Adhesion molecules in lung diseases

Adhesion Molecules in Lung Inflammation from Repeated Glyphosate Exposures

Glyphosate is an active ingredient in herbicides. Exposure to glyphosate-based herbicides has been associated with respiratory dysfunctions in agricultural workers. The ability of inhaled glyphosate to induce lung inflammation is not well understood. Further, the role of adhesion molecules in glyphosate-induced lung inflammation has not been studied. We evaluated lung inflammatory responses from single and repeated glyphosate exposures. Male C57BL/6 mice were intranasally exposed to glyphosate (1 μg/40 μL) for 1 day or once daily for 5 days or 10 days. Lung tissue and bronchoalveolar lavage (BAL) fluid were collected and analyzed. Repeated exposure to glyphosate for 5 days and 10 days resulted in an increase in neutrophils in BAL fluid and higher eosinophil peroxidase levels in lungs, with leukocyte infiltration further confirmed through lung histology. Repetitive exposure to glyphosate increased IL-33 and Th2 cytokines IL-5 and IL-13. A single glyphosate treatment revealed expression for ICAM-1, VCAM-1, and vWF adhesion molecules in the perivascular region of lung sections; with repeated treatment (5 and 10 days), adhesion molecule expression was found in the perivascular, peribronchiolar, and alveolar regions of the lungs. Repetitive exposure to glyphosate induced cellular inflammation in which adhesion molecules may be important to the lung inflammatory process.

Probiotic Prato cheese attenuates cigarette smoke-induced injuries in mice

The efficacy of probiotic Prato cheese against the inflammatory and oxidative damage in mice organs induced by cigarette smoke exposure was investigated. Forty C57BL/6 male mice were assigned to four groups: (CS) exposed to cigarette smoke and fed regular chow; (CS + C) exposed to cigarette smoke and fed daily conventional cheese ad libitum; (CS + PC) exposed to cigarette smoke and fed daily probiotic (Lactobacillus casei-01) cheese ad libitum; and a control group (C) exposed to ambient smoke-free air and fed regular chow. Bronchoalveolar lavage (BAL), blood, gut and liver homogenates were used for biochemical assays. The (CS + PC) group exhibited fewer BAL leukocytes, reactive oxygen species (ROS), and BAL and gut lipid peroxidation than the (CS) and (CS + C) groups, which had findings similar to the (C) group. Probiotic cheese consumption did not change the red blood cell count, but lower lactate dehydrogenase (LDH) levels in plasma, inducible nitric oxide synthase (iNOS) and peroxynitrite expression were observed compared to the (CS) and (CS + C) groups, with findings similar to the (C) group. These results suggest that probiotic Prato cheese consumption reduced oxidative stress in the lungs, gut, and liver.

Scintillation proximity assay (SPA) technology to study biomolecular interactions

Scintillation proximity assay (SPA) is a versatile homogeneous technique for radioactive assays which eliminates the need for separation steps. In SPA, scintillant is incorporated into small fluomicrospheres. These microspheres or "beads" are constructed in such a way as to bind specific molecules. If a radioactive molecule is bound to the bead, it is brought into close enough proximity that it can stimulate the scintillant contained within to emit light. Otherwise, the unbound radioactivity is too distant, the energy released is dissipated before reaching the bead, and these disintegrations are not detected. In this unit, the application of SPA technology to measuring protein-protein interactions, Src Homology 2 (SH2) and 3 (SH3) domain binding to specific peptide sequences, and receptor-ligand interactions are described. Three other protocols discuss the application of SPA technology to cell-adhesion-molecule interactions, protein-DNA interactions, and radioimmunoassays. In addition, protocols are given for preparation of SK-N-MC cells and cell membranes.

Flow cytometrical analysis of adhesion molecules, T-lymphocyte subpopulations and inflammatory markers in pterygium

BACKGROUND/AIM

Pterygium is a relatively frequent ocular surface disease with an unexplained etiopathogenesis. Our study was carried out with the aim to identify the presence of inflammatory cells and mediators such as T-lymphocyte subgroups (CD4 and CD8), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and human leukocyte antigen-DR (HLA-DR) in pterygium tissue.

