Biomedical subjects

A M Southcott

Publications and source records attributed to A M Southcott.

18 recordsLinked to original sources

PubMed2001

Tumour necrosis factor-alpha production in fibrosing alveolitis is macrophage subset specific.

BACKGROUND: Previous studies have revealed that tumour necrosis factor (TNF)-alpha is upregulated in fibrosing alveolitis (FA) in humans. The aim of this study was to compare the TNF-alpha secretory profile of alveolar macrophages (AMs) and peripheral blood monocytes (Mos) of patients with cryptogenic FA and systemic sclerosis (SSc), a rheumatological disorder in which lung fibrosis can occur. In particular, we wished to assess whether TNF-alpha levels differ between SSc patients with FA (FASSc) and a nonfibrotic group. METHODS: The reverse haemolytic plaque assay was used to evaluate the secretion of cytokine at a single cell level while immunostaining allowed subtyping of AMs and Mos. RESULTS: This study demonstrated a difference in total TNF-alpha levels produced by AMs when the levels in subjects with FA (cryptogenic FA and FASSc) were compared to levels in either SSc patients without FA (P = 0.0002) or normal healthy controls (P < 0.001). In addition, AMs from patients with FASSc secreted more TNF-alpha than those of patients with no FA (P = 0.003). In contrast, there were no significant differences in Mo TNF-alpha secretion between the groups. A positive correlation was found between total TNF-alpha level and number of neutrophils obtained by bronchoalveolar lavage from patients with FA (r = 0.49, P < 0.04). Finally, it was demonstrated that there was significant heterogeneity of TNF-alpha secretion and that a numerically significant subset of mononuclear phagocytes, RFD7, was responsible for more than 80% of TNF-alpha production. CONCLUSION: By demonstrating the primary cell source of TNF-alpha in FASSc, more accurately targeted, possibly localized, anti-TNF strategies might be employed with success in the future.

Animals↗

PubMed2001

Increased effective lung volume following lung volume reduction surgery in emphysema.

STUDY OBJECTIVES: Lung volume reduction surgery (LVRS) for emphysema has a variable effect on spirometry with improvement linked to increases in lung elastic recoil. The mechanism by which recoil increases following LVRS has not been described completely. This study examines preoperative and postoperative pulmonary function to describe a mechanism for changes in airflow obstruction. DESIGN: Change in pulmonary function following LVRS. Setting : Public teaching hospital in Australia. PATIENTS: Patients with severe emphysema and pulmonary function measurements made before and after LVRS. MEASUREMENTS: Routine pulmonary function testing performed with ventilated lung alveolar volume (VA) derived from the gas transfer measurement used as a proxy for the effective lung volume. RESULTS: Pulmonary function tests from 36 consecutive patients with measurements made at the same laboratory were analyzed. The mean FEV(1) was 29.1% predicted presurgery and increased following LVRS from 0.900 L (SD, 0.427 L) to 1.283 L (SD, 0.511 L; p < 0.0001) and TLC (143% predicted) decreased from 8.19 L (SD, 1.492 L) to 7.07 L (SD, 1.52 L; p < 0.0001; n = 35). The mean VA increased by 0.674 L (SD, 0.733 L) from 4.04 to 4.72 L (p < 0.0001; n = 34). The change in FEV(1) correlated well with the change in VA (r = 0.63). The change in FEV(1) in those patients whose VAs did not increase (n = 7) was not significant. CONCLUSIONS: The increase in VA reflects an increase of functional or ventilating lung volume and is associated with an improvement in spirometry following LVRS.

Aged↗

PubMed2000

Multiple respiratory symptoms predict quality of life in chronic lung disease: a population-based study of Australian adults.

