Ronald P. Daniele

Dexamethasone inhibition of interleukin 1 beta production by human monocytes. Posttranscriptional mechanisms.

Dexamethasone is known to have an inhibitory effect on IL-1 production. To determine the mechanism(s) of this inhibition, adherent human blood monocytes were stimulated with Escherichia coli lipopolysaccharide (LPS) (10 micrograms/ml) in the presence of dexamethasone. Nuclear transcription run-off assays showed that LPS induced IL-1 beta gene transcription two- to fourfold and that this induction was unaffected by dexamethasone exposure (10(-5) M). The lack of dexamethasones transcriptional effects was further supported by the absence of any significant change in IL-1 beta mRNA accumulation between LPS-stimulated monocytes exposed or unexposed to dexamethasone, as determined by Northern blot analysis. Posttranscriptionally, dexamethasone was found to have multiple effects: slight prolongation of IL-1 beta mRNA half-life, moderate inhibition of translation of the IL-1 beta precursor, and profound inhibition of the release of IL-1 beta into the extracellular fluid. The data indicate that IL-1 beta is first translated as the 33,000-D pro-IL-1 beta protein, the predominant intracellular form, and the processed to a 17,500-D IL-1 beta protein before or during extracellular transport. The major inhibitory effects of dexamethasone appear to be directed at the translational and posttranslational steps involved in these events.

Bronchoalveolar Lavage: Role in the Pathogenesis, Diagnosis, and Management of Interstitial Lung Disease

Bronchoalveolar lavage has emerged as a useful technique for the study of pulmonary interstitial disorders. Several types of information are provided by the evaluation of lavage fluid. First, the identification of cellular constituents helps to separate inflammatory processes in which lymphocytes predominate (for example, sarcoidosis, hypersensitivity pneumonitis, and berylliosis) from those in which neutrophils or macrophages predominate (for example, idiopathic pulmonary fibrosis and histiocytosis X). Second, the cells removed during lavage can be studied for their immune properties and function; tested with specific antigens, in diseases such as berylliosis and hypersensitivity pneumonitis; and examined for the presence of unique surface antigens with monoclonal antibodies (for example, histiocytosis X). Third, in conjunction with scanning electron microscopy and electron probe analysis, lavage makes possible the identification of inorganic particles in alveolar macrophages of patients with pneumoconiotic lung disease. Finally, although lavage is still an investigative procedure for most pulmonary disorders, it has an established role in the diagnosis of opportunistic infections in the immunocompromised patient.

Immunologic Abnormalities in Sarcoidosis

Patients with active sarcoidosis (acute and chronic) have a depression in systemic cell-mediated immunity manifested by a reduction in the number of circulating T cells and impaired responses of these cells to polyclonal mitogens and recall antigens. These abnormalities are absent in patients with resolved disease and contrast with heightened B-cell activity. The latter includes elevated serum immunoglobulins and the presence of autoantibodies and circulating immune complexes. Similarly, many humoral abnormalities (for example, immune complexes) are absent in patients with resolved disease. Studies of bronchoalveolar cells have revealed changes that are opposite to what is found in peripheral blood. The number of lymphocytes recovered by bronchoalveolar lavage is increased. This is mainly due to an increase in the number of T cells and a subpopulation of activated T cells. These findings suggest that the lung (when involved) is the site of an immune inflammatory response.

