Lungs Of Cigarette Smokers Research Articles

Secretion of the endoplasmic reticulum stress protein, GRP78, into the BALF is increased in cigarette smokers

BackgroundIdentification of biomarkers of cigarette smoke –induced lung damage and early COPD is an area of intense interest. Glucose regulated protein of 78 kD (i.e., GRP78), a multi-functional protein which mediates cell responses to oxidant stress, is increased in the lungs of cigarette smokers and in the serum of subjects with COPD. We have suggested that secretion of GRP78 by lung cells may explain the increase in serum GRP78 in COPD. To assess GRP78 secretion by the lung, we assayed GRP78 in bronchoalveolar lavage fluid (BALF) in chronic smokers and non-smokers. We also directly assessed the acute effect of cigarette smoke material on GRP78 secretion in isolated human airway epithelial cells (HAEC).MethodsGRP78 was measured in BALF of smokers (S; n = 13) and non-smokers (NS; n = 11) by Western blotting. GRP78 secretion by HAEC was assessed by comparing its concentration in cell culture medium and cell lysates. Cells were treated for 24 h with either the volatile phase of cigarette smoke (cigarette smoke extract (CSE) or the particulate phase (cigarette smoke condensate (CSC)).ResultsGRP78 was present in the BALF of both NS and S but levels were significantly greater in S (p = 0.04). GRP78 was secreted constitutively in HAEC. CSE 15% X 24 h increased GRP78 in cell-conditioned medium without affecting its intracellular concentration. In contrast, CSC X 24 h increased intracellular GRP78 expression but did not affect GRP78 secretion. Brefeldin A, an inhibitor of classical Golgi secretion pathways, did not inhibit GRP78 secretion indicating that non-classical pathways were involved.ConclusionThe present study indicates that GRP78 is increased in BALF in cigarette smokers; that HAEC secrete GRP78; and that GRP78 secretion by HAEC is augmented by cigarette smoke particulates. Enhanced secretion of GRP78 by lung cells makes it a potential biomarker of cigarette smoke–induced lung injury.

Oral Cell DNA Adducts as Potential Biomarkers for Lung Cancer Susceptibility in Cigarette Smokers.

This perspective considers the use of oral cell DNA adducts, together with exposure and genetic information, to potentially identify those cigarette smokers at highest risk for lung cancer, so that appropriate preventive measures could be initiated at a relatively young age before too much damage has been done. There are now well established and validated analytical methods for the quantitation of urinary and serum metabolites of tobacco smoke toxicants and carcinogens. These metabolites provide a profile of exposure and in some cases lung cancer risk, but they do not yield information on the critical DNA damage parameter that leads to mutations in cancer growth control genes such as KRAS and TP53. Studies demonstrate a correlation between changes in the oral cavity and lung in cigarette smokers, due to the field effect of tobacco smoke. Oral cell DNA is readily obtained in contrast to DNA samples from the lung. Studies in which oral cell DNA and salivary DNA have been analyzed for specific DNA adducts are reviewed; some of the adducts identified have also been previously reported in lung DNA from smokers. The multiple challenges of developing a panel of oral cell DNA adducts that could be routinely quantified by mass spectrometry are discussed.

Induction of murine macrophage M2 polarization by cigarette smoke extract via the JAK2/STAT3 pathway.

Cigarette smoking is a major pathogenic factor in lung cancer. Macrophages play an important role in host defense and adaptive immunity. These cells display diverse phenotypes for performing different functions. M2 type macrophages usually exhibit immunosuppressive and tumor-promoting characteristics. Although macrophage polarization toward the M2 phenotype has been observed in the lungs of cigarette smokers, the molecular basis of the process remains unclear. In this study, we evaluated the possible mechanisms for the polarization of mouse macrophages that are induced by cigarette smoking (CS) or cigarette smoke extract (CSE). The results showed that exposure to CSE suppressed the production of reactive oxygen species (ROS) and nitric oxide (NO) and down-regulated the phagocytic ability of Ana-1 cells. The CD163 expressions on the surface of macrophages from different sources were significantly increased in in vivo and in vitro studies. The M1 macrophage cytokines TNF-α, IL-12p40 and enzyme iNOS decreased in the culture supernatant, and their mRNA levels decreased depending on the time and concentration of CSE. In contrast, the M2 phenotype macrophage cytokines IL-10, IL-6, TGF-β1 and TGF-β2 were up-regulated. Moreover, phosphorylation of JAK2 and STAT3 was observed after the Ana-1 cells were treated with CSE. In addition, pretreating the Ana-1 cells with the STAT3 phosphorylation inhibitor WP1066 inhibited the CSE-induced CD163 expression, increased the mRNA level of IL-10 and significantly decreased the mRNA level of IL-12. In conclusion, we demonstrated that the M2 polarization of macrophages induced by CS could be mediated through JAK2/STAT3 pathway activation.