STUDY OBJECTIVES: Previous studies have shown that it is possible to improve the health-related quality of life (HRQoL) of chronic lung disease (CLD) patients without a concurrent change in morbidity. A valid CLD index that discriminates between different levels of CLD severity and is associated with HRQoL status is an important tool for primary care settings. In this study a symptom-based CLD index was assessed for its validity and relationship with HRQoL in a representative Australian population sample. The study also measured the prevalence of self-reported CLD. DESIGN: Representative population survey of adults aged 18 years and over using a multistage, systematic, clustered area sample. SETTING: Metropolitan Adelaide and country centres in South Australia with a population of over 1000 persons. PARTICIPANTS: Three hundred twenty-nine adults with CLD identified through a representative population survey of 3010 South Australians. MEASUREMENTS AND RESULTS: The CLD index and the SF-36 were administered to participants to assess the association between each subscale of the CLD index with each HRQoL scale. The CLD index was also used to assess the prevalence of CLD and the distribution of severity in self-reported CLD in the South Australian population. Each symptom sub-scale of the CLD index was significantly correlated with all scales of the SF-36. The prevalence of CLD as measured by the CLD index was 7.7% (mild), 2.2% (moderate) and 1.0% (severe). CONCLUSIONS: In the Australian context the CLD index is a reliable patient interview instrument that can be used to assess the effects of CLD on general HRQoL, improve assessment, and lead to interventions for physicians and their patients.

Adolescent↗

PubMed2000

Videoscopic lung volume reduction surgery in an Australian public teaching hospital.

BACKGROUND: Lung volume reduction surgery (LVRS) has been a frequent literature topic in emphysema management recently. Opinions differ in regard to usefulness, efficacy, and selection criteria. AIMS: To present the results of our first 55 bilateral videoscopically resected group, with follow-up of up to three years, and to present some of the local methodology problems faced. METHODS: Thirty-nine men and 16 women, age range 40-77, had either upper lobe (42), mixed (two), or lower lobe (11) resections without buttressing (except for unilateral buttressing in several of the latter patients as part of an intrapatient comparison trial) according to their pattern of emphysema determined by CT and perfusion scanning. RESULTS: Thirty day mortality was 5.5%. Follow-up pulmonary function is available for 44 patients, and demonstrates a mean 51% improvement in FEV1, and significant improvement in FVC, PaO2, dyspnoea indices and walking distance, with a reduction in mean RV, TLC, PaCO2. FEV1 improvement is maintained above baseline at three years. Lower lobe surgery outcomes are at least as good as their upper lobe counterparts. CONCLUSIONS: Outcomes confirm improvements reported elsewhere, and suggest that videoscopic resection may provide worthwhile benefit to lower lobe patterns of emphysema. Other managment issues are discussed.

Activities of Daily Living↗

PubMed1999

A South Australian population survey of the ownership of asthma action plans.

OBJECTIVE: To examine the relationships between ownership of written asthma action plans, asthma morbidity, use of devices, and patients' perceptions of their asthma management. DESIGN AND SETTING: A random population survey (in 1996) of the South Australian population aged 15 years or over, using interviewers to administer a questionnaire. PARTICIPANTS: People who reported that they had current, doctor-diagnosed asthma. MAIN OUTCOME MEASURES: Prevalence of written asthma action plans; night-time awakenings from asthma; ownership of peak flow meters; and people's perceptions of their asthma management. RESULTS: The ownership of asthma action plans by people with self-reported asthma was 33% and has declined since 1995 (42%; P < 0.001). Fifteen per cent were awakened weekly or more frequently by asthma symptoms. These people were more likely to have a peak flow meter and a written action plan, but less likely to consider they had been provided with enough information about their asthma, to feel comfortable managing their asthma, or to find it easy to see their doctor. Having a written asthma action plan was associated with regular corticosteroid use, understanding asthma, having enough information and owning a peak flow meter. CONCLUSIONS: Ownership of asthma action plans in South Australia is suboptimal. Before we develop new strategies to improve asthma outcomes, we must determine whether there is a need to target people with less severe asthma and/or improve the use of guidelines by health professionals.

Asthma↗

PubMed1999

T-cell receptor gene usage in patients with fibrosing alveolitis and control subjects.

