Bronchoalveolar lavage and transbronchial lung biopsy during acute rejection and infection in heart-lung transplant patients. Studies of cell counts, lymphocyte phenotypes, and expression of HLA-DR and interleukin-2 receptor

The total and differential cell counts of 135 bronchoalveolar lavages (BAL) in 48 heart-lung transplant (HLT) patients were compared with the histologic findings in concurrent transbronchial lung biopsies (TBBs). Counts of CD3+, CD4+, and CD8+ lymphocytes were recorded, and a semiquantitative assessment of HLA-DR and interleukin-2 receptor (IL-2R) expression was made on 29 occasions. There were five diagnostic categories: normal (n = 8), acute rejection (ALR) (n = 57), treated rejection (TR) (n = 19), infection (INF) (n = 24), and chronic rejection (CR) (n = 24). Total cell counts in INF were significantly higher than counts in all the other diagnostic groups. The highest BAL lymphocyte counts, significantly higher than in INF, were found in ALR because of increased CD8+ cells, exceeding 15% in 13 of 57 BALs. TBBs in ALR by contrast showed significantly increased numbers of both CD8+ and CD4+ cells. High dose corticosteroid treatment of ALR caused a fall in cellularity of BAL and TBB specimens but not always to values seen when patients were well. During INF and CR, significantly increased numbers of PMNs were seen in the BAL. HLA-DR and IL-2R expression was enhanced in cells of BAL and TBB in all complications. BAL can only supplement at present histologic examination of TBB in the diagnosis of complications after HLT.

Pleuropulmonary abnormalities in primary Sjögren's syndrome

Sixteen patients with primary Sjögren's syndrome (1 degree SS) who complained of dyspnea were investigated with high resolution computerized tomography of the thorax, bronchoalveolar lavage, and transbronchial biopsy. Six patients had evidence of interstitial fibrosis, 5 had a peribronchiolar lymphocytic infiltration and 3 had pleural thickening. We conclude that significant pulmonary disease is not uncommon in patients with 1 degree SS.

Increased pulmonary response to inhaled endotoxin in lactating rats

An important aspect of risk assessment is identification of subpopulations particularly susceptible to the effects of inhaled pollutants. The present study examined whether female rats were more sensitive during lactation to the acute pulmonary injury produced by inhaled endotoxin. Lactating and age-matched virgin female rats were exposed to aerosols of saline or endotoxin for 3 h and lavaged at 24 h after exposure. No significant differences in lactate dehydrogenase, beta-glucuronidase, total protein, and total cell and PMN counts were observed between virgin and lactating rats after exposure to saline. Each marker of pulmonary injury except beta-glucuronidase was 1.5- to 3-fold greater in lactating than in virgin female rats exposed to 29.6 micrograms/m3 endotoxin. PMNs (6-fold), total cell counts, and protein were also significantly increased (p < 0.05) in lactating rats exposed to 1.3 micrograms/m3 endotoxin, a concentration reported to occur in a number of agricultural settings. These results demonstrate that the physiologic state of lactation is associated with an increased sensitivity to the acute pulmonary injury produced by inhaled endotoxin and are consistent with previous work demonstrating a similar increased sensitivity to ozone exposure. The possibility of a similar pattern of enhanced response in analogous groups of humans merits examination.

Distribution of asbestos bodies in the human lung as determined by bronchoalveolar lavage