Respiratory Bronchiolitis with Fibrosis. High-Resolution Computed Tomography Findings and Correlation with Pathology

Recent pathology studies report that the lungs of cigarette smokers may demonstrate small localized subpleural foci of interstitial fibrosis associated with emphysema. Pathologically, this lesion has been termed smoking-related interstitial fibrosis, respiratory bronchiolitis-interstitial lung disease (ILD) with fibrosis, or airspace enlargement with fibrosis, but it is commonly misinterpreted on imaging and biopsy as a diffuse fibrosing interstitial pneumonia. The high-resolution computed tomography (HRCT) appearance of this process has not been defined. We describe HRCT imaging of seven patients with this lesion present histologically. HRCT features consisted of patchy areas of mild reticulation around predominantly subpleural upper/mid zone emphysematous changes in all cases, with variable patchy ground-glass change in six cases. Pathologically, there were distinctly circumscribed foci of dense, often hyalinized, interstitial fibrosis mixed with emphysema; variable numbers of smoker's macrophages were present in the airspaces. The fibrosis was confined to the subpleural regions. Three patients with follow-up information were clinically stable. These data suggest that a CT pattern of patchy areas of reticular changes about predominantly upper zone emphysematous spaces may be seen in smokers who do not have clinical evidence of a diffuse ILD. We propose that this lesion be called respiratory bronchiolitis with fibrosis (RBF) to avoid confusion with other forms of ILD. RBF probably accounts for some of the cases of ILD seen in large radiologic surveys of smokers. The pathology literature indicates that RBF either has no functional effects or at worst represents mild, usually nonprogressive disease, and hence separation from other, more serious, forms of ILD is important. Recognition of this lesion on imaging may obviate the need for lung biopsy.

Mucin5B expression by lung alveolar macrophages is increased in long-term smokers

This study investigated the expression of MUC5B by AMs in the lungs of cigarette smokers and nonsmokers. We analyzed MUC5B expression by measuring the levels of apomucin and mRNA in human BALF cells from 50 subjects (20 nonsmokers, 17 patients with CB, and 13 patients with COPD). apoMUC5B was observed in BALF mononuclear cells in 60% of all subjects, but a significantly higher frequency of apoMUC5B(+) cells was found in subjects with CB (95% CI, 4.5-24.9) or COPD (95% CI, 6.2-39.6) than in nonsmokers (95% CI, 0.5-2.5). apoMUC5B(+) mononuclear cells showed strong expression of CD163, confirming their identity as AMs. MUC5B mRNA expression was detected by ISH in AMs of subjects investigated, and real-time qPCR analysis confirmed MUC5B mRNA expression. In conclusion, MUC5B is expressed in a subset of lung AMs and long-term cigarette smoking may increase the level of MUC5B produced by these cells.

Procarcinogenic and anticarcinogenic effects of beta-carotene.

A large body of observational epidemiologic studies has consistently demonstrated that individuals who eat more fruits and vegetables, which are rich in carotenoids, and people who have higher serum beta-carotene levels have a lower risk of cancer, particularly lung cancer. In contrast to these observations, two human intervention studies that used high-dose beta-carotene supplements reported an increased risk for lung cancer among smokers. Recently, in vitro and in vivo studies have shed light on the present conundrum regarding the potential chemopreventive activity of beta-carotene; that is, beta-carotene itself may act as an anticarcinogen, but its oxidized products may facilitate carcinogenesis. These studies support the hypothesis that the carcinogenic response to high-dose beta-carotene supplementation reported in the human intervention trials is related to the instability of the beta-carotene molecule in the free radical-rich environment in the lungs of cigarette smokers. This is especially possible because smoke also causes decreased tissue levels of other antioxidants, such as ascorbate and alpha-tocopherol, which normally have a stabilizing effect on the unoxidized form of beta-carotene. Nutritional intervention using a combination of antioxidants (beta-carotene, alpha-tocopherol, and vitamin C) as anticarcinogenic agents could be an appropriate way to rationally and realistically reduce cancer risk.

