypic characteristics have earlier been associated with clonally expanded, replicatively senescent cells of the Th1 type.

Two-colour flow-cytometric analysis of pulmonary alveolar macrophages from smokers

The study of alveolar macrophages (AM) from smokers by flow cytometry (FCM) has been limited by strong autofluorescence and the lack of reliable markers to identify macrophages. Crystal violet quenching was reported to be effective in reducing autofluorescence of AM. CD68 is a marker for macrophages in immunohistochemistry, but has been less useful in FCM because of poor surface expression. This study evaluated the effectiveness of a method for two-colour FCM analysis of AM combined with membrane permeabilization and crystal violet quenching. Bronchoalveolar lavage cells, fixed in 4% paraformaldehyde and permeabilized using 0.5% Triton X100, were incubated with fluorescent-labelled antibodies for 30 min and quenched with a saturated crystal violet solution. Two-colour FCM was then performed using forward/side scatter gating to select AM. Autofluorescence at 525 nm (fluorescein isothiocyanate) and 575 nm (phycoerythrin) markedly decreased after quenching. After permeabilization, 97.1+/-2.8% of the gated cells were CD68+, while 53.9+/-18.6% of the AM were positive without permeabilization. CD68+ cells were sorted and proved to be AM morphologically. Analysis of CD71 (transferrin receptor) expression by FCM correlated with immunocytochemistry (r=0.77, p<0.05). The permeabilization/quenching technique, therefore, represents a satisfactory means to evaluate alveolar macrophages by flow cytometry.

The lymphocytic alveolitis in sarcoidosis is associated with increased amounts of soluble and cell-bound adhesion molecules in bronchoalveolar lavage fluid and serum

OBJECTIVES

Pulmonary sarcoidosis is a chronic inflammatory disorder of unknown aetiology accompanied by a lymphocytic alveolitis. It is likely that a selective and temporal expression of adhesion molecules plays a crucial role in the recruitment of cells to the inflammatory site. We investigated the expression of adhesion molecules on alveolar T-lymphocytes and in bronchoalveolar lavage (BAL) fluid and serum to elucidate mechanisms behind the accumulation of cells in the lung in sarcoidosis.

DESIGN

In a cross-sectional study in patients with active and inactive sarcoidosis and in healthy volunteers, we examined, in serum and in BAL fluid, the soluble adhesion molecules, VCAM-1, ICAM-1, and P-, E- and L-selectin. In addition, the expressions of alpha4-beta1 (VLA-4) and alpha5-beta1 (VLA-5) integrins on alveolar T-lymphocytes were analysed.

SETTING

The subjects attended the outpatient clinic at the Division of Respiratory Medicine, Karolinska Hospital, Stockholm, Sweden.

SUBJECTS

Nineteen sarcoidosis patients, nine with clinically active disease, and 13 healthy volunteers were included in the study. The sarcoidosis diagnosis was based on a typical histological and/or clinical (symptoms, radiograph, lung function) picture.

RESULTS

In sarcoidosis patients, particularly in those with active disease, an increase of the expressions of beta1-integrins was accompanied by elevated concentrations in BAL fluid of soluble VCAM-1. In serum, the levels of E-selectin and ICAM-1 were significantly higher in patients with active disease than in those with inactive disease and controls.

CONCLUSIONS

The findings offer some mechanistic explanations as to how the cell-rich alveolitis in sarcoidosis occurs, and furthermore suggest additional markers, such as s-ICAM-1, for assessment of disease activity.

