Number Of Cells In Bronchoalveolar Lavage Research Articles

Inhibition of tobacco smoke-induced lung inflammation by a catalytic antioxidant.

Cigarette smokers experience airway inflammation and epithelial damage, the mechanisms of which are unknown. One potential cause may be free radicals either in tobacco smoke or produced during persistent inflammation. Inflammation may also be a driving force to cause airway epithelium to undergo changes leading to squamous cell metaplasia. To test whether tobacco smoke-induced inflammation could be reduced by a catalytic antioxidant, manganese(III)meso-tetrakis(N,N'-diethyl-1,3-imidazolium-2-yl) porphyrin (AEOL 10150) was given by intratracheal instillation to rats exposed to filtered air or tobacco smoke. Exposure to tobacco smoke for 2 d or 8 weeks (6 h/d, 3 d/week) significantly increased the number of cells recovered by bronchoalveolar lavage (BAL). AEOL 10150 significantly decreased BAL cell number in tobacco smoke-treated rats. Significant reductions in neutrophils were noted at 2 d and macrophages at 8 weeks. Lymphocytes were significantly reduced by AEOL 10150 at both time points. Squamous cell metaplasia following 8 weeks of tobacco smoke exposure was 12% of the total airway epithelial area in animals exposed to tobacco smoke without AEOL 10150, compared with 2% in animals exposed to tobacco smoke, but treated with AEOL 10150 (p <.05). We conclude that a synthetic catalytic antioxidant decreased the adverse effects of exposure to tobacco smoke.

Simultaneous determination of pulmonary and intestinal permeability in patients with alcoholic liver cirrhosis.

The aim of this prospective study was to assess pulmonary and intestinal permeability (PP and IP, respectively) in patients with alcoholic liver cirrhosis (ALC). Thirty-five non-smoking patients with biopsy-proven ALC were included (mean grade B in Child's classification). None had a previous history of pulmonary disease and all had a normal chest radiograph and computed tomography scan. Lung function tests and bronchoalveolar lavage (BAL) were also performed. The PP was studied by measuring the lung to blood clearance of inhaled 99mTc-DTPA aerosol. Clearance half-time (T 1/2, in minutes) and residual activity (RA in %) were obtained from exponential fitting of the right pulmonary clearance curve. IP was concurrently evaluated by measuring the urinary recovery of ingested 51Cr-EDTA, according to Bjarnason's technique and expressed as a percentage of the total oral dose. Results were compared with those obtained in non-smoking healthy control subjects. PP was significantly (P<0.05) increased in patients with ALC (T 1/2 65.9 +/- 32.2 min, RA 87.1% +/- 6.7%) versus control subjects (T 1/2 85.2 +/- 20.8 min, RA 92.8% +/- 2.6%). IP was not significantly different between patients and controls (2.39% +/- 2.20% vs 1.74% +/- 0.81%). A significant correlation (P<0.05) was found between PP and total cell number in BAL and total lymphocyte number in BAL. In conclusion, in patients with ALC, PP is increased without any association with IP, the severity of cirrhosis according to Child's classification or the results of pulmonary function tests. These findings may reflect primary involvement of the alveolar epithelium. In patients with ALC, PP is correlated with total cell number and total lymphocyte number. Increased PP may be due to activated cytotoxic lymphocytes and/or abnormal macrophage activity.

Inhalation toxicity of 1,6-hexamethylene diisocyanate homopolymer (HDI-IC) aerosol: results of single inhalation exposure studies.