BACKGROUND: Fibrosing alveolitis is characterized by inflammation, fibrosis and increased numbers of activated CD4+ T-cells in the lower respiratory tract. The aims of this study were to compare the T-cell antigen receptor repertoire in the lungs of subjects with fibrosing alveolitis systemic sclerosis (FASSc) with cryptogenic fibrosing alveolitis (CFA) and normal control subjects, to determine whether FASSc is driven by a specific T-cell trigger and is determined by a T-cell driven immune response, and to assess the clonality of CD4+ and CD8+ TcR usage in subjects with FASSc. MATERIALS AND METHODS: We used reverse transcription polymerase chain reaction with specific V alpha- and V beta-chain primers to identify the TcR gene usage in biopsy material, bronchoalveolar lavage fluid or peripheral blood from our subjects. RESULTS: We found individual-specific restriction of V alpha- and V beta-chain usage in lung biopsies from patients and control subjects. To establish whether this was due to expression bias in the CD4+ or CD8+ T-cells and was restricted to the lung, the alpha beta-T-cell receptor chain usage was assessed in T-cell subsets separated from the lungs of patients with fibrosing alveolitis and was compared with that of the peripheral blood. There was no consistent difference in the expression of any variable family chain among the population studied, although there was a significant difference between lung and peripheral blood lymphocyte V beta-families in CD8+ T-cells (P = 0.0007). CONCLUSION: We conclude that there is individual TcR V alpha- and V beta-expression bias in subjects with fibrosing alveolitis.

Adult↗

PubMed1999

The effect of a respiratory home nurse intervention in patients with chronic obstructive pulmonary disease (COPD).

BACKGROUND: Chronic obstructive pulmomary disease (COPD) is associated with substantial mortality, morbidity, and costs to the health care system. With the increasing interest in outreach care programmes it is important to evaluate their impact upon patients and health services, for conditions such as COPD. AIM: To determine the effectiveness of an outreach respiratory nurse in a shared care approach, with collaboration between general practitioners and hospital services, in the management of patients with severe COPD. METHODS: Patients with severe COPD attending The Queen Elizabeth Hospital, Adelaide participated in a randomised controlled trial of a home based nursing intervention (HBNI) over 12 months with outcome measures including mortality rate, hospital service utilisation, FEV1 and health related quality of life (HRQL) using a modified Dartmouth Primary Care Co-operative Quality of Life questionnaire. RESULTS: There were 48 subjects in each study arm, with no differences in mortality rate (eight deaths in the HBNI group and seven in the control group), hospital admissions, length of stay, number of outpatient and Emergency Service visits. The study had inadequate follow-up of FEV1 and HRQL within the control group. Within the HBNI group, a small improvement in HRQL (in three of ten indices measured) was demonstrated, despite a deterioration in FEV1 (11% reduction, p=0.04) compared to baseline. Quality of life of HBNI subjects' carers did not change. CONCLUSION: An increased level of care given by an outreach respiratory nurse in a shared care approach for patients with severe COPD produced small improvements in HRQL but did not result in the prevention of deaths or reduced health care utilisation.

Aged↗

PubMed1999

Randomized trial of inhaled fluticasone propionate in chronic stable pulmonary sarcoidosis: a pilot study.

Pulmonary sarcoidosis is a disease in which the pathological processes are distributed along lymphatic pathways, particularly those around the bronchovascular bundles. Delivery of disease-modulating drugs by the inhaled route is therefore an attractive option. The aim of this study was to determine the efficacy of inhaled fluticasone propionate 2 mg x day(-1) in adults with stable pulmonary sarcoidosis. Forty-four adult patients (22 from each centre) were enrolled from outpatient clinics in two London teaching hospitals in a two centre, double-blind, randomized, placebo-controlled trial. Primary end points were home recordings of peak expiratory flow rate (PEFR), forced expiratory volume in one second (FEV1), and forced vital capacity (FVC). Secondary end points were symptom scores, use of rescue bronchodilator medication, and clinic values for PEFR, FEV1, FVC, forced mid-expiratory flow (FEF25-75%), diffusion capacity of the lung for carbon monoxide (DL,CO), and total lung capacity (TLC). Symptom scores of cough, breathlessness and wheeze were lower in the active treatment group, but this did not reach statistical significance, and a general health perception assessment (Short Form (SF)-36) showed a difference between active and placebo treatment. No significant differences were found between the two groups in any physiological outcome measure. No new adverse reactions were detected. The results of this pilot study do not show an objective benefit of inhaled fluticasone propionate in pulmonary sarcoidosis where the disease is stable and is controlled without the use of inhaled corticosteroids.

