Circulating intercellular adhesion molecule-1 (ICAM-1) antigen in sera of patients with idiopathic pulmonary fibrosis

Research Progress of Fibroblasts in Human Diseases

Fibroblasts, which originate from embryonic mesenchymal cells, are the predominant cell type seen in loose connective tissue. As the main components of the internal environment that cells depend on for survival, fibroblasts play an essential role in tissue development, wound healing, and the maintenance of tissue homeostasis. Furthermore, fibroblasts are also involved in several pathological processes, such as fibrosis, cancers, and some inflammatory diseases. In this review, we analyze the latest research progress on fibroblasts, summarize the biological characteristics and physiological functions of fibroblasts, and delve into the role of fibroblasts in disease pathogenesis and explore treatment approaches for fibroblast-related diseases.

Trimetazidine Alleviates Bleomycin-Induced Pulmonary Fibrosis by Targeting the Long Noncoding RNA CBR3-AS1-Mediated miRNA-29 and Resistin-Like Molecule alpha 1: Deciphering a Novel Trifecta Role of LncRNA CBR3-AS1/miRNA-29/FIZZ1 Axis in Lung Fibrosis

INTRODUCTION

Pulmonary fibrosis (PF) and tissue remodeling can greatly impair pulmonary function and often lead to fatal outcomes.

METHODOLOGY

In the present study, we explored a novel molecular interplay of long noncoding (Lnc) RNA CBR3-AS1/ miRNA-29/ FIZZ1 axis in moderating the inflammatory processes, immunological responses, and oxidative stress pathways in bleomycin (BLM)-induced lung fibrosis. Furthermore, we investigated the pharmacological potential of Trimetazidine (TMZ) in ameliorating lung fibrosis.

RESULTS

Our results revealed that the BLM-treated group exhibited a significant upregulation in the expression of epigenetic regulators, lncRNA CBR3-AS1 and FIZZ1, compared to the control group (P<0.0001), along with the downregulation of miRNA-29 expression. Furthermore, Correlation analysis showed a significant positive association between lnc CBR3-AS1 and FIZZ1 (R=0.7723, p<0.05) and a significant negative association between miRNA-29 and FIZZ1 (R=-0.7535, p<0.05), suggesting lnc CBR3-AS1 as an epigenetic regulator of FIZZ1 in lung fibrosis. BLM treatment significantly increased the expression of Notch, Jagged1, Smad3, TGFB1, and hydroxyproline. Interestingly, the administration of TMZ demonstrated the ability to attenuate the deterioration effects caused by BLM treatment, as indicated by biochemical and histological analyses. Our investigations revealed that the therapeutic potential of TMZ as an antifibrotic drug could be ascribed to its ability to directly target the epigenetic regulators lncRNA CBR3-AS1/ miRNA-29/ FIZZ1, which in turn resulted in the mitigation of lung fibrosis. Histological and immunohistochemical analyses further validated the potential antifibrotic effects of TMZ by mitigating the structural damage associated with fibrosis.

DISCUSSION

Taken together, our study showed for the first time the interplay between epigenetic lncRNAs CBR3-AS1 and miRNA-29 in lung fibrosis and demonstrated that FIZZ1 could be a downregulatory gene for lncRNA CBR3-AS1 and miRNA-29. Our key findings demonstrate that TMZ significantly reduces the expression of fibrotic, oxidative stress, immunomodulatory, and inflammatory markers, along with epigenetic regulators associated with lung fibrosis. This validates its potential as an effective antifibrotic agent by targeting the CBR3-AS1/miRNA-29/FIZZ1 axis.

Exploring the evolving function of soluble intercellular adhesion molecule-1 in junction dynamics during spermatogenesis

Intercellular adhesion molecule-1 (ICAM-1) is a transmembrane glycoprotein expressed on immune, endothelial, and epithelial cells. Its ectodomain can be proteolytically cleaved to release a circulating soluble form called sICAM-1. Clinical studies demonstrate sICAM-1 is upregulated in various diseases and associated with disease severity. Research has identified sICAM-1 as a regulator of the blood-testis barrier (BTB) and spermatogenesis. Overexpression of sICAM-1 weakened the BTB in vitro and in vivo, downregulated junction proteins including N-cadherin, γ-catenin, and connexin 43, and caused germ cell loss. This contrasts with barrier-strengthening effects of membrane-bound ICAM-1. sICAM-1 may act as a molecular switch enabling germ cells to open BTB and Sertoli-germ cell adhesion for transport across the seminiferous epithelium. While the mechanism remains unclear, reduced SRC family kinase (SFK) signaling was observed following sICAM-1 overexpression. SRC promotes BTB protein endocytosis and degradation, influences cytoskeletal dynamics, and affects cell polarity. As sICAM-1 overexpression phenocopies SRC inhibition, SRC may operate downstream of sICAM-1 in regulating BTB dynamics and spermatogenesis. Investigating sICAM-1's structure-function regions and downstream targets will elucidate the molecular mechanisms of junction disruption. This knowledge could enable strategies targeting sICAM-1/SRC to modulate BTB permeability and treat male infertility or diseases involving endothelial/epithelial barrier dysfunction.

