Alveolar macrophages located on the alveolar surface have contact with air pollutants. We evaluated the dose-dependent effect of nitrogen dioxide exposure on the oxidative metabolism of alveolar ...macrophages and peripheral blood mononuclear cells by measuring the spontaneous and stimulated reactive oxygen intermediates production. Alveolar macrophages or peripheral blood mononuclear cells were placed on a polycarbonate membrane, which was in direct contact with the surface of a nutrient reservoir. The cells were exposed to nitrogen dioxide during different periods of time, varying between 30 and 120 min at concentrations ranging from 0.1 to 0.5 ppm. Exposure of alveolar macrophages to nitrogen dioxide for 30 min yielded a dose-dependent stimulation of reactive oxygen intermediates generation of 1.7- to 2.9-fold of control. An 120-min exposure to nitrogen dioxide at concentrations between 0.1 and 0.5 ppm resulted in a similar reactive oxygen intermediates production of about 1.9- to 2.2-fold of control at all concentrations tested. The nitrogen dioxide exposure to peripheral blood mononuclear cells yielded identical results. These experiments demonstrate that alveolar macrophages and peripheral blood mononuclear cells become activated by nitrogen dioxide and that concentrations up to 0.5 ppm nitrogen dioxide induce an increase in reactive oxygen intermediates production after 30 to 120 min exposure of the cells.
An activation of T-cells that is restricted to the lung has been demonstrated in pulmonary sarcoidosis. The role of blood monocytes (MO) and alveolar macrophages (AM) in this concept of ...compartmentalized inflammation has not yet been evaluated. In order to elucidate this question, we measured the release of tumor necrosis factor alpha (TNF alpha) and interleukin-1 (IL-1) by peripheral blood mononuclear cells (PBMNC) and AM in 43 patients with sarcoidosis (32 with active, 11 with inactive disease) without therapy and correlated the spontaneous monokine release to parameters of the T-cell alveolitis and the course of the disease. TNF alpha as well as IL-1 were spontaneously released by AM of the active group, i.e., 2,385 +/- 735 pg/ml/10(8) cells/24 h and 7/12 (IL-1+/total), respectively. Autologous PBMNC were quiescent, releasing only baseline levels of any monokine. AM were not activated in the inactive group, releasing 500 +/- 212 pg/ml/10(6) cells/24 h TNF alpha, whereas 1/5 were IL-1-positive (p less than 0.05 in both comparisons), which is within the range of the control group. Kinetic experiments revealed that the TNF alpha gene of AM is activated in vivo, resulting in TNF alpha mRNA-positive, TNF alpha-releasing cells that, cultured in vitro, regulate the TNF alpha gene transcription down and cease to release TNF alpha. Interestingly, there is no stringent correlation between the spontaneous release of TNF alpha by AM and signs of T-cell activation as soluble interleukin-2 (IL-2) receptor serum concentration, release of IL-2, and expression of IL-2 receptor by alveolar T-cells.
Clinical manifestations of interstitial lung diseases of occupational origin cover a wide spectrum and they are a moving target. They change their appearance in response to safety measures and new ...types of exposure. Recently recognized but long existing exposure requests new diagnostic approaches and safety measures. Thus, the incidence of well known disorders like asbestosis is reducing while newly identified exposure fields for beryllium lead to an increase of chronic beryllium disease which needs to be separated from chronic sarcoidosis, its perfect phenocopy. New techniques and new products cause new disorders like indium tin oxide-lung and flock worker’s lung disease which are hard to diagnose since pathognomonic features are missing. For timely diagnoses an intense cooperation of pulmonary and occupational specialists is mandatory. New hazardous techniques and materials like nanoparticles are introduced and widely used even with exposures of consumers without an in-depth knowledge of their toxicological features. These new developments request surveillance measures which still are in their infancy.
The evaluation of activation markers such as T4/T8 ratio and HLA-DR expression of lymphocytes of bronchoalveolar lavage (L-BAL) is an important clinical approach for the staging of sarcoidosis. ...However, it is not known to what extent this is paralleled by an exaggerated lymphocyte function. We investigated the dependence of L-BAL activation markers on the production of interleukin-2 (IL-2) by L-BAL and on the soluble IL-2 receptor serum level (sIL-2R) in 116 patients with sarcoidosis. In none of the combinations tested was a correlation between the two groups of parameters found; r less than 0.5, upper 90% confidence limit of r less than 0.8. Interestingly, IL-2 production is independent of HLA-DR+ T4 L-BAL, and sIL-2R production is independent of the percentage of IL-2+ L-BAL. Our data indicate that the L-BAL activation markers and the functional activity of T-cells represent independent phenomena.