Complementary Structural Mass Spectrometry Techniques Reveal Local Dynamics in Functionally Important Regions of a Metastable Serpin

Serpins display a number of highly unusual structural properties along with a unique mechanism of inhibition. Although structures of numerous serpins have been solved by X-ray crystallography, little is known about the dynamics of serpins in their inhibitory active conformation. In this study, two complementary structural mass spectrometry methods, hydroxyl radical-mediated footprinting and hydrogen/deuterium (H/D) exchange, were employed to highlight differences between the static crystal structure and the dynamic conformation of human serpin protein, alpha(1)-antitrypsin (alpha(1)AT). H/D exchange revealed the distribution of flexible and rigid regions of alpha(1)AT, whereas footprinting revealed the dynamic environments of several side chains previously identified as important for the metastability of alpha(1)AT. This work provides insights into the unique structural design of alpha(1)AT and improves our understanding of its unusual inhibition mechanism. Also, we demonstrate that the combination of the two MS techniques provides a more complete picture of protein structure than either technique alone.

Cigarette smoke extract inhibits angiogenesis of pulmonary artery endothelial cells: the role of calpain.

Angiogenesis is an integral part of both the pulmonary inflammatory response to chronic exposure to cigarette smoke and the lung tissue remodeling associated with cigarette smoke-induced chronic obstructive pulmonary disease (COPD). To investigate the role of angiogenesis in the pathogenesis of COPD, we evaluated the effect of cigarette smoke extract (CSE) on angiogenesis of pulmonary artery endothelial cells (PAEC). Incubation of PAEC with 2.5-10% CSE resulted in a dose-dependent inhibition of endothelial monolayer wound repair. CSE also caused inhibition of tube formation on Matrigel, migration in a Boyden chamber, and proliferation of PAEC. Because calpain, a family of calcium-dependent intracellular proteases, mediates cytoskeletal signaling in endothelial motility, we explored the role of calpain in the CSE-induced inhibition of endothelial angiogenesis. Incubation of CSE resulted in a dose-dependent decrease in calpain activity. Calpain inhibitor-1, a specific inhibitor of calpain, potentiates inhibitory effect of CSE on the endothelial monolayer wound repair, tube formation, cell migration, and cell proliferation. Transfection of PAEC with antisense oligodeoxyribonucleotides of calpastatin, the major endogenous calpain inhibitor, prevented CSE-induced increase in calpastatin protein content and CSE-induced decreases in calpain activity. It also prevented CSE-induced decreases in monolayer wound repair, tube formation, and migration. These results suggest that CSE attenuates angiogenesis of PAEC and the mechanism involves inhibition of calpain. Impaired angiogenesis may impede the repair process in the lungs of cigarette smokers and contribute to the altered structural remodeling observed in the lungs of patients with cigarette smoke-related COPD.

Smoke Extract Stimulates Lung Epithelial Cells to Release Neutrophil and Monocyte Chemotactic Activity

Inflammatory cells accumulate within the lungs of cigarette smokers. Current concepts suggest that these cells can induce protease-antiprotease and/or oxidant-antioxidant imbalance(s), which may damage the normal lung alveolar and interstitial structures. Because type II pneumocytes line the alveolar space, and because the inflammatory cells migrate and reside at the alveolus, we postulated that the type II pneumocytes might release chemotactic activity for neutrophils and monocytes in response to smoke extract. To test this hypothesis, A549 cells were cultured and the supernatant fluids were evaluated for the neutrophil and monocyte chemotactic activity (NCA and MCA) by a blind-well chamber technique. A549 cells released NCA and MCA in response to smoke extract in a dose- and time-dependent manner (P < 0.05). Checkerboard analysis showed that the activity was chemotactic. Partial characterization of NCA and MCA revealed that the activity was partly heat labile, trypsin sensitive, and ethyl acetate extractable. Lipoxygenase inhibitors and cycloheximide inhibited the release of NCA and MCA. Molecular sieve column chromatography showed multiple peaks for both NCA and MCA. NCA was inhibited by anti-human-interleukin (IL)-8 antibody, granulocyte colony-stimulating factor (G-CSF) antibody, or leukotriene (LT)B4 receptor antagonist. Monocyte chemoattractant protein (MCP)-1 antibody or LTB4 receptor antagonist inhibited MCA. Immunoreactive IL-8, G-CSF, MCP-1, and LTB4 significantly increased in the supernatant fluids in response to smoke extract. These data suggest that the type II pneumocytes may release NCA and MCA and modulate the inflammatory cell recruitment into the lung.

