Ultrastructure of high altitude pulmonary oedema

Heath, D., Moosavi, H., and Smith, P. (1973).Thorax, 28, 694-700. Ultrastructure of high altitude pulmonary oedema. When rats are exposed for 12 hours to simulated high altitude corresponding to the summit of Mount Everest, they develop ultrastructural changes in the lungs. These consist of the formation and protrusion of multiple endothelial vesicles into the pulmonary capillaries. It seems likely that they are associated with the development of high altitude pulmonary oedema.     

Angiotensin converting enzyme in bronchoalveolar lavage fluid in pulmonary sarcoidosis.

Alveolar angiotensin converting enzyme (ACE) and serum ACE were measured simultaneously in 16 patients with histologically confirmed sarcoidosis and in 16 control subjects. Although alveolar ACE was abnormally elevated in all 15 cases of active sarcoidosis, serum ACE was not. No correlations were found between radiographic staging of pulmonary sarcoidosis and the levels of these enzymes. There was a clear correlation, however, between the levels of alveolar ACE and counts made on bronchoalveolar lavage fluid. This correlation was closer than that existing between serum ACE and bronchoalveolar lavaged lymphocytes. It is suggested that alveolar ACE is an additional biological marker of pulmonary sarcoidosis which is possibly more sensitive than serum ACE.     

Lipids in bronchoalveolar lavage fluid from patients with sarcoidosis

The recovery of protein and two specific surfactant lipids, phosphatidylcholine and phosphatidylglycerol, from bronchoalveolar lavage fluid is altered in chronic and acute non-granulomatous interstitial lung disease. This study set out to determine whether the same is true for patients with sarcoidosis. The median value for recovery of protein from lavage fluid was significantly higher in 21 patients with sarcoidosis than in 19 normal subjects (18 v 11 mg), while the median value for phospholipid recovery was significantly lower (4 v 1.7 mg). There were no changes in the proportions of phosphatidylcholine and phosphatidylglycerol. In addition, significantly less of the neutral lipid, cholesterol, was recovered (3.2 v 1.5 mg). The combined values of three biochemical measurements, non-phospholipid polar lipid, non-polar lipid, and protein, correctly classified all 40 subjects in our series; in a further group of nine normal subjects and 11 patients with sarcoidosis it allowed all but one normal subject to be classified correctly. These results are discussed in terms of alterations in epithelial cell function in interstitial disease.     

Granulocyte-colony stimulating factor levels in bronchoalveolar lavage fluid from patients with idiopathic pulmonary fibrosis

BACKGROUND: Granulocyte-colony stimulating factor (G-CSF) is known as a potent neutrophil chemotactic glycoprotein in vitro but its contribution to chemotactic activity in neutrophil mediated lung diseases is not yet known. The aims of this study were to determine whether G-CSF is present in high concentrations in bronchoalveolar lavage (BAL) fluid of patients with idiopathic pulmonary fibrosis (IPF, also called cryptogenic fibrosing alveolitis), a neutrophil mediated lung disease, and to what extent G-CSF in BAL fluid contributes to neutrophil accumulation in the lung of patients with IPF. METHODS: G-CSF concentrations in BAL fluid samples from 16 healthy volunteers, 24 patients with IPF, and 73 patients with non-IPF lung disease were measured by enzyme linked immunosorbent assay. The relationship between G-CSF concentrations and neutrophil count in BAL fluid was also examined. Neutrophil chemotactic activity (NCA) was measured in BAL fluid in healthy volunteers and patients with IPF. The contribution of G-CSF to overall NCA in lungs with IPF was assessed by repeating the measurement of NCA after a complete neutralisation of G-CSF bioactivity by anti-human G-CSF antiserum. RESULTS: Detectable levels of G-CSF were found in BAL fluid of 83% of patients with IPF while the levels in all healthy volunteers were below the detection limit. In patients with IPF a significant correlation was observed between the BAL fluid neutrophil count and the concentration of G-CSF in the BAL fluid. The neutrophil count also correlated significantly with percentage forced vital capacity. In BAL fluid samples from patients with IPF the mean NCA value was reduced by 35% after neutralisation with an anti-human G-CSF antiserum. CONCLUSIONS: G-CSF may be involved in enhancing neutrophil accumulation in the lungs of patients with IPF.     

Pneumococcal antigen detection in bronchoalveolar lavage fluid from patients with pneumonia.