Molecular and Genetic Biomarkers in Idiopathic Pulmonary Fibrosis: Where Are We Now?

Idiopathic pulmonary fibrosis (IPF) represents a chronic progressive fibrotic interstitial lung disease of unknown cause with an ominous prognosis. It remains an unprecedent clinical challenge due to its delayed diagnosis and unpredictable clinical course. The need for accurate diagnostic, prognostic and predisposition biomarkers in everyday clinical practice becomes more necessary than ever to ensure prompt diagnoses and early treatment. The identification of such blood biomarkers may also unravel novel drug targets against IPF development and progression. So far, the role of diverse blood biomarkers, implicated in various pathogenetic pathways, such as in fibrogenesis (S100A4), extracellular matrix remodelling (YKL-40, MMP-7, ICAM-1, LOXL2, periostin), chemotaxis (CCL-18, IL-8), epithelial cell injury (KL-6, SP-A, SP-D), autophagy and unfolded protein response has been investigated in IPF with various results. Moreover, the recent progress in genetics in IPF allows for a better understanding of the underlying disease mechanisms. So far, the causative mutations in pulmonary fibrosis include mutations in telomere-related genes and in surfactant-related genes, markers that could act as predisposition biomarkers in IPF. The aim of this review is to provide a comprehensive overview from the bench to bedside of current knowledge and recent insights on biomarkers in IPF, and to suggest future directions for research. Large-scale studies are still needed to confirm the exact role of these biomarkers.

Biomarkers and their potential functions in idiopathic pulmonary fibrosis

Introduction: Idiopathic pulmonary fibrosis (IPF) is a chronic, devastating, and progressive lung disease that is characterized by fibrosis and respiratory failure. IPF holds high morbidity and poor prognosis and still faces considerable problems of reliable diagnosis and valid prognosis. A growing body of literature have reported changes in the level of various biomarkers in IPF patients, which means that they are expected to become a new tool for the clinical practice of IPF.Areas covered: We reviewed the recent literature about biomarkers and focus on the role they play in IPF. We systematically searched Medline/PubMed through February 2020. Many works of literature have shown that a variety of biomolecules and genomics played multiple roles in the diagnosis or differential diagnosis, prognosis, and indication of acute deterioration of IPF and so on.Expert opinion: Significant advances have been made in the role of biomarkers for IPF these years; however, current data indicate that a single biomarker is unlikely to have a transformative effect on clinical practice; therefore, the combined effect of various biomarkers can be considered to improve the accuracy of diagnosis and prognosis. Further research of biomarkers may provide new insights for the diagnosis, prognosis, and even therapy of IPF.

Circulating lung biomarkers in idiopathic lung fibrosis and interstitial lung diseases associated with connective tissue diseases: Where do we stand?

Interstitial lung diseases (ILDs) are complex diseases with various courses where personalized medicine is highly expected. Biomarkers are indicators of physiological, pathological processes or of pharmacological response to therapeutic interventions. They can be used for diagnosis, risk-stratification, prediction and monitoring of treatment response. To better delineate the input and pitfalls of biomarkers in ILDs, we performed a systematic review and meta-analysis of literature in MEDLINE and Embase databases from January 1960 to February 2019. We focused on circulating biomarkers as having the highest generalizability. Overall, 70 studies were included in the review and 20 studies could be included in the meta-analysis. This review highlights that ILD associated with connective tissue diseases (CTD-ILD) and idiopathic pulmonary fibrosis (IPF) share common biomarkers, suggesting common pathophysiological pathways. KL-6 and SP-D, could diagnose lung fibrosis in both IPF and CTD-ILD, with KL-6 having the strongest value (OR: 520.95[110.07-2465.58], p<0.001 in IPF and OR:26.43[7.15-97.68], p<0.001 in CTD-ILD), followed by SPD (OR: 33.81[3.20-357.52], p = 0.003 in IPF and 13.24 [3.84-45.71] in SSc-ILD), MMP7 appeared as interesting for IPF diagnosis (p<0.001), whereas in SSc, CCL18 was associated with ILD diagnosis. Both CCL18 and KL-6 were predictive for the outcomes of ILDs, with higher predictive values for CCL18 in both IPF (OR:10.22[4.72-22.16], p<0.001 and in SSc [2.62[1.71-4.03], p<0.001). However, disease specific biomarkers are lacking and large longitudinal studies are needed before the translational use of the potential biomarkers in clinical practice. With the recent availability of new effective therapies in ILDs, further studies should assess response to treatment.

Objectively Measured Chronic Lung Injury on Chest CT

BACKGROUND

Tobacco smoke exposure is associated with emphysema and pulmonary fibrosis, both of which are irreversible. We have developed a new objective CT analysis tool that combines densitometry with machine learning to detect high attenuation changes in visually normal appearing lung (Norm_HA) that may precede these diseases.