The early acute pulmonary response of female Wistar rats exposed nose-only to a mixture of 1,6-hexamethylene diisocyanate homopolymer (HDI-IC) aerosol was examined. This study was designed to investigate the time course of the relationship between acute pulmonary irritation and ensuing disturbances of the air/blood barrier in rats exposed to concentrations of 3.9, 15.9, 54.3, or 118. 1 mg HDI-IC/m(3). The duration of exposure was 6 h, followed by serial sacrifices 0 h, 3 h, 1 day, 3 days, and 7 days postexposure. Concentrations were selected based on the results of a 4-h acute inhalation study in rats (LC(50) = 462 mg/m(3)). Bronchoalveolar lavage (BAL) fluid was analyzed for markers indicative of injury of the bronchoalveolar region, including phospholipids as proxy of altered surfactant homeostasis. Glutathione (GSH) was determined in BAL fluid and lung tissue. BAL cells with increased intracellular phospholipids were observed on day 1 and especially day 3, with some residual increase on day 7. Increased intracellular phospholipids and activity of acid phosphatases appear to suggest that phagocytized phospholipids may transiently affect lysosomal function. Following exposure to 15.9 mg/m(3), changes returned almost entirely to the level of the air-exposed control on day 7. Especially at higher exposure concentrations, lung weights and total number of cells in BAL were still statistically significantly elevated at this time point. Experimental evidence suggests that markers indicative of a dysfunction of the air/blood barrier, such as angiotensin-converting enzyme, total protein, and phospholipids engulfed by alveolar macrophages, were most sensitive to probe this type of changes. Although GSH in BALF was increased following exposure, there was an apparent depletion of tissue GSH immediately after cessation of exposure. In summary, this study suggests that respirable HDI-IC aerosol appears to cause a transient dysfunction of the air/blood barrier indicated by an increased extravasation of plasma constituents. Despite the remarkable extent of effects observed, most changes were reversible within a postexposure period as short as 7 days. First evidence of increased leakage of pulmonary epithelial barrier was observed at 3.9 mg/m(3). With respect to changes of early markers of pulmonary epithelial barrier dysfunction, approximately 3 mg HDI-IC/m(3) was considered to be the threshold concentration for acute pulmonary irritation.

Pollution and the immune response: atopic diseases--are we too dirty or too clean?

The effect of pollutants on the immune system has filled tomes and is almost always controversial whether the topic is disinfectants in drinking water or particulates and lung cancer. Even whether outdoor and indoor air quality is improving or declining has been a source of considerable investigation, consultation and often litigation. Few areas, however, yield so much uncertainty and debate as the role of airborne pollutants in atopy. Atopy is defined as an immunoglobulin E- (IgE) mediated allergic response to environmental antigens and can be manifested as rhinitis, asthma or atopic dermatitis. While there is some debate over whether there has been a real increase in atopy over the last decades, it is indisputable that there has been a dramatic change over the last 200 years. While isolated cases of anaphylaxis had been noted before, allergies were unheard of until the early 19th century. Only 54 years after the first description of hay fever in England in 1819, it was considered an epidemic and a clear association with urbanization had been reported.1 What aspect of urbanization is involved has been much debated. There has been much discussion amongst both experimental immunologists and epidemiologists over whether pollutants are responsible for increased allergic sensitization and/or severity.2,3 In the last few years new studies have supported an alternative explanation, namely the decline in infectious diseases in industrialized countries.4,5 Does this ‘hygiene theory’ toll the death knell for the ‘pollution theory’? In this review I will argue that there is a compelling case to be made for both theories and that even this is not the entire picture.

Effect of cellular changes and onset of humoral immunity on the replication of porcine reproductive and respiratory syndrome virus in the lungs of pigs.

Twenty-two 4- to 5-week-old gnotobiotic pigs were intranasally inoculated with 10(6.0) TCID(50) of porcine reproductive and respiratory syndrome virus (PRRSV) (Lelystad) and euthanized at different time intervals post-inoculation (p.i.). Bronchoalveolar lavage (BAL) cell populations were characterized, together with the pattern of virus replication and appearance of antibodies in the lungs. Total BAL cell numbers increased from 140x10(6) at 5 days p.i. to 948x10(6) at 25 days p.i. and remained at high levels until the end of the experiment. The number of monocytes/macrophages, as identified by monoclonal antibodies 74-22-15 and 41D3, increased two- to fivefold between 9 and 52 days p.i. with a maximum at 25 days p.i. Flow cytometry showed that the population of differentiated macrophages was reduced between 9 and 20 days p.i. and that between the same time interval, both 74-22-15-positive and 41D3-negative cells, presumably monocytes, and 74-22-15- and 41D3-double negative cells, presumably non-phagocytes, entered the alveolar spaces. Virus replication was highest at 7 to 9 days p.i., decreased slowly thereafter and was detected until 40 days p.i. Anti-PRRSV antibodies were detected starting at 9 days p.i. but neutralizing antibodies were only demonstrated in one pig euthanized at 35 days and another at 52 days p.i. The decrease of virus replication in the lungs from 9 days p.i. can be attributed to (i) shortage of susceptible differentiated macrophages, (ii) lack of susceptibility of the newly infiltrated monocytes and (iii) appearance of anti-PRRSV antibodies in the lungs. Neutralizing antibodies may contribute to the clearance of PRRSV from the lungs.

Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) suppresses the humoral and cell-mediated immune responses to influenza A virus without affecting cytolytic activity in the lung.

The immune response to influenza virus is exquisitely sensitive to suppression by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD); however, the cellular mechanisms underlying the suppressive effects of TCDD are unknown. Mice exposed to TCDD exhibited a dose-responsive increase in mortality following an otherwise non-lethal influenza virus infection. Given that cytotoxic T lymphocytes (CTL) are generally thought to resolve primary infections in the lung, we tested the hypothesis that exposure to TCDD suppresses T-cell responsiveness, leading to decreased CTL in the lung. After infection with influenza virus, naive CD8+ lymphocytes are activated and differentiate in the mediastinal lymph node (MLN). In mice exposed to TCDD and infected with influenza virus, the number of CD8+ MLN cells was reduced 60% compared to vehicle-treated mice. Moreover, MLN cells from TCDD-treated mice failed to develop cytolytic activity, and the production of interleukin (IL)-2 and interferon (IFN)-gamma was suppressed. Exposure to TCDD also altered the production of virus-specific antibodies, decreased the recruitment of CD8+ cells to the lung, reduced the percentage and number of bronchoalveolar lavage cells bearing a CTL phenotype (CD8+CD44hiCD62L(l) degrees ), and suppressed IL-12 levels in the lung. Despite our findings that exposure to TCDD suppressed T cell-dependent functions, the cytolytic activity of lung lavage cells from TCDD and vehicle treated mice was equivalent, and IFN gamma levels in the lungs of mice treated with TCDD were enhanced 10-fold. Thus, while exposure to TCDD suppressed a number of responses associated with the development of adaptive immunity to influenza virus, a direct link between these effects and enhanced susceptibility to influenza remains unclear.

Role of interferon gamma in the pathogenesis of primary respiratory syncytial virus infection in BALB/c mice.

Immunologic mechanisms are thought to contribute to the pathogenesis of respiratory syncytial virus (RSV) bronchiolitis in humans. RSV-infected BALB/c mice exhibit tachypnea and signs of outflow obstruction, similar to symptoms in humans. Interferon gamma (IFNgamma) has been found to be the predominant cytokine produced in humans and mice with RSV infection. We therefore undertook this study to evaluate the role of IFNgamma in the development of respiratory illness in RSV-infected mice. BALB/c mice were infected with RSV, and lung function was assessed by plethysmography. Bronchoalveolar lavage (BAL) fluids were analyzed for the concentration of interferon gamma (IFNgamma) and the presence of inflammatory cells, and lung tissue sections were examined for histopathologic changes. The role of IFNgamma was further addressed in studies of IFNgamma knock-out mice (IFNgamma(-/-)) and of mice depleted of IFNgamma by in vivo administration of a neutralizing antibody. After infection, mice developed respiratory symptoms that were strongly associated with the number of inflammatory cells in BAL, as well as with the concentrations of IFN-gamma. Both IFN-gamma(-/-) mice and mice treated with anti-IFNgamma developed more extensive inflammation of the airways than control mice. However mice lacking IFNgamma exhibited less severe signs of airway obstruction. Together these data suggest a protective role of IFNgamma in RSV infection in terms of limiting viral replication and inflammatory responses but also a pathogenic role in causing airway obstruction.

Common respiratory viruses in lower airways of patients with acute hypersensitivity pneumonitis.

