Asbestos bodies in bronchoalveolar lavage fluid and in lung parenchyma

Numerical concentrations of asbestos bodies (AB) were measured by light microscopy both in samples of bronchoalveolar lavage (BAL) fluid and in samples of lung parenchyma from 69 patients with suspected asbestos-related diseases who had had lavages and later open lung biopsies or autopsies. Objectives were to study the recovery of pulmonary AB by BAL and the ability of BAL concentrations to predict parenchymal concentrations. BAL and parenchymal concentrations were both spread over 6 orders of magnitude and were positively correlated (r = 0.74 between logarithmic values). It is believed that, by a process of progressive elution, AB firmly adherent to the alveolar wall become suspended in BAL fluid; such suspended bodies represent roughly 2% of all the bodies stored in the portion of lung lavaged. Recovery is associated with great interindividual variations. When a measured BAL concentration exceeds 1 AB/ml, it can be quite confidently predicted, however, that the parenchymal concentration is in excess of 1,000 AB/g and that the patient has experienced a nontrivial asbestos exposure.     

Localized pulmonary neutrophil influx induced by lung lavage in sheep

The kinetics and distribution of neutrophil (PMN) influx into lung air spaces subsequent to bronchoalveolar lavage (BAL) were studied in adult sheep. The concentration of PMNs in BAL fluid peaked at 6 h and remained elevated for 48 h after the initial lavage. The response was observed primarily in the lung segment originally lavaged although minor changes were seen in BAL from immediately adjacent regions. No response was observed in the contralateral lung. Except for a transient decrease in pulmonary alveolar macrophages and monocytes at 6 h, changes in mononuclear cell populations (pulmonary alveolar macrophages, monocytes and lymphocytes) were minimal.     

Cellular and noncellular components of bronchoalveolar lavage fluid in HIV-1-infected children with radiological evidence of interstitial lung damage

Children with acquired immune deficiency syndrome (AIDS) commonly have recurrent infectious and noninfectious lung complications that ultimately end in death. To study the intensity of alveolar inflammation and to evaluate the clinical utility of bronchoalveolar lavage (BAL) in children with HIV-1 infections, we retrospectively analyzed differential cell counts, lymphocyte subsets, and fibronectin and hyaluronic acid concentrations in BAL fluid of 18 HIV-1-positive children (9 boys, mean age 3.5 years, range 5 months-8 years) with radiological evidence of interstitial lung disease, and 19 control children who had undergone BAL for clinical indications not involving the lung parenchyma (13 boys, mean age 3 years, range 2 months-14 years). BAL fluid from 89% of the HIV-1 infected children showed CD8+ve lymphocytic alveolitis expressing HLA-DR, CD54, and CD 69 antigens. BAL fluid from HIV-infected patients typically contained markedly increased percentages and numbers of lymphocytes (P < 0.0001) and eosinophils (P < 0.04) and significantly higher concentrations of albumin (P < 0.05) and fibronectin (P < 0.0006) than fluids from control children. Whereas BAL cellular components did not differ in P. carinii-positive and P. carinii-negative HIV-1-infected children, fibronectin concentrations were significantly higher in P. carinii-positive than negative children. BAL cell differentials and noncellular components were related neither to severity of disease nor to patients' disease progression. These findings indicate that BAL is useful in studying the intensity of lung inflammation in children with HIV-1 infections and radiologically documented interstitial lung disease, but provides no information on the subsequent clinical course.     

Differential production of metalloproteinases after instilling various urban air particle samples to rat lung

Lung injury and inflammation are associated with exposure to various types of particulate air pollutants. The present study was used to determine whether metalloproteinases (MMPs) are secreted after instilling dust samples into the lung, and to relate levels of specific MMPs to different fractions of the ambient air particle sample EHC-93. Rats received an intratracheal injection of 5 mg dust samples in 0.5 ml water and were killed at intervals from 4 hours to 28 days later particle samples were EHC-93 whole dust, and the insoluble, leached, and soluble fractions of the same dust. Samples prepared from EHC-2K dust were also used, as were solutions of zinc and copper chloride. All samples induced inflammation as measured by increased inflammatory cells in bronchoalveolar lavage (BAL) fluid; the highest levels were found 1 to 3 days after instilling the whole dust. This dust also induced production of MMP-2 and MMP-9 as shown in zymograms. The leached dust induced predominantly MMP-9, which was maximal at 4 hours and 1 day. In contrast, the soluble fraction induced almost exclusive 4 MMP-2, also maximal at 4 hours and 1 day; this enzyme was also produced in response to soluble zinc, the most prevalent soluble metal in the EHC samples. The results demonstrate the rapid production and secretion of MMPs in the lung after particle deposition. A differential pattern of MMP production is seen with MMP-9, likely from inflammatory cells, being produced in response to the insoluble particles, and MMP-2, likey from epithelial cells, being produced in response to the water-soluble fraction of the atmospheric dust.     