Mechanisms of cigarette smoke induced increased airspace permeability.

Increased epithelial permeability of the airspaces occurs commonly in the lungs of cigarette smokers. It is likely to be important in augmenting the inflammatory response in the airspaces and hence may have a role in the pathogenesis of emphysema. It has previously been shown that intratracheal instillation of cigarette smoke condensate induces increased epithelial permeability in vivo in rats and in vitro in epithelial cell monolayers, associated with a disturbance in the lung antioxidant, glutathione (GSH). The aim of this study was to assess the role of neutrophils, GSH, and tumour necrosis factor (TNF) in the increased epithelial permeability following intratracheal instillation of cigarette smoke condensate. Epithelial permeability of the airspaces was measured in rat lungs as the passage of intratracheally instilled 125-iodine labelled bovine serum albumin (BSA) into the blood. The permeability of a monolayer of human type II alveolar epithelial cells to 125I-BSA was also measured. Cigarette smoke condensate produced a 59.7% increase in epithelial permeability over control values peaking six hours after instillation and returning to control values by 24 hours. Depletion of neutrophils and, to a lesser extent, macrophages by an intraperitoneal injection of antineutrophil antibody did not influence the increased epithelial permeability induced by cigarette smoke condensate. Although instillation of human recombinant TNF alpha produced an increase in epithelial permeability in the rat lung from 0.62 (0.61)% to 1.27 (0.08)%, only a trivial amount of TNF alpha was detected in bronchoalveolar lavage (BAL) fluid in vivo or in culture medium from BAL leucocytes obtained from animals treated with cigarette smoke condensate (94.9 (28.8) units/ml). Furthermore, antiTNF antibody did not abolish the increased epithelial permeability produced by cigarette smoke condensate. The role of GSH was assessed by measuring the changes in both the reduced (GSH) and oxidised form (GSSG) in lung tissue and in BAL fluid. One hour after instillation of cigarette smoke condensate there was a marked fall in the GSH content in the lung (from 809.8 (31.8) to 501.7 (40.5) nmol/g) in association with increased GSSG levels (from 89.8 (2.7) to 148.7 (48.8) nmol/g). This was followed by a return of GSH levels to control values, with a concomitant decrease in GSSG levels six hours after instillation. GSH levels in BAL fluid fell dramatically following cigarette smoke condensate (from 2.56 (0.30) to 0.31 (0.21) nmol/ml) and this fall was sustained up to six hours after instillation of cigarette smoke condensate. These studies suggest that neutrophils and TNF do not have a major role in the increased epithelial permeability induced by cigarette smoke condensate. However, the data support a role for the depletion of the antioxidant glutathione in the increased epithelial permeability caused by cigarette smoke condensate.

Regional variation in iron and iron-binding proteins within the lungs of smokers.

The lungs of cigarette smokers are known to contain increased concentrations of extracellular ferritin-bound iron. Reductants present in cigarette smoke may mobilize alveolar ferritin-bound iron, which could then promote oxidative injury to lung cells. Because iron-mediated oxidative injury may be relevant to the pathogenesis of emphysema and lung cancer, which have a predilection for upper lobes, we sought to determine whether concentrations of extracellular iron, ferritin, and transferrin differed in upper and lower lobes of cigarette smokers. Bronchoalveolar lavage (BAL) was performed in the upper and lower lobes of 15 asymptomatic smokers and six healthy nonsmokers. BAL fluid recovered from upper lobes of smokers contained higher concentrations of iron (p < 0.01) and ferritin (p < 0.006) and lower concentrations of transferrin (p < 0.003) compared with the lower lobes. In contrast, BAL fluid recovered from upper and lower lobes of nonsmokers contained much lower concentrations of iron and ferritin, and concentrations were similar in both sites. These findings indicate that, compared with the lower lobes, upper lobes of the lungs of smokers contain higher extracellular concentrations of ferritin-bound iron and decreased concentrations of transferrin. This distribution of lung iron and iron-binding proteins may promote oxidative injury in the upper lobes of smokers.

Altered cytokine regulation in the lungs of cigarette smokers.

Cigarette smoking is the major factor responsible for chronic obstructive lung disease, but it occurs in only a minority of smokers. Smoking is associated with increased susceptibility to pulmonary infections and with a neutrophil- and macrophage-rich inflammation of the small airways. We compared concentrations of tumor necrosis factor (TNF), interleukin (IL)-6, and IL-8 in bronchoalveolar lavage fluid (BALF) and measured the capacity of BALF macrophages to release TNF and IL-6 in vitro in nine smokers (19.1 +/- 4.2 pack-years; mean +/- SE) and nine nonsmokers. Compared with nonsmokers, BALF from smokers contained more cells (65.3 +/- 13.2 versus 27.2 +/- 4.8 x 10(6); p < 0.02), but much lower concentrations of IL-6 (1.8 +/- 1.0 versus 15.9 +/- 5.8 pg/ml; p < 0.05). The two smokers with the highest number of BALF cells had increased BALF concentrations of interleukin-8 (IL-8), but there was no difference in BALF IL-8 concentrations between the two groups (p = 0.08). Compared with BALF macrophages from nonsmokers, cells from smokers released less TNF (211 +/- 77 versus 1,406 +/- 348 units per 10(8) cells; p < 0.01) and IL-6 (5.8 +/- 2.6 versus 64.9 +/- 23.3 hybridoma units per ml; p < 0.02) during a 6-h incubation with lipopolysaccharide (LPS). We conclude that even in young, healthy smokers the pulmonary microenvironment is markedly abnormal, characterized by depressed levels of IL-6, macrophages that have a markedly depressed capacity for LPS-induced cytokine release and, in some smokers, increased concentrations of IL-8.

Polymorphisms for aromatic amine metabolism in humans: relevance for human carcinogenesis.

The metabolic pathways associated with carcinogenic aromatic amines in humans provide an excellent example of polymorphisms that appear to be relevant to human carcinogenesis. In this regard, the N-acetylation of arylamines and the O-acetylation of their N-hydroxy metabolites are catalyzed preferentially by a genetically polymorphic acetyltransferase, high activity of which has been correlated with decreased risk for urinary bladder cancer and increased susceptibility to colorectal cancer. Cytochrome P450IA2, the principal liver enzyme involved in aromatic amine N-oxidation, exhibits a wide interindividual variation that appears trimodal in several populations and is clearly inducible by cigarette smoking and probably other host factors as well. UDP-Glucuronosyltransferases, which catalyze the N-glucuronidation of N-hydroxyarylamines and are likely to be responsible for their transport to the colon, show widely varied but unimodal distributions in humans. In contrast, human liver sulfotransferase activity for N-hydroxyarylamines, which would be expected to decrease their transport through the circulation, is catalyzed by a polymorphic enzyme(s) that is expressed at higher levels in blacks, as compared to whites, and could contribute to their relatively lower incidence of urinary bladder cancer. Peroxidative activation of aromatic amines can also occur, especially from prostaglandin H synthase in the urinary bladder and myeloperoxidase in the lungs of cigarette smokers, and both show considerable individual variability, apparently due to the extent of tissue inflammation.(ABSTRACT TRUNCATED AT 250 WORDS)

The Destructive Index and Early Lung Destruction in Smokers

The destructive index (DI), a measure of alveolar septal damage and emphysema, has been proposed as a sensitive index of lung destruction that closely reflects functional abnormalities, especially loss of elastic recoil. To better understand the progression of lung destruction in smokers, we studied the contribution of its principal components: breaks in the alveolar septa (DIb) and the presence of emphysematous spaces (DIe), and compared them to the mean linear intercept (Lm) and DI as originally described. To do this we employed lungs obtained at autopsy from non-smokers and smokers. Lungs were selected by emphysema score (ES) so that all cases were emphysema free (nonsmokers and seven smokers) or had minimal emphysema (nine smokers; ES = 5). Of these indices, only DIb was significantly increased in the lungs of smokers: 17.8 +/- 1.2 versus 12.4 +/- 1.6, p less than 0.05. We also investigated the regional distribution of destruction by comparing results in upper and lower lobes. DIe, but not DIb, was significantly increased in upper lobes of smokers. These data support the notion that increases in DI in the lungs of smokers that occur before increases in Lm or ES reflect the presence of alveolar septal breaks and highlight the importance of alveolar septal destruction as a precursor to the development of airspace enlargement in the lungs of cigarette smokers.