Hypersensitivity pneumonitis (HP), a lung disease with "flulike" symptoms, results from repeated exposures to well defined, nonpathogenic antigens. This study examined whether respiratory viruses are present in the lower airways, the likely site of hypersensitivity reaction, in patients with HP. The polymerase chain reaction (PCR) method was used to test for 10 common respiratory viruses in bronchoalveolar lavage (BAL) cells obtained from patients with acute HP and from unexposed healthy volunteers. Immunocytochemistry was subsequently used to localize viral proteins within BAL cells. The results of PCR showed that influenza A virus was the most frequently detected virus in the BAL cells of our study patients (six of 13) and control subjects (two of six). Influenza A proteins were detected within alveolar macrophages in nine of 13 patients and in two of six control subjects. The number of total BAL cells, but not lymphocytes, was higher in patients with documented influenza A proteins than in patients with no influenza A proteins (p = 0.017) and correlated with the proportion of influenza-A-positive alveolar macrophages (r = 0.7; p = 0.036). This report documents the presence of viruses in the lower airways of patients with acute HP. The findings may imply a potential role for influenza A in the modulation of HP during antigen exposure.

Bronchoalveolar interferon-alpha, tumor necrosis factor-alpha, interleukin-1, and inflammation during acute influenza in pigs: a possible model for humans?

Biologically active interferon-α, tumor necrosis factor-α (TNF-α), and interleukin-1 (IL-1) were detected in bronchoalveolar lavage (BAL) fluids of 3-week-old cesarian-derived colostrum-deprived pigs inoculated with H1N1 influenza virus. Cytokine titers and lung virus titers were significantly higher 18–24 h after inoculation than at 48–72 h after inoculation in all 4 litters of pigs examined. All three cytokines were positively correlated with a 3- to 4-fold increase in BAL cell numbers (P < .036) and with a drastic neutrophil infiltration (24%–77% of BAL cells vs. 0–1.5% in controls) (P < .001). In addition, cytokine production coincided with the onset of general and respiratory symptoms of influenza and with the development of a necrotizing bronchopneumonia. This study is the first demonstration of TNF-α and IL-1 in BAL fluids of a natural influenza virus host. It documents that pigs may be a highly valuable experimental model in human influenza virus pneumonia.

Effect of Inhaled Cyclosporin on the Rat Airway: Histologic and Bronchoalveolar Lavage Assessment

Airway inflammation plays a pivotal role in asthma. Over the last 10 years, evidence has accumulated for the potential role of lymphocytes in airway inflammation. Since cyclosporin A (Cyc-A) can profoundly influence lymphocyte activation, it is appropriate to consider this drug as a novel antiasthmatic. The effect of inhalation of low doses of Cyc-A on airway inflammation remains unclear. The purpose of this study was to investigate the bronchoalveolar lavage (BAL), peripheral blood cell profiles, and lung biopsy specimens in Cyc-A-pretreated rats. Twenty-nine rats (8 controls, 10 ovalbumin sensitized, and 11 Cyc-A inhaling and ovalbumin sensitized) were included in the study. A commercial intravenous Cyc-A solution was given as a single dose of 20 mg/kg 1 h prior to inhalation of ovalbumin via nebulizer. The total number of BAL cells significantly increased in rats inhaling Cyc-A when compared with ovalbumin-sensitized rats (2.37 ± 2.34 × 10⁶/ml and 1.01 ± 0.49 × 10⁶/ml respectively, p < 0.05). There was a significant increase in the percentage of lymphocytes (14.5 ± 8.5 versus 27.4 ± 7.4%, p < 0.03), a nonsignificant increase in the percentage of eosinophils (0.8 ± 1.0 versus 3.0 ± 4.6%), and a significant decrease in the percentage of polymorphonuclear leukocytes (9.4 ± 6.9 versus 3.4 ± 3.8%, p < 0.01) and macrophages (75.4 ± 5.1 versus 50.2 ± 11.8%, p < 0.02) in BAL in the ovalbumin-sensitized group as compared with controls. Differential cell counts revealed a higher percentage of neutrophils and macrophages in the BAL of Cyc-A-pretreated rats than in that of the ovalbumin-sensitized group (26.3 ± 26.8 versus 3.4 ± 3.8%, p < 0.01 and 66.1 ± 7.7 versus 50.2 ± 11.8%, p < 0.02). There was a nonsignificant decrease of lymphocytes and eosinophils in the Cyc-A-pretreated group when compared with the ovalbumin-sensitized group (27.4 ± 7.4 versus 21.1 ± 12.4 and 3.0 ± 4.6% versus 2.4 ± 2.6%). The peripheral blood total white blood cell count decreased in the ovalbumin-sensitized and Cyc-A-pretreated groups as compared with the control group (2,520 ± 1,098/mm³, 3,591 ± 2,251/mm³, and 5,975 ± 2,787/mm³, respectively, p < 0.01). In addition, peripheral eosinophilia was detected in the Cyc-A-pretreated group when compared with controls and the ovalbumin-sensitized group (6.9 ± 4.7, 2.4 ± 1.1, and 2.6 ± 2.4%, respectively, p < 0.01). Light-microscopic examination of the airways revealed prominent eosinophilia in tracheal, bronchial, and bronchiolar sections in the ovalbumin-sensitized group: counts were 1.8 ± 2.3/HPF, 10.3 ± 11.4/HPF, 63.3 ± 45.0/HPF, respectively. Cyc-A resulted in a decrease of the eosinophil counts/HPF to 0/HPF in trachea (p < 0.05), to 4.3 ± 9.4/HPF in bronchi (p < 0.02), to 19.4 ± 38.4 in bronchioles (p < 0.004).In conclusion, the present study supports the theory that locally administered inhaled low-dose Cyc-A is effective on inflammatory cells of sensitized airways and peripheral cells. It may therefore be useful in elucidating the inflammatory mechanisms involved in asthma.