METHODS

Pterygium tissue, obtained from 24 patients, and normal conjunctival tissue, from the nasal bulbar conjunctiva obtained from 14 patients operated for ocular perforations or vitrectomy, were separated into epithelial and stromal components under the microscope and suspended with phosphate-buffered saline solution to form a suspension. Cell suspensions were treated with specific antibodies for ICAM-1, VCAM-1, and HLA-DR and T-lymphocyte subgroups and evaluated with flow cytometry. The obtained data were compared statistically.

RESULTS

When compared to the control tissue samples, higher rates of ICAM-1-positive cells, VCAM-1-positive cells and HLA-DR-positive cells were recorded in pterygium tissue samples. CD4 and CD8 lymphocytes were also found to be at higher levels when compared to the control group. There was a statistically significant difference between the two groups.

CONCLUSION

When compared with normal conjunctival tissue, pterygium tissue had increased levels of T-lymphocyte infiltration and inflammatory markers demonstrating the possible contribution of cellular immunity to the pathogenesis.

Expression of adhesion molecules in lungs of mice infected with Paracoccidioides brasiliensis conidia

In infected tissues, leukocyte recruitment is mediated by interactions between adhesion molecules, expressed on activated vascular endothelial cells, and ligands present on circulating cells. We evaluated the inflammatory response and the expression of cellular adhesion molecules (ICAM-1, VCAM-1, CD18, LFA-1 and Mac-1) in lungs of BALB/c mice infected with Paracoccidioides brasiliensis conidia. When compared with uninfected animals, infected mice had a significant increase in the inflammatory response during the first 4 days, peaking 2-3 days post-challenge, 40.3% vs. 0.0% and 41.8% vs. 0.7%, respectively. This inflammatory infiltrate was composed mainly of neutrophils and macrophages with a few eosinophils and lymphocytes. An increase in the intensity of immunofluorescence (IF) for ICAM-1 was also observed during days 1-4. ICAM-1 was present in bronchiolar epithelium, type II pneumocytes, and macrophages, as well as on vascular endothelium. The control animals presented ICAM-1 constitutively. In infected mice, VCAM-1 was only observed on vascular endothelium during the first 2 days, with some macrophages expressing this molecule throughout the study periods. CD18 and Mac-1 but not LFA-1 were expressed with a high intensity on neutrophils and macrophages present in the inflammatory infiltrate. In addition, we observed a significant decrease in Colony forming units (CFUs) after the first 2 days post-challenge. These findings suggest that during these early stages, up-regulation of ICAM-1, VCAM-1, CD18 and Mac-1 expression occurs, participating in the inflammatory process and as such, in the pathogenesis of paracoccidioidomycosis (PCM).

Immunomodulatory effects of mineral fibres in occupationally exposed workers

In the context of a large-scale molecular epidemiology study, the possible immunomodulatory effects of mineral fibres, in workers occupationally exposed to asbestos, rockwool and glass fibres, were examined. In each plant, 61, 98 and 80 exposed workers and 21, 43 or 36 control clerical subjects, respectively, were recruited. In the case of the asbestos-exposed subjects, an additional town-control group of 49 people was included. Evidence of pulmonary fibrosis was found in 42% of the asbestos-exposed workers, while evidence of pleural fibrosis was found in 24%. The asbestos-exposed cohort had significantly decreased forced vital capacity of lungs as well as forced expiratory volume per first second. Our findings indicate that exposure to all three types of fibres examined modulates to different degrees the immune response. Suppression of T-cell immunity and to a lesser extent, B-cell immunity was found in the case of workers from a former asbestos cement plant, while stimulation of T-cell response was observed in rockwool workers, and stimulation of T- and B-cell response was seen in glass fibre workers. Depression of the percentage of lymphocyte subpopulation of CD 16+56 (natural killer cells) in peripheral blood was found in glass fibre workers. Statistical analysis showed increased levels of proinflammatory cytokines (IL-6 asbestos; IL-8 all three fibres), expression of adhesion molecule L-selectin on granulocytes and monocytes (asbestos), levels of soluble adhesion molecules (SAMs) in sera (ICAM-1 all three fibres; E-selectin glass fibres), increased levels of immunoglobulin E (asbestos and rockwool) and elevated expression of activation markers on eosinophils (CD66b asbestos, glass fibres; CD69 asbestos). Significant correlations were observed between lymphocyte proliferation and markers of DNA damage and repair. Increased levels of proinflammatory cytokines, SAMs, immunoglobulin E and elevated expression of activation markers on eosinophils was found in people with symptoms of hypersensitivity and an elevated inflammatory status.