Proliferative Response of Bronchoalveolar Lymphocytes to Beryllium: A Test for Chronic Beryllium Disease

STUDY OBJECTIVE to ascertain whether measuring the proliferative response of bronchoalveolar lymphocytes to beryllium salts is useful for diagnosing chronic beryllium disease. DESIGN prospective case series compared to normal volunteers and patients with sarcoidosis. SETTING university referral center. PATIENTS twenty-three consecutive beryllium workers were evaluated. Fourteen had chronic beryllium disease diagnosed on the basis of histologic evidence of a progressive pulmonary granulomatosis. Four had biopsy evidence of non-beryllium disease. Three had probable chronic beryllium disease but did not have lung biopsies. Two did not have biopsies and had basilar fibrosis on chest roentgenogram suggestive of non-beryllium lung disease. These patients were compared with 6 normal volunteers and 16 patients with sarcoidosis. MEASUREMENTS AND MAIN RESULTS bronchoalveolar lavage was done and the proliferative response of the lung cells to two beryllium salts was tested. A positive proliferative test was defined as a stimulation index of more than five on two determinations. The sensitivity of this test was 100% in the 14 patients with definite chronic beryllium disease. The specificity of the test was also 100% among the normal volunteers and the 16 patients with sarcoidosis. The test was positive in none of the four patients with biopsy evidence of non-beryllium disease, none out of two patients with lower lobe fibrosis suggestive of non-beryllium disease, and all of three patients with probable chronic beryllium lung disease. CONCLUSIONS the proliferative response of bronchoalveolar lymphocytes to beryllium appears to be a useful test for chronic beryllium disease.

Bronchoalveolar lavage in a patient with chronic berylliosis: evidence for hypersensitivity pneumonitis.

Because immunologic mechanisms are thought to have a role in chronic berylliosis, we studied the immunologic properties of peripheral blood and bronchoalveolar lymphocytes in a patient with this disease. Although the percent of peripheral blood T cells was slightly reduced compared with that in controls (59% versus 70%), there was a large increase in the number and proportion (94% versus 62%) of bronchoalveolar T cells. The percent of activated bronchoalveolar T cells was nearly five times the control value (64.5% versus 14%). Both peripheral blood and bronchoalveolar lymphocytes proliferated in response to BeSO4 and BeF2 exposure but the response of bronchoalveolar lymphocytes was greater than comparable numbers of peripheral blood lymphocytes. These findings are consistent with the concept that chronic berylliosis is a form of hypersensitivity pneumonitis and that bronchoalveolar lavage may be helpful in establishing the diagnosis of this disease.

Immunocompetent cells from the lower respiratory tract of normal human lungs.

Subpopulations of lymphocytes in the broncho-alveolar air spaces of normal human lungs were compared with those in peripheral blood. Bone marrow-derived (bursal-equivalent) cells (B cells) were identified by complement receptors (EAC rosettes) and by surface immunoglobulin. Thymus-derived lymphocytes (T cells) were identified by their proliferative response to mitogens and the E rosette technique. Cells in lung air spaces were recovered from eight healthy nonsmoking volunteers by segmental lavage with the flexible bronchofiberscope. On the average, macrophages constituted 78% and lymphocytes 17% of the cells in the aspirates. B cells detected by surface immunoglobulin and complement receptors equaled 22% and 15% of lung lymphocytes, respectively. The distribution of lung B cells into heavy chain immunoglobulin classes revealed IgM and IgG to be the predominant classes, with mean values of 14.5% and 9.3%, respectively; the corresponding value for IgA was 5%. A comparable order of frequency (IgM greater than IgG greater than IgA) was observed for purified peripheral blood lymphocytes in the same and other control subjects. T cells comprised the majority (47%) of identifiable lung lymphocytes by the E rosette method. The presence of lung T cells was also corroborated by their proliferative response to mitogens (phytohemagglutinin and concanavallin A), but the response was less than that of equal numbers of peripheral blood lymphocytes from the same subjects. The B/T cell ratio for lung lymphocytes was comparable to results with peripheral blood lymphocytes in the same subjects, but a higher proportion of lung lymphocytes could not be identified as either T or B cells. It is postulated that lung lymphocytes participate in the local immune defenses of the lung.