Role of interleukin-10 in the lung response to silica in mice.

There is evidence that, following exposure to crystalline silica, the release of several proinflammatory cytokines contributes to the induction of unbalanced inflammatory reaction leading to lung fibrosis. We have examined the potential contribution of interleukin-10 (IL-10), an anti-inflammatory cytokine, in the development of silicosis. In a mouse model of inflammatory lung reaction induced by intratracheal instillation of silica (0.5 mg and 5 mg DQ12/mouse), the levels of IL-10 protein (determined by ELISA) both in cells obtained after bronchoalveolar lavage (BAL) and in lung tissue homogenates were significantly increased when compared with controls. After in vitro lipopolysaccharide (LPS) stimulation (1 microg/ml), BAL cells obtained from silica-treated animals produced significantly more IL-10 protein and mRNA than cells obtained from control animals. To examine the role of IL-10 in the lung reaction induced by silica, IL-10-deficient animals were instilled with 5 mg of silica. Twenty-four hours after treatment, the amplitude of the inflammatory response (lactate dehydrogenase [LDH], protein and number of inflammatory cells in BAL) was significantly greater in IL-10-deficient animals than in the wild type. In contrast, the fibrotic response, evaluated by measuring lung hydroxyproline content and by histopathologic analysis 30 days after silica, was significantly less important in IL-10-deficient than in wild-type mice. Together, these data suggest that increased IL-10 synthesis induced by silica can limit the amplitude of the inflammatory reaction, but also contributes to amplify the lung fibrotic response.

Methylmercury-induced alterations in lung and pulmonary surfactant properties of adult mice

Exposure to methylmercuric chloride (MMC) has been shown to significantly affect development of the lung and pulmonary surfactant system of the fetus. Preliminary results suggest it may also affect adult lung and associated bronchoalveolar lavage (BAL), which represents the extracellular surfactant pool. To determine if mercury exposure has the potential to alter surfactant function, adult mice were treated with MMC, 15 mg/kg by intragastric intubation on 4 successive days. BAL was collected by repeated intratracheal lavage 24 h after the last treatment. Nucleated cell numbers in lavage were determined. Tissue was prepared for scanning electron microscopy (SEM). Lavage fluid was extracted into chloroform:methanol and phospholipid concentration determined. A sample of the extract was used at a constant phospholipid concentration to measure surface activity on a bubble surfactometer. Lung weight to body weight ratio increased whereas total numbers of nucleated cells in BAL were not altered by MMC. SEM of samples from lungs of animals exposed to MMC showed normal architecture. Surface tension measurements suggest that the mean time to minimum surface tension and the minimum surface tension were greater in BAL from mice exposed to MMC for 4 days. In addition samples of BAL were prepared for Fourier-transform infrared spectrophotometry (FT-IR). Spectra showed changes in both lipid and protein components of BAL. Morphometric analyses of micrographs showed that mean alveolar diameter was reduced and wall thickness increased after mercury exposure. These results suggest that methylmercury exposure may significantly affect surface tension characteristics and composition of BAL, possibly through leakage of edematous interstitial tissue.