Leukocyte counts and macrophage phenotypes in induced sputum and bronchoalveolar lavage fluid from normal subjects

It is unclear whether leukocytes in induced sputum (IS) and bronchoalveolar lavage (BAL) represent the same cell populations. To compare leukocyte counts and macrophage phenotypes and investigate any measurable dithiothreitol (DTT)-mediated effect on macrophage immunocytochemical staining results, IS and BAL samples from nine healthy smokers and seven nonsmokers were examined. BAL and IS samples were processed and cell viability and cell counts were assessed. The macrophages were characterized by seven monoclonal antibodies (RFD1, RFD7, CD11b, CD54, CD68, CD71 and HLA-DR) using an indirect immunoalkaline phosphatase method. Intraindividual comparison of IS and BAL showed that IS samples from smokers and nonsmokers contained a lower total cell count (p<0.01 smokers, p<0.05 nonsmokers), a lower percentage of macrophages (both p<0.05) and a higher percentage of neutrophils (both p<0.05) than BAL samples. In addition, nonsmokers sputum samples contained a lower proportion of lymphocytes (p<0.05) than BAL. The macrophage expression of RFD7 and CD71 was higher in smokers sputum samples (both p<0.05) than in BAL, while nonsmokers sputum macrophages showed a higher expression of CD54 and CD71 (both p<0.05) than BAL macrophages. DTT-incubated BAL samples showed no difference in macrophage antigen expression from BAL samples not exposed to DTT. In conclusion, the relative proportions of leukocytes and the macrophage phenotypes differed between induced sputum and bronchoalveolar lavage suggesting that the methods provide samples from different lung compartments, inhabited by cells with different phenotypes.

Differences between rat alveolar and interstitial macrophages 5 wk after quartz exposure

Macrophages play an essential role in pulmonary host defense. We investigated differences between rat alveolar (AM) and interstitial (IM) macrophages after exposure in vivo to quartz, an inducer of intensive alveolitis. Rats were exposed to 0.5 ml of saline without (n = 8) or with (n = 8) 10 mg of quartz by intratracheal instillation. In a third group (n = 8), 10 mg of surfactant were added to the quartz mixture. Five weeks later, AM were recovered by bronchoalveolar lavage and IM by mechanical fragmentation of the lung, followed by enzymatic treatment. Contamination of AM to the IM fraction was calculated to be 12-15%. After quartz exposure, the expression of major histocompatibility complex class Ia was increased in both AM and IM fractions. The receptor corresponding to human complement receptor 3 increased in AM after quartz exposure, and AM from quartz-exposed animals had a lower metabolic activation. Our findings indicate that IM are immunocompetent cells and that differences between AM and IM fractions occur upon quartz-induced inflammation. This response is not affected by addition of surfactant.

Human bronchial epithelial cells modulate collagen gel contraction by fibroblasts

Connective tissue contraction is an important aspect of both normal wound healing and fibrosis. This process may contribute to small airway narrowing associated with certain airway diseases. Fibroblast-mediated contraction of a three-dimensional collagen gel has been considered a model of tissue contraction. In this study, the ability of primary cultured human bronchial epithelial cells (HBEC) obtained by bronchial brushings to modulate fibroblast gel contraction was evaluated. Human lung fibroblasts (HFL1) were cast into type I collagen gels. The gels were floated both in dishes containing a monolayer of HBEC or in dishes without HBEC. Contraction assessed by measuring the area of gels was increased at all time points from 24 h up to 96 h of coculture. At 48 h, coculture of HBEC with fibroblasts resulted in significantly more contraction than fibroblasts alone (36.6 +/- 1.2 vs. 20.4 +/- 1.7%, P < 0.05). Lipopolysaccharide (LPS, 10 micrograms/ml) stimulation of the HBEC augmented the contraction (44.9 +/- 1.0%, P < 0.05 vs. HBEC). In the presence of indomethacin, the augmentation by LPS was increased further (52.2 +/- 4.3%, P < 0.05 vs. HBEC with LPS), suggesting that prostaglandins (PGs) are present and may inhibit contraction. Consistent with this, PGE was present in HBEC-conditioned medium. Bronchial epithelial cell conditioned medium had an effect similar to coculturing. SG-150 column chromatography revealed augmentive activity between 20 and 30 kDa and inhibitory activity between 10 and 20 kDa. Measurement by enzyme-linked immunosorbent assay confirmed the presence of the active form of transforming growth factor (TGF)-beta 2. The stimulatory activity of conditioned medium was blocked by adding anti-TGF-beta antibody. These data demonstrate that, through the release of factors including TGF-beta 2 which can augment and PGE which can inhibit, HBEC can modulate fibroblast-mediated collagen gel contraction. In this manner, HBEC may modulate fibroblast activities that determine the architecture of bronchial tissue.