The relationship between the serum intercellular adhesion molecule-1 level and the prognosis of the disease in lung cancer

BACKGROUND

Adhesion molecules are related to cell-to-cell interaction and inflammatory interaction. In addition, adhesive interactions between tumor cells and adjacent cells and/or extracellular matrix play important roles in the complex process of tumor growth and development. Among these adhesion molecules, expression of intercellular adhesion molecule-1 (ICAM-1) has been identified in colon cancer, bladder cancer, lung cancer, melanoma, pancreatic cancer and hepatocellular carcinoma. In the current study, we analyzed serum ICAM-1 concentrations to investigate the relationship between the serum ICAM-1 level and prognosis in patients with lung cancer.

METHODS

Serum ICAM-1 was measured in 84 patients with lung cancer according to the pathologic type and clinical stage using the ICAM-1 ELISA kit. The Kaplan-Meier method was used to analyse survival time.

RESULTS

There was no difference in serum ICAM-1 concentration among the different stages of lung cancer. Furthermore, there was no difference observed between histologic tumor type with regard to serum ICAM-1 concentration. Although the difference was not significant, the overall survival times of patients with a low serum ICAM-1 concentration (< 306 ng/mL) was longer than that of patients with a high concentration (> or = 306 ng/mL) in non-small cell lung cancer patients.

CONCLUSION

These results suggest that high levels of serum ICAM-1 reflect poor prognosis for patients with non-small cell lung cancer.

L-selectin in health and disease

This article reviews recent advances in the knowledge of the role of L-selectin, an adhesion molecule that is expressed on the surface of circulating leucocytes, in animal and human physiology and pathophysiology. After a brief discussion on nomenclature and structure, it progresses through the evidence for expression and regulation of L-selectin, cell collection and purification, physiological function and roles. The special role of knock out mice and monoclonal antibodies in determining a role for L-selectin in inflammatory states is described before proceeding to discuss the importance of L-selectin ligands and shed L-selectin. A second section describes a role for L-selectin in pathophysiological states in animals and man, with special reference to trauma, systemic inflammatory syndromes and sepsis. The review concludes with a summary of the potential role of anti-inflammatory medication and L-selectin blockers in the management of inflammation.

Early role of neutrophil L-selectin in posttraumatic acute lung injury

OBJECTIVE

To investigate whether early numerical and functional changes in circulating neutrophils and expression of neutrophil L-selectin and soluble L-selectin are related to the subsequent development of posttraumatic acute lung injury (ALI), the systemic inflammatory response syndrome, sepsis, and organ failure.

DESIGN

Prospective study of whole blood and plasma samples to assess numerical and functional changes in circulating neutrophils and in soluble L-selectin.

SETTING

The emergency department of a university hospital.

PATIENTS

A total of 147 patients admitted to the resuscitation room after trauma were compared with 69 control subjects. Ten patients developed ALI.

LABORATORY ANALYSIS

Flow cytometry of whole blood and ELISA of plasma.

RESULTS

Total leukocyte and neutrophil counts, expression of L-selectin, and the ratio of neutrophil to plasma L-selectin increased with injury and were highest in those who developed ALI. Soluble L-selectin decreased with injury severity and was lowest in those who developed ALI.

CONCLUSIONS

Early changes in the average expression of L-selectin per cell do not correlate with the development of subsequent posttraumatic ALI. However, the development of ALI is related to the total expression of L-selectin in the neutrophil mass, and the most striking association is in those with lower concentrations of plasma L-selectin.