Interleukin-4 receptor blockade prevents airway responses induced by antigen challenge in mice.

The functional role of interleukin (IL)-4 in the development of airway hyperresponsiveness (AHR) and pulmonary eosinophilia in response to sensitization and challenge of mice with sheep red blood cells (SRBC) was examined. Control- and SRBC-sensitized A/J mice were treated with an antibody to the murine IL-4 receptor (anti-IL-4R) 3 days before intratracheal challenge with the antigen or vehicle only. Blockade of IL-4R significantly reduced antigen-induced AHR and prevented increases in goblet cells and bronchoalveolar lavage (BAL) eosinophils. Treatment with anti-IL-4R did not affect antigen-induced increases in lung mRNA and BAL protein levels of IL-5 and interferon-gamma or IL-4 mRNA but did significantly increase IL-4 protein levels. Antigen-induced AHR was not reduced by treatment with antibodies to the adhesion molecules, vascular cell adhesion molecule-1 and very late activation antigen-4. Administration of IL-4 over a 7-day period did not increase airway reactivity or induce any changes in BAL cell numbers in naive mice. These results demonstrate that IL-4 is necessary for in vivo development of antigen-induced AHR, goblet cell metaplasia, and pulmonary eosinophilia.

Effect of contact avoidance or treatment with oral prednisolone on bronchoalveolar lavage surfactant protein A levels in subjects with farmer's lung.

Surfactant protein A (SP-A) acts as an immune system modulator in the lungs and may therefore be involved in the pathogenesis of hypersensitivity pneumonitis. The levels of SP-A in bronchoalveolar lavage (BAL) fluid were measured in 20 subjects with acute farmer's lung, 16 asymptomatic dairy farmers, and 14 normal controls. Eight patients had a second evaluation after one month of treatment by either contact avoidance (n = 3) or oral prednisolone (20 or 25 mg/day, n = 5). Chest radiographs and lung function measurements were also obtained in all farmers, twice in those re-evaluated after treatment. Patients with acute farmer's lung had significantly higher levels of SP-A than asymptomatic farmers and normal controls (p = 0.005) with mean (SE) values of 1.43 (0.29) micrograms/ml, 0.62 (0.09) microgram/ml, and 0.68 (0.11) microgram/ml, respectively. In eight subjects tested after one month of treatment the level of SP-A was unchanged although all were clinically improved. No correlations were seen between levels of SP-A in BAL fluid and numbers of BAL cells, lung function measurements, or chest radiographic scores. Although the level of SP-A is increased in the BAL fluid of patients with acute farmer's lung, it is not correlated with clinical abnormalities of this disease.

Freshly fractured quartz inhalation leads to enhanced lung injury and inflammation. Potential role of free radicals.

Silicosis is a devastating pulmonary disease that continues to occur in industrial workplaces. Its pathogenesis is under critical evaluation, and this report provides new concepts on the possible early events that occur in lungs resulting from the inhalation of freshly fractured versus aged quartz in the development of two diverse disease entities. In this study, we evaluated the biochemical and pathologic changes in the lavagate and lungs of rats exposed to freshly fractured quartz (generated by jet milling), aged quartz (milled then aged for 2 mo prior to use), or clean air 5 h a day for 10 d over a 2-wk period. The concentration of crystalline quartz in the chambers averaged 20 mg/m3. Particle concentrations and particle size were similar for the freshly milled and aged quartz exposures. However, free radical concentrations associated with the freshly milled quartz samples were significantly higher than those for aged quartz. After a 2-wk exposure, animals were killed and studied by bronchoalveolar lavage and pulmonary histopathology. Inhalation of aged quartz increased the number of bronchoalveolar lavage cells, demonstrated histopathologic evidence of increased pulmonary infiltrates, showed enhanced concentrations of biochemical markers of lung injury, increased lipid peroxidation, and the ability of pulmonary phagocytes to produce more oxygen radicals. In general, all these pulmonary responses were significantly more pronounced after inhalation of freshly fractured quartz compared with aged quartz. In contrast, antioxidant enzymes showed decreased concentrations in the freshly fractured quartz-exposed group compared with the aged quartz-exposed animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Dysregulation of interleukin 4, interleukin 5, and interferon gamma gene expression in steroid-resistant asthma.