Asbestos-related lung diseases tend to have distinct local distributions, for example, asbestosis first appears and tends to be more severe in the peripheral parts of the lower lung zones. The risk for asbestosis is related to the total asbestos burden of the lung. This suggests that the lower lobes in asbestos-exposed individuals may contain more asbestos than the other lobes. To test whether such topographic differences exist, we compared the number of retrieved asbestos bodies (AB) per ml BAL fluid in three groups of occupationally asbestos-exposed subjects who underwent BAL at different sampling sites. In Group 1 (n = 24) we performed BAL at three sites, namely in a segment of the right upper, right middle, and right lower lobe, to evaluate differences in asbestos body burden from lung apex to basis. There was a distinct increase in BAL asbestos body concentrations from the upper (21.2 +/- 9.1 AB/ml BAL fluid) to the middle (30.4 +/- 12.8 AB/ml BAL fluid) and to the lower lobe (56.0 +/- 20.2 AB/ml BAL fluid), all differences being significant (p < 0.01). In Group 2 (n = 40), we found good interlobar correlations for asbestos body counts between the right middle lobe (21.0 +/- 5.8 AB/ml BAL fluid) and the lingula (22.4 +/- 5.9 AB/ml BAL fluid) (r = 0.941, p < 0.001) and, in Group 3 (n = 15), between the ventral basal segment of the right (41.2 +/- 13.6 AB/ml BAL fluid) and left lung (39.0 +/- 13.6 AB/ml BAL fluid) (r = 0.966, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Modulation of biochemical and cytological profile of bronchoalveolar lavage constituents in rats following split-dose multiple inhalation exposure to methyl isocyanate

1. Studies were carried out to explore the acute pulmonary effects of equal, split-dose, multiple inhalation exposures of rats to methyl isocyanate (MIC), (0.32 mg l-1, 8 min x 10 exposures) as reflected by alterations in bronchoalveolar lavage fluid (BALF) constituents and to evaluate recovery, if any, following survival in a MIC-free environment, 10 d after the last MIC exposure. 2. In the BALF of MIC-exposed rats, there was an increase in the total number of cells and the number of cells showing enhanced dye uptake and reduction of nitroblue tetrazolium chloride. The cell-free BALF showed increases in total protein, sialic acids and lactic acid contents and lactate dehydrogenase activity. 3. In rats exposed to MIC and sacrificed 10 d after survival in a MIC-free environment, there was a reduction in the cellular and biochemical constituents of BALF. The phagocytic potential of macrophages was, however, also decreased under this regime.

Effect of stabling on bronchoalveolar cells obtained from normal and COPD horses

Bronchoalveolar lavages (BAL) were performed before and after 3 weeks of housing in 5 horses suffering from COPD and 5 normal horses. In the two groups, the total number of cells recovered remained unchanged after stabling. The most common cell populations in BAL fluid of control animals were alveolar macrophages (46.4%) and lymphocytes (44.9%). The percentage of neutrophils increased after stabling from 8.7% to 27.6%. In COPD horses, lymphocytes predominated (40.7%) in animals at pasture with neutrophils increasing from 29.4% to 71.6% after stabling. After fractionation by Percoll density gradient, alveolar macrophages and neutrophils from normal and COPD horses had a similar density distribution. After stabling, these cells from normal horses were increased in the low density layers, while those from COPD horses were predominantly in the hyperdense layers. Therefore, BAL cells obtained from COPD animals at pasture and after stabling differ from those of control horses in the same environment, not only in their populations but also in their buoyant densities. These differences could be related to different states of cellular activation and perhaps be responsible for disease activity in the COPD horses.

Cytologic diagnosis of metastatic malignant melanoma of the lung in sputum and bronchial washings. A case report

A 60-year-old woman with a fever, productive cough, anorexia, weight loss and past history of malignant melanoma of the finger proved to have metastatic melanoma in both lungs on cytologic study of sputum and bronchial washings. The literature in English over 40 years (1952-1992) gives only a few hints about the value of cytologic diagnosis of metastatic malignant melanoma of the lung. Cytologic features include a variable amount of melanin pigment, isolated or loosely cohesive groups of round to oval cells with eccentric nuclei, regular nuclear outline, anisocytosis, binucleation and multinucleation, fine chromatin pattern and prominent nucleoli.

Transbronchial lung biopsy in the diagnosis of suspected ocular sarcoidosis

We conducted clinical research using transbronchial lung biopsy in 60 patients with suspected ocular sarcoidosis who showed no bilateral hilar lymphadenopathy and sparse contributory evidence for sarcoidosis. The patients had a combination of granulomatous iritis with mutton-fat keratic precipitates or iris nodules, trabecular nodules, tent-like peripheral anterior synechiae, snowball or string-of-pearls vitreous opacities, retinal perivasculitis, and spotty retinochoroidal exudates. The transbronchial lung biopsy specimen showed noncaseating epithelioid granuloma in 37 patients (61.7%); these patients were diagnosed as having sarcoidosis. Bronchoalveolar lavage showed a high percentage of patients with an increased lymphocyte fraction among those with positive transbronchial lung biopsy results. The present results may serve as a basis for a clinical diagnosis of sarcoidosis in patients with suspected sarcoidosis without apparent extraocular manifestations.