Possible role of L-selectin in T lymphocyte alveolitis in patients with active pulmonary sarcoidosis

A number of adhesion molecules participate in the recruitment of inflammatory cells to the site of inflammation, and selectins together with their ligands are important in the early transient adhesion phase. In this study, we evaluated the role of L-selectin in T lymphocyte alveolitis in patients with active pulmonary sarcoidosis. We measured serum and bronchoalveolar lavage fluid (BALF) concentrations of soluble (s)L-selectin using an ELISA. Serum and BALF concentrations of sL-selectin were significantly elevated in patients with sarcoidosis compared with control healthy subjects and idiopathic pulmonary fibrosis (IPF) patients (P < 0.05 and P < 0. 01, respectively). The lymphocyte surface marker was also examined in peripheral blood and BALF by flow cytometric analysis. The percentage of CD3+CD62L+ cells (L-selectin-bearing T lymphocytes) was significantly lower in peripheral blood of sarcoidosis than in that of healthy subjects (P < 0.01). In contrast, the percentage of CD3+CD62L- cells (L-selectin-negative T lymphocytes) in BALF of patients with sarcoidosis was significantly higher than in healthy subjects (P < 0.05) and IPF patients (P < 0.01). Furthermore, there was a significant correlation between serum concentrations of sL-selectin and the number of L-selectin-negative T lymphocytes in BALF (r = 0.535, P < 0.01). Our results suggest that L-selectin may be involved in T lymphocyte alveolitis in patients with active pulmonary sarcoidosis.

Selective inflammatory response induced by intratracheal and intravenous administration of poly-L-arginine in guinea pig lungs

Major basic protein (MBP) is a cationic protein found in eosinophil granules that was postulated to participate in the pathogenesis of bronchial asthma. Recently, it has been demonstrated that MBP level in serum or bronchoalveolar lavage (BAL) fluid was correlated with bronchial hyperresponsiveness (BHR) in asthmatics. A number a studies have established that MBP actions could be mimicked by synthetic polycations as poly-L-arginine. In this study, we investigated the effects of intratracheal and intravenous administration of poly-L-arginine on lung inflammatory response development. The intratracheal injection of poly-L-arginine at the doses of 1, 10, 100 nmol/animal increased the number of eosinophils (up to 3.2 fold) and neutrophils (up to 12 fold) in BAL fluid. Eosinophil and neutrophil infiltration was reversed by 88% and 67% respectively following low molecular weight heparin treatment (500 microg/animal). The intravenous injection of increasing doses of poly-L-arginine (1, 10, 100, 500 nmol/animal) increased the number of eosinophils (up to 2.7 fold) but not neutrophil infiltration in guinea pig lungs. Eosinophil infiltration was reversed by 87% following low molecular weight heparin treatment (1.5 mg/animal). Intratracheal treatment with poly-L-arginine (100 nmol/animal) produced an important increase of beta-glucuronidase, histamine, eosinophil peroxidase (EPO) and albumin levels in BAL fluid, whereas the intravenous treatment (500 nmol/animal) did not. These results show that the route of administration of poly-L-arginine greatly influences its effect on inflammatory cell recruitment since both administration routes elicited eosinophil migration but only the intratracheal route stimulated the migration of neutrophils. Moreover, poly-L-arginine appeared to induce other inflammatory responses since it increased beta-glucuronidase, histamine, EPO and albumin levels in BAL fluid following intratracheal treatment. These results also showed that low molecular weight heparin significantly blocks the inflammatory responses elicited by poly-L-arginine.

Value of ICAM-1 expression and soluble ICAM-1 level as a marker of activity in sarcoidosis

BACKGROUND

The natural course of sarcoidosis is variable, but no single parameter has been generally accepted as a good marker for disease activity. Adhesion molecules are required for the migration of inflammatory cells; thus, they may be markers of activity in sarcoidosis.

METHODS

In 16 patients with active sarcoidosis and 11 with inactive disease (10 were male, 17 were female; mean age [-/+ SD], 39.6+/-11.0 years; mean follow-up, 21+/-16 months), the expression of adhesion molecules on cells obtained with BAL (measured by flow cytometry) and the level of soluble intercellular adhesion molecule 1 (sICAM-1) in the serum and BAL fluid (BALF) were measured at the time of diagnosis and during the follow-up. The changes in serum sICAM-1 level and ICAM-1 expression on cells obtained with BAL were compared with the clinical course of the disease.