Administration, Inhalation↗

PubMed1998

Adhesion molecule expression in the lung: a comparison between normal and diffuse interstitial lung disease.

Cellular adhesion molecules are crucial determinants of the migration of immune effector cells to the tissues. In chronic inflammatory diseases, upregulation of the expression of these molecules may contribute to the persistent inflammatory process. The aim of this study was to determine whether there is evidence of adhesion molecule expression in chronically inflamed lung. Soluble adhesion molecules in bronchoalveolar lavage fluid (BALF) were measured by enzyme-linked immunoassay in 54 patients with chronic interstitial lung diseases and 16 normal controls. Adhesion molecule expression in fibrosing alveolitis (FA) lung and in control lung was assessed using immunohistology and reverse transcription-polymerase chain reaction (RT-PCR) amplification. Soluble intercellular adhesion molecule-1 (ICAM-1) was detected in all but two subjects. There was no difference in ICAM-1 concentration between disease groups and normal subjects. In contrast, soluble E-selectin was detected in 17 of the 70 subjects and was significantly associated with the presence of lung disease (p=0.0173). Furthermore, the presence of soluble E-selectin was associated with a raised lymphocyte percentage in BALF (p=0.0069). Soluble VCAM was only detected in five of the 70 subjects (two normals, three patients). There was no difference in adhesion molecule expression in lung parenchyma between FA and controls assessed by immunohistology and RT-PCR. The most striking finding of our study was the universal expression of intercellular adhesion molecule-1 in both normal and diseased lung, emphasizing the important role of the lung in immune function. Upregulation of E-selectin may contribute to inflammatory cell accumulation in chronic interstitial lung diseases.

Adolescent↗

PubMed1997

Up-regulation of IL-8 secretion by alveolar macrophages from patients with fibrosing alveolitis: a subpopulation analysis.

Neutrophil accumulation in the lower respiratory tract of patients with fibrosing alveolitis is thought to be facilitated by IL-8, a neutrophil chemoattractant primarily secreted by mononuclear phagocytes. The aims of this study were: (i) to explore IL-8 secretion by lung and blood mononuclear phagocytes in subjects with cryptogenic fibrosing alveolitis, systemic sclerosis with and without fibrosing alveolitis, sarcoidosis and normal individuals; (ii) to examine IL-8 secretory heterogeneity in alveolar macrophages and peripheral blood monocytes; and (iii) to correlate alveolar macrophage phenotypic profile to IL-8 secretion. We observed that more monocytes secreted IL-8 than autologous macrophages and that there was heterogeneity in the in vitro IL-8 secretion by alveolar macrophages and peripheral blood monocytes. IL-8 secretion by alveolar macrophages was significantly higher in subjects with fibrosing alveolitis compared with subjects without fibrosing alveolitis, due to a higher percentage of IL-8-secreting alveolar macrophages in the fibrotic group both in the absence (P < 0.002) and presence of lipopolysaccharide (LPS) (P < 0.04) and correlated with bronchoalveolar lavage neutrophil percentage. Using the MoAbs RFD1, RFD7 and RFD9, that distinguish subsets of alveolar macrophages, we have been able to identify associations between secretion of IL-8 and smaller cells and the cells identified by the MoAb RFD7. In situ hybridization of the bronchoalveolar lavage cell population revealed that alveolar macrophages are the predominant source of IL-8 in the lung. We conclude that there is an increased number of IL-8-secreting alveolar macrophages in the lungs of patients with fibrosing alveolitis, and IL-8 secretion by these cells is associated with specific phenotypic profile expression.

Adult↗

PubMed1997

The source and role of RANTES in interstitial lung disease.