Detection of extrathoracic manifestations in sarcoidosis with somatostatin analogue scintigraphy

BACKGROUND AND AIM OF WORK

Scintigraphy using a long lived radiolabelled somatostatin analogue [111In-DTPA-D-Phe1]-octreotide (OctreoScan) has previously been shown to be useful in the detection and management of neuroendocrine tumours, as well as in the imaging of various other malignant tumours. It was recently reported that the radiopharmaceutical accumulates also in the granulomatous lesions in Wegener's disease and in sarcoidosis. The present study was undertaken in order to evaluate the usefulness of the technique in detection of extrathoracic manifestations.

METHODS

OctreoScan scintigraphy was performed in 5 patients with biopsy-proven sarcoidosis. A patient with a familial history of multiple endocrine neoplasia served as control.

RESULTS

In 4/5 patients previously unknown granulomas were registered, and in the remaining subject the findings at the physical examination were confirmed.

CONCLUSIONS

We conclude that somatostatin analogue scintigraphy may be helpful in finding extrathoracic granulomatous lesions in sarcoidosis, thus providing good prerequisites for focused biopsy attempts.

Functional, morphological, and phenotypical differences between rat alveolar and interstitial macrophages

Alveolar macrophages (AM) and interstitial macrophages (IM) from rat lungs were characterized with respect to morphology, phagocytosis, adhesion properties, and phenotype. AM were recovered by lung lavage and IM by treatment of the lung tissue with DNAse and collagenase. The AM were enzyme treated in the same way as the IM. The IM were smaller than AM and had a higher nuclear to cytoplasm ratio. They had markedly lower phagocytic capacity. The attachment of particles to the cell surface was significantly lower in IM than in AM, but the capacity to ingest the particles was the same. Adherence to vitronectin- as well as fibronectin-coated surfaces was significantly higher in AM. The phagolysosomal pH was similar in IM and AM, around pH 5, indicating that dissolution of inorganic particles can take place effectively also in IM. Five surface receptors were studied, and the expression differed significantly in all five between AM and IM. The expression of OX-1 (CD 45), a common leukocyte antigen, was significantly higher on AM as was the expression of CD 71 (transferrin receptor). The receptor density for OX-42 was higher on a fraction of IM. This might be compatible with a stronger interaction between these cells and, for example, matrix components. IM had more surface antigen expressing MHC class Ia (OX-6) and CD 54. Both receptors are important for the antigen presentation capacity of macrophages. These findings show profound differences in phenotype between AM and IM and indicate that IM is a highly immunocompetent cell and should not be regarded only as a precursor to AM.

Adhesion properties of human alveolar macrophages with respect to extracellular matrix components and chemotactic agonists

Adherence has an essential impact on the differentiation and activation of tissue dwelling monocytes/macrophages. We have considered the effect of selected chemotactic agonists (fMLP, RANTES, IL-8) on the adhesion properties of human alveolar macrophages prepared by bronchoalveolar lavage. The macrophages were co-incubated in buffer alone or buffer supplemented with respective agonist, for different time points, in culture wells precoated with albumin, vitronectin and fibronectin, respectively. The macrophages displayed a gradual increase in adhesion in all three surfaces and discriminated between the different matrix components, but did not respond to the selected agonists with increased adhesion.