Whole-body hyperthermia combined with hyperfractionated irradiation of the thorax in dog: acute physiological response

Whole-body hyperthermia has potential as an adjuvant treatment with chemotherapy and radiation therapy for diseases such as lung cancer which require both local and systemic control. The acute toxicity of whole-body hyperthermia combined with whole-thorax irradiation was studied in dogs. Twenty-eight dogs received three 2-h whole-body hyperthermia (WBH) treatments at 42.0 degrees C deep rectal temperature. Twenty-four of these dogs were also randomized to receive radiation doses of 18, 22.5, 27, 31.5, 40.5 or 45 Gy. Irradiation was given in 1.5 Gy fractions over 6 weeks. Three WBH treatments were given to 28 dogs with all dogs surviving treatment. WBH was given on days 1, 22 and 40 of the 6-week interval. Thirty-one dogs received radiation doses of 18-49.5 Gy without WBH. Deep rectal temperature was maintained at 41.9 +/- 0.3 degrees C over 2 h with an average of 20 min outside the chamber for irradiation. Two dogs required intervention with emergency medications during WBH treatment. One of the two dogs developed permanent neurological injury. Continuous physiological monitoring was necessary for successful WBH. WBH plus thoracic irradiation was well tolerated. All dogs survived all treatments. A significant but transient increase in peripheral blood leucocytes and a decrease in platelet counts occurred after each WBH treatment. The addition of thoracic irradiation up to 45 Gy in 1.5 Gy fractions did not appear to alter the acute toxicity of WBH with the exception of an increase in the protein content of lung lavage fluids. In conclusion, multiple WBH treatments of 2 h at a target temperature of 42 degrees C in addition to thoracic irradiation up to 45 Gy in 1.5 Gy fractions was administered with only mild acute toxicities occurring. Core temperature could be maintained for up to 20 min outside of the WBH chamber which allowed irradiation to be given concurrently with hyperthermia at a core temperature of 42 degrees C +/- 0.1 degree C.

Controlled short-time terpene exposure induces an increase of the macrophages and the mast cells in bronchoalveolar lavage fluid

Eight healthy nonsmoking volunteers underwent terpene exposure (450 mg/m3 air) on 4 different occasions within a 2 week period. Total exposure time was 12 hours. Before and after the sequences of exposure, bronchoalveolar lavage was performed. Twenty hours after the exposure there was a significant (p < 0.05) increase of the alveolar cell concentration (median pre-exposure value 76 x 10(6) cells/L, post-exposure value 126 x 10(6) cells/L), predominantly due to an increment of the macrophages (from 72 x 10(6) cells/L to 121 x 10(6) cells/L). The mast cells also increased from 1/10 to 5/10 visual fields. No elevated concentrations of albumin, fibronectin, hyaluronan (hyaluronic acid), and tryptase were observed. We conclude that terpene exposure, in a concentration regarded as moderate, induces an acute alveolar cellular reaction in healthy subjects.

