The role of intercellular adhesion molecule-1 in chronic airway inflammation

We have examined the role of intercellular adhesion molecule-1 (ICAM-1) in chronic airway inflammation and airway hyperresponsiveness in a primate model of asthma. Airway cellular composition was assessed by bronchoalveolar lavage (BAL) and airway responsiveness was measured as the bronchoconstrictor response to inhaled methacholine. In animals with chronic airway inflammation (increased BAL eosinophils) and sustained airway hyperresponsiveness, a 7 day dosing scheme with a murine anti-human ICAM-1 monoclonal antibody (R6.5, 2 mg/kg/day; i.v.) did not reduce the existing airway inflammation or airway hyperresponsiveness. In contrast, a similar dosing scheme with dexamethasone (0.2 mg/kg/day, i.m.) was found to significantly reduce both the airway eosinophilia and hyperresponsiveness. However, one week after cessation of dexamethasone treatment, the airway inflammation and hyperresponsiveness returned to pre-treatment levels. In further experiments where animals were first treated with dexamethasone (7 days) followed by a 7 day treatment with R6.5, the reoccurrence of airway inflammation and subsequent increase in airway responsiveness was prevented. We conclude that the efficacy of ICAM-1 is primarily associated with inhibition of the influx of inflammatory cells into the airways and subsequent reduction in airway responsiveness. These data suggest that in lungs with pre-existing inflammation the modulation of ICAM-1 following treatment with glucocorticoids may be a novel and more selective long-term treatment for control of the chronic airway inflammation and hyperresponsiveness associated with bronchial asthma.

Dimethyl sulfoxide decreases lung neutrophil sequestration and lung leak

To investigate basic mechanisms of acute edematous lung injury (adult respiratory distress syndrome), the formylated tripeptide formyl-norleucyl-leucyl-phenylalanine (FNLP) was instilled intratracheally into hamsters. Intratracheal FNLP produced time-dependent and dose-dependent increases in neutrophils recoverable by lung lavage (neutrophil alveolitis) and leak of intravenously injected albumin into the extravascular lung space (lung leak). Treatment with dimethyl sulfoxide (DMSO) decreased (p less than 0.05) neutrophil alveolitis and lung leak in hamsters given FNLP intratracheally. The effect of DMSO on various neutrophil functions was also studied in vitro. Addition of DMSO at concentrations (about 0.20%) measured in plasma of hamsters given DMSO decreased (p less than 0.05) neutrophil chemotaxis but not neutrophil superoxide anion generation or adherence to cultured endothelial cell monolayers or nylon fiber in vitro. We conclude that intratracheal FNLP causes neutrophil alveolitis and lung leak and that DMSO treatment ameliorates these processes, possibly by inhibiting neutrophil chemotaxis.

In vivo expression of CD69 on lung eosinophils in eosinophilic pneumonia: CD69 as a possible activation marker for eosinophils

The antigen, CD69, has been demonstrated to be expressed on activated T cells and natural killer cells. There have been no studies concerning the expression of CD69 on eosinophils. In this article, we demonstrate that lung eosinophils obtained from the bronchoalveolar lavage fluid of patients with eosinophilic pneumonia expressed significant levels of CD69, whereas peripheral blood (PB) eosinophils did not express CD69. We also activated PB eosinophils in vitro using phorbol myristate acetate and cytokines to determine whether CD69 was expressed. PB eosinophils expressed CD69 after short-term culture with phorbol myristate acetate and eosinophil hemopoietic cytokines (interleukin-3, granulocyte-macrophage--colony-stimulating factor, and interleukin-5). These findings suggest that CD69 may be a useful marker for activated eosinophils at inflammatory sites.

Instillation of chemotactic factor to silica-injected lungs lowers interstitial particle content and reduces pulmonary fibrosis

Silica-induced pulmonary fibrosis usually follows exposure to increased levels of this particulate and its retention in interstitial macrophages of the lung. It is suggested that accelerated clearance of particles from the pulmonary interstitium may ameliorate subsequent fibrosis. To test this hypothesis, one group of mice received 2-mg intratracheal (IT) silica; some particles were phagocytized and cleared during the subsequent inflammatory response, other particles were translocated across the epithelium to reach interstitial macrophages by 2 weeks. These mice later showed increased fibroblast growth, a doubling of lung collagen levels and large silicotic nodules by 16 weeks when much of the silica was still present in the lung. A second group of mice received IT silica, then 2 and 3 weeks later received IT injections of N-formyl-L-methionyl-leucyl-phenylalanine (FMLP), a leukocyte chemoattractant. Subsequently, a significant increase in inflammatory cells was seen and silica was observed mostly in phagocytes within the alveolar spaces. Few interstitial particles were found at 4 weeks, and extensive fibrosis did not develop by 16 weeks; only a few small nodules were seen and little silica was present in the lung. The results indicate that clearance of interstitial particles by a controlled inflammatory response is possible, and that removal of silica from the interstitium decreases the fibrotic response.