Complement activation by cigarette smoke

Lung disease secondary to cigarette smoking is associated with an influx of neutrophils and monocytes into the lower respiratory tract. To determine whether cigarette smoke can generate chemotactic activity, human serum was exposed to cigarette smoke and evaluated for neutrophil and monocyte chemotactic activity. Serum exposed to cigarette smoke attracted significantly greater numbers of neutrophils and monocytes compared with normal human serum exposed to air (P less than 0.01, both comparisons). The increase in chemotactic activity was partially attenuated by EDTA but not by ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) and MgCl2 (P greater than 0.05, both comparisons), suggesting activation of the alternate complement pathway. To evaluate the capacity of cigarette smoke to activate the complement system, smoke-exposed serum was evaluated for cleavage of properdin factor B and C3 using immunoelectrophoresis and for C5a using a radioimmunoassay. Cleavage of properdin factor B and C3 was observed in the smoke-exposed serum and C5a was detected in the smoke-exposed serum (112 +/- 31 ng/ml). These data suggest that complement activation may play a role in directing the influx of neutrophils and monocytes into the lungs of cigarette smokers.

Inactivation of Chemotactic Factor Inactivator by Cigarette Smoke: A Potential Mechanism of Modulating Neutrophil Recruitment to the Lung

Activation of the complement system with generation of the potent neutrophil chemotactic factor C5a has been proposed to play a significant role in the neutrophil accumulation in the lungs of cigarette smokers. Chemotactic factor inactivator (CFI) can inhibit C5a-directed neutrophil chemotaxis by binding to the C5a cochemotaxin GcGlobulin (GcG), a vitamin-D-binding protein, and inhibiting the capacity of GcG to enhance the chemotactic activity of C5a. Because cigarette smoke can inhibit the function of some proteins, a loss of CFI functional activity induced by cigarette smoke would allow an increased capacity of GcG to augment C5a-directed neutrophil chemotaxis. In order to test this hypothesis, cigarette smoke was bubbled through a CFI solution, and the solution was evaluated for its ability to inhibit the chemotactic activity of C5a and GcG. Smoke-treated CFI inhibited only 36% of the C5a-GcG chemotactic activity. In contrast, a CFI solution treated with air inhibited 62% of the chemotactic activity (p less than 0.001). Consistent with these observations, smoke-treated CFI exhibited a decreased capacity to bind to GcG and a decreased capacity to inhibit the binding of C5a des Arg to GcG. CFI contained in the bronchial lavage fluids obtained from patients with chronic obstructive pulmonary disease secondary to cigarette smoking and asymptomatic smokers exhibited a decreased capacity to inhibit C5a-GcG neutrophil chemotaxis and to bind to GcG (p less than 0.05, both comparisons). Furthermore, smoke bubbled through normal bronchial lavage fluid decreased the capacity of CFI to bind to GcG.(ABSTRACT TRUNCATED AT 250 WORDS)

A Controlled Trial of Colchicine to Reduce the Elastase Load in the Lungs of Cigarette Smokers with Chronic Obstructive Pulmonary Disease

Current data suggest that emphysema in smokers is caused at least in part by the unrestrained action of neutrophil elastase on pulmonary tissues. Since colchicine reduces the secretion of enzymes from stimulated neutrophils, we designed a clinical trial to determine if colchicine could reduce the elastase load in the lungs or several putative indicators of elastin destruction. We carried out a prospective, double-blind, randomized, and placebo-controlled clinical trial. Outpatients seeking treatment for chronic obstructive pulmonary disease at the University of Texas Health Center at Tyler who met specific criteria were recruited into the study. A group of 46 cigarette smokers between 45 and 75 yr of age with chronic obstructive pulmonary disease (COPD) were studied. Colchicine or placebo was given orally in disguised capsules, 0.6 mg three times per day. Volunteers were placed on a baseline bronchodilator regimen of Theodur orally and albuterol by inhalation. Blood, urine, and bronchoalveolar lavage fluids were obtained after 1 wk of stabilization. The patients were then randomized and treated for 14 days with colchicine, and the measurements were repeated. Modifications in plasma elastin peptides and neutrophil elastase-generated fibrinopeptide A, urinary desmosines, and bronchoalveolar lavage fluid neutrophils or neutrophil elastase were the indicators of success or failure of the treatment. Pre- and posttreatment measurements in each patient and the difference between colchicine-treated and placebo-treated groups were compared. There were no statistically significant differences in either of the two types of analyses in any of the variables. We conclude that variables related to elastase load in the lungs were not modified by colchicine treatment. If a drug can be identified that is successful in modifying one of these variables, it would then have to be tested in a large-scale clinical trial in which the rate of decline in the FEV1.0 or mortality would be measured. The data presented here may provide useful information about the variability of key measurements of elastase load in the lungs and the breakdown of elastin and may aid investigators in designing similar trials in the future.