Transient increases in albumin and hyaluronan in bronchoalveolar lavage fluid after quitting smoking: possible signs of reparative mechanisms

Inhalation of tobacco smoke results in an accumulation of cells in the lower respiratory tract. The inflammatory response in the alveoli and lung interstitium may also be reflected by increased bronchoalveolar lavage (BAL) fluid concentrations of extracellular matrix components. The present study investigated the influence of smoking on the BAL fluid concentrations of albumin (ALB), hyaluronan (HA) and fibronectin (FN). Lavage fluids from 18 smokers were analysed before and at 1, 3, 6, 9 and 15 months after smoking cessation. Never-smokers (n = 112) served as a reference group. The total cell concentration and the concentrations of macrophages, lymphocytes, neutrophils and eosinophils were higher (P < 0.001-0.01) in smokers' BAL fluid than in never-smokers', but the values returned to normal within 9 months of smoking cessation. The HA concentration was higher (P < 0.001) in smokers' than in never-smokers' BAL fluid, but FN and ALB did not differ. Transient increases in the concentrations of ALB and HA (P < 0.01 for both) was observed within 6 months of smoking cessation. These findings indicate a temporary heightened alveolar-capillary permeability and an increased production and/or degradation of HA, being enhanced following smoking cessation. The findings probably reflect an initiation of a reparative process.

Chronic smoke exposure alters the phenotype pattern and the metabolic response in human alveolar macrophages

Smoking induces a chronic inflammatory process in the lower respiratory tract, where the alveolar macrophages (AM) are the main phagocytes. In the present study, the expressions of different membrane glycoproteins (CD11abc, CD71, CD54, CD14 and CD16) were determined by flow cytometry in AM from smokers and non-smokers after quenching of the intracellular autofluorescence. The metabolic activity of the AM was quantified as a functional test. The expressions of CD11a, CD54 and CD71 were higher in non-smokers' AM than in smokers'. The expressions of CD11b and CD16 were similar between the groups, while the CD11c was higher in smokers' AM compared with non-smokers'. The expression of CD14 was weak in both groups, therefore there was no clear-cut difference between the background and positively labelled cell populations. The metabolic response after in vitro stimulation with the phorbol ester phorbol myristate acetate (PMA) was higher in non-smokers' than in smokers' AM. Our results indicate that chronic exposure to tobacco smoke influences both the expression of AM membrane antigens and the metabolic activity. AM from non-smokers express a phenotype more related to cell proliferation and an accessory function. In contrast, receptors reflecting adhesion and phagocytosis were unaltered or even increased in smokers' AM. The findings suggest a functional change in the AM population after chronic smoke exposure.

Monocyte and neutrophil adhesion to matrix proteins is selectively enhanced in the presence of inflammatory mediators

The authors investigated the time course of monocyte and neutrophil adhesion to fibronectin, vitronectin and albumin precoated culture wells, using mixed leucocyte populations from healthy blood donors. Moreover, the influence of chemotactic agonists on the adhesion properties as well as the quantitative expression of CD29, CD11b/CD18 and CD61 was analysed by flow cytometry. Different chemotactic agonists were used representing a classical chemotactic agonist (fMLP), and agonists with a preferential effect on monocytes (RANTES) and neutrophils (IL-8), respectively. The authors found a gradual increase in monocyte and neutrophil adhesion to all three surfaces, reaching a plateau at 15 min of incubation. Adhesion to fibronectin was significantly higher at all time points (5, 15 and 60 min, respectively) compared with vitronectin and albumin in both monocytes and neutrophils. Neutrophil adhesion to vitronectin was significantly lower at 60 min compared with 15 min. Monocyte adhesion to albumin was increased by fMLP and RANTES and to vitronectin also by IL-8. Neutrophil adhesion to albumin and vitronectin was increased by fMLP and IL-8, but not RANTES. The adhesion to fibronectin was not altered by any of the chemotactic agonists used. The quantitative levels of CD11b/CD18, but not CD29 and CD61, was increased by fMLP, but not RANTES nor IL-8. The authors conclude that the adhesion of human monocytes and neutrophils to vitronectin and albumin, but not fibronectin, is selectively enhanced by chemotactic agonists and may contribute to the selective accumulation of different leucocyte subsets at the inflammatory site.