Association of 59iron oxide with alveolar macrophages during alveolar clearance

Long-Evans hooded rats were exposed for 2 h to aerosols of hydrated, radiolabeled iron (59Fe) oxide (MMAD = 1.6 micron; sigma g = 3.0) in order to produce a low mass burden of particles (approximately equal to 30 micrograms) in the lung. The kinetics of particle clearance and the association of the particles with alveolar macrophages (AM) were measured. Two to four hours after exposure, lavaged particles were linearly related to AM numbers harvested, and 60% of the 59Fe activity was physically associated with AM. By 24 h, greater than 90% of the lavaged particles were associated with AM. Such an association was found for at least 75% of the particulate burdens in the lungs. If all the 59Fe is assumed to be AM associated, the 59Fe per AM predicts the total AM population size to be 2.14 X 10(7) cells. This number, in conjunction with the alveolar clearance rate of the particles, suggested the number of AM leaving the lung daily was 2.8 X 10(5) cells.     

Volumetric loading of alveolar macrophages (AM): a possible basis for diminished AM-mediated particle clearance.

Using intratracheal instillation of radioactively labeled plastic microspheres of 3.3 and 10.3 microns diameter at two dose levels, this 7-month study in male Fischer 344 rats was designed to test a volumetric particulate burden hypothesis that has been proposed as a mechanistic basis for the condition of dust overloading of the lungs with highly insoluble particles of very low toxicity and to explain the prolongation of pulmonary particle retention. The study utilized airway and deep lung lavage techniques, scanning electron and optical microscopy of lavaged cells and lungs of sacrificed animals, particle distribution in alveolar macrophages (AM), fecal recovery of radioactive particles, and lung retention measurements by external counting. Microscopic assessments revealed that essentially all of the 3.3- and 10.3-microns-diameter particles were phagocytized by AM within 24 h postinstillation. One phagocytized 10.3-microns particle is capable of producing the hypothesized 600-microns 3/AM overload criterion for virtual AM immobilization. Neither the number nor the volume of 3.3-microns-diameter particles instilled was large enough to produce volumetric overloading assuming uniform distribution of the particles in the lung. In contrast to the 3.3-microns particles, the 10.3-microns particles were apparently sequestered to a greater extent and capable of greatly prolonging AM-mediated clearance of particles from the pulmonary region. The measured pulmonary retention half-times for the small and large particles were 86-109 days and 870-1020 days, respectively. Fecal recovery data closely complemented pulmonary clearance data for both particle sizes. The two-particle approach was found supportive of the volumetric overload hypothesis.     

Lung inflammation induced by concentrated ambient air particles is related to particle composition

The objectives of this study were (1) to determine whether short-term exposures to concentrated air particles (CAPs) cause pulmonary inflammation in normal rats and rats with chronic bronchitis (CB); (2) to identify the site within the lung parenchyma where CAPs-induced inflammation occurs; and (3) to characterize the component(s) of CAPs that is significantly associated with the development of the inflammatory reaction. Four groups of animals were studied: (1) air treated, filtered air exposed (air-sham); (2) sulfur dioxide treated (CB), filtered air exposed (CB-sham); (3) air treated, CAPs exposed (air-CAPs); and (4) sulfur dioxide treated, CAPs exposed (CB-CAPs). CB and normal rats were exposed by inhalation either to filtered air or CAPs during 3 consecutive days (5 hours/day). Pulmonary inflammation was assessed by bronchoalveolar lavage (BAL) and by measuring the numerical density of neutrophils (Nn) in the alveolar walls at the bronchoalveolar junction and in more peripheral alveoli. CAPs (as a binary exposure term) and CAPs mass (in regression correlations) induced a significant increase in BAL neutrophils and in normal and CB animals. Nn in the lung tissue significantly increased with CAPs in normal animals only. Greater Nn was observed in the central compared with peripheral regions of the lung. A significant dose-dependent association was found between many CAPs components and BAL neutrophils or lymphocytes, but only vanadium and bromine concentrations had significant associations with both BAL neutrophils and Nn in CAPs-exposed groups analyzed together. Results demonstrate that short-term exposures to CAPs from Boston induce a significant inflammatory reaction in rat lungs, with this reaction influenced by particle composition.     