Endotoxin-induced cytokine gene expression in vivo. IV. Expression of interleukin-1 alpha/beta and interleukin-1 receptor antagonist mRNA during endotoxemia and during endotoxin-initiated local acute inflammation

After the intravenous (IV) injection of endotoxin, (lipopolysaccharide [LPS]), in the rat, interleukin-1 alpha/beta (IL-1 alpha/beta) mRNA expression peaks at 1 hour in whole organ RNA preparations of the lung, liver, spleen, and bowel. Interleukin-1 receptor antagonist (IL-1ra) mRNA peaks at 2 to 4 hours, consistent with the hypothesis that IL-1ra acts as an endogenous negative feedback mechanism to downregulate the proinflammatory effects of IL-1. After the intratracheal (IT) injection of LPS, however, IL-1 and IL-1ra mRNA levels in whole lung peak at 6 hours, concurrent with the maximum influx of neutrophils (PMNs) into the bronchoalveolar space. To address the cellular source of IL-1 and IL-1ra mRNA in the lung during acute pneumonitis, mRNA levels were studied in bronchoalveolar lavage (BAL) macrophages incubated with LPS in vitro for 6 hours as compared with BAL cells (95% PMNs) obtained 6 hours after IT injection of LPS. A much greater expression of IL-1 and IL-1ra mRNA was observed in PMN-rich BAL cells obtained after IT injection of LPS, suggesting that PMNs contribute substantially to IL-1 and IL-1ra mRNA expression. Fractionation of alveolar macrophage-enriched and PMN-enriched subpopulations from the BAL cells obtained at 6 hours after IT injection of LPS confirmed that neutrophils are a source of IL-1 and IL-1ra mRNA. The difference in the kinetics of IL-1 and IL-1ra mRNA expression in whole lung RNA preparations after IV and IT injections of LPS is due to the contribution of PMNs that appear in the lung in large numbers after IT injection. Finally, human peripheral blood PMNs were found to express IL-1ra mRNA and protein after in vitro incubation with LPS. PMNs may contribute to the up- and downregulation of their own accumulation by expressing both IL-1 and IL-1ra.

Recovery of rat alveolar macrophages by bronchoalveolar lavage under normal and activated conditions

When rat (female Wistar) lungs were lavaged (bronchoalveolar lavage, BAL) six times with physiological saline, approximately the same number of alveolar macrophages (AM) were found in the first and second BAL, whereas in the third fourth, fifth, and sixth BAL, the number of AM decreased exponentially. Morphometric counting of the number of AM in histological sections of lung tissue showed that only 14% of the AM population had been recovered by BAL. Although additives to the BAL fluid such as lidocaine and/or fetal calf serum increased the AM count in the first washing considerably, the total number of AM washed out remained unaltered. Addition of the phagocytosis stimulant zymosan increased the AM count in BAL by a factor of more than 2. On stimulation of the lungs with an inert dust (silicon carbide), the AM count in the BAL and the lung was only slightly increased 8 weeks after intratracheal instillation. In contrast, after exposure to fibrogenic and cytotoxic quartz, the AM count in BAL and lung was significantly increased, and the recovery of AM had also increased by a factor of approximately 2. The experiments show that it is the micromilieu of the alveoli and the condition of the AM (certain physiological activation states, such as phagocytic activity) that essentially determine the degree of recovery.