METHODS

We trained the classification tool by placing 34,528 training points in chest CT scans from 297 COPDGene participants. The tool was then used to classify lung tissue in 9,038 participants as normal, emphysema, fibrotic/interstitial, or Norm_HA. Associations between the quartile of Norm_HA and plasma-based biomarkers, clinical severity, and mortality were evaluated using Jonckheere-Terpstra, pairwise Wilcoxon rank-sum tests, and multivariable linear and Cox regression.

RESULTS

A higher percentage of lung occupied by Norm_HA was associated with higher C-reactive protein and intercellular adhesion molecule 1 (P for trend for both < .001). In analyses adjusted for multiple covariates, including high and low attenuation area, compared with those in the lowest quartile of Norm_HA, those in the highest quartile had a 6.50 absolute percent lower percent predicted lower FEV₁ (P < .001), an 8.48 absolute percent lower percent predicted forced expiratory volume, a 10.78-meter shorter 6-min walk distance (P = .011), and a 56% higher risk of death (P = .003). These findings were present even in those individuals without visually defined interstitial lung abnormalities.

CONCLUSIONS

A new class of Norm_HA on CT may represent a unique tissue class associated with adverse outcomes, independent of emphysema and fibrosis.

Blood Biomarkers in Idiopathic Pulmonary Fibrosis

PURPOSE

Idiopathic pulmonary fibrosis (IPF) is a progressive and lethal lung disease of unknown origin whose incidence has been increasing over the latest decade partly as a consequence of population ageing. New anti-fibrotic therapy including pirfenidone and nintedanib have now proven efficacy in slowing down the disease. Nevertheless, diagnosis and follow-up of IPF remain challenging.

METHODS

This review examines the recent literature on potentially useful blood molecular and cellular biomarkers in IPF. Most of the proposed biomarkers belong to chemokines (IL-8, CCL18), proteases (MMP-1 and MMP-7), and growth factors (IGBPs) families. Circulating T cells and fibrocytes have also gained recent interest in that respect. Up to now, though several interesting candidates are profiling there has not been a single biomarker, which proved to be specific of the disease and predictive of the evolution (decline of pulmonary function test values, risk of acute exacerbation or mortality).

CONCLUSION

Large scale multicentric studies are eagerly needed to confirm the utility of these biomarkers.

Systematic phenotyping and correlation of biomarkers with lung function and histology in lung fibrosis

To date, phenotyping and disease course prediction in idiopathic pulmonary fibrosis (IPF) primarily relies on lung function measures. Blood biomarkers were recently proposed for diagnostic and outcome prediction in IPF, yet their correlation with lung function and histology remains unclear. Here, we comprehensively assessed biomarkers in liquid biopsies and correlated their abundance with lung function and histology during the onset, progression, and resolution of lung fibrosis, with the aim to more precisely evaluate disease progression in the preclinical model of bleomycin-induced pulmonary fibrosis in vivo. Importantly, the strongest correlation of lung function with histological extent of fibrosis was observed at day 14, whereas lung function was unchanged at days 28 and 56, even when histological assessment showed marked fibrotic lesions. Although matrix metalloproteinase-7 (MMP-7), MMP-9, and PAI-1 were significantly elevated in broncheoalveolar lavage of fibrotic mice, only soluble ICAM-1 (sICAM-1) was elevated in the peripheral blood of fibrotic mice and was strongly correlated with the extent of fibrosis. Importantly, tissue-bound ICAM-1 was also elevated in lung homogenates, with prominent staining in hyperplastic type II alveolar epithelial and endothelial cells. In summary, we show that lung function decline is not a prerequisite for histologically evident fibrosis, particularly during the onset or resolution thereof. Plasma levels of sICAM-1 strongly correlate with the extent of lung fibrosis, and may thus be considered for the assessment of intraindividual therapeutic studies in preclinical studies of pulmonary fibrosis.

The diagnosis of idiopathic pulmonary fibrosis and its complications

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a devastating, progressive condition with a median survival of 2.8 - 4 years from diagnosis. Clinicians confronted with a patient with fibrosing lung disease need to be reliably able to distinguish IPF from other diffuse parenchymal lung diseases. Furthermore, they need to be able to gauge prognosis, evaluate timing of interventions including referral for transplant, assess reliably the effectiveness of treatment and be able to detect rapidly the development of disease complications.

OBJECTIVE/METHOD

This paper provides an overview of currently available diagnostic tests for IPF and its complications and evaluates the possible future role of candidate biomarkers in the diagnosis and assessment of patients with IPF. A literature search was performed for papers evaluating diagnostic tests in the diagnosis of IPF and its complications.

CONCLUSION

Computed tomography combined with clinical data is sufficient for diagnosing IPF in approximately two-thirds of patients with the condition. For the remaining patients, histological assessment is important in achieving a precise diagnosis. Serial measurements of carbon monoxide diffusing capacity and forced vital capacