Fibronectin In Bronchoalveolar Lavage Fluid Research Articles

The role of fibronectin in bronchoalveolar lavage fluid of asthmatic patients.

Allergic and chronic inflammation of the airway is regarded as the main pathogenesis of bronchial asthma, in which adhesion of inflammatory cells requires the expression of adhesion molecules. Thus, to clarify the role of fibronectin (FN) in the airway inflammation of bronchial asthma, FN levels in plasma and bronchoalveolar lavage fluid (BALF) from bronchial asthmatics were determined. FN concentrations in plasma and BALF were measured by enzyme-linked immunosorvent assay (ELISA) in 17 asthmatic patients and 10 healthy controls to elucidate the role of FN in allergic inflammation. The mean FN/albumin (Alb) level in the BALF of asthmatic patients was 2.973 micrograms/mg, which was significantly higher than that of healthy controls (0.727 microgram/mg). Non-atopic asthmatics showed a significantly higher level of FN in their BALF in comparison with atopic asthmatics, although the ratio of FN to albumin showed no significant difference. FN levels in BALF correlated significantly with total cell density (r = 0.71, P < 0.05) and alveolar macrophage density (r = 0.64, P < 0.05). FN levels in plasma did not correlate with those in BALF. In conclusion, increased FN in BALF, which was produced locally in the airways of asthmatic patients, is actively involved in the regulation of allergic inflammation.

Fibronectin and Hyaluronan in Bronchoalveolar Lavage Fluid from Young Patients with Chronic Obstructive Pulmonary Diseases

Fibronectin (FN) and hyaluronan (HA) in bronchoalveolar lavage fluid (BALF) and FN released by alveolar macrophages (AM) were examined in 7 nonsmoking healthy control subjects, and 20 smoking patients with chronic obstructive pulmonary diseases (COPD). All patients and subjects were no more than 40 years old. According to the 95% confidence limits of HA and FN in BALF from nonsmoking healthy control subjects, the smoking patients were divided into two groups, those who had HA and FN levels within the limits for nonsmoking controls were classified as the first group (group 1) and those with levels above the control limits were classified as the second group (group 2). Our data showed that the concentrations of HA and FN in BALF and FN released by AM were significantly higher in group 2 than in group 1 patients. There were also significant differences between the two groups in pulmonary function measurements (DLco, FEV1, and FEV1/FVC) which were lower in group 2. HA levels in group 2 patients correlated directly with counts of inflammatory cells in BALF (BALF cells/ml, and numbers/ml of total cells, macrophages, neutrophils and lymphocytes), and the concentration of FN released by AM, and showed an inverse correlation with pulmonary function (DLco and FEV1/FVC). Our results suggest that the inflammatory repair response and fibrosis may play a role in the development of emphysema in young patients with COPD.

Quantification of Fibronectin in Bronchoalveolar Lavage Fluid and in Lung Parenchyma: Differences between Smokers and Non-Smokers

Fibronectin (FN) is a glycoprotein present in the epithelial surface of airways and in the interstitial parenchyma of the lung. The aim of this study was to quantify the amount of FN in human lung parenchyma, and to investigate possible differences between smokers and non-smokers, both in lung parenchyma and in bronchoalveolar lavage (BAL) fluid. BAL fluid was recovered in 21 individuals. Quantification of FN in BAL was done by a non-competitive ELISA. Twenty-six lung parenchyma samples were also obtained from lung resections. FN was extracted with urea and heparin. Quantification of FN in lung parenchyma was determined by a competitive ELISA. The mean +/- SD FN content in BAL fluid from smokers was 1.59 +/- 1.65 micrograms/mg total protein and 0.53 +/- 0.26 in non-smokers (p < 0.05). However, the amount of FN/ml BAL fluid was not statistically different between smokers (0.15 +/- 0.13 micrograms/ml) and non-smokers (0.106 +/- 0.07). The mean extractable FN in human lung tissue was 38.6 micrograms/g wet weight (31.7-45.5, 95% mean confidence interval) with no statistical difference between smokers and non-smokers. We conclude that in smokers, FN accounts for a higher proportion of the total protein in BAL fluid, and that there were no differences in FN content in lung parenchyma between smokers and non-smokers.

Longitudinal changes in lung function among asbestos-exposed workers.

To prospectively identify the determinants of persistent or accelerated loss of lung function among workers occupationally exposed to asbestos and assess the relative contribution of cigarette smoking, asbestos-induced pleural fibrosis, and specific findings from bronchoalveolar lavage and high resolution CT scans, we examined the determinants of lung function changes in 117 subjects occupationally exposed to asbestos for at least 1 yr in a high exposure setting. A minimum of 20 yr was required between the first exposure to asbestos and entry into the study. Baseline studies included an independent assessment of dyspnea, lung volumes, diffusing capacity of carbon monoxide (DLCO), a chest radiograph, a high resolution CT (HRCT) scan, and bronchoalveolar lavage (BAL). Subjects were observed for an average of 2 yr (range, 0.5 to 4.0 yr), and lung function was measured on at least two separate occasions (mean, 4.1 separate tests). During the period of observation, there was an average 1.5% decrease in the TLC and a 2.5% decrease in the DLCO. In this longitudinal data set, after controlling for age, height, pack-years of cigarette smoking, and follow-up time, persistently lower measures of TLC were independently related to moderate to severe dyspnea (p = 0.005), diffuse pleural thickening (p = 0.007), and higher concentrations of fibronectin in BAL fluid (p = 0.01). Interstitial lung disease either on the chest radiograph or HRCT scan was not independently associated with persistently lower measures of TLC during the period of observation. However, none of the clinical variables we examined were associated with an accelerated decline in TLC.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical Relevance of Cellular Mediators of Inflammation in Workers Exposed to Asbestos

To identify the clinical relevance of cellular mediators of inflammation in workers exposed to asbestos, we investigated the relationship between inflammatory products primarily released by alveolar macrophages and the clinical expression of asbestos-induced interstitial fibrosis. Our study population consisted of 93 white men who had been occupationally exposed to asbestos and were on average 60 yr of age. Pulmonary function tests, chest radiographs, high-resolution CT scans, and bronchoalveolar lavage (BAL) were performed on almost all study subjects; 11 (11.8%) had restrictive lung function, 22 (23.7%) had abnormal gas exchange, 30 (32.3%) had interstitial fibrosis on chest x-ray, and 24 (25.8%) had interstitial changes on high-resolution CT scan. The cellular markers of parenchymal inflammation that we examined included fibronectin in BAL fluid and alveolar macrophage release of prostaglandin E2 (PGE2), interleukin-1 beta (IL-1 beta), and tumor necrosis factor (TNF-alpha) under unstimulated and endotoxin (LPS)-stimulated culture conditions. Significantly higher concentrations of fibronectin in BAL fluid were observed among those with restrictive lung function. In addition, higher concentrations of PGE2, released from cultured but otherwise unstimulated alveolar macrophages, were associated with restrictive lung function. However, the inverse relationship with PGE2 was observed among subjects with abnormal gas exchange. Interestingly, no consistent changes in these inflammatory mediators were observed in those with interstitial changes identified on either the chest radiograph or the high-resolution CT scan.(ABSTRACT TRUNCATED AT 250 WORDS)

Radiation-induced increase in hyaluronan and fibronectin in bronchoalveolar lavage fluid from breast cancer patients is suppressed by smoking

Bronchoalveolar lavage (BAL) fluid was analysed from 21 patients with breast cancer, stage T1N0M0, who had undergone tumour resection and post-operative local irradiation (accumulated dose 56 Gy). The lavage was performed two months after radiotherapy, in the anterior part of the lingula (left side) or of the right middle lobe (right side), depending on which side had been exposed to radiation. The patients had significantly increased concentrations of fibronectin (FN) (p less than 0.001), hyaluronan (HA) (p less than 0.01) and albumin (p less than 0.05) in BAL fluid compared with the healthy controls (n = 19). However, when the patients were separated, according to smoking history, it was obvious that the inflammatory reaction occurred entirely in the nonsmoking patient group (n = 10), whilst no difference could be found between the smoking patients (n = 11) and the controls. In the nonsmoking patient group, there was a sevenfold increase in BAL concentrations of FN and a threefold increase in HA. Moreover, four patients had detectable levels of procollagen III peptide in BAL, all were nonsmokers. The smoking habits of the controls had no influence on the BAL measurements. These findings indicate that smoking interferes with the radiation-induced early inflammatory connective tissue reaction of the lung. Finally, the results justify further investigation of interaction of smoking with cancer treatment, both from the view of therapy effectiveness and reduction of adverse effects.