Iron content in human alveolar macrophages

Intracellular iron can be estimated semi-quantitatively by histochemical determination using the ferrocyanide reagent's score. Particle-induced X-ray emission (PIXE) allows accurate determination of various elements including iron in cells and biological fluids. Both techniques have been used to measure iron in alveolar macrophages gathered by bronchoalveolar lavage. The purpose of this study was to investigate the clinical usefulness of the PIXE technique in occupational respiratory medicine and in various pulmonary diseases. Using the PIXE method, we measured the iron content of alveolar macrophages in healthy subjects, with and without occupational exposure to iron dust, and in patients with pulmonary diseases (chronic obstructive pulmonary disease (COPD), lung cancer, Goodpasture's syndrome). Our results were then compared with those obtained with the ferrocyanide reagent. Intramacrophagic iron was 0.33 +/- 0.21 micrograms.10(-6) (mean +/- SD) cells in healthy non-smoking subjects without occupational exposure. Intramacrophagic iron was increased in smokers, iron-steelworkers, and in patients with COPD or lung cancer even in the absence of pulmonary haemorrhage. The two patients with Goodpasture's syndrome had high intramacrophagic iron content. About 80% of the whole bronchoalveolar lavage fluid iron content was in the cells. Mean iron content of blood monocytes, lymphocytes and neutrophils of eight healthy subjects was significantly lower than that of alveolar macrophages. A significant correlation was found between iron determination by the PIXE method and the ferrocyanide reagent's score (r = 0.89). We conclude that intramacrophagic iron may be increased in steelworkers and subjects with pulmonary haemorrhage, but also in asymptomatic smokers, in COPD and lung cancer patients without occupational exposure to iron dust.

Irreversible pulmonary changes induced in rat lung by dust overload

The objective of this study was to investigate whether the effects of dust overload are reversible upon cessation of subchronic exposure to test toner. Female rats were exposed 6 hr/day, 5 days/week for 3 months to a test toner at 0, 10, and 40 mg/m3. The retained quantity of test toner in the lungs at the end of exposure was 0.4 and 3.0 mg for the low and high exposure groups, respectively. Fifteen months later, the corresponding values were 0.12 and 2.65 mg in the lungs. Alveolar clearance of tracer aerosols as well as cytologic and enzymatic parameters in the bronchoalveolar fluid was investigated at the end of exposure and subsequently up to 15 months later. The alveolar clearance of 59Fe2O3, 51Cr-polystyrene, and 85Sr-polystyrene tracer aerosols was slightly retarded at the low and substantially impaired at the high exposure level. At the low exposure level, there was some recovery in the clearance behavior up to 6 months after exposure. In contrast, at the high exposure level there was no indication of a reversal of the impaired clearance. For the beta-glucuronidase activity and the number of polymorphonuclear cells, the pattern of the effects was similar to the effects on the half-time tracer particle clearance. In conclusion, the dust overload at a lung burden of 3 mg test toner in rats was persistent for at least 15 months after termination of exposure.

Hypersensitivity pneumonitis induced by hexamethylene diisocyanate

A case of hypersensitivity pneumonitis (HP) induced by hexamethylene diisocyanate (HDI) is described. Serial determinations of the lymphocyte surface phenotypes by two-color assay revealed the following: 1) increased activated cytotoxic T lymphocytes in the bronchoalveolar lavage fluid (BALF), and 2) increased percentage and absolute number of non-major histocompatibility complex (MHC)-restricted natural killer (NK) cells in the peripheral blood (PB) during the recovery phase of the disease. These findings were considered to be related to the activity of the disease.

Erythromycin reduces neutrophils and neutrophil-derived elastolytic-like activity in the lower respiratory tract of bronchiolitis patients

Diffuse panbronchiolitis (DPB) is a disease of adults characterized by chronic inflammation of the respiratory bronchioles and the infiltration of chronic inflammatory cells. The clinical efficacy of erythromycin therapy has been demonstrated in DPB patients, but the mechanism of action of this drug is unknown. We investigated the localization of neutrophils in lung biopsy specimens, as well as the cell population and elastolytic-like and chemotactic activity of bronchoalveolar lavage (BAL) fluid, before and after treatment with erythromycin or ampicillin in 11 DPB patients (six biopsy-proven and five clinically diagnosed) and one follicular bronchiolitis patient. These bronchiolitis patients had a high percentage of neutrophil and a high neutrophil-derived elastolytic-like activity in BAL fluid compared with chronic bronchitis patients and normal control subjects. The number of neutrophils and the neutrophil-derived elastolytic-like activity in BAL fluid decreased significantly after treatment with erythromycin along with a significant improvement in pulmonary function studies, although there was no significant change in the chemotactic activity of BAL fluid. No significant reduction in BAL fluid neutrophilia was found in the ampicillin-treated patients. These results suggest an important role for the neutrophil in the pathogenesis or development of bronchiolitis, and also suggest that erythromycin may be useful for the treatment of bronchiolitis through its direct action upon host phagocytic cells.