CD69 surface expression on human lung eosinophils after segmental allergen provocation.

CD69 expression on eosinophils is observed in asthma and has been proposed as a marker of eosinophil activation. The role of allergens in the in vivo regulation of CD69 expression on eosinophils, however, remains incompletely understood. It was therefore investigated whether CD69 expression on eosinophils can be induced by allergen provocation in vivo. Ten allergic asthmatics were studied by segmental allergen provocation. Two segments of the right and left lung were challenged with allergen or saline. CD69 expression was determined by flow cytometry and concentrations of interleukins were analysed by enzyme-linked immunosorbent assay in bronchoalveolar lavage (BAL) fluid. Expression of CD69 on BAL eosinophils in the segments lavaged 10 min following saline instillation (28.3+/-8.8 specific mean fluorescence (SMF)) was not significantly different to segments lavaged 10 min after allergen (80.2+/-21.8 SMF) and segments lavaged 18 h after saline challenge (87.2+/-23.3 SMF). However, CD69 expression on eosinophils increased significantly 18 h after allergen challenge (128.6+/-21.9 SMF, p<0.03) which was accompanied by elevated granulocyte-macrophage colony-stimulating factor (GM-CSF) concentrations (114.9+/-42.9 pg x mL(-1), p<0.05). CD69 expression on eosinophils and GM-CSF concentrations correlated 18 h following allergen provocation (r = 0.7, p<0.025). These results suggest that in allergic asthma there is an allergen dependent, endobronchial upregulation of eosinophil activation as assessed by CD69 expression on eosinophils.     

Translocation of particles to the tracheobronchial lymph nodes after lung deposition: kinetics and particle-cell relationships

One of the pathways for particle clearance from the lung involves the translocation of particles from the alveoli to the tracheobronchial lymph nodes. Details of the mechanisms involved in this translocation process have not been well delineated. In the present study, we: assessed the kinetics of particle transfer to the tracheobronchial lymph nodes in the rat over a 30-day period following the intrapulmonary deposition of 4 X 10(8), 1.9 micron, fluorescent polystyrene microspheres; utilized multiparameter flow cytometric technology to quantitatively differentiate between "free" and cell-associated particles that accumulated in the lymph nodes; and assessed the role of alveolar macrophages (AM) in carrying particles to the lymph nodes by comparing the distributions of particles in lavaged AM with distributions of particles found in nodal mononuclear phagocytes (NMP). The accumulation of particles, most of which were extracellular, in the nodes was biphasic with the most rapid phase occurring within the first 24 hr. Over the Day 1-30 period, the numbers of particles in the lymph nodes increased linearly to approximately equal to 1.2 X 10(6) microspheres, or approximately equal to 0.3% of the originally instilled lung burden. The percentages of the nodal particles that were associated with NMP over the course of the study were inversely proportional to nodal particulate burdens, even though the percentage of cells with engulfed particles increased; the percentage of NMP asymptotically approached a maximum value over the range of nodal burdens of 6-12 X 10(5) particles. The distributions of the microspheres in the NMP were essentially identical on Days 1, 14, and 30. Major differences in the distributions of particles in lavaged AM and NMP were not consistent with the notion that the latter represented translocated AM.     

Regional differences in bronchoalveolar lavage and thoracic high-resolution computed tomography results in dyspneic patients with systemic sclerosis

OBJECTIVE: Interstitial lung disease (ILD) is the leading cause of death in systemic sclerosis (SSc). Although early identification and treatment of alveolitis may prevent deterioration of lung function, the best approach for diagnosing active alveolitis remains controversial. This study was undertaken to investigate the utility of high-resolution computed tomography (HRCT) of the chest, in comparison with bronchoalveolar lavage (BAL), in the diagnosis of alveolitis in these patients. METHODS: Eighteen patients with SSc and dyspnea were evaluated for ILD by pulmonary function testing and bronchoalveolar lavage (BAL), and 15 of these patients underwent chest HRCT. BAL was performed in either the middle lobe or the lingula, and also in a lower lung segment. Differential cell counts were determined by clinical cytopathology, with retrospective recounting in a blinded manner by a single technician. Active alveolitis was defined as the presence of > or =3.0% polymorphonuclear cells and/or > or =2% eosinophils in BAL fluid. BAL fluids were cultured for bacteria, mycobacteria, and fungi. HRCT scans were evaluated in a blinded manner for ground-glass opacification and fibrosis in the lavaged lobes. RESULTS: Nine of the 18 patients had active alveolitis recorded in both lavaged segments, while in 4 patients it was recorded in only 1 segment (lower lobe in 3). Following repeat differential cell counting, 3 patients were reclassified as having active alveolitis and 1 as having no alveolitis. Culture of BAL fluid identified clinically unsuspected infection in 3 patients. For the right middle lung lobe or lingula there was excellent agreement between ground-glass opacification and the finding of alveolitis on BAL from segments in the same lung regions, but this was not observed for the lower lobes. The correlation between fibrosis on HRCT and the presence of alveolitis on BAL was significant for the lower lobes but not the middle lung fields. CONCLUSION: BAL of the middle lobe or lingula may underestimate the presence of active alveolitis. Similarly, while ground-glass opacification on HRCT accurately predicted alveolitis in the middle lung fields, HRCT did not detect all sites of inflammation and did not identify infectious etiologies. These data suggest that, in addition to HRCT, BAL with lavage, differential cell counting, and culture from at least 2 segments of lung be performed for diagnosing SSc alveolitis.     

Rewash bronchoalveolar lavage

A significant limitation of standard bronchoalveolar lavage (BAL) technique is the inability to measure or calculate epithelial lining fluid (ELF) volume and, therefore, in vivo concentrations of substances in the ELF. We evaluated a new rewash BAL procedure with the radiolabeled tracer technetium pertechnetate (99mTcO4-) that theoretically should be immune to even exaggerated fluid shifts during BAL. To test this theory, we measured ELF volume in control sheep using isosmotic (280 mosm/L) hypoosmotic (140 mosm/L) and hyperosmotic (570 mosm/L) BAL solutions to induce exaggerated fluid shifts during the lavage procedure. The mean ELF volume of the lavaged lung segment was not significantly different for the three solutions (isosmotic, 1.7 +/- 0.8 ml; hypoosmotic, 1.1 +/- 1.2 ml; hyperosmotic, 2.1 +/- 1.6 ml). The slope of the 99mTcO4- disappearance curve, however, was significantly steeper for the hyperosmotic solution (-0.40 +/- 0.04%/min) compared with the other solutions (isosmotic, -0.14 +/- .01%/min; hypoosmotic, -0.12 +/- 0.07%/min). Calculation of ELF volume using sodium as an endogenous tracer gave consistently smaller values with each of the mannitol solutions (isosmotic, 0.21 +/- 0.30 ml; hypoosmotic, 0.02 +/- 0.03 ml; hyperosmotic, 0.18 +/- 0.18 ml). The failure of sodium to provide accurate estimates of the ELF volume may be due to complicated sodium movement in the lung and errors in our assumption of the initial concentration of sodium in the ELF fluid. We conclude that the rewash BAL technique with 99mTcO4- gives values of ELF volume that are not significantly affected by even exaggeration of the fluid flux that invariably accompanies BAL.     

Exogenous mineral particles in the human bronchial mucosa and lung parenchyma. I. Nonsmokers in the general population

We extracted mineral particles from 7 different regions of the bronchial tree and 4 regions of lung supplied by these airways from 11 morphologically normal adult autopsy right lungs. All patients were nonsmokers. Particles were identified, counted, and sized by analytical electron microscopy. Both particle concentration and particle size showed a significant negative correlation with airway diameter; detailed analysis showed that the correlation for concentration was only true of large particles. Distance from the carina (pathlength) showed a weaker correlation with particle concentration. The lowest particle concentration was found in the mainstem bronchi, and there was a consistent (case to case) increase in particle concentration with airway generation. Parenchyma supplied by the apical segmental bronchus had a higher particle concentration than that in other sample sites. Segmental bronchial particle size was consistently larger than particle size in the supplied lung tissue, and particles from both upper-lobe tissue sample sites were slightly larger than those from the two lower-lobe sample sites. Bronchial mucosa from all sites showed a predominance of silica, whereas tissue sites appeared to preferentially concentrate silicates, especially kaolin and mica. These observations suggest that in morphologically normal lungs from lifetime nonsmokers (1) in the noncarinal portions of the larger airways, airway diameter and, to a much lesser extent, pathlength are the major influences on long-term bronchial particle concentration and size; (2) tissue particle concentration does not appear to relate to pathlength; (3) the airways accumulate very specific sizes and types of particles compared to the parenchyma, an effect that may influence the location of specific pathologic lesions; and (4) the pattern of long-term particle concentration appears to be fairly similar to acute bronchial deposition patterns seen in experimental human systems, an observation that may imply that long-term burden is the result of translocation of a fraction of the locally deposited particles to the interstitial tissues.     

Bronchoalveolar mastocytosis in farmer's lung is related to the disease activity

Patients (n = 10) at the acute phase of farmer's lung were investigated with chest roentgenography, lung function tests, and bronchoalveolar lavage (BAL) fluid analysis (n = 9). They had diffuse interstitial lung infiltrates and a reduction of the diffusion capacity. The dominating recovered cell types during BAL were lymphocytes; and in two patients, granulocytes. A prominent increase in mast cell numbers was seen in all patients. After avoidance of contact with moldy plant material for four to ten weeks (n = 7), lung function started to improve; and the BAL cell counts, to decrease. At clinical remission six to 14 months later (n = 7), the chest roentgenogram was normal and the diffusion capacity was slightly subnormal. The BAL numbers of mast cells and lymphocytes had further decreased but still remained increased compared with those in the healthy controls. Parallel to the normalization of the lung function and the recovery of BAL fluid cells, the increased BAL fluid concentrations of hyaluronic acid and procollagen III peptide started to decrease. These potential markers of fibroblast activation were significantly related to the mast cell number, but not to the lymphocyte number. The study has demonstrated that pulmonary mastocytosis is a prominent finding in farmer's lung and is related to the disease activity. The observed relationship between pulmonary mastocytosis and biochemical signs of lung fibroblast activation is further evidence to support the hypothesis of a mast cell interaction with lung connective tissue.     

Comparison of induced sputum with bronchial wash, bronchoalveolar lavage and bronchial biopsies in COPD.

It is unclear how cellular and soluble inflammatory markers in induced sputum relate to markers in lavage fluid and biopsies in chronic obstructive pulmonary disease (COPD). This was investigated and also the possible differences between subjects with COPD and healthy controls assessed. Eighteen nonatopic subjects with COPD and 11 healthy controls were studied. Sputum was induced by inhalation of hypertonic saline. The airways were lavaged, using the first 50 mL for bronchial wash (BW) and the subsequent 150 mL for bronchoalveolar lavage (BAL), and biopsies were taken from subsegmental carinae. Neutrophils were the predominant cell type in sputum in COPD (median 77.3%) but not in BW (5.5%) and BAL fluid (1.7%). Differential cell counts in sputum did not correlate with the counts in BW or BAL fluid or biopsies, whereas sputum eosinophil cationic protein (ECP) levels correlated with BW fluid ECP levels (p=0.66, p=0.007) and sputum interleukin-8 (IL-8) concentration with BAL fluid IL-8 concentration (p= 0.52, p=0.026). Subjects with COPD had a higher percentage of sputum neutrophils and eosinophils and higher concentrations of ECP and IL-8 than healthy controls. The higher percentages of eosinophils and concentrations of ECP were also seen in BW and BAL fluid. Finally, higher numbers of macrophages and eosinophils were found in biopsies. In conclusion, induced sputum is derived from a different compartment from BW and BAL fluid and biopsies. Induced sputum may be useful for studying the contribution of luminal neutrophils and eosinophils in chronic obstructive pulmonary disease.     

The eosinophil component of the alveolitis in idiopathic pulmonary fibrosis. Signs of eosinophil activation in the lung are related to impaired lung function

The number of eosinophils and the concentrations of eosinophil cationic protein (ECP), a specific granule constituent of eosinophil granulocytes, were measured in bronchoalveolar lavage (BAL) fluid from patients (n = 22) with idiopathic pulmonary fibrosis (IPF). The median recovery of eosinophils during lavage performance was 4% (range, zero to 49) of the nonepithelial cells and significantly increased compared with the recovery in healthy control subjects (less than 1%) and in control patients with sarcoidosis (1%; range, zero to 7). The median BAL fluid concentration of ECP was in IPF 13.3 micrograms/L (range, 2 to 118) and significantly increased compared with the concentrations in healthy control subjects (2.7 micrograms/L; range, less than 2 to 8) and in control patients (6.6 micrograms/L; range, less than 2 to 64). The BAL fluid concentrations of myeloperoxidase (MPO) were also significantly increased in IPF, indicating a local neutrophil activation. A significant correlation was found between BAL fluid ECP and MPO, suggesting a common activator of eosinophils and neutrophils. BAL fluid eosinophils and ECP correlated with the reduced diffusion capacity of the lung but not with vital capacity or forced expiratory volume. It is concluded that eosinophil activation is part of the inflammatory process in IPF. ECP and other cytotoxic eosinophil products may play a pathophysiologic role for the lung damage in this disease.     

Soluble and insoluble air particle fractions induce differential production of tumor necrosis factor alpha in rat lung

Altered cytokine production in the lung follows the deposition of urban air particles. The present study was designed to measure changes in tumor necrosis factoralpha (TNFalpha) and endothelin-1 (ET-1) levels in rat lung after instilling various fractions of the dust EHC-93, while in vitro, alveolar macrophages (AMs) and type 2 epithelial cells were studied to determine relative production of these molecules in response to the same particles. Whole dust and its soluble and leached components were instilled into rat lung and the animals were killed at intervals to 2 weeks; they received tritiated thymidine by intraperitoneal injection 1 hour before death. All samples induced some inflammation, with the highest cellular efflux being found by bronchoalveolar lavage 1 day after leached particles. Lung injury, illustrated by protein levels in lavage fluid, was maximal after instilling the soluble fraction and subsequently epithelial regeneration was also maximal in this group. TNFalpha levels were highest after instilling whole dust or its leached fraction at 4 hours and 1 day, and cell culture studies indicated a predominant AM source for this cytokine. ET-1 levels were also increased in BAL from 4 hours to 3 days and were mostly associated with the instillation of leached particles. The results demonstrate that the rapid production/release of TNFalpha and ET-1 after particle deposition is largely due to the insoluble particulate fraction. There appears to be a differential response to whole dust where the soluble components cause some inflammation and epithelial cell necrosis, whereas the leached particles are more likely to react with macrophages to induce the production of proinflammatory cytokines such as TNFalpha.     

Measurement of carcinoembryonic antigen, squamous cell carcinoma related antigen and neuron-specific enolase in the bronchoalveolar lavage fluid in patients with peripheral lung cancer

Carcinoembryonic antigen (CEA), squamous cell carcinoma related antigen (SCC) and neuron-specific enolase (NSE) in bronchoalveolar lavage fluid were measured in 30 patients with peripheral lung cancer, 11 patients with benign lung disease and 19 healthy controls. The mean levels and positive rates of lavaged fluid CEA were 128.0 +/- 16.9 ng/mg and 33.3% in patients with lung cancer, 68.1 +/- 25.9 ng/mg and 9.1% in patients with benign lung disease, and 68.3 +/- 11.6 ng/mg and 5.2% in healthy controls, respectively. The mean levels and positive rates of lavaged fluid CEA in patients with lung cancer were significantly higher than those in patients with benign lung disease (p less than 0.05) and those in healthy controls (p less than 0.05). The mean levels of lavaged fluid SCC and NSE showed no significant difference between cases of lung cancer and benign lung disease or healthy controls. No lavaged tumor marker level in patients with lung cancer showed any close correlation with histologic types and serum levels. In conclusion, measurement of lavaged fluid CEA was considered to be useful in the differential diagnosis of peripheral lung cancer.     

Heterogeneity of phagocytosis for inhaled versus instilled material.