Human blood monocytes, but not alveolar macrophages, reveal increased CD11b/CD18 expression and adhesion properties upon receptor-dependent activation

The beta 2 integrin receptor CD11b/CD18 mediates adhesion to the endothelial lining as well as to extracellular matrix components. The present study was undertaken to investigate peripheral human blood monocytes (BMs) and alveolar macrophages (AMs) with respect to quantitative levels of CD11b/CD18 and adhesion properties in relation to the state of activation. BMs and AMs were recruited from healthy subjects. Quantitative analysis of the surface expression of CD11b/CD18 by flow cytometric technique and adhesion properties to albumin-coated surfaces were performed both on resting and N-formyl-methionyl-leucyl-phenylalanine (fMLP)-activated cells. Receptor independent stimuli (phorbol-12-myristate-13-acetate (PMA) and ionomycin) were used in additional experiments. Intracellular stored CD11b/CD18 was evaluated by flow cytometry and immunofluorescence microscopy. The surface expression of CD11b/CD18 on resting BMs increased fivefold (p < 0.01) upon fMLP activation. On resting AMs, the surface expression of CD11b/CD18 was significantly higher (p < 0.01) compared to resting BMs but did not increase further upon activation with fMLP, PMA or ionomycin. In contrast to BMs, no evidence for an additional intracellular pool of CD11b/CD18 was found in AMs. The adherence of resting BMs did not significantly differ from the adherence of resting AMs. After fMLP activation, the adherence of BMs, but not AMs, increased significantly (p < 0.05). Our results indicate that in vivo differentiation of human blood monocytes into alveolar macrophages implies reduced responsiveness to fMLP in terms of CD11b/CD18 upregulation and adhesion properties, and that the lack of upregulation of CD11b/CD18 on alveolar macrophages presumably depends on the absence of an additional intracellular pool.

The immotile cilia syndrome: characterization of the inflammatory response in nonsmoking patients with dysfunction of the cilia

In order to demonstrate how patients with immotile cilia syndrome (ICS) are associated with lower respiratory tract inflammation, bronchoscopy and fractionated BAL were performed on eight ICS patients. Their VC was 84.5 +/- 16.7% (mean +/- SD) and FEV1 73.1 +/- 19.9% of predicted. Endobronchial signs of bronchitis were observed in all patients. The total cell concentrations in the BAL fluid were increased, compared to healthy nonsmokers (n = 10), both in the bronchial (BP) and alveolar portion (AP) (p < 0.01 for both). In the BP, this was mainly due to a high concentration of neutrophils (p < 0.001), whereas in the AP, the concentrations of lymphocytes (p < 0.01) as well as all types of granulocytes (p < 0.001-0.01) were elevated. The signs of active inflammation in the lower respiratory tract were confirmed by the concomitantly elevated (p < 0.001-0.05) concentrations of the soluble BAL components albumin, fibronectin and hyaluronan. Thus, the inflammatory response is not restricted to the ciliated conducting airways, but also occurs in the alveolar space and results-surprisingly-in only a slightly impaired lung function.

Different functional and morphological characteristics in a nonadherent subpopulation of human macrophages recovered by bronchoalveolar lavage