Heterogeneity of alveolar macrophages in experimental silicosis

The alveolar macrophage (AM) population has been shown to be heterogeneous in composition as well as in function. The aim of our study was to assess morphological and functional features of AM in an experimental model of quartz-induced lung fibrosis by flow cytometric methods. Twelve cynomolgus monkeys were exposed 8 hr/day, 5 days/week for 26 months to either normal atmosphere (n = 5) or 5 mg/m3 DQ12 less than 5 microns quartz dust (n = 7). After 20 months of exposure, we studied AM phagocytosis by incubating bronchoalveolar lavage cells with fluorescent polystyrene microspheres (mean diameter 1.91 microns). Using a fluorescence-activated cell sorter analyzer, AM subpopulations were identified via their volume/side scatter properties. After selective electronic "gating" of the AM populations, both the percentage of phagocytic AM and the mean number of ingested microspheres per AM were determined. In addition, a phagocytic index (microspheres/AM x % phagocytic AM x 10(-2) and a hypothetical total phagocytic capacity of one lung (phagocytic index x total number of AM x 10(-6) were calculated. The total bronchoalveolar lavage cell counts rose (75.6 +/- 11.3 x 10(6) versus 10.1 +/- 0.8 x 10(6)) significantly after quartz exposure. In contrast, the percentage of phagocytic AM was significantly (p less than 0.05) reduced (43.5 +/- 5.0% versus 74.2 +/- 1.4%). Flow cytometric measurements revealed the appearance of an AM subpopulation characterized by size/granularity features identical to blood monocytes. Only minimal numbers of these cells were found under normal conditions, but they constituted 50% of the entire AM population in the quartz group.(ABSTRACT TRUNCATED AT 250 WORDS)

Overview of pulmonary alveolar macrophage renewal in normal rats and during different pathological processes

We report experimental results on pulmonary alveolar macrophage (PAM) renewal in healthy rats and in rats treated with particles introduced in the lungs. Morphometric studies showed that the lungs of normal rats of the strain used in our study contain 20 x 10(6) PAM, 50 x 10(6) monocytes in alveolar capillaries, and about 3 x 10(5) interstitial macrophages. Pulse labeling with a tritiated thymidine (3HT) gave a labeling index of 0.4% for the monocytes, of which a few could be observed in mitosis within alveolar capillaries. These monocytes are likely to be the PAM precursors. The daily input (greater than 4%) by PAM proliferation exceeds PAM loss by migration to the upper respiratory tract (2.5%). The life span of PAM was measured by sequential counting of lavaged cells after labeling with [125I]iododeoxyuridine instilled intratracheally. The pulmonary lavage procedure used allowed us to recover at least 80% of the whole PAM population. A daily loss of PAM of 8-9% was measured, of which loss by death in the endoalveolar compartment was estimated at 5-6%. During the pathological processes studied, several parameters of PAM renewal were shown to be modified. PAM migration to the upper respiratory tract was frequently inhibited, PAM cytotoxicity was observed, and PAM proliferation increased in some cases and decreased in others. Under most of the pathological conditions investigated, the renewal of endoalveolar macrophages appeared quite different from that in normal rats, and direct blood monocyte migration to the endoalveolar compartment became a major component of PAM renewal.

Lymphocyte and lymphocyte subset numbers in blood and in bronchoalveolar lavage and pleural fluid in various forms of human pulmonary tuberculosis at presentation and during recovery

BACKGROUND

Lymphocytes have a central role in human defences against mycobacteria. A study was designed to assess the relation between lymphocyte responses and clinical pattern of disease, nutrition and recovery during treatment in patients with tuberculosis.

METHODS

Lymphocyte numbers and subsets (on the basis of CD3, CD4, and CD8 monoclonal antibodies) were measured in peripheral blood and, where appropriate, bronchoalveolar lavage or pleural fluid of patients with different forms of pulmonary tuberculosis. Eleven had localised pulmonary tuberculosis, 18 miliary tuberculosis and seven a tuberculous pleural effusion.

RESULTS

CD4 lymphocytes were found in greatly increased numbers in pleural fluid and were relatively depleted in the blood. Lymphocyte numbers in bronchoalveolar lavage fluid varied widely in localised pulmonary and miliary tuberculosis but were highest in lavage fluid from patients with miliary tuberculosis. This was due to an increase in CD8 lymphocytes, which were also increased in the blood. Lymphocyte numbers bore no relation to nutrition, symptom duration, or radiographic profusion scores. In miliary tuberculosis the time taken for the chest radiograph to clear (mean (SD) 17.6 (7.8) weeks) correlated with lymphocyte numbers in lavage fluid, especially CD8 cells (r = 0.74), but not with the patients' age or nutrition. After 8 weeks' treatment, total and CD4 lymphocyte numbers in lavage fluid showed a substantial increase.

CONCLUSION

The association of CD8 cells with delayed recovery is compatible with suppression of the antimycobacterial action of macrophages. The switch to predominance of CD4 cells in lavage fluid during successful treatment supports the view that they may have a role in eliminating mycobacteria.

[A case of pulmonary eosinophilic granuloma with involvement of the ocular fundus]

A 37-year-old man was admitted to our hospital because of abnormal shadows on chest X-ray film at routine medical examination. The chest X-ray showed diffuse granular shadows in the bilateral upper and middle lung fields. Chest CT showed multiple cystic lesions and nodular lesions. Bronchoalveolar lavage (BAL) and transbronchial lung biopsy (TBLB) were performed. Electron microscopic examination of BAL fluid revealed Langerhans' cells, and lung tissue specimen obtained by TBLB showed granuloma with infiltration of histiocytes and eosinophils. During the clinical course, the patient complained of cough and decrease of right visual acuity in association with an increase of abnormal shadows on chest X-ray. The lung disease gradually resolved after the cessation of smoking in spite of no therapy. In the right eye, an exudative lesion with retinal elevation was noted in the ocular fundus. Corticosteroid administration was effective for the treatment of this lesion. There was no pathological evidence of the right ocular lesion. However, the correlation of its clinical course with the lung disease suggests a relationship between the ocular lesion and pulmonary eosinophilic granuloma.

The differing patterns of interstitial lung involvement in connective tissue diseases

Connective tissue disorders (CTD) have a relatively high incidence of pulmonary complications but their delineation has been hampered by difficulties inherent in the diagnostic techniques. One fresh approach to this problem is based on a clustering method that uses data from 8 separate investigations to cluster the patients into 4 distinctly separate categories representing normal nonsmoker, normal smokers, those with active interstitial lung disease and those with bronchiolitis. Using this method, a large group of patients with CTD have been examined to assess the nature and extent of their pulmonary complications. Subjects in the first cluster had a normal test profile across all variables, and included no current active smokers. The normal smoking cluster contained only smokers who had a high total lavage cell number with a relative increase in macrophages and a decrease in lymphocytes. In this group, all respiratory variables were normal with the exception of a mildly depressed DLCO, also known to be associated with smoking. The general characteristics of the active interstitial lung disease cluster was a markedly depressed DLCO indicating impaired gas exchange, and elevated gallium index, bronchoalveolar lavage (BAL) cell number and neutrophil and lymphocyte percentages, all indicating an active inflammatory process. However more careful analysis of this group suggested the presence of 2 subgroups, one with a lymphocytic alveolitis, and another with a neutrophilic alveolitis. The bronchiolitis cluster characteristics were a markedly depressed maximal mid expiratory flow rate and raised BAL lymphocyte percentage and gallium index. The distribution of patients within the cluster groupings suggested that Sjögren's syndrome, often an accompaniment of other CTD, is most frequently associated with pulmonary disease.(ABSTRACT TRUNCATED AT 250 WORDS)

The site of disruption of the bronchial epithelium in asthmatic and non-asthmatic subjects

BACKGROUND

Attention has recently been focused on the basal cells of the tracheobronchial epithelium as the mechanism of anchorage of the tall columnar cells, which themselves do not appear to form hemidesmosomes with the basement membrane of the epithelium. Residual basal cells have been described as remaining attached to the basement membrane after epithelial denudation. This led this group to formulate the hypothesis that there may be a potential plane of cleavage between the basal cells and the overlying columnar cell layer within the bronchial epithelium, which becomes disrupted in asthma.

METHODS

Bronchoalveolar lavage samples were obtained during bronchoscopy from eight patients with atopic asthma and four normal controls. Ultrathin sections of lavage cell pellets were examined by electron microscopy and the number of columnar and basal cells found in each epithelial cell cluster was counted. Cytocentrifuge preparations of the lavage samples from the same subjects were also examined for free epithelial cells and epithelial cell clusters.