The chemokine "regulated on activation, normal T-cell expressed and secreted" (RANTES) is a potent eosinophil and lymphocyte attractant with particular preference for CD45RO+ T-cells and eosinophils. These cells accumulate in the lungs of patients with sarcoidosis and fibrosing alveolitis. The purpose of this study was to determine whether RANTES mediates the inflammatory cell influx in these diffuse lung diseases. Cell types and number of bronchoalveolar cells expressing RANTES protein were investigated by immunocytochemistry using lavage cells obtained from 22 patients and 11 control subjects. Subsequently, RANTES messenger ribonucleic acid (mRNA) was semiquantitated using reverse transcription polymerase chain reaction (RT-PCR) methodology in unseparated lavage cell pellets in 26 patients and 13 control subjects. Cells expressing RANTES mRNA were identified by in situ hybridization. RANTES protein expression in lower respiratory tract (LRT) cells was identified in all study groups. The percentage of RANTES+ lavage cells in sarcoidosis was higher than in controls. RANTES was localized in the cytoplasm, mainly in alveolar macrophages (CD68+ cells) in sarcoidosis, and both in alveolar macrophages and eosinophils in fibrosing alveolitis. The same cell types which expressed RANTES protein expressed RANTES mRNA, as assessed by in situ hybridization. Sarcoidosis patients had higher levels of RANTES mRNA than the other groups. RANTES protein was higher in individuals with abnormal lymphocyte numbers: RANTES protein and mRNA expression was significantly correlated with lavage CD45RO+ lymphocyte numbers. These results indicate that RANTES may mediate T-lymphocyte influx in diffuse lung disease, particularly sarcoidosis. Moreover, they suggest that the cellular source of RANTES is the alveolar macrophage in sarcoidosis, and both macrophages and eosinophils in fibrosing alveolitis.

Bronchoalveolar Lavage Fluid↗

PubMed1996

HLA-DPB polymorphisms: Glu 69 association with sarcoidosis.

Sarcoidosis is a chronic granulomatous disorder, which is characterized by the accumulation of activated CD4+ T lymphocytes (T cells) at disease sites. There is up-regulation of cell surface expression of MHC molecules in sarcoidosis, and it has been suggested that specific MHC class II alleles are associated with the disease. A study of chronic beryllium disease (CBD), a granulomatous disorder which is pathologically similar to sarcoidosis, has identified an association between this disease and the presence of a glutamine residue at position 69 (Glu 69+) of the B1 chain of the HLA-DPB molecule. A further study also suggested the importance of Glu at position 55 of the same chain. The aims of the present study were to attempt to define MHC class II alleles associated with sarcoidosis by comparison of their frequency in two groups of subjects and to compare the frequency of HLA-DPB1 Glu 69+/- and Glu 55+/-alleles in the same subjects. Forty-one subjects with sarcoidosis and 76 normal subjects were studied. The polymorphic regions of the class II MHC were identified by PCR in association with sequence-specific oligonucleotide probes. There were no significant differences in the phenotype frequencies of MHC class II or Glu 55+ alleles between the two groups of subjects. However, there was a significant increase (P = 0.02) in the frequency of HLA-DPB1* Glu 69+ alleles compared with the control population. We therefore suggest that the presence of a Glu residue at position 69 on the DPB1 chain may play an important role in antigen presentation and recognition in chronic granulomatous diseases.

Alleles↗

PubMed1996

Neutrophil activation in fibrosing alveolitis: a comparison of lone cryptogenic fibrosing alveolitis and systemic sclerosis.

Fibrosing alveolitis complicating systemic sclerosis (FASSc) carries a better prognosis than lone cryptogenic fibrosing alveolitis (CFA). We wanted to determine whether this improved prognosis is associated with differential neutrophil migration and activation in the lower respiratory tract. We therefore compared bronchoalveolar lavage (BAL) neutrophil numbers and levels of neutrophil-derived enzymes in FASSc, CFA and normal individuals. Bronchoalveolar lavage was performed on 45 subjects (FASSc n = 20; CFA n = 15; normals n = 10); cell counts and levels of neutrophil-derived enzymes, myeloperoxidase, elastase (total elastase and elastase/alpha 1 antitrypsin complexes), collagenase and lactoferrin were measured. Lung function testing was performed in subjects with fibrosing alveolitis. Significant differences in the levels of collagenase, myeloperoxidase and elastase/ alpha 1-antitrypsin complexes were present in the BAL fluid from the three groups. Patients with CFA had significantly higher neutrophil percentages and levels of collagenase and myeloperoxidase than those with FASSc. Disease extent, as judged by lung volumes and gas transfer, was comparable in the CFA and FASSc groups. Forced vital capacity (% predicted) was significantly lower in patients with evidence of increased neutrophil enzyme release than those without. We conclude that: 1) increased neutrophil migration to the lung is accompanied by release both of primary and secondary granule enzymes in cryptogenic fibrosing alveolitis; and 2) the lower amounts of neutrophil products in fibrosing alveolitis complicating systemic sclerosis may account for the improved prognosis, even when disease is as extensive as in cryptogenic fibrosing alveolitis.