Effect of chronic hypoxia on fibronectin in plasma, bronchoalveolar lavage fluid and liver of rats.

The present study was undertaken to measure fibronectin (FN) concentration in plasma and bronchoalveolar lavage fluid (BALF) with an enzyme linked immunosorbent assay (ELISA) method, to observe the distribution of FN in liver with an immunohistochemical stain method and to investigate the effect of chronic normobaric hypoxia on them in experimental rats. The results showed that chronic hypoxia caused a significant decrease in plasma FN concentration while BALF FN concentration and the distribution of FN in the liver were not significantly affected, suggesting that the change in FN in the lower respiratory tract can not be reflected by the change in plasma FN concentration and that the decrease in plasma FN concentration can not be attributed to the change in liver FN secretion. The decrease in plasma FN concentration may lead to a decrease in the defence ability of the body and may contribute to the development of hypercoagulability observed in some patients with chronic hypoxia.

Pulmonary function and immunologic abnormalities in miliary tuberculosis.

In a group of 33 patients with miliary tuberculosis (MTB), pulmonary function testing and bronchoalveolar lavage (BAL) were each performed in 31. The arterial blood gas analysis was done in 13 patients. Mild restrictive ventilatory defect, hypoxemia, and hypocapnia were observed. BAL revealed lymphocytic alveolitis. The lymphocyte subsets were measured in the BAL fluid and peripheral blood in 10 patients. The helper lymphocytes were decreased in the peripheral blood and increased in the BAL fluid. The immunoglobulins (IgG, IgA, and IgM) were significantly increased in the peripheral blood and BAL fluid in 18 patients. Serum complement (C3) (n = 23) and BAL fluid fibronectin (n = 22) were also significantly increased. Lymphocytic alveolitis and the raised levels of IgG and IgA in the peripheral blood and BAL fluid persisted at the end of 9 months of standard chemotherapy for tuberculosis. Long-term studies with larger numbers of patients are required to monitor the course of alveolitis in MTB. An addition of corticosteroids to the antituberculosis drug regimen may be considered in the treatment of these patients.

Procollagen-III in serum, plasminogen activation and fibronectin in bronchoalveolar lavage fluid during and following irradiation of human lung

In the search for predictors of late radiation-induced lung injury we studied procollagen type III peptide concentration (P-III-P) in serum as well as fibronectin and plasminogen activation in bronchoalveolar lavage (BAL) fluid during and following irradiation of human lung. The patients received either high-dose hemithorax irradiation for pleural mesothelioma (11 patients) or high-dose irradiation with individually shaped fields for non-small cell lung cancer (12 patients). The severity of radiation fibrosis was assessed clinically from CT scans 6 months and 12 months after treatment. Four scores were used: severe, moderate, mild, or normal. Radiological lung injury varied from “severe” (9 patients) to near absence of injury-“normal” (6 patients). Serum levels of P-III-P, when measured weekly during the 5-week period of radiotherapy or at several time-points after treatment, did not show consistent changes, nor did the levels correlate with the score for radiation fibrosis as assessed by CT scanning. Changes in fibronectin levels or in markers of plasminogen activation in BAL fluid did not correlate with the development of late lung injury. The levels of BAL fluid plasmin and plasminogen activator as assessed zymographically, but not the free net enzyme values, showed a tendency to be elevated in patients with severe radiation-induced lung injury, suggesting a possible role for inhibitors of the plasminogen activation cascade in the process of radiation-induced lung injury.

Fibronectin in bronchoalveolar lavage fluid and plasma of dogs with acute inflammation of the lungs

Bronchoalveolar inflammation, which was generated in dogs by Broncho-Vaxom instilled into the right lower lobe, was characterized first of all by an increased influx of macrophages. In this non-purulent acute-subacute inflammatory reaction, the lavage fibronectin decreased rapidly three hours after the incubation and then a marked gradual elevation was observed, which persisted throughout the whole two-week process, while plasma fibronectin concentrations were not altered significantly. Changes in the levels of lavage fibronectin may be an important sign for the control of the inflammatory reaction activity in the lungs.