In steroid-resistant (SR) asthma, there is a lack of clinical responsiveness to oral prednisone. Previous studies indicate that this may be explained by the effect of the combination of interleukin 2 (IL-2) and IL-4 on glucocorticoid receptor binding affinity. By contrast, steroid-sensitive (SS) asthmatics respond well to glucocorticoids, and this is accompanied by a decrease in the numbers of bronchoalveolar lavage (BAL) messenger RNA+ (mRNA+) cells expressing IL-4 and IL-5, and an increase in interferon gamma (IFN-gamma) transcripts. In the present study, we hypothesized that SR asthma is associated with alterations in T helper types 1/2 (Th2/Th1)-type cytokine gene expression. BAL was performed in six SR asthmatics and six SS asthmatics, before and after a 1-wk course of 40 mg daily prednisone. mRNA+ cells for IL-2, IL-4, IL-5, and IFN-gamma was measured by in situ hybridization using 35S-labeled RNA probes. Before prednisone therapy, there were significantly greater numbers of BAL cells (per 1,000) expressing IL-2 mRNA (p < 0.01) and IL-4 mRNA (p < 0.05) in SR asthmatics as compared with SS asthmatics, but no differences between the two groups in the numbers of BAL cells expressing IFN-gamma or IL-5 mRNA expression were observed. After a 1-wk course of prednisone, IL-2 expression was not altered in either group. However, SS asthmatics had a significant decrease in the numbers of BAL cells expressing mRNA for IL-4 (p < 0.01) and IL-5 (p < 0.001), and a rise in the numbers of IFN-gamma mRNA+ cells (p < 0.01). In contrast, after prednisone treatment, SR asthmatics had no significant change in either the number of BAL cells expressing mRNA for IL-4 or IL-5. Of note, there was an unexpected decrease in the numbers of IFN-gamma mRNA+ cells (p = 0.05). Our current findings indicate that SR asthma is associated with a dysregulation of the expression of the genes encoding for Th2/Th1 cytokines in airway cells and is compatible with the concept that a combination of IL-2 and IL-4 induce glucocorticoid (GR) binding affinity and T cell responsiveness to glucocorticoids.

Differential cell count and lymphocyte subsets in bronchoalveolar lavage during pneumonia with and without peripheral neutropenia.

One hundred immunocompromised HIV negative patients with microbiologically positive pneumonia underwent bronchoalveolar lavage (BAL) studies. Thirty cases showed peripheral neutropenia (< 1000 neutrophils/microL), 70 did not. The total cell number in BAL, the differential cell counts, and the lymphocyte subsets (CD4, CD8, CD19, CD57) were measured. Patients with pneumonia and normal or elevated peripheral neutrophils had a significantly increased total number of cells in BAL compared to patients with peripheral neutropenia (3.2 +/- 2 vs 1.3 +/- 0.6 x 10(5) cells/ml2 lavage fluid, p < 0.01). Ninety percent of the BAL differential cell counts obtained in patients exceeding 1000 neutrophils/microL showed a lymphocytic and/or neutrophilic alveolitis, whereas only 54% of patients with peripheral neutropenia displayed abnormal counts (p < 0.01). Yet the typical pattern of neutrophilic alveolitis was found more often for peripheral neutrophil counts over 1000/microL with high significance (p < 0.0001). Abnormal BAL cell patterns for neutropenic patients uniformly showed a lymphocytic alveolitis, only 10% additionally conformed with the pattern of neutrophilic alveolitis. Patients with pneumonia with and without peripheral neutropenia had similar findings in BAL lymphocyte subsets and exhibited a reduced CD4/CD8 ratio compared to controls (p < 0.05). The high susceptibility of severe neutropenic patients to pulmonary, especially fungal infections may be explained by the local lack of neutrophils.