Pulmonary toxicity of deferoxamine in iron-poisoned mice

Previously we have shown that a group of patients treated for iron overdose with prolonged deferoxamine (DFO) infusion died of adult respiratory distress syndrome (ARDS). We now describe a model to investigate the mechanism of this pulmonary toxicity. Mice treated with 1 oral dose of iron (Fe) and then multiple injections of DFO, or with the chelated product ferrioxamine alone, did not develop lung lesions, even at doses which induced mortality. To potentiate any possible free radical reaction, other groups of mice were treated similarly while exposed to 75-80% O2 over a 4-day period. Ten of 12 mice receiving 0.75 mg Fe and then DFO (10 mg, 4 times/day for 4 days) with hyperoxia died suddenly. At autopsy the lungs were dark red and solid; sections showed hyaline membranes and alveolar exudates of edema, fibrin, and PMN. Electron microscopy showed massive destruction of the alveolar epithelium; using cerium chloride, a free radical reaction product was demonstrated at the alveolar surface. Lung lavage fluid contained 10-12 x normal levels of protein when the Fe-DFO-O2 group was compared to air or O2 controls. Mice receiving DFO or Fe, plus O2, showed only slight injury and a small increase in alveolar protein. The results indicate that Fe plus DFO generates free radicals in the lung, a reaction potentiated by hyperoxia to produce an ARDS-like picture. This suggests that the pulmonary toxicity of DFO in iron-poisoned patients is due to its prooxidant activity resulting in free radical destruction of the airblood barrier.

Cyclophosphamide and low-dose prednisone therapy in patients with systemic sclerosis (scleroderma) with interstitial lung disease

Fourteen patients with systemic sclerosis (SSc, scleroderma) and interstitial lung disease were treated with oral cyclophosphamide (1-2 mg/kg/day) and low dose prednisone (< 10 mg/day). There was a significant improvement in FVC after 6 months compared to entry values (2.21 +/- 0.19 l vs. 2.03 +/- 0.15 l, p < 0.02). Improvement was maintained at 12 months (2.27 +/- 0.27 l, p < 0.05) and 18-24 months (2.60 +/- 0.28 l, p < 0.001). In 12 cases followed for 18-24 months, FVC was stable or improved. No significant improvement or decline was noted for the DLCO. Side effects included cytopenia (2), infection (1), and hemorrhagic cystitis (2), and one possible related malignancy. A controlled prospective trial of cyclophosphamide is warranted in patients with SSc and active interstitial lung disease.

Peripolesis in alveolar sarcoidosis

We observed that in bronchoalveolar lavages (BAL) of patients with active sarcoidosis (SARC) a mononuclear cell infiltrate is present that often contains clusters consisting of lymphocytes adhering to a macrophage. In order to investigate what kind of cellular interactions are involved in such a process, cell suspensions obtained from BAL of patients with SARC or extrinsic allergic alveolitis (EAA) were cultured for 1 to 2 days, during which time lapse cinematography was applied. We were able to show that such clusters consist of lymphocytes gathered around a macrophage. This is known as peripolesis. Peripolesis, as observed in our BAL, could last for some minutes or for some hours during which time a number of lymphocytes were moving around a single alveolar macrophage, without losing contact with the macrophage. Short interactions were mostly observed in EAA, whereas SARC was characterized by long periods of lymphocyte-macrophage cooperation. We also found a correlation between the time-dependent peripolesis t > 30 min/t < 30 min and the CD4/CD8 ratio. Although the precise mechanisms of peripolesis are not well understood, some interactions between lymphocytes and macrophages have now become more comprehensive.

Epithelial-fibroblast interactions in bleomycin-induced lung injury and repair

Intercellular communication between epithelial cells and fibroblasts of the alveolar wall contributes to regulatory control of each cell type. We examined whether lung injury and subsequent fibrosis are associated with disturbance of this mutual control system. Rats received bleomycin intratracheally, and after 10 days, when acute epithelial injury occurs, and at 6 weeks, when repair with fibrosis is found, pure populations of type 2 epithelial cells and lung fibroblasts were prepared to study interactions with respect to growth control. Epithelial cells were cultured alone, on a permeable filter over fibroblasts, and in co-culture with fibroblasts. The results showed that the low growth rate of normal epithelial cells increased when cells were exposed to fibroblast supernatants. This effect was also seen using cells from the 10-day bleomycin group, but it was diminished in the group treated for 6 weeks. However, epithelial cells from exposed or control rats did not show increased DNA synthesis when grown in contact with fibroblasts in co-culture. In contrast, fibroblast growth was inhibited when exposed to epithelial cell secretions in control cultures and when using cells from the 10-day bleomycin group. No inhibition of fibroblast growth by epithelial cells was found using cells from the fibrotic lungs. These results suggest that after lung injury by bleomycin, a fibroblast-secreted factor promotes epithelial growth; however, during repair, regenerating epithelial cells lose the ability to inhibit fibro-blast proliferation. These local changes in cellular control at the alveolar wall may be sufficient to produce pulmonary fibrosis.