RESULTS

Electron microscopic examination of the cell pellets showed that basal cells were present in very small numbers in the epithelial clusters in all subjects (mean 0.03 (SE 0.02)/cluster) and the ratio of columnar cells to basal cells was far greater than was encountered in the intact bronchial epithelium (167 nu 4). The cytocentrifuge preparations showed an increased number of epithelial cell clusters and epithelial cells in the asthmatic patients. Although these clusters were similar in size in the two groups of subjects (6.3 nu 5.1 cells/cluster) the ratio of free epithelial cells to cells within the cluster was higher in the non-asthmatic subjects.

CONCLUSIONS

It is proposed that shedding of epithelial cells occurs along a suprabasal plane and that there is a potential plane of cleavage between the suprabasal and the basal cell layers, which might be more vulnerable to the various insults.

Bronchiolitis obliterans organizing pneumonia (BOOP): the cytological and immunocytological profile of bronchoalveolar lavage

The cytological and immunocytological profile of bronchoalveolar lavage (BAL) was studied in 10 patients with idiopathic bronchiolitis obliterans organizing pneumonia (BOOP) and compared with the data in idiopathic pulmonary fibrosis (IPF) (n = 22), chronic eosinophilic pneumonia (CEP) (n = 9), and extrinsic allergic alveolitis (EAA) (n = 24). Lymphocyte subsets were enumerated using an immunoperoxidase slide assay. The BAL pattern in BOOP patients was characterized by several features: 1) colorful cell differentials with an increase in all cell types, most markedly in lymphocytes, and more moderately in neutrophils, eosinophils and mast cells, as well as the presence of foamy macrophages and, occasionally, of plasma cells; 2) decreased CD4/CD8 ratio; 3) normal percentage of CD57+ cells; and 4) increase in activated T-cells in terms of human leucocyte antigen-DR (HLA-DR) expression, and occasionally also interleukin-2 receptor (CD25) expression. The findings were most similar to those in EAA except for the CD25 expression, which was always normal, and the CD57+ cells, which were increased in EAA. The increase in lymphocytes discriminated best between BOOP and IPF. The eosinophils were significantly higher in CEP than in BOOP with little overlap. In conclusion, BAL may be of value to distinguish between BOOP and other interstitial lung disease.

Acute and chronic eosinophilic pneumonia: clinical evaluation and the criteria

The clinical courses of 11 cases of eosinophilic pneumonia which were clinico-pathohistologically diagnosed and found to be unassociated with organic disorders producing peripheral blood eosinophilia were extensively investigated and compared with various types of eosinophilic pneumonia previously reported. Five cases of acute eosinophilic pneumonia fulfilled the following criteria: 1) less than a one-month history of symptoms prior to diagnosis, 2) a short clinical course and 3) no recurrence. Six cases of chronic eosinophilic pneumonia fulfilled the following criteria: 1) more than a two-month history of symptoms prior to diagnosis, 2) a prolonged clinical course and 3) recurrence. The results suggested that various types of previously reported eosinophilic pneumonia classified by sex, the presence or absence of peripheral blood eosinophilia, the degree of clinical symptoms or peripheral blood eosinophilia, and the degree of abnormalities on chest X-ray films should be extensively reevaluated.

An immune model of beryllium-induced pulmonary granulomata in mice. Histopathology, immune reactivity, and flow-cytometric analysis of bronchoalveolar lavage-derived cells

BACKGROUND

Beryllium compounds can cause acute and chronic lung injury in humans. Although models of chronic granulomatous lung disease have been established in various animal species, a murine model of beryllium-induced chronic lung disease has not been established.

EXPERIMENTAL DESIGN

Beryllium was introduced intratracheally either as a soluble salt (BeSO4) or in particulate form (BeO). Various preimmunization protocols were used to enhance immune-mediated pulmonary changes. Cells obtained by bronchoalveolar lavage (BAL) were analyzed using flow cytometry, and the observations correlated with in vitro immune responses and with lung histopathology.