The alveolar macrophages (AMs) constitute a morphologically and functionally heterogenous cell population. The adhesive properties of these cells are important for their role in host defence. To focus on the heterogeneity, a population of nonadherent macrophages were characterized functionally and morphologically. These cells were then compared with the total alveolar macrophage population. Alveolar cells (> 95% alveolar macrophages), were recovered by bronchoalveolar lavage (BAL) from healthy smokers. Nonadherent macrophages were separated by adhesion. The phagocytic capacity and the autofluorescent properties of the cell populations were determined in flow cytofluorometric assays. In addition, electron microscopic evaluation was performed. The alveolar macrophage adhesion to wells coated with albumin increased in a time-dependent manner. After 15 min, median 47%, interquartile range 42-52% (uncoated wells 68%, 67-72%) of the alveolar macrophages were attached; and after 60 min, 56%, 51-58% (uncoated wells 73%, 71-76%) of the alveolar macrophages were attached. The nonadherent alveolar macrophage population had less phagocytic capacity. The cell autofluorescence increased with increasing cell size and cell complexity/granularity in both populations. The nonadherent cells were more autofluorescent, indicating an increased granularity/complexity. These findings were confirmed with electron microscopy. Thus, the nonadherent alveolar macrophages had more cytoplasmic inclusions than the total alveolar macrophage population (volume density median 0.39, interquartile range 0.35-0.46 and 0.31, 0.26-0.34, respectively), but less surface protusions. We conclude that in lavage fluid from human smokers there is an ultrastructurally specific subpopulation of alveolar macrophages, showing less adhesive properties and impaired phagocytic capacity in vitro. These macrophages may be older alveolar cells or, alternatively, airway macrophages. Since only alveolar macrophages from smokers were investigated, we cannot draw any conclusions regarding alveolar cells from nonsmokers. Nevertheless, the heterogeneity of the lavaged cells should be taken into consideration when the functional ability of the alveolar macrophages are evaluated.

Altered expression of CD11b/CD18 and CD62L on human monocytes after cell preparation procedures

We have investigated the effect of different cell preparation procedures on the surface expression of CD11b/CD18 and CD62L on human monocytes. Both EDTA and heparin anticoagulated blood were used as sources for leukocytes. The monocytes were analysed by flow cytometry in a mixed leukocyte suspensions obtained after ammonium chloride mediated lysis and in mononuclear cell suspension prepared by density gradient centrifugation (Ficoll-Paque) performed both at 4 degrees C and at 20 degrees C. Monocytes from heparinized blood had a higher expression of CD11b/CD18 and a more pronounced inter-individual variation than monocytes from EDTA blood. Monocytes isolated by Ficoll-Paque had a higher degree of ex vivo activation by means of altered expression of CD11b/CD18 and CD62L compared to monocytes prepared by ammonium chloride mediated lysis. This was more pronounced when the isolation procedure was performed at 20 degrees C. Our findings indicate that monocytes prepared by ammonium chloride mediated lysis of EDTA blood and with the cell handling temperature kept at 4 degrees C are exposed to the smallest ex vivo modulation by means of receptor alteration. An awareness of ex vivo modulation by different cell preparation procedures is of importance especially when comparing the expression of functional receptors on leukocytes of disparate origin.

Sarcoidosis patients have bronchial hyperreactivity and signs of mast cell activation in their bronchoalveolar lavage

An increased (p < 0.001) frequency of bronchial hyperreactivity (BHR) was found in sarcoidosis patients as compared with healthy volunteers. The patients had more mast cells (p < 0.001) and tryptase (p < 0.001) in their bronchoalveolar lavage fluid, but there were no differences between BHR-positive and BHR-negative patients. Furthermore, the bronchoalveolar lavage fluid concentrations of macrophages, lymphocytes, and of the soluble components albumin, fibronectin, and vitronectin were also elevated in the sarcoidosis patients, indicating an ongoing inflammation in the airways and/or in the interstitium. We observed no significant differences in the parameters when the sarcoidosis patients were subdivided into BHR, clinical activity, or chest X-ray stages. Our findings may indicate a multifactorial background to the hyperreactivity.