The diagnosis of Pneumocystis carinii pneumonia by cytologic evaluation of Papanicolaou and Leishman-stained bronchoalveolar specimens in patients with the acquired immunodeficiency syndrome

The presence of foamy alveolar casts or flocculent material in Papanicolaou and Leishman-stained smears of bronchoalveolar lavage (BAL) fluid is said to be indicative of infection with Pneumocystis carinii. We have investigated the sensitivity and specificity of this method of diagnosing pneumocystis pneumonia in patients with the acquired immunodeficiency syndrome (AIDS). Patients (n = 114) with diffuse lung infiltrates were submitted to fibreoptic bronchoscopy and BAL. Seventy of them were patients with AIDS. The other 44 individuals were not infected by the human immunodeficiency virus (HIV). Pneumocystis carinii organisms were identified on Grocott's methenamine silver (GMS)-stained BAL smears in 30 patients with AIDS. Flocculent material was present in the Papanicolaou and Leishman-stained smears from all of these cases. Conversely, P. carinii were not seen on GMS-stained smears in the remaining 84 individuals with or without AIDS. No flocculent material was observed in Papanicolaou or Leishman-stained smears in these 84 patients. We concluded that the presence of flocculent material in Papanicolaou or Leishman-stained smears of BAL fluid is indicative of P. carinii pneumonia in patients with AIDS.

Rapid diagnosis of cytomegalovirus pneumonia in marrow transplant recipients by bronchoalveolar lavage using the polymerase chain reaction, virus culture, and the direct immunostaining of alveolar cells

The objective was to compare the use of the polymerase chain reaction (PCR), virus culture, and immunostaining of alveolar cells used alone and in combination as diagnostic methods for the rapid diagnosis of cytomegalovirus (CMV) pneumonia in marrow transplant recipients. Seventy-five marrow transplant recipients with clinical and radiological evidence of pneumonitis were used as subjects. Bronchoalveolar lavage was performed on all patients to obtain material for conventional and/or rapid CMV culture, immunostaining of alveolar cells with monoclonal antibodies (MoAbs), and amplification of CMV-DNA by PCR. Assay results were then prospectively correlated with clinical outcome. Seven of the 75 patients (9.3%) had CMV pneumonitis and 6 patients (8%) had CMV infection without pneumonia. PCR is the most sensitive assay for the detection of CMV in bronchoalveolar lavage fluid. For the diagnosis of CMV pneumonitis, the sensitivity of alveolar cell immunostaining and PCR were both 100%. The sensitivity of virus culture was 85.7%. The positive predictive value for each test, used alone, for the identification of CMV pneumonitis was low. However, when the result of the PCR assay was assessed in combination with CMV immunostaining of alveolar cells, the sensitivity, specificity, positive, and negative predictive value of this strategy was 100%. The concomitant use of PCR and the rapid immunostaining of alveolar cells for CMV has facilitated the development of a sensitive and specific diagnostic algorithm for the detection and early treatment of CMV pneumonitis in transplant recipients.

Acrolein increases airway sensitivity to substance P and decreases NEP activity in guinea pigs

The effects of acrolein exposure on airway responses to intravenous substance P were determined in guinea pigs exposed to vehicle or 1.6 ppm acrolein for 7.5 h on 2 consecutive days and examined 1, 4, 8, 15, and 28 days after exposure by use of pulmonary mechanics and bronchoalveolar lavage (BAL). Lung, trachea, liver, and BAL fluid were also assayed for neutral endopeptidase (NEP) activity 1, 7, and 28 days after exposure. Pulmonary inflammation and epithelial damage were prominent 1 day after acrolein exposure. NEP activity was decreased in the lungs, trachea, and liver 1 and 7 days after acrolein. Twenty-eight days after exposure, NEP activity in the lungs and liver was not significantly different in vehicle- and acrolein-exposed guinea pigs but was still reduced in tracheal tissue. The BAL NEP activity in acrolein-exposed guinea pigs was approximately twice that of vehicle control guinea pigs at all three time points. Acrolein caused a prolonged increase in airway sensitivity to substance P. Experiments performed in the presence of thiorphan suggested that the acrolein-induced reduction in NEP may contribute to increased airway sensitivity to aerosolized substance P, but the increase in airway sensitivity to intravenous substance P may occur by additional mechanisms.