Characteristics of alveolar cells and soluble components in bronchoalveolar lavage fluid from non-smoking aluminium potroom workers.

Aluminium potroom workers have been reported to develop severe pneumoconiosis and bronchial hyperreactivity. The influence of inhalation of aluminium oxide and fluorides on the alveolar milieu was studied by bronchoalveolar lavage (BAL) in 14 male non-smoking potroom workers; 28 non-smoking healthy volunteers served as controls. The total numbers, concentrations, and proportions of various alveolar cells did not differ between the groups. The concentrations of albumin and fibronectin in BAL fluid were significantly higher (p less than 0.01 for both) in the exposed workers, reflecting an increased alveolar capillary permeability and an activation of alveolar macrophages (AMs). The concentration of angiotensin converting enzyme, another AM marker, was, however, decreased (p less than 0.01) in the workers. The concentration of hyaluronan, a fibroblast marker, did not differ between the groups. AMs from workers had a decreased capacity (p less than 0.05) to interact with yeast C3b particles but not to ingest them. The expression of HLA-DR and OKM1 on the cell surfaces of AMs were equal in the two groups. The BAL findings were not accompanied by restrictive lung disease in the workers. The fact that only a discrete alveolitis was found in the potroom workers may be due to a low grade of exposure to alumina and fluorides and to frequent use of respiratory protection equipment.

Effects of dexamethasone and indomethacin on elastase, α1-proteinase inhibitor, and fibronectin in bronchoalveolar lavage fluid from neonates

Elastase activity and concentrations of alpha 1-proteinase inhibitor, albumin, and fibronectin were measured in bronchoaleolar lavage (BAL) fluid from ventilated lungs in preterm neonates with lung disease before and after treatment with dexamethasone or indomethacin. Treatment with dexamethasone was associated with a significant decrease in BAL elastase activity but no change in fibronectin, albumin, or alpha 1-proteinase inhibitor concentrations. In contrast, treatment with indomethacin was associated with an increase in BAL elastase activity and fibronectin concentration, with no change in albumin or alpha 1-proteinase inhibitor concentrations. Control groups showed no changes in these BAL fluid biochemical markers during a similar time period. These data indicate that treatment with corticosteroids decreases lung inflammation as measured by BAL elastase activity. Corticosteroid treatment may not inhibit the development of pulmonary fibrosis, because fibronectin concentrations in BAL fluid were unaffected. Indomethacin treatment may augment lung inflammation and fibrosis by increasing BAL elastase activity and fibronectin concentration.

Fibronectin in Bronchoalveolar Lavage Fluid and Plasma from Children with Chronic Inflammation of Lungs

Fibronectin/albumin ratios in plasma and in bronchoalveolar lavage fluid were evaluated in patients (1-6 years of age) with recurrent obstructive bronchitis and different interstitial lung diseases. These inflammatory reactions were characterized by increased influx of macrophages on the bronchoalveolar surface, but an increase in the proportion of lymphocytes or neutrophils was also detected in the group of patients with lymphocyte-macrophage or neutrophil-macrophage alveolitis. There was no considerable difference in plasma fibronectin concentrations obtained from healthy children and patients with moderate obstructive bronchitis and slight inflammation of the bronchial mucosa observed bronchoscopically. Levels of plasma fibronectin were elevated in patients with serious bronchial inflammation and different alveolitis, but they were within the normal range. A comparison of lavage fibronectin/albumin ratios with plasma fibronectin/albumin ratios with plasma fibronectin/albumin ratios indicated significant local production of fibronectin in subjects with serious bronchial inflammation and interstitial lung disorders. Fibronectin detected on the bronchoalveolar surface seems to be an important factor in mediating cell-to-cell interactions in the repair of the bronchoalveolar structures, and in tracing the activity of the inflammatory reactions not only in patients with interstitial lung diseases, but also in patients with serious chronic bronchial inflammation.

Release of soluble fibronectin containing an extra type III domain (ED1) during acute pulmonary injury mediated by oxidants or leukocytes in vivo.