Blockade of leukocyte function-associated antigen (LFA-1) in a murine model of lung inflammation.

We examined the contribution of the leukocyte function-associated antigen (LFA-1) in a murine model of lung inflammation determined by exposure to the thermophilic actinomycete Faeni rectivirgula. The exposure generated a large influx of cells in the bronchoalveolar space and in the lung parenchyma, as seen from enhanced numbers of cells recovered by bronchoalveolar lavage (BAL) and histologic scoring of lung lesions. Repeated intranasal exposure to F. rectivirgula also resulted in a significant increase in lung hydroxyproline levels. Histologic analysis showed that alveolar wall inflammation, interstitial swelling and congestion, epithelial cell destruction, and granulomas with occasional epithelioid cells were observed in the lungs of challenged mice. Mice injected with rat antibodies against LFA-1 concomitantly with an antigen challenge showed no reduction in the number of BAL inflammatory cells, but lung fibrosis was significantly reduced by anti-LFA-1 treatment as assessed by lung hydroxyproline levels; parenchymal inflammation and tissue damage were also significantly reduced as seen from morphometric analysis. Anti-LFA-1 treatment of mice with established hypersensitivity pneumonitis was found to significantly reduce the levels of lung hydroxyproline and tissue damage; the numbers of BAL cells remained unaffected. From these results, we conclude that the fibrosis and tissue-damaging reactions in hypersensitivity pneumonitis, but not the alveolitis, are partly dependent on LFA-1-mediated cellular interactions.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental allergic bronchopulmonary aspergillosis in the mouse: immunological and histological features.

C57BL/6 mice treated with intranasal instillation of 100 micrograms of Aspergillus antigen three times a week developed a pulmonary eosinophilia, observed in the bronchoalveolar lavage (BAL) and on histopathological examination. At week 3, the instillation of Aspergillus antigen provoked a 10-fold increase in the BAL cell number and eosinophils were the predominant inflammatory cells (66.4%). Histopathological findings showed focal alveolar lesions with peribronchial and perivascular infiltration of lymphoid cells, numerous eosinophils, epithelioid cells, and granulomas with giant cells. Increases in total IgE and IgG1 levels in BAL fluid (33-fold and 14-fold) and serum (67-fold and 8-fold) were observed also (P < 0.05). IgG1 specific to Aspergillus fumigatus (Af) was detected only in the antigen-treated mice. At 12 weeks, there was a persistent but less intense eosinophilia both in BAL and on histopathological examination accompanied by steadily elevated total IgE and total IgG1 and a higher level of specific IgG1-Af in BAL fluids and sera. No bronchocentric granulomatosis, mucoid impaction nor bronchiectasis could be observed. Data from the study described here showed that in mice repeated exposure to Aspergillus antigen leads to a strong inflammatory pulmonary response, characterized by remarkable pulmonary eosinophilia and elevations of total IgE, total IgG1 and specific IgG1-Af in both BAL and serum, which are the hallmarks of human allergic bronchopulmonary aspergillosis also. However, this inflammation did not induce the chronic histological features of the human disease.

Pneumonia in pigs inoculated with pseudorabies virus by means of a bronchoscope

Pigs inoculated endobronchially (EB) with 2 ml of virus suspension containing 10(4) TCID50 per ml of the YS-81 strain of pseudorabies virus (PRV), by means of a bronchoscope, all developed viral pneumonia. No pneumonic lesions were observed in intranasally inoculated pigs. Macroscopical and microscopical lesions were localized to the middle to caudal parts of the right caudal lobe and were closely associated with the site at which the inoculum was deposited. PRV became attached to all types of cells and caused destruction of epithelial cells, and viral antigen persisted in the alveolar macrophages. After PRV infection, the total cell number in broncho-alveolar lavage (BAL) fluid was slightly increased and a high titre of PRV was found in the cells of BAL fluid in EB infected pigs. The findings suggest that PRV infection leads to dysfunction of alveolar macrophages before cell death is produced by virus replication.