RESULTS

In patients with active disease, the ICAM-1 on alveolar macrophage (AM) (relative linear median fluorescence intensity [RMFI], 3.21+/-1.55) and sICAM-1 levels in serum (575+/-221 ng/mL) and BALF (47.3+/-19.3 ng/mL) were higher than those for patients with inactive disease (RMFI, 1.67+/-0.66; p = 0.0034; serum, 263+/-98.5 ng/mL; p = 0.0001; BALF, 27.5+/-19.0 ng/mL; p = 0.0209). In the patients with active disease, ICAMN-1 on AM and serum sICAM-1 decreased (RMFI, 1.51+/-0.84; 284+/-118 ng/mL, respectively) after steroid therapy, but no significant change was noted in patients with inactive disease. We also found that the initial ICAM-1 on AM and serum sICAM-1 had a significant correlation with the degree of improvement in pulmonary function tests after the therapy. The disease relapsed in four patients after the discontinuation of steroids, and the serum sICAM-1 level was elevated again at the time of relapse.

CONCLUSION

Our data suggest that the serum sICAM-1 level and the ICAM-1 expression on AM may be good markers of disease activity and also a predictor of outcome in sarcoidosis.

The lymphocytic alveolitis in sarcoidosis is associated with increased amounts of soluble and cell-bound adhesion molecules in bronchoalveolar lavage fluid and serum

OBJECTIVES

Pulmonary sarcoidosis is a chronic inflammatory disorder of unknown aetiology accompanied by a lymphocytic alveolitis. It is likely that a selective and temporal expression of adhesion molecules plays a crucial role in the recruitment of cells to the inflammatory site. We investigated the expression of adhesion molecules on alveolar T-lymphocytes and in bronchoalveolar lavage (BAL) fluid and serum to elucidate mechanisms behind the accumulation of cells in the lung in sarcoidosis.

DESIGN

In a cross-sectional study in patients with active and inactive sarcoidosis and in healthy volunteers, we examined, in serum and in BAL fluid, the soluble adhesion molecules, VCAM-1, ICAM-1, and P-, E- and L-selectin. In addition, the expressions of alpha4-beta1 (VLA-4) and alpha5-beta1 (VLA-5) integrins on alveolar T-lymphocytes were analysed.

SETTING

The subjects attended the outpatient clinic at the Division of Respiratory Medicine, Karolinska Hospital, Stockholm, Sweden.

SUBJECTS

Nineteen sarcoidosis patients, nine with clinically active disease, and 13 healthy volunteers were included in the study. The sarcoidosis diagnosis was based on a typical histological and/or clinical (symptoms, radiograph, lung function) picture.

RESULTS

In sarcoidosis patients, particularly in those with active disease, an increase of the expressions of beta1-integrins was accompanied by elevated concentrations in BAL fluid of soluble VCAM-1. In serum, the levels of E-selectin and ICAM-1 were significantly higher in patients with active disease than in those with inactive disease and controls.

CONCLUSIONS

The findings offer some mechanistic explanations as to how the cell-rich alveolitis in sarcoidosis occurs, and furthermore suggest additional markers, such as s-ICAM-1, for assessment of disease activity.

High frequency oscillatory ventilation attenuates the activation of alveolar macrophages and neutrophils in lung injury

BACKGROUND: Recent investigations have shown that leukocyte activation is involved in the pathogenesis of ventilator-associated lung injury. This study was designed to investigate whether the inflammatory responses and deterioration of oxygenation in ventilator-associated lung injury are attenuated by high-frequency oscillatory ventilation (HFO). We analyzed the effects of HFO compared with conventional mechanical ventilation (CMV) on the activation of pulmonary macrophages and neutrophils in 10 female rabbits. RESULTS: After surfactant depletion, the rabbits were ventilated by CMV or HFO at the same mean airway pressure. Surfactant-depletion followed by 4 h mechanical ventilation hindered pulmonary oxygenation in both groups. Impairment of oxygenation was less severe in the HFO group than in the CMV group. In the HFO group the infiltration of granulocytes into alveolar spaces occurred more readily than in the CMV group. Compared with CMV, HFO resulted in greater attenuation of beta2-integrin expression, not only on granulocytes, but also on macrophages. CONCLUSIONS: In the surfactant-depleted lung, the activation of leukocytes was attenuated by HFO. Reduced inflammatory response correlated with decreased impairment of oxygenation. HFO may reduce lung injury via the attenuation of pulmonary inflammation.