A study of monokine release and natural killer activity in the bronchoalveolar lavage of subjects with farmer's lung

We examined the interleukin-1 (IL-1) and tumor necrosis factor alpha (TNF alpha) releasability of alveolar macrophages and the natural killer (NK) cell activity in the bronchoalveolar lavage (BAL) cells of 11 patients with Farmer's lung at different stages of the disease. Although there were some variations in the levels of monokine release, macrophages of patients with acute disease secreted significantly higher spontaneous levels of TNF alpha than did a nonfarming control group (p = 0.0002). Conversely, TNF alpha release stimulated by bacterial lipopolysaccharide (LPS) was similar in patients with acute disease when compared with that in normal control subjects. IL-1 was also spontaneously secreted in significantly greater amounts by patients with acute Farmer's lung than by subjects in a control group (p = 0.0001). However, LPS-induced IL-1 release was significantly diminished in BAL macrophages from patients with acute manifestations of the disease when compared with that in control subjects (p = 0.001). Treating hypersensitivity pneumonitis with corticosteroids or by contact avoidance resulted in very significant decrease in spontaneous and LPS-stimulated IL-1 production by BAL macrophages (p = 0.0001 and p = 0.03, respectively), as well as in a decrease in spontaneous TNF alpha release that was also significant (p = 0.01). In addition, BAL cells of patients in the acute phase had a significant NK cell activity (mean +/- SEM of 18.33 +/- 2.65%). Treatment of these patients resulted in an increase in NK cell activity (mean of 40.17 +/- 7.86%), which was significantly different from values of patients with acute disease (p = 0.037).(ABSTRACT TRUNCATED AT 250 WORDS)

Quantification of histamine in plasma and pulmonary fluids from horses with chronic obstructive pulmonary disease, before and after 'natural (hay and straw) challenges'

A commercial radioimmunoassay kit was used to quantify histamine concentrations of plasma, bronchoalveolar lavage fluid (BALF) and pulmonary epithelial lining fluid (PELF) of normal horses and horses with chronic obstructive pulmonary disease (COPD), before and after 'natural (hay and straw) challenge' (NC). There were no significant changes in the concentrations of histamine in plasma or BALF at 0.5 or 5 h after NC, but the PELF histamine concentration of COPD affected horses was significantly increased at 5 h, but not at 0.5 h, following NC. As the histamine concentrations of whole BALF lysates were significantly correlated with the numbers of metachromatically staining cells, presumed to be mast cells and/or basophils, these findings support involvement of a late phase, IgE mediated, hypersensitivity reaction in the pathogenesis of equine COPD.

Endotoxin priming followed by high altitude causes pulmonary edema in rats

Rapid ascent to high altitude may be associated with the development of high-altitude pulmonary edema (HAPE) in susceptible individuals. Because lung lavage fluid obtained from such patients can be rich in protein and neutrophils, we considered that an element of lung injury and inflammation contributed to the pathogenesis of some forms of HAPE. On the basis of such a likely contribution of inflammatory mechanisms, we induced pulmonary lung injury and inflammation by priming rats with Salmonella enteritidis endotoxin (ETX) (0.1 or 0.5 mg/kg body wt ip) and examined the influence of added exposure to simulated hypobaric hypoxia (24 h, 4,300 m). The animals that were primed with ETX and exposed to hypoxia, but not those that received either ETX or hypoxia alone, developed lung vascular damage. This vascular damage manifested itself histologically and by increases in the lung vascular permeability-surface area product and the lung bloodless wet weight-to-dry weight ratio. The bronchoalveolar lavage fluid of ETX-primed hypoxia-exposed rats contained a greater number of white blood cells and a higher concentration of protein compared with that of the ETX-primed rats. Hearts of ETX + hypoxia-treated rats showed an increased ratio of right ventricular weight divided by body weight (RV/BW). Neutropenia prevented the development of pulmonary edema and the increase in ETX + hypoxia rats with a Ca2+ entry blocker inhibited lung injury and RV hypertrophy, these results indicate that ETX priming causes pulmonary edema at high altitude and suggest a role for neutrophils and Ca2+ in this rat model of lung injury.