In a recent phase I study of inhalative, human natural interleukin-2 (hnIL-2) treatment of pulmonary metastases from previously resected solid tumors (mainly renal carcinoma), we have reported that ...this treatment resulted in an increased accessory function of alveolar macrophages (AM) 1. Encouraged by these data, we investigated the influence of hnIL-2 inhalation on proinflammatory cytokines spontaneously released by AM. Bronchoalveolar lavage was performed in four groups, each of four patients, before and after 2 weeks of daily inhalation of 0, 200,000, 600,000 and 1,200,000 IU of hnIL-2, respectively. Bronchoalveolar cells were cultured without stimulation to allow spontaneous release over a period of 24 h, into the supernatant. Concentrations of tumor necrosis factor-alpha (TNF-alpha), IL-6, IL-8 and macrophage inflammatory protein-1alpha (MIP-1alpha) were determined by the ELISA technique. Before hnIL-2 inhalation, we measured the following spontaneous cytokine release: TNF-alpha: 1,115.4 +/- 469.1 pg/ml, IL-6: 267.5 +/- 67.7 pg/ml cells, IL-8: 137.8 +/- 40.5 ng/ml, MIP-1alpha: 9.5 +/- 6.8 ng/ml. Inhalation of hnIL-2 did not result in any significant changes in these cytokines. Comparing TNF-alpha release in healthy controls (250.6 +/- 46.7 pg/ml) with that of tumor patients (1,115.4 +/- 469.1 pg/ml), we observed significantly (p < 0.05) elevated TNF-alpha levels in the patient group, which did not change significantly in response to IL-2 inhalation. Our data demonstrate that the activation of AM previously observed after hnIL-2 inhalation is not directly related to a hnIL-2-induced cytokine release by bronchoalveolar cells.
Sarcoidosis is a systemic granulomatous disorder of unknown origin. In respect to clinical and immunological characteristics, it is indistinguishable from berylliosis. As an approach to develop a ...murine model reflecting some aspects of sarcoidosis, we attempted to induce berylliosis in mice by treating inbred F1 mice (C57B16 x DBA/2) with 3 mg beryllium sulfate (BeSO4) per kg body weight intraperitoneally. Either pure BeSO4 or BeSO4 in combination with incomplete Freund's adjuvant was administered. Alternatively, pure BeSO4 was injected 2 days after a single application of cyclophosphamide (150 mg/kg). The spleen index, the spontaneous and phorbolmyristate acetate (PMA)-induced radical oxygen intermediates (ROI) released by peritoneal macrophages, and the proliferative activity of spleen mononuclear cells in response to BeSO4 and concanavalin A (ConA) were evaluated and compared to the corresponding changes observed in sarcoidosis. In all three modes of BeSO4 treatment, the spontaneous ROI release by peritoneal macrophages was significantly elevated. These elevations were very similar to those observed with alveolar macrophages in active sarcoid alveolitis. After BeSO4 treatment, a small proliferative activity of spleen mononuclear cells in response to BeSO4 could be observed. Further, BeSO4-treated spleen mononuclear cells exhibited a markedly reduced response to ConA stimulation (approximately 20% of control) which parallels the reduced proliferative capacity of sarcoid peripheral blood mononuclear cells (approximately 45% of control). This reduction could be abolished by pretreating the mice with cyclophosphamide. BeSO4 treatment in combination with incomplete Freund's adjuvant resulted in a significant increase of spleen mononuclear cell proliferation (1.9-fold) after in vitro stimulation with BeSO4, and prevented the low responsiveness to ConA.
In pulmonary sarcoidosis an activation of alveolar T lymphocytes and alveolar macrophages (AM) has been demonstrated. There is evidence that in contrast to acute disease a heightened T-cell response ...cannot be observed in the chronic phase of sarcoidosis. The role of AM in the inflammatory process of chronic sarcoidosis is not yet intensively evaluated. To address this question we measured the release of tumor necrosis factor alpha (TNF alpha) and interleukin-1 (IL-1) by AM of 39 patients with chronic sarcoidosis (duration greater than 4 years; 30 active, 9 inactive diseases) without therapy and correlated the monokine release with parameters of T-cell alveolitis and the course of the disease. The T4/T8 ratio was higher in the active than in the inactive group without reaching statistical significance. TNF alpha as well as IL-1 is spontaneously released by AM of the active group 2,099 +/- 518 pg/ml TNF alpha/10(6) cells/24 h and 8/13 (IL-1+/total) respectively. In the inactive group the AM release 375 +/- 246 pg/ml TNF alpha/10(6) cells/24 h which is in the range of the control and 1 out of 5 patients was IL-1-positive. There was no correlation between the monokine release and any parameter of T-cell alveolitis. These data support the hypothesis that the inflammatory process in chronic sarcoidosis is dominated by the activity of AM and that this activity determines the course of the disease.
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