Inhibition of Human Alveolar Macrophage Production of Leukotriene B4 by Acute In Vitro and In Vivo Exposure to Tobacco Smoke

The number of neutrophils in the lungs of cigarette smokers is increased. This could be a consequence of the chemotactic mediator synthesis by alveolar macrophages (AM). In order to evaluate the possible role of leukotriene B4 (LTB4) in this condition, we studied the formation of LTB4 by nonsmokers' AM exposed in vitro and in vivo to cigarette smoke and by smokers' AM. In the absence of stimulus or upon stimulation, nonsmokers' AM exposed in vitro to tobacco smoke formed less LTB4 than did nonexposed AM, e.g., the cells incubated with arachidonic acid and ionophore produced, respectively, 241 +/- 132 and 425 +/- 106 pmol LTB4/10(6) cells (mean +/- SEM) (P less than 0.01). In other experiments, smokers' AM were incubated in absence of stimulus and produced less LTB4 than did nonsmokers' AM; during a 3-h incubation, smokers' and nonsmokers' adherent AM released, respectively, 3 +/- 2 and 40 +/- 28 pmol LTB4/10(6) cells (P less than 0.05). Similarly stimulated smokers' AM produced less LTB4 than did nonsmokers' AM, e.g., the cells incubated with arachidonic acid and ionophore formed, respectively, 225 +/- 41 and 573 +/- 150 pmol LTB4/10(6) cells (P less than 0.05). In a group including mild smokers and nonsmokers, in vivo exposure to the smoke of 4 cigarettes produced a decrease in the release of LTB4 by AM, e.g., in the presence of arachidonic acid and ionophore, nonexposed and exposed AM produced, respectively, 198 +/- 38 and 143 +/- 38 pmol LTB4/10(6) cells (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Alterations in Immunoregulatory T-Cell Subsets in Cigarette Smokers: A Phenotypic Analysis of Bronchoalveolar and Blood Lymphocytes

Abnormalities in the proportions of immunoregulatory T-lymphocytes in bronchoalveolar lavage fluid have been reported in interstitial pulmonary diseases, yet the effect of cigarette smoking on T-cell subsets in bronchoalveolar lavage fluid from normal subjects has not been investigated. We applied an immunoperoxidase technique performed on glass slides using the monoclonal antibodies, OKT3, OKT4, OKT8, OKIa, and Leu-7 to study T-cell subsets in bronchoalveolar lavage fluid and blood of 11 normal nonsmokers and 12 smokers. In the bronchoalveolar lavage fluid of smokers, a decrease in the percentage of OKT4+ helper/inducer and an increase in OKT8+ suppressor/cytotoxic cells resulted in a markedly decreased OKT4/OKT8 ratio (0.9 +/- 0.4) compared with nonsmokers (1.9 +/- 0.8) (p less than 0.005). These abnormalities of lymphocyte subsets in bronchoalveolar lavage fluid correlated with the cumulative pack-years of smoking history but were not reflected in the peripheral blood. These results suggest that cellular immunoregulation is disturbed in the lungs of cigarette smokers. This may play a role in pulmonary defense mechanisms and tumor immunity.

Tissue origin of serum placental-like alkaline phosphatase in cigarette smokers

A variety of solubilised tissue extracts from cigarette smokers and non-smokers have been screened quantitatively for both placental alkaline phosphatase (PLAP) and placental-like alkaline phosphatase (PLAP-like AP) in order to identify the possible tissue origins of the circulating PLAP-like AP found in most smokers. Lung alveolar tissue, and to a lesser extent colonic tissues, contained both PLAP-like AP and PLAP. Tissues from smokers and non-smokers contained comparable proportions and amounts of PLAP and PLAP-like AP. No other tissue source of PLAP-like AP was found other than those previously reported for testicular, endometrial and thymic tissue. Selective release of PLAP-like AP from the lung in cigarette smokers seems likely to be a major source for this isoenzyme in peripheral circulation.