Adhesion molecules in vernal keratoconjunctivitis

AIMS/BACKGROUND

Adhesion molecules play a key role in the selective recruitment of different leucocyte population to inflammatory sites. The purpose of the present study was to investigate the presence and distribution of adhesion molecules in the conjunctiva of patients with vernal keratoconjunctivitis (VKC).

METHODS

The presence and distribution of adhesion molecules were studied in 14 conjunctival biopsy specimens from seven patients with active VKC and in four normal conjunctival biopsy specimens. We used a panel of specific monoclonal antibodies (mAbs) directed against intercellular adhesion molecule-1 (ICAM-1), intercellular adhesion molecule-3 (ICAM-3), lymphocyte function associated antigen-1 (LFA-1), very late activation antigen-4 (VLA-4), vascular cell adhesion molecule-1 (VCAM-1), and endothelial leucocyte adhesion molecule-1 (ELAM-1) In addition, a panel of mAbs were used to characterise the composition of the inflammatory infiltrate.

RESULTS

In the normal conjunctiva, ICAM-1 was expressed on the vascular endothelium only, LFA-1 and ICAM-3 on epithelial and stromal mononuclear cells, and VLA-4 on stromal mononuclear cells. The expression of VCAM-1 and ELAM-1 was absent. The number of cells expressing adhesion molecules was found to be markedly increased in all VKC specimens. This was concurrent with a heavy inflammatory infiltrate. Strong ICAM-1 expression was induced on the basal epithelial cells, and vascular endothelial cells. Furthermore, ICAM-I was expressed on stromal mononuclear cells. LFA-1 and ICAM-3 were expressed on the majority of epithelial and stromal infiltrating mononuclear cells. VLA-4 expression was noted on stromal mononuclear cells. Compared with controls, VKC specimens showed significantly more ICAM-3+, LFA-3+, LFA-1+, and VLA-4+ cells. VCAM-1 and ELAM-1 were induced on the vascular endothelial cells.

CONCLUSIONS

Increased expression of adhesion molecules may play an important role in the pathogenesis of VKC.

LOWER RESPIRATORY TRACT INFECTIONS IN ELDERLY PATIENTS WITH ASTHMA

Infection plays a significant role in the morbidity and mortality of the elderly. One population in which infection has not been adequately studied is the elderly asthmatic. This article examines the problems of lower respiratory tract infections in elderly asthmatics in the context of their host defenses, the severity of infection, and their risk of infection with specific organisms. The role of infection in the pathogenesis of asthma and consideration of prophylaxis and therapy are presented.

Shed soluble ICAM-1 molecules in bronchoalveolar lavage cell supernatants and serum of patients with pulmonary sarcoidosis

The soluble form of intercellular adhesion molecule-1 (sICAM-1) might be a serum parameter of inflammatory activity gauging cellular interactions with possible relevance in sarcoidosis. To address this question we measured sICAM-1 by enzyme-linked immunosorbent assay in serum and shedding of this molecule by bronchoalveolar lavage (BAL) cells in sarcoidosis patients (44 and 40, respectively) and in controls (10 and 19, respectively). Serum concentrations of sICAM-1 (588.3 +/- 72.2 ng/ml) and its spontaneous release by BAL cells (9.9 +/- 1.5 ng/ml) in patients with active sarcoidosis were significantly higher than in those with inactive disease or controls, although no correlation was observed. Significant correlations of sICAM-1 shedding by nonstimulated BAL cells with the serum level of neopterin and of shedding by lipopolysaccharide-stimulated BAL cells with percentage of alveolar macrophages were observed in active sarcoidosis. Kinetic cell culture experiments with peripheral blood mononuclears disclosed a rapid up-regulation of sICAM-1 shedding and tumor necrosis factor-alpha release; however, at 5 h after stimulation a dissociation of their releases was observed. sICAM-1 release was maintained over 2 days, whereas tumor necrosis factor-alpha release peaked at 5 and ceased after 43 h. These results provide evidence that circulating and BAL cell culture-derived sICAM-1 reflect the stage of sarcoid inflammation. Although sICAM-1 in BAL cell supernatants originates from alveolar macrophages; the absence of a correlation with serum sICAM-1 concentration indicates that other cells are additional sources of the circulating pool of this molecule.

Endothelial cell activity varies in patients at risk for the adult respiratory distress syndrome

OBJECTIVE

The endothelial cell produces many bioactive compounds that are presumed to play important roles in the pathogenesis of the adult respiratory distress syndrome (ARDS). We postulated that individuals with sepsis and trauma-two at-risk diagnoses for the development of ARDS--might demonstrate differences in the degree of endothelial cell activity.

DESIGN

Prospective cohort study.

SETTING

Intensive care unit patients in a tertiary, university-affiliated, city hospital.

PATIENTS

Fifty-five intensive care unit patients (19 with sepsis and 36 trauma patients).

INTERVENTIONS

Plasma measurements of three endothelial cell products--von Willebrand factor antigen, soluble intercellular adhesion molecule-1 (ICAM-1), and soluble E-selectin-were performed within 8 hrs of patients meeting our inclusion criteria, and at the clinical onset of ARDS.

MEASUREMENTS AND MAIN RESULTS

Twenty-six percent of the septic patients and 25% of the trauma patients developed ARDS. The median (and 25% to 75% quartiles) concentrations of all three mediators measured in the sepsis patients (von Willebrand factor antigen 399% [375% to 452%], ICAM-1 573 ng/mL [470 to 980], and soluble E-selectin 180 ng/mL [81 to 340]) were significantly higher (p < .001 for each individual analysis) than in the trauma patients (von Willebrand factor antigen 256% [217% to 310%], ICAM-1 148 ng/mL [113 to 210], and soluble E-selectin 42 ng/mL [31 to 65 ng/ mL]). In addition, neither the ICAM-1 nor soluble E-selectin concentrations measured in the trauma patients were different (p = .17 and p = .24, respectively) from normal controls. In those patients who developed ARDS, the differences in the concentrations of all three endothelial cell mediators between the sepsis and trauma patients persisted (p = .008 for von Willebrand factor antigen, p = .003 for ICAM-1, and p = .003 for E-selectin).

CONCLUSION

These findings suggest that differences in endothelial cell activity exist between sepsis and trauma patients who are at risk for the development of ARDS.

New concepts in the immunology of sickle cell disease

OBJECTIVE

Our objective is to review the role of adhesion molecules, cytokines, and inflammation in the abnormal adherence of sickle red blood cells to vascular endothelia in the pathogenesis of vascular complication in patients with sickle cell anemia.

DATA SOURCES

The MEDLINE database was used to review the hematologic, immunologic, and allergy literature in English with respect to the adhesion molecules involved in sickle hematopoiesis and vascular complications.

STUDY SELECTION

Studies selected for review were those that identified the adhesion molecules involved in reticulocyte-endothelial adhesion and the influence that cytokines, infections, and atopy have upon the expression of these molecules.

RESULTS

In sickle cell disease, a constant low level of inflammation caused by abnormal adhesion of sickle erythrocytes to endothelial cells in the microvasculature produces low-level tissue ischemia. Allergic and infectious inflammations are likely to lead to increased sickle erythrocyte trapping in the microvascular endothelia which progresses to vessel obstruction, end organ ischemic damage, and dysfunction.

CONCLUSION

The identification of underlying immune defects that predispose patients to infections and inflammation needs to be emphasized. Anti-inflammatory medications, anti-adhesion molecule monoclonal antibodies, and adhesion molecule binding-site analogs may have a future in the treatment of the acute vascular complications of sickle cell disease.