This study was undertaken to determine if fibronectin containing an extra type III domain (ED1) is released during inflammatory injury of pulmonary tissue in vivo. ED1 fibronectin, measured by quantitative immunoassay, was markedly increased in bronchoalveolar lavage (BAL) fluid (2 and 4 h posttreatment) from rabbits with lung injury resulting from intrabronchial treatment with glucose oxidase and glucose to generate H2O2. This protein comprised a greater portion of total fibronectin in BAL fluid than in plasma, suggesting local release. Leukocyte-mediated lung injury after intrabronchial or intravenous treatment with phorbol myristate acetate (PMA) also affected ED1 fibronectin, triggering specific accumulation of this fibronectin variant in both BAL fluid and plasma. ED1 fibronectin in tissue fluids was largely intact and dimeric during injury, as demonstrated by Western blot analysis. Compartmental release of soluble ED1 fibronectin reflects acute pulmonary injury induced by oxidants or leukocytes in vivo.

Collagenase and fibronectin in bronchoalveolar lavage fluid in patients with sarcoidosis.

Bronchoalveolar lavage fluid from 43 patients with biopsy proved sarcoidosis and 10 control subjects were assayed for fibronectin and collagenase activity. Fibronectin was significantly increased in the group with sarcoidosis and was found to be positively correlated with angiotensin converting enzyme activity, protein concentration, percentage of T cells and helper:suppressor ratios in the lavage fluid. Increased fibronectin in the bronchoalveolar lavage fluid was not related to functional or radiographic indices of interstitial disease and did not identify patients subsequently requiring treatment. Latent collagenase was present in bronchoalveolar lavage fluid from 16 patients with sarcoidosis but not in any control sample. There was no association between the collagenase activity and the cell profiles of the lavage fluid. Yet carbon monoxide transfer factor was decreased in patients with bronchoalveolar lavage fluid collagenase. Ten of 16 patients with bronchoalveolar lavage fluid collagenase had radiographic class III or IV disease and a disease duration of more than two years. On follow up 62% of patients with bronchoalveolar lavage fluid collagenase required subsequent treatment, compared with only 23% of patients without collagenase. These results indicate an association between bronchoalveolar lavage fluid collagenase and progressive, prolonged disease in sarcoidosis, whereas increased bronchoalveolar lavage fluid fibronectin is associated with indices of disease activity.

Fibronectin and Procollagen 3 Levels in Bronchoalveolar Lavage of Asbestos-Exposed Human Subjects and Sheep

To evaluate the potential interest of levels of fibronectin and procollagen 3 in bronchoalveolar lavage fluid as markers of fibrogenic activity, we characterized the time course of changes in fibronectin and procollagen 3 levels in the tracheal lobe of sheep exposed to nonfibrogenic and fibrogenic materials. We correlated these observations with those of bronchoalveolar lavage in long-term asbestos workers in various stages of disease activity. Following studies before exposure, the tracheal lobe of three groups of 24 sheep were exposed once to 100 ml of phosphate-buffered saline solution (PBS), to 100 mg of latex beads in 100 ml of PBS, or to 100 mg of chrysotile fibers in 100 ml of PBS. Bronchoalveolar lavages were obtained at 0, 1, 2, 4, 8, and 12 months after exposure, and four or five sheep per group were killed after each lavage for histopathologic analysis. Fibronectin in bronchoalveolar lavage fluid increased significantly only in the asbestos-exposed sheep to values two to three times above controls or latex-exposed sheep and remained elevated during the 12 months of the study. Levels of procollagen 3 in bronchoalveolar lavage fluid were increased significantly only during the first two months following exposure in the asbestos-exposed sheep only. In the asbestos workers without disease, levels of fibronectin and procollagen 3 in bronchoalveolar lavage fluid were comparable to controls, but these levels were significantly elevated in those with asbestos-associated alveolitis or asbestosis. This study documents that the measurement of levels of fibronectin and procollagen 3 in bronchoalveolar lavage fluid assesses fibrogenic activity of alveolitis and should be useful to predict its progression in a fibrotic process. In asbestos workers the potential use of these markers is primarily related to early detection of asbestos-induced pulmonary injury.