BACKGROUND--Pneumococcal pneumonia can be diagnosed by the detection of capsular antigen in sputum, serum, pleural fluid, or urine using countercurrent immunoelectrophoresis and latex agglutination. In addition, quantitative cultures of bronchoalveolar lavage (BAL) fluid are also reliable for establishing the aetiology of pneumonia. This study investigated the value of rapid detection of pneumococcal antigen in BAL fluid from patients with pneumonia. METHODS--Pneumococcal antigen was detected by countercurrent immunoelectrophoresis and latex agglutination. Patients were grouped according to BAL quantitative culture results into pneumococcal pneumonia (n = 24), other known aetiology (n = 18), and unknown aetiology (n = 17). Thirteen patients with interstitial lung disease and without pneumonia served as a control group. RESULTS--In patients with pneumococcal pneumonia, antigen was detected by countercurrent immunoelectrophoresis in 50% and by latex agglutination in 54% of cases. In patients with pneumonia of unknown aetiology pneumococcal antigen was detected by latex agglutination in 53% of cases. Antigen was not detected in patients with pneumonia of other known aetiology or in control patients, yielding a specificity of 100%. CONCLUSIONS--In patients with pneumococcal pneumonia requiring fibreoptic bronchoscopy detection of pneumococcal antigen in BAL fluid may rapidly and accurately confirm the aetiology. Furthermore, in nearly half the cases of pneumonia of unknown aetiology antigen can be detected, suggesting that Streptococcus pneumoniae is a major causative agent in such patients.     

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.     

Hyaluronic acid in bronchoalveolar lavage fluid in patients with sarcoidosis: relationship to lavage mast cells.

Hyaluronate (hyaluronic acid), a potential marker for activated pulmonary fibroblasts, appears in increased concentrations in bronchoalveolar lavage fluid from patients with sarcoidosis. The mechanisms underlying fibroblast proliferation are largely unknown but activated alveolar T lymphocytes and macrophages probably play a part; the mast cell is also important for fibroblast proliferation. This study was designed to determine whether there is any association between pulmonary mast cells in lavage fluid, which are known to be increased in patients with sarcoidosis, and signs of pulmonary fibroblast activation. A strong correlation was found between lavage fluid hyaluronate and recovered mast cells (r = 0.72, p less than 0.001). Moreover, mast cell and hyaluronate estimations correlated inversely with lung volume and transfer factor for carbon monoxide, and both indices increased with advancing radiological sarcoid stage. Macrophage and granulocyte counts were normal in lavage fluid from patients with sarcoidosis and were not related to lavage fluid hyaluronate or laboratory signs of the disease in the lungs. Lymphocytes were recovered in increased numbers (p less than 0.001) and were related to the lavage fluid mast cells and hyaluronate. It is concluded that in sarcoidosis release of hyaluronate into the airways is related to the degree of lung disease and to the local inflammatory reaction in the lung as defined by increased numbers of mast cells and lymphocytes in lavage fluid. The findings may reflect a link between the immune system, activation of mast cells, and a pulmonary fibroblast proliferation.     

Alveolar haemorrhage in a case of high altitude pulmonary oedema

A case of high altitude pulmonary oedema (HAPE) in a climber who made a rapid ascent on Mt McKinley (Denali), Alaska is described. The bronchoalveolar lavage (BAL) fluid contained increased numbers of red blood cells and an abundance of haemosiderin laden macrophages consistent with alveolar haemorrhage. The timing of this finding indicates that alveolar haemorrhage began early during the ascent, well before the onset of symptoms. Although evidence of alveolar haemorrhage has been reported at necropsy in individuals dying of HAPE, previous reports have not shown the same abundance of haemosiderin laden macrophages in the BAL fluid. These findings suggest that alveolar haemorrhage is an early event in HAPE.     

Doppler assessment of hypoxic pulmonary vasoconstriction and susceptibility to high altitude pulmonary oedema.

BACKGROUND--Subjects with previous high altitude pulmonary oedema may have stronger than normal hypoxic pulmonary vasoconstriction. Susceptibility to high altitude pulmonary oedema may be detectable by echo Doppler assessment of the pulmonary vascular reactivity to breathing a hypoxic gas mixture at sea level. METHODS--The study included 20 healthy controls, seven subjects with a previous episode of high altitude pulmonary oedema, and nine who had successfully climbed to altitudes of 6000-8842 m during the 40th anniversary British expedition to Mount Everest. Echo Doppler measurements of pulmonary blood flow acceleration time (AT) and ejection time (ET), and of the peak velocity of the tricuspid regurgitation jet (TR), were obtained under normobaric conditions of normoxia (fraction of inspired oxygen, FIO2, 0.21), of hyperoxia (FIO2 1.0), and of hypoxia (FIO2 0.125). RESULTS--Hypoxia decreased AT/ET by mean (SE) 0.06 (0.01) in the control subjects, by 0.11 (0.01) in those susceptible to high altitude pulmonary oedema, and by 0.02 (0.02) in the successful high altitude climbers. Hypoxia increased TR in the three groups by 0.22 (0.06) (n = 14), 0.56 (0.13) (n = 5), and 0.18 (0.1) (n = 7) m/s, respectively. However, AT/ET and/or TR measurements outside the normal range, defined as mean +/- 2 SD of measurements obtained in the controls under hypoxia, were observed in only two of the subjects susceptible to high altitude pulmonary oedema and in five of the successful high altitude climbers. CONCLUSIONS--Pulmonary vascular reactivity to hypoxia is enhanced in subjects with previous high altitude pulmonary oedema and decreased in successful high altitude climbers. However, echo Doppler estimates of hypoxic pulmonary vaso-constriction at sea level cannot reliably identify subjects susceptible to high altitude pulmonary oedema or successful high altitude climbers from a normal control population.     

Gastrin levels in serum and bronchoalveolar lavage fluid of patients with lung cancer: comparison with patients with chronic obstructive pulmonary disease.

BACKGROUND: The gastrin gene is known to be expressed in all classes of bronchogenic carcinomas. Furthermore, high levels of gastrin have been reported in both the bronchoalveolar lavage (BAL) fluid and serum of patients with lung cancer. Based on these preliminary data a study was conducted to evaluate the usefulness of gastrin measurements in the diagnosis and staging of lung cancer. METHODS: Thirty-five patients with lung cancer (26 non-small cell (NSCLC) and nine small cell (SCLC)) and 25 patients with chronic obstructive pulmonary disease underwent fibreoptic bronchoscopy and BAL. Gastrin levels were determined in both BAL fluid and the serum and compared with each other and with staging. RESULTS: No difference was found between the gastrin levels in the BAL fluid or serum of the study groups. There was no correlation with the stage in NSCLC and no correlation was found between the gastrin levels in the serum and the BAL fluid. A significant difference was seen in gastrin levels in BAL fluid between extensive and limited SCLC (p < 0.05). CONCLUSION: There is no evidence of clinical usefulness for gastrin measurements in lung cancer.     

Beta-defensins and LL-37 in bronchoalveolar lavage fluid of patients with cystic fibrosis.

BACKGROUND: The antimicrobial peptides human beta-defensin 1 and 2 (hBD-1 and 2) and the cathelicidin LL-37/hCAP-18 are key factors in innate immune responses of the respiratory tract. The aim of this study was to determine the concentrations of these peptides in airway surface fluid of CF patients with mild lung disease. METHODS: We measured the concentrations of hBD-1, hBD-2, and LL-37 in bronchoalveolar lavage fluid of 20 patients (5-34 years) participating in the prospective BEAT-study (bronchoalveolar lavage for the evaluation of anti-inflammatory treatment) using an immuno-dot blot-assay. RESULTS: All three peptides could be detected in lavage fluid of the study population. Increased levels of inflammatory markers in bronchoalveolar lavage fluid were associated with elevated concentrations of LL-37/hCAP-18 (total cell count, P = 0.006; relative neutrophil count, P = 0.002). Deterioration of lung function, measured by MEF25 (maximal flow rate at 25% of residual forced vital capacity), correlated with decreased hBD-2 (P = 0.026), but increased LL-37/hCAP-18 concentrations (P = 0.016). CONCLUSIONS: The data suggest that concentrations of antimicrobial peptides are correlated with severity of CF lung disease: Levels of LL-37/hCAP-18 are associated with bronchial inflammation and, therefore disease severity, whereas decreased levels of beta-defensins in advanced lung disease likely contribute to a secondary defect of the local host defense.     

Pepsin concentrations are elevated in the bronchoalveolar lavage fluid of patients with idiopathic pulmonary fibrosis after lung transplantation

Background

Aspiration of gastroesophageal refluxate has been implicated in the pathogenesis of idiopathic pulmonary fibrosis (IPF) and the progression of bronchiolitis obliterans syndrome after lung transplantation. The goals of the present study were to identify lung transplant patients at the greatest risk of aspiration and to investigate the causative factors.

Materials and methods

From September 2009 to November 2011, 252 bronchoalveolar lavage fluid (BALF) samples were collected from 100 lung transplant patients. The BALF pepsin concentrations and the results of transbronchial biopsy, esophageal function testing, barium swallow, and gastric emptying scan were compared among those with the most common end-stage lung diseases requiring lung transplantation: IPF, chronic obstructive pulmonary disease, cystic fibrosis, and α₁-antitrypsin deficiency.

Results

Patients with IPF had higher BALF pepsin concentrations and a greater frequency of acute rejection than those with α₁-antitrypsin deficiency, cystic fibrosis, or chronic obstructive pulmonary disease (P = 0.037). Moreover, the BALF pepsin concentrations correlated negatively with a lower esophageal sphincter pressure and distal esophageal amplitude; negatively with distal esophageal amplitude and positively with total esophageal acid time, longest reflux episode, and DeMeester score in those with chronic obstructive pulmonary disease; and negatively with the upright acid clearance time in those with IPF.

Conclusions

Our results suggest that patients with IPF after lung transplantation are at increased risk of aspiration and a greater frequency of acute rejection episodes, and that the risk factors for aspiration might be different among those with the most common end-stage lung diseases who have undergone lung transplantation. These results support the role of evaluating the BALF for markers of aspiration in assessing lung transplant patients as candidates for antireflux surgery.     

Computed tomography-guided bronchoalveolar lavage in idiopathic pulmonary fibrosis.

BACKGROUND: High resolution computed tomography (HRCT) is now recognised as a sensitive tool for predicting the histological characteristics of the lung parenchymal abnormalities in patients with idiopathic pulmonary fibrosis (IPF). A reticular pattern on HRCT scanning is indicative of fibrotic histology while a ground glass pattern has been associated with inflammatory disease. The purpose of the present study was to investigate whether the cell population in the bronchoalveolar lavage (BAL) fluid from different lobes differs according to HRCT characteristics in patients with IPF. METHODS: Twenty six patients with IPF (18 men) of mean (SE) age 67 (2) years were included in the study. A semiquantitative analysis of the extent of the abnormalities on the HRCT scan was applied by summing the proportion of both reticular and ground glass patterns in each lobe (expressed as percentage of total area evaluated) and 100 ml double BAL was then randomly performed in the lobe with the most extensive involvement (lobe A) and that with the least extensive involvement (lobe B). RESULTS: Twenty three of the 26 patients (88%) had an abnormal cell count in the BAL fluid from lobe A compared with 18 patients (69%) with abnormalities in the BAL fluid from lobe B. The median (range) percentage of 8.5% (0-34%) and the absolute numbers of neutrophils (1.3 x 10(4)/ml, 0-14.6 x 10(4)/ml) in lobe A were significantly higher than those in lobe B (5% (0-26%) and 1.2 x 10(4)/ml (0-5 x 10(4)/ml), respectively). The percentage (3%, 0-19%) and absolute numbers (0.65 x 10(4)/ml, 0-4 x 10(4)/ml (0-4.8 x 10(4)/ml), respectively). For the group as a whole a correlation was found between the percentage and absolute numbers of neutrophils in the BAL fluid and the total score of abnormalities on the HRCT scan in the most involved lobe (lobe A). Multiple regression analysis indicated that both the percentage and absolute numbers of neutrophils were significantly and independently related to the extent of ground glass pattern. CONCLUSIONS: In patients with IPF the cell population in the BAL fluid is not homogeneous and seems to be related to the characteristics of the abnormalities on the HRCT scan present in the lavaged lobe.     

Lymphocyte fluctuation in bronchoalveolar lavage fluid in normal volunteers.

In an attempt to understand the widely varying bronchoalveolar lavage lymphocyte counts reported in normal subjects, we performed bronchoalveolar lavage in 42 healthy nonsmokers. The mean (SD) lymphocyte percentage in this first lavage was 9.6% (7.7%). The values did not fit a normal distribution. Five subjects had more than 20% of lymphocytes, and when they were excluded the distribution of lymphocyte counts was normal. Bronchoalveolar lavage was repeated once or twice in these five subjects 47 days or more after the previous lavage and the lymphocyte count decreased below 14% in four. Eight volunteers with an initial lymphocyte percentage less than 20% also had repeat lavages; two presented a transient increase of lymphocyte count above 20%. These data show that the percentage of lymphocytes in lavage fluid fluctuates significantly in normal subjects and suggest that lymphocyte counts counts higher than 14% should not be considered as normal.     

Hyaluronan and type III procollagen peptide concentrations in bronchoalveolar lavage fluid in idiopathic pulmonary fibrosis.

The connective tissue components hyaluronan (hyaluronic acid) and type III procollagen peptide were measured in bronchoalveolar lavage fluid in 22 patients with idiopathic pulmonary fibrosis and 21 healthy control subjects. The patients with idiopathic pulmonary fibrosis had higher concentrations of hyaluronan (median 46 micrograms/l) and type III procollagen peptide (median 0.45 micrograms/l) than the healthy controls (9 and less than 0.02 micrograms/l; p less than 0.001). The patients had normal serum concentrations of hyaluronan and of the procollagen peptide, and albumin concentrations in lavage fluid similar to those of the control subjects. Neutrophil and lymphocyte counts in lavage fluid were increased on average 10 and two fold respectively in the patients with idiopathic pulmonary fibrosis and both correlated with the amount of hyaluronan recovered (p less than 0.05). An inverse correlation was seen between the transfer factor for carbon monoxide and hyaluronan concentrations in lavage fluid in the patients (p less than 0.05). Deterioration in lung function and radiographic progression were seen over six months in 12 of the patients. These patients had higher lavage fluid concentrations of hyaluronan and type III procollagen peptide than the patients whose disease was stable (p less than 0.01). Increased synthesis of hyaluronan and type III procollagen peptide in lung parenchyma may reflect activation or proliferation (or both) of pulmonary fibroblasts in idiopathic pulmonary fibrosis and seems to be linked to the severity and activity of the lung disease.     

Fibroblast chemotactic response elicited by native bronchoalveolar lavage fluid from patients with fibrosing alveolitis.

BACKGROUND--In fibrosing alveolitis activation of lung fibroblasts is the decisive event in the pathogenetic sequence leading to pulmonary fibrosis. Fibroblast stimulating activity was measured in bronchoalveolar lavage (BAL) fluid to assess its relationship to the activity of fibrosing alveolitis. METHODS--Nine control subjects and 40 patients with fibrosing alveolitis caused by idiopathic pulmonary fibrosis (n = 22) or pulmonary involvement in systemic sclerosis (n = 18) were studied. All patients were followed up by lung function testing for a minimum of six months (mean (SE) 13.3 (1.4) months). Twenty five patients received immunosuppressive therapy and 15 refused. At the beginning of follow up BAL was performed and, as a possible indicator of fibroblast stimulating mediators within the lungs, chemotactic migration of cultured human fibroblasts elicited by native BAL fluid was measured in Boyden-type chambers and expressed as a percentage of the chemoattractant effect of 25 ng/ml platelet derived growth factor. The procollagen III peptide level in BAL fluid served as a marker for collagen synthesis. RESULTS--Chemoattractant activity was elevated in the patients with idiopathic pulmonary fibrosis and systemic sclerosis compared with the control group, (mean (SE) 56.4% (8.5%)) and 72.3% (16.3%) v 12.6% (4.0%). Chemoattractant activity was inversely correlated with total lung capacity (TLC) (r = -0.45) and with vital capacity (VC) (r = -0.33). Procollagen III peptide concentrations in BAL fluid and chemoattractant activity were not significantly correlated. For further evaluation chemoattractant activity of 36% (mean value of controls +2 SD) was used to separate normal (< 36%) from elevated (> or = 36%) activity. At the end of follow up, untreated patients with high chemoattractant activity (> or = 36%) showed a significant reduction of VC, TLC, and exercise arterial oxygen tension (PaO2) and a small decrease in carbon monoxide transfer factor (TLCO), whereas a significant improvement in VC, TLC, and TLCO and a small increase of exercise PaO2 occurred in treated patients with high chemoattractant activity. Patients with low chemoattractant activity (< 36%) showed no consistent change in lung function measurements, irrespective of treatment. In contrast, lung function results and differential cell counts in BAL fluid failed to identify progressive disease. CONCLUSIONS--In patients with fibrosing alveolitis the chemoattractant activity of BAL fluid seems to be an independent indicator of lung fibroblast stimulating activity providing relevant information about disease activity, and may help to improve the clinical management of these patients.