RESULTS

Histologic changes were consistently found in mice preimmunized with BeSO4.4H2O plus syngeneic serum. Addition of complete or incomplete Freund's adjuvant to the preimmunization protocol was not necessary to induce granulomatous changes. BAL showed a significant increase in lymphocytes at 2, 4, and 8 weeks after intratracheal BeSO4. Approximately one-third of BAL lymphocytes expressed the gamma/delta T lymphocyte receptor at 2 weeks; at 4 weeks the lymphocytes were predominantly Thy1+, L3T4+ (CD4+) and expressed only the alpha/beta T lymphocyte receptor. Only BAL lymphocytes from mice preimmunized with BeSO4/serum and challenged with BeSO4/serum showed significant in vitro proliferation in response to BeSO4. Macrophage activation antigens (Mac-2, Mac-3) were expressed only during the acute inflammatory phase (2 weeks) whereas increased expression of a monocyte/macrophage antigen (Mac-1) remained elevated beyond the inflammatory period in some instances. Attempts to induce similar lesions in BALB/c and C57BL6/J mice were unsuccessful. Genetic differences at the H-2 major histocompatibility complex gene complex may account for the differential responses to BeSO4 among various mouse strains. A single exposure to BeO also induced histopathologic changes in the lung which correlated with BAL cellularity, but these changes were only observed 8 months after exposure and did not proceed to frank granulomas.

CONCLUSIONS

A murine model of granulomatous lung disease may prove useful in understanding the genetic and immunologic factors that determine the response to beryllium. The animal model may also have implications for pulmonary sarcoidosis, a disease of unknown cause(s), whose disease manifestations and BAL profiles are difficult to distinguish clinically and pathologically from chronic beryllium disease.

Interleukin-5 modulates eosinophil accumulation in allergic guinea pig lung

Based on its involvement in eosinophil biology, interleukin 5 (IL-5) may play a role in the pulmonary eosinophilia associated with allergic reactions. We have examined that hypothesis using a neutralizing antibody to IL-5 in ovalbumin-sensitized guinea pigs challenged with aerosolized antigen. The extent of eosinophilia has been quantitated in bronchoalveolar lavage (BAL) and by histologic evaluation of lung tissue sections. Acute intraperitoneal administration of a rat IgG, monoclonal antibody to murine IL-5 derived from TRFK-5 cells prevented lung and BAL eosinophilia in a dose-dependent fashion at and above 10 micrograms per guinea pig. Treatment with either an experimentally irrelevant, isotype-matched antibody from GL113 cells or with heat-denatured IL-5 antibody was without effect. These studies demonstrate the importance of IL-5 to pulmonary eosinophilia in challenged, allergic guinea pigs.

Protection by N-acetylcysteine of the histopathological and cytogenetical damage produced by exposure of rats to cigarette smoke

Adult male Sprague-Dawley rats were exposed whole-body to mainstream cigarette smoke (CS) once daily for 40 consecutive days. Such a treatment resulted in a significant decrease of body weight growth and in intense histopathological changes of terminal airways, including a severe inflammation of bronchial and bronchiolar mucosae, with multiple hyperplastic and metaplastic lesions and foci of micropapillomatous growth as well as emphysema, with extensive disruption of alveolar walls. All histopathological changes were efficiently prevented by the daily administration of the thiol N-acetyl-L-cysteine (NAC) by gavage. Cytological and cytogenetical changes were monitored in bronchoalveolar lavage (BAL) fluid and bone marrow cells of groups of rats killed after 1, 3, 8, 28, or 40 days of treatment. From the first day of exposure, CS significantly enhanced the proportion of polymorphonucleates among BAL cells and the frequency of micronucleated (MN) bone marrow polychromatic erythrocytes. After 8 days, a reduction was observed in the polychromatic/normochromatic erythrocytes ratio and an increase in the frequency of MN pulmonary alveolar macrophages (PAM) was also recorded, followed, after 28 days, by an increase of binucleated PAM. All these alterations immediately reached a plateau and persisted unchanged until the end of the experiment. NAC administration exhibited a significant and considerable protective effect towards the CS-induced alterations of BAL cellularity, the increase of MN PAM and bone marrow cytotoxicity.