Lymphocytes in the lung: an often neglected cell. Numbers, characterization and compartmentalization

The lung is continuously in contact with inhaled particles, some of which are of microbial origin. This requires adequate defence mechanisms in the form of immune reactions. These can be subdivided into the afferent and efferent limb. Specific immune reactions depend on the interactions between lymphoid and accessory cells. Therefore, the local histotopographic localization of lymphocyte subsets has to be known to understand pulmonary immune reactions. As lymphocytes have often not been mentioned when cells in the respiratory tract have been characterized, their compartmentalization, number and subset composition in the lung are outlined here. Lymphocytes are found in the epithelium and lamina propria of the bronchi with different subset compositions. In some species, like the rabbit, bronchus-associated lymphoid tissue (BALT) is found as follicle-like aggregations with lymphocytes infiltrating the epithelium, which shows specialized epithelial cells. BALT, however, is not a constitutive structure in all species, e.g. in humans. Nevertheless, certain (probably) microbial stimuli can induce BALT in adult humans. In contrast to many other organs, the lung vascular bed contains large numbers of lymphocytes. Little is known about the adhesion molecules that make this margination possible. In the lung interstitium about 10 x 10(9) lymphocytes have been calculated for healthy adults. The most easily accessible pool of lymphocytes in the human lung are those recovered by bronchoalveolar lavage. The vast majority of such lymphocytes express markers typical for "memory lymphocytes". The intrapulmonary migratory routes of lymphocytes and the integration of the lung in the common mucosal immune system are described.(ABSTRACT TRUNCATED AT 250 WORDS)

Lymphocyte subsets in bronchoalveolar lavage after exposure to Actinobacillus pleuropneumoniae in pigs previously immunized orally or by aerosol

Young pigs were immunized with the lung-pathogenic bacterium Actinobacillus (Haemophilus) pleuropneumoniae by aerosol or orally using viable and inactivated bacteria. The cellular changes in the bronchoalveolar lavage (BAL) were studied in repeated lavages after the pigs were infected with live bacteria. The nucleated cells in the BAL were differentiated and lymphocyte subsets determined. There were no major differences between the two routes of immunization or between viable and inactivated bacteria. The immunization induced an increase in all lymphocyte subsets studied and in the appearance of plasma cells and lymphoid blasts. The infection did not cause a further increase except in granulocytes. The lack of a booster-type increase in lymphocytes in the BAL might indicate a different immunologic reaction of the lung or that lymphocytes of the BAL do not represent lung lymphocytes in general. The protective effect of the immunization might be deduced from the increase in lymphocytes after immunization but not from the reaction pattern after infection.

Increased expression of intercellular adhesion molecule-1 (ICAM-1) in a murine model of pulmonary eosinophilia and high IgE level

T lymphocytes and eosinophils are probably involved in the pathogenesis of allergic bronchopulmonary aspergillosis (ABPA), a disease characterized by pulmonary eosinophilia and high serum and lavage IgE levels. We recently developed a murine model of ABPA. To investigate the mechanisms of T lymphocyte and eosinophil recruitment to the lung in this disease, we examined the expression of ICAM-1 in the lung tissue of mouse challenged with Aspergillus fumigatus (Af) antigen. C57B1/6 mice were intranasally exposed to Af (Af group) or saline (control group) three times a week for 1, 2 or 3 weeks. On days 4, 7, 14 and 21, mice were killed and lung tissue was fixed in acetone and embedded in glycol methacrylate. Serial 2-microns sections were stained with chromotrope 2R and MoAbs against ICAM-1, CD11a/CD18 (LFA-1) and CD3. Af-challenged mice presented significant increases in eosinophil, T lymphocyte and LFA-1-positive cell count and up-regulated expression of ICAM-1 in the lung tissue at all the time points examined. ICAM-1 expression intensity correlated with the number of T lymphocytes (r = 0.59, P < 0.01), LFA-1-positive cells (r = 0.68, P < 0.001), but not of eosinophils (r = -0.24, P > 0.05). These findings suggest that up-regulation of ICAM-1 expression is involved in the inflammatory process of this murine model of ABPA, and that this up-regulation may be more relevant to the the T lymphocyte accumulation in the lung.