Lymphocyte Subpopulations in Sarcoidosis: Correlation with Disease Activity and Duration

We studied lymphocytes from the peripheral blood of 29 sarcoid patients to relate T- and B-cell populations with disease activity and duration. In patients with acute (less than 1 year) and chronic (greater than or equal to 9 years) active disease, the absolute lymphocyte count was reduced; the absolute number of T cells was reduced; and the proliferative response of lymphocytes to phytohemagglutinin was depressed compared with control subjects. Ten of 21 patients with active disease had 5% to 32% atypical lymphocytes. The proportion of cells bearing surface immunoglobulin (Ig) was increased in patients with active disease, but the absolute number of cells bearing surface Ig did not differ significantly from controls. However, studies using overnight in-vitro culture indicated that a large fraction of these cells bound exogenous Ig. The number of cells indentified by complement receptors was significantly reduced in patients with active disease. In contrast, patients who had complete reasolution of their disease showed no significant differences from controls in either T- or B-cell populations or in the proliferative response of their lymphocytes to phytohemagglutinin.

Stimulation of oxygen consumption and superoxide anion production in pulmonary macrophages by N-formyl methionyl peptides.

A number of metabolic changes occur when phagocytic cells (i.e., polymorphonuclear neutrophils (PMN)) interact with certain soluble and particulate stimuli (reviewed [l-4]). These metabolic changes include an increase in oxygen consumption, stimulation of hexose monophosphate shunt activity, superoxide anion production (O;), hydrogen peroxide prnduction and chemiluminescence. It has been proposed that some of these stimulants act at specific receptor sites on the plasma membrane of the PMN [S-7]. Less information is available concerning the effects of similar metabolic stimuli on the alveolar macrophage [3]. Furthermore, the stoichiometry of the various reactions in the alveolar macrophage, particularly the proportion of the increase in oxygen consumption, that results in the formation of 0; and HzOz has not been established [8,9]. One effective stimulus in the PMN are the soluble N-formyl methionyl peptides [S,lO-121. Attention has been drawn not only to the metabolic but also to the biologic actions of these peptides on phagocytic cells since they are similar in structure to the N-formyl methionyl peptides produced by bacteria. For example, the peptide ,N-formyl methionyl phenylalanine (FMP), has also been shown to induce enzyme release in PMN [ 121 and to stimulate chemotaxis in PMN and guinea pig alveolar macrophages [ 13 1. Here, the effects of FMP on oxygen consumption and superoxide anion production in guinea pig alveolar macrophages are compared to concanavalin A (Con A). Con A is a plant lectin shown to be a reversible soluble

Blunted respiratory drive in congenital myopathy

Two patients with clinically mild congenital myopathies presented with chronic respiratory failure. Muscle weakness alone could not account for the respiratory insufficiency since static respiratory pressures were not markedly impaired, ventilation during exercise was normal, and daytime ventilation was normal if ventilatory assistance was provided at night. The ventilatory responses to inhaled carbon dioxide were very low, suggesting that impairment of the central nervous respiratory chemoreceptor contributed to hypoventilation. These patients and others described in the literature suggest that central depression of ventilation may occur more frequently than previously recognized in patients with muscular disorders. Patients with chronic respiratory failure due to central depression of respiratory drive can be effectively managed by assisted ventilation at night.

Cytogenetics of chronic T cell leukemia, including two patients with a 14q+ translocation.

SummaryChromosome studies were done on 7 patients with chronic T cell leukemia. Their lymphocytes responded in culture to one or more T cell mitogens: PHA, Con A, or the calcium ionophore A23187. Clones of cytogenetically-abnormal cells were present in all seven patients, but on occasion the frequency of such cells varied greatly in cultures stimulated with different mitogens. There was no consistent chromosome change, but alterations of chromosome 2 were noted in four individuals and of chromosome 14 in three. In two patients, there was a translocation to the long arm of chromosome 14, producing a 14q+, with the break point in the terminal portion, an abnormality previously observed in B cell lymphomas. One of these patients also showed evidence of clonal evolution in sequential cytogenetic studies, but more data are needed to determine whether such investigations are of prognostic value with respect to the clinical course of the disease.