Adult↗

PubMed1995

Role of thrombin in pulmonary fibrosis.

Pulmonary fibrosis commonly develops in systemic sclerosis. We assessed the role of thrombin in promoting fibroblast proliferation in the lungs in this disorder. Bronchoalveolar lavage fluid (BALF) thrombin concentrations were higher in ten patients with systemic sclerosis than in 12 healthy controls (14.6 vs 3.6 nmol/L, p < 0.02), but values in patients with cryptogenic fibrosing alveolitis (n = 10) or sarcoidosis (n = 10) were not increased. BALF from all patients induced fibroblast proliferation. This proliferation was attenuated by thrombin inhibitors for BALF from systemic sclerosis patients only. We suggest thrombin contributes to lung fibroblast proliferation in this disorder.

Alveolitis, Extrinsic Allergic↗

PubMed1995

Interleukin-8. Differential expression in lone fibrosing alveolitis and systemic sclerosis.

Fibrosing alveolitis may occur alone (CFA) or in association with systemic sclerosis (FASSc). FASSc was recently shown to have a prognostic advantage over CFA. Because interleukin-8 (IL-8) is likely to be a major determinant of neutrophil alveolitis, we evaluated IL-8 expression in patients with CFA and FASSc and compared it with that in normal individuals and sarcoidosis and systemic sclerosis patients without pulmonary involvement (SSc no FA). IL-8 protein in bronchoalveolar lavage fluid (BALF) was assessed by immunoassay, and IL-8 mRNA expression was assessed using Northern analysis and reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization of lung parenchyma. Compared with normal subjects, IL-8 concentration was significantly greater in both CFA (p < 0.001) and FASSc groups (p < 0.05) but no different in sarcoidosis. The IL-8 concentration in CFA was higher than in FASSc (p < 0.01) and was related to BAL % neutrophils (rs = 0.48, p < 0.01). IL-8 mRNA expression evaluated by Northern analysis was seen only in patients with CFA and FASSc and was related to BAL % neutrophils (rs = 0.63, p < 0.01). We suggest that IL-8 is a key factor in the pathogenesis of fibrosing alveolitis and that the poorer prognosis of CFA compared with FASSc is related to higher levels of IL-8 within the lower respiratory tract.

Adult↗

PubMed1994

Insulin-like growth factor-I is partially responsible for fibroblast proliferation induced by bronchoalveolar lavage fluid from patients with systemic sclerosis.

1. Interstitial lung disease is a common complication of systemic sclerosis. The mechanism by which excess collagen is deposited in the lung is poorly understood, but is thought to involve release of mediators which activate lung fibroblasts. In this study we investigated and partially characterized the fibroblast proliferative activity of bronchoalveolar lavage fluid from 29 patients with systemic sclerosis, 19 with and 10 without evidence of lung disease assessed by thin-section computed tomography. 2. Bronchoalveolar lavage fluid from both groups of patients stimulated fibroblast proliferation compared with control subjects: systemic sclerosis with normal computed tomography, 27.7 (range 10.5-57.9)% above control; systemic sclerosis with abnormal computed tomography, 26.7 (range 5.0-47.8)% above control, P < 0.02 in both cases. 3. The activity was reduced by about one-third by neutralizing antibodies to insulin-like growth factor-1 but not platelet-derived growth factor. Levels of insulin-like growth factor-1 of bronchoalveolar fluid were increased in patients with systemic sclerosis [2.10 (range 1.10-3.48) ng/ml of bronchoalveolar lavage fluid] compared with controls [1.45 (range 1.10-2.05) ng/ml; P < 0.01]. When patients were subdivided into those with abnormal computed tomography [2.10 (range 1.20-3.48) ng/ml] and those with normal computed tomography [1.85 (range 1.10-2.90) ng/ml] only the values for the group with evidence of lung disease were increased compared with control subjects (P < 0.02). Platelet-derived growth factor could not be detected in bronchoalveolar lavage fluid from any group. Fractionation of bronchoalveolar lavage fluid demonstrated activity in several fractions consistent with the molecular masses of insulin-like growth factor-1 associated with binding proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Activation of peripheral blood mononuclear cells in bronchoalveolar lavage fluid from patients with sarcoidosis: visualisation of single cell activation products.