Changes in bronchoalveolar lavage inflammatory cells in asthmatic patients treated with high dose inhaled beclomethasone dipropionate

Using serial bronchoalveolar lavage (BAL), we have studied changes in the airway inflammatory cell populations in 20 asthmatic patients, before and after treatment with inhaled beclomethasone dipropionate (BDP), 2,000 micrograms daily in an uncontrolled study. There was a significant improvement in asthma severity, as measured by symptom score and airways responsiveness, and there were significant reductions in the total BAL eosinophil, epithelial cell and mast cell counts, with a significant increase in the percentage BAL lymphocyte count. No significant correlations were found between the changes in airway inflammatory cell numbers and the reduction in asthma severity. In contrast, the fall in ROS generation by the pulmonary macrophage and granulocyte populations was nonsignificant, but the improvement in airways responsiveness was positively correlated to the reduction in the unstimulated pulmonary macrophage activity. Although these data are uncontrolled, the results are compatible with previous studies in suggesting an effect of steroids on the eosinophil, mast cell and epithelial cell in asthmatic airways. They also highlight the probable importance of the luminal lymphocyte population and pulmonary macrophage activation within the asthmatic airway, the beneficial modulatory effect of inhaled BDP treatment upon them, and the relative steroid-resistance of pulmonary inflammatory cell activity.

Role of beta 1, beta 2 integrins and ICAM-1 in lung injury after deposition of IgG and IgA immune complexes

After intrapulmonary deposition of IgG or IgA immune complexes, injury has been recently shown to be CD18-dependent in both cases and E-selection-dependent only in the former case. In our studies further evaluation of the requirements for beta 1 and beta 2 integrins and intercellular adhesion molecule-1 (ICAM-1) has been undertaken. In the IgG immune complex model, which is neutrophil dependent, anti-CD11a reduced injury (as measured by changes in permeability and hemorrhage) by 61 and 43%, respectively, whereas a newly developed anti-CD11b produced minimal protection (16 and 19%, respectively). Treatment of rats with increasing doses (1.5- and 3.0-fold) of antibody to rat CD11b failed to demonstrate additional protective effects in this model of injury. Anti-ICAM-1 reduced the parameters of injury by 61 and 78%, respectively, while anti-VLA-4 reduced the injury parameters by 40 and 35%, respectively. There were reductions in lung content of myeloperoxidase, roughly corresponding to the protective effects of the interventions. In the IgA immune complex model of injury, in which lung macrophages appear to be the effector cells, anti-CD11a reduced the injury parameters (permeability and hemorrhage) by 36 and 33%, respectively, whereas anti-CD11b reduced the parameters of injury by 63 and 67%, respectively. In this model, anti-ICAM-1 reduced the parameters of injury by 61 and 56%, respectively, while anti-VLA-4 reduced the parameters by 77 and 62%, respectively. The cell content of bronchoalveolar lavage fluids revealed changes that have been shown to reflect protective interventions in both models of immune complex-induced injury. These findings suggest that, in IgG and IgA immune complex models of lung injury, both VLA-4 and ICAM-1 are required, although lymphocyte function-associated Ag-1 is the predominant beta 2 integrin requirement in the IgG immune complex-induced model of injury and Mac-1 is the predominant requirement for IgA immune complex-induced lung injury. Thus, engagement in the lung of adhesion molecules in a manner leading to injury depends on the nature of the inflammatory stimulus and the type of phagocytic cells involved in the development of injury.