Role for the submandibular gland in modulating pulmonary inflammation following induction of systemic anaphylaxis

Previous studies have shown that bilateral decentralization of the superior cervical ganglia (SCG; decentralization) attenuates allergen-induced pulmonary inflammatory responses in male rats sensitized to the nematode Nippostrongylus brasiliensis. The present report examines the neuronal and glandular mechanisms mediating the protection against pulmonary inflammation afforded by decentralization. Tissues and organs innervated by the SCG are responsible for this protection since, in a manner similar to decentralization, bilateral removal of the SCG (ganglionectomy) reduced anaphylaxis-induced accumulation of inflammatory cells in bronchoalveolar lavage fluid. Removal of the submandibular gland (sialadenectomy) did not modify the severity of the pulmonary inflammation, but concurrent sialadenectomy and decentralization abolished the protective effect of decentralization. Thus, we postulate that cervical sympathetic nerves tonically inhibit release of anti-inflammatory factors from submandibular glands. No relationship was found between noradrenaline and serotonin content of submandibular glands and the degree of protection against pulmonary inflammation offered by decentralization and ganglionectomy. Both decentralization and ganglionectomy appeared to increase the level of transcripts that encode immunomodulatory growth factors (nerve growth factor and epidermal growth factor) in submandibular glands, but these denervations evidently did not modify the transcripts for TGF beta 2. Systemic inflammatory events are regulated by the central nervous system at a level superior to the SCG probably through modulation of immunoregulatory factors in submandibular glands.

Correlation of Pneumocystis carinii cyst density with mortality in patients with acquired immunodeficiency syndrome and pneumocystis pneumonia

Fifteen percent to 20% of patients with the acquired immunodeficiency syndrome and pneumocystis pneumonia do poorly despite early intervention. It is not known what distinguishes those who die, despite early intervention and aggressive therapy, from those who readily respond to therapy. We used image analysis to determine the relative abundance of cysts within aggregates of Pneumocystis carinii found in induced sputa (21 patients) and bronchoalveolar lavage fluid (14 patients) from 35 patients with pneumocystis pneumonia. We calculated a cyst density (number of cysts per area of aggregate) for each aggregate and a mean cyst density for all of the aggregates on the smear. Six patients died within 2 weeks of diagnosis; four of these six patients who had autopsies all had residual P carinii. The mean cyst density for those who died was 9.7 +/- 3.9 (range, 5 to 15 x 10(-3)). The 29 patients who survived beyond 2 weeks had a mean cyst density of 18.4 +/- 8.7 (range, 5 to 35 x 10(-3); P = .01). Mean cyst density was not influenced by the number of aggregates present in the smear, the variation in cyst density among aggregates in a smear, or the episode of pneumocystis pneumonia. Cyst density determinations alone should not be used to predict outcome for individuals with P carinii pneumonia until further study is completed. Nevertheless, the current study suggests that a low cyst density specimen, which may indirectly indicate a greater proportion of trophozoites compared with a high cyst density specimen, may be associated with an unfavorable outcome in acquired immunodeficiency syndrome-associated pneumocystis pneumonia.

Cytological diagnosis of bronchial malignancies using the fibreoptic bronchoscope

Bronchial brush and wash material were obtained by fibreoptic bronchoscopy in 200 patients suspected of having bronchial carcinoma. Malignancy was diagnosed in 42, giving a diagnostic yield of 21%. Bronchial brush material showed the highest yield. Morphological cell typing was done on cytological material. Technical considerations, diagnostic criteria, diagnostic yield and accuracy are discussed.

Effect of dexamethasone and cyclosporin A on allergen-induced airway hyperresponsiveness and inflammatory cell responses in sensitized Brown-Norway rats

We studied the effects of dexamethasone and cyclosporin A on the airway hyperresponsiveness (AHR) and the influx of inflammatory cells into the bronchoalveolar lavage (BAL) fluid seen 18 to 24 hr after exposure to aerosolized ovalbumin in actively ovalbumin-sensitized Brown-Norway rats. Allergen exposure resulted in an approximately sevenfold increase in bronchial responsiveness to inhaled acetylcholine associated with a significant increase in eosinophils and lymphocytes in BAL fluid. Dexamethasone (0.5 mg/kg administered intraperitoneally for 3 days) abolished the AHR and the increase in eosinophil and lymphocyte counts. However, cyclosporin A at two doses (5 and 50 mg given orally for 5 days) did not significantly prevent the induction of AHR while producing a significant inhibition of the eosinophil and lymphocyte influx. Dexamethasone (0.5 mg/kg for 3 days) or cyclosporin A (5 mg/kg for 5 days) on their own had no effect on airway responsiveness. We conclude that specific inhibition of T-lymphocyte activation in this Brown-Norway rat model is not sufficient to inhibit the induction of AHR despite suppressing allergen-induced eosinophilia in BAL fluid. However, corticosteroids, which have inhibitory effects on a wider range of inflammatory cells, are more effective. Our observations are in line with the potent effect of corticosteroids in airway inflammatory conditions such as asthma.