Short-term in vivo exposure to cigarette-smoke increases the fluorescence in rat alveolar macrophages

Alveolar macrophages (AMs) from human smokers exhibit a strong intracellular fluorescence. In order to study the mechanisms behind the fluorescence, we wanted to determine whether it could be induced by short term exposure to smoke. We therefore exposed rats for either one or five days to cigarette smoke. AMs were recovered by bronchoalveolar lavage (BAL), and their fluorescence was quantified by flow cytofluorometry. AMs from rats exposed to two cigarettes, on a single occasion, showed an increased fluorescence compared to controls. The fluorescence was further enhanced by exposing rats to two cigarettes, for five consecutive days. Larger and more granular/complex AMs were more fluorescent than smaller and less granular/complex cells. Smoke-exposed rats (five consecutive days) lavaged immediately after the exposure, had less cells in their BAL fluid than control animals. However, when rats were lavaged three smoke-free days after the exposure, the cell recovery increased, probably due to less airway obstruction. In conclusion, we found that a short-term in vivo exposure to cigarette smoke results in an increased AM fluorescence. The findings can be one explanation for the strong fluorescence seen in AMs from human smokers, possibly due to endocytosis of fluorescent material.

Metabolic activity in human alveolar macrophages increases after cessation of smoking

Alveolar macrophages (AMs) were recruited by bronchoalveolar lavage (BAL) from human smokers before and one, three, and six months after smoking cessation. The metabolic activity of the AM was quantified as luminol-enhanced chemiluminescence (CL) both at rest and after in vitro stimulation with phorbol myristate acetate (PMA). The resting CL values did not differ before and after smoking cessation. The activity after PMA stimulation was unaltered at one and three months. However, the maximal metabolic response, as well as the rate, were significantly (P < 0.02 and P < 0.01, respectively) higher at six months, compared to prior smoking cessation. In addition, the time to reach the maximal peak was reduced after six smoke-free months, indicating a more rapid cell activation. The cell concentration in the BAL-fluid decreased (P < 0.001) as soon as after one smoke-free month and remained low at the following lavages. The lower metabolic response one and three months after smoking cessation, and the increased response six months after, together with a rapid normalization of the cell concentration in the BAL fluid, may be explained by the persistence of tobacco-smoke particles in the alveolar space, which could influence cell activity.

Elevated levels of tryptase in bronchoalveolar lavage fluid from patients with sarcoidosis

Sarcoidosis affecting the lungs may cause obstructive and/or restrictive lung function impairment. The bronchial reactivity is related to the release of histamine from the mast cells. Upon activation mast cells also release tryptase. This enzyme may activate latent collagenase and thus possibly contribute to the fibrosis formation observed in sarcoidosis. We analyzed the bronchoalveolar lavage fluid (BALF) from 13 nonsmoking and untreated patients with sarcoidosis and from 30 healthy volunteers (18 smokers) with regard to the number of mast cells and the tryptase concentration. Concomitantly albumin, fibronectin and hyaluronan were measured as markers of the inflammatory reaction in the alveoli and interstitium. The number of mast cells was higher (p < 0.001) in patients with sarcoidosis than in controls. Also, the concentration of tryptase was significantly higher in patients (225.3 +/- 83.9 [SEM] mU/L) compared to nonsmoking and smoking controls (34.7 +/- 7.8 and 44.7 +/- 13.0 mU/L, respectively; p < 0.01 for both). In addition, the concentrations of albumin, fibronectin and hyaluronan were higher in patients with sarcoidosis compared to the nonsmoking controls (p < 0.001 for all). However, there was no relationship between either the mast cell number or the tryptase concentration and the lung function parameters (VC, TLC, FEV1, FEV%, DLCO). As our patients did not show any functional signs of bronchial obstruction (FEV1 91.7% +/- 13.3 [SD] and FEV% 99.5% +/- 6.4 of predicted) the lack of correlation is not surprising. The high concentrations observed in the BALF of the noncellular components may just reflect an ongoing inflammatory process that may resolve or, if exaggerated, lead to fibrosis.