Animal experiments involving lung exposure to particles and toxins often use intratracheal instillation, although inhalation is more physiologically relevant to human respiratory tract exposures. Using nontoxic magnetic particles, we examined the particle content distribution within the macrophage population lavaged from the lungs of Syrian golden hamsters exposed either by inhalation or by intratracheal instillation. One to 3 days after iron oxide particle delivery to the lungs, lung macrophages were harvested from animals in pairs, one exposed by inhalation and one exposed by instillation. The macrophages were then magnetically fractionated according to magnetic iron oxide content by flowing the cell suspension through tubing placed within the magnetic field gradient of an electromagnet. Macrophages that had ingested the largest quantity of magnetic iron oxide preferentially collected adjacent to the tubing wall when the electromagnet was at its lowest current; those with fewer particulates collected at correspondingly higher amperages; those cells that were never pulled out of the flowing stream had little or no magnetic iron oxide content. Our results showed that 80% of the lavaged cell population from animals exposed by inhalation had measurable particle content, whereas by instillation, many cells (70%) received no dose at all. Exposure by inhalation produced a more even distribution of dose among lung macrophages. Macrophage intracellular motions showed a decrease when cell content exceeded 7 to 8% of cell volume. We conclude that the method of particle delivery to lungs can influence the dose distribution among lung macrophages.     

Secretory leukocyte proteinase inhibitor is preferentially increased in patients with acute respiratory distress syndrome.

Inappropriate release of proteases from inflammatory and stromal cells can lead to destruction of the lung parenchyma. Antiproteinases such as alpha-1-proteinase inhibitor (alpha1-Pi), secretory leukocyte proteinase inhibitor (SLPI) and elastase-specific inhibitor (elafin) control excess production of human neutrophil elastase. In the present study, the concentrations of alpha1-Pi, SLPI and elafin found in bronchoalveolar lavage (BAL) fluid from control subjects, patients at risk of developing acute respiratory distress syndrome (ARDS) and patients with established ARDS were determined. Levels of all three inhibitors were raised in patients compared with normal subjects. SLPI was increased in the group of patients who were at risk of ARDS and went on to develop the condition, compared with the "at-risk" group who did not progress to ARDS (p=0.0083). Alpha1-Pi and elafin levels were similar in these two populations. In patients with established ARDS, both alpha1-Pi and SLPI levels were significantly increased, compared to patients at risk of ARDS who did (p=0.0089) or did not (p=0.0003) progress to ARDS. The finding of increased antiproteinases shortly before the development of acute respiratory distress syndrome provide further evidence for enhanced inflammation prior to clinical disease.     

Acute phase reactants and cytokine levels in unilateral community-acquired pneumonia

BACKGROUND: Bacterial infection of the lower respiratory tract initiates an acute inflammatory response. Regulation of the inflammatory response in bacterial pneumonia depends on a complex interaction between immune cells and inflammatory cytokines. OBJECTIVES: We investigated the initial levels of proinflammatory cytokines and acute phase reactants (APR), e.g. C-reactive protein (CRP), upon presentation of community-acquired pneumonia (CAP) in relation to clinical and laboratory indices of infection. METHODS: We prospectively studied 28 consecutive patients with unilateral CAP. Tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, IL-6 and IL-8 concentrations were measured by ELISA in both bronchoalveolar lavage (BAL) fluid and serum. RESULTS: The concentrations of IL1-beta and IL-6 in BAL fluid were found to be significantly higher in the involved lung than those in either the uninvolved lung (p = 0.008 and p = 0.012, respectively) or serum (p = 0.002 and p = 0.025, respectively). Serum CRP concentrations were increased compared to those in the involved and uninvolved lung in BAL fluid (p = 0.000 and p = 0.000, respectively). In serum and BAL from involved lung, IL-6 concentrations were higher in the systemic inflammatory response syndrome (SIRS) group than in the non-SIRS group (p < 0.05), whereas CRP, TNF-alpha, IL-1beta and IL-8 concentrations showed no difference between SIRS and non-SIRS. There was no significant correlation between the acute physiology and chronic health evaluation II score and the cytokines. CONCLUSIONS: Our results indicate that the CRP level is higher in the serum than in the BAL fluid in the lung, and that IL-6 is the most important cytokine for the determination of the severity of the disease.