BACKGROUND: Interstitial lung diseases are characterised by the recruitment of mononuclear cells to disease sites where maturation occurs and activation products, including lysozyme (LZM), are released. Analysis of in vitro cell culture supernatants for activation products masks the functional heterogeneity of cell populations. It is therefore necessary to examine the secretion of activation products by single cells to assess whether the activation of newly recruited mononuclear phagocytes at the sites of disease in the lung is uniform and controlled by the local microenvironment. METHODS: The reverse haemolytic plaque assay was used to evaluate, at a single cell level, the ability of bronchoalveolar lavage (BAL) fluid from seven patients with sarcoidosis to activate Ficoll-Hypaque-separated peripheral blood mononuclear cells by comparison with BAL fluid from six normal volunteers and nine patients with systemic sclerosis. Monolayers of peripheral blood mononuclear cells and sheep red blood cells were cultured either alone or in the presence of 20% (v/v) BAL fluid with a polyclonal anti-LZM antibody. LZM/anti-LZM complexes bound to red blood cells surrounding the secreting cells were disclosed following complement lysis of red blood cells and quantification of plaque dimensions using microscopy and image analysis. RESULTS: Bronchoalveolar lavage fluid from all the patients with sarcoidosis increased LZM secretion by peripheral blood mononuclear cells compared with unstimulated mononuclear cells. By contrast, BAL fluid from the other individuals had no effect on LZM secretion. CONCLUSIONS: Single cells activated by BAL fluid can be evaluated by the reverse haemolytic plaque assay. BAL fluid from patients with sarcoidosis, but not from patients with systemic sclerosis or normal individuals, contains components capable of activating mononuclear phagocytes to secrete lysozyme.

Adult↗

PubMed1994

Increased levels of endothelin-1 in bronchoalveolar lavage fluid from patients with systemic sclerosis contribute to fibroblast mitogenic activity in vitro.

Pulmonary fibrosis is a major cause of morbidity and mortality in patients with systemic sclerosis (SSc). The pathogenesis of this condition is poorly understood, but one of the earliest pathologic features is endothelial and epithelial cell injury with subsequent regeneration. Endothelial and epithelial cells can release several mediators, including endothelin-1 (ET-1). In this study, we investigated the levels of ET-1 in bronchoalveolar lavage fluid (BALF) from patients with SSc and assessed the contribution of ET-1 to the fibroblast mitogenic activity induced by these fluids. A total of 26 patients were evaluated and divided into those with evidence of pulmonary fibrosis, assessed by thin-section computed tomography (group I, n = 16), and those with a normal scan (group II, n = 10). BALF from both groups of patients stimulated fibroblast proliferation. Values expressed as median (range) percentage increase above media controls were 25.5% (5.0 to 47.8%) and 27.6% (10.9 to 51.6%) for groups I and II, respectively (P < 0.02 in both cases). Mitogenic activity was inhibited by about 40% in the presence of either a neutralizing antibody to ET-1 or two synthetic ET-1 receptor ligands. Levels of ET-1 in BALF, expressed as medians (range) were 2.90 ng/mg albumin (0.68 to 5.75) in patients with SSc and 1.23 ng/mg albumin (0.84 to 2.0) in control patients (P < 0.02). Furthermore, ET-1 levels in BALF from patients in group II (3.83 ng/mg albumin, range 1.76 to 5.75) were elevated compared with those in group I (2.62 ng/mg albumin, range 0.68 to 3.81; P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