Smoking cessation rapidly reduces cell recovery in bronchoalveolar lavage fluid, while alveolar macrophage fluorescence remains high

Bronchoalveolar lavage (BAL) was performed in smokers (22.6 +/- 7.8 pack-years) before (n = 18) and 1 (n = 14), 3 (n = 13), 6 (n = 11), 9 (n = 9), and 15 (n = 8) months after smoking cessation. The recovery of the BAL fluid increased after smoking cessation (p less than 0.05). The total number of cells and the cell concentration were significantly lower already at one month (p less than 0.05 and p less than 0.01, respectively), and this decline was more pronounced at the following lavages. By using flow cytofluorometry, alveolar macrophage (AM) fluorescence was quantified, since it is known that AMs lavaged from smokers have an increased fluorescence, due to interaction with fluorescent substances in the inhaled smoke. Not until six months after smoking cessation was a significant (p less than 0.05) decrease in AMs fluorescence noted. At 15 months, the fluorescence was still increased, with great individual variations, compared with AMs from nonsmokers. The decline in fluorescence of AMs after smoking cessation was negatively correlated to the previous cigarette consumption. The absence of new, low fluorescent cells in the BAL fluid, despite a slow, but significant decrease in the fluorescence intensity of the whole cell population, suggests that the fluorescent material is redistributed from older AMs to newly recruited cells. These substances can thus remain in the alveolar space for a longer time than the estimated life span of the AMs.

Endocytosis of cigarette-smoke condensate by rabbit alveolar macrophages in vitro measured as fluorescence intensity

It has previously been shown that alveolar macrophages (AMs) from smokers have increased fluorescence compared to AMs from nonsmokers. In the present investigation, AMs lavaged from rabbits were exposed to a cigarette-smoke condensate (CSC) in order to study its influence on the fluorescence of AMs. Flow cytofluorometry was used. Alveolar cells exposed to 0.01% of CSC showed a fluorescence which increased with higher concentrations of the CSC. Incubation with CSC for 5 min was enough to give a significant rise (p less than 0.001) in cell fluorescence compared to controls. After incubating fluorescent cells with untreated non-fluorescent AMs, fluorescent material was distributed to the non-fluorescent AMs within 30 min. Further more, fluorescence decreased when exposed cells were cultured in CSC-free medium. When incubating CSC with blood leucocytes, an almost threefold increase in fluorescence was observed among the phagocytic cells at 37 degrees C compared to 4 degrees C, whereas the fluorescence in the non-phagocytic cell population only showed a minor enhancement. Endocytosis of fluorescent material in CSC can explain the strong fluorescence seen in AMs from smokers. Exocytosis and re-endocytosis of the material by new AMs may explain the slow decline in the fluorescence of AMs observed after cessation of smoking.

Quenching of intracellular autofluorescence in alveolar macrophages permits analysis of fluorochrome labelled surface antigens by flow cytofluorometry

We report a new technique in which the autofluorescence of alveolar macrophages from smokers is quenched by crystal violet. This technique permits immunostaining of surface antigens of these cells and enables the stained cells to be analysed by flow cytofluorometry. The variable solubility of crystal violet makes it important to characterize the crystal violet solution by its quenching properties and not rely on the assumed concentration of dissolved dye. High concentrations of crystal violet lowered the number of cells and gave a decreased amount of surface antigen (CD11b). However, a lower concentration of crystal violet could be used if the cells were fixed with paraformaldehyde (4%) and the membranes were permeabilized with n-octyl-beta-D-glucopyranoside (0.6%). Using a phagocytic model with FITC-conjugated particles we were able to show that this treatment gave an efficient permeabilization of phagolysosomal membranes.

Bilateral spontaneous pneumothorax and sarcoidosis

We report on a 44-year-old smoking man with sarcoidosis stage III presenting with bilateral spontaneous pneumothorax. The diagnosis was confirmed by biopsies from the lung parenchyma, visceral pleura and bronchial mucosa. Bilateral pleurectomy was needed since long-term tube drainage turned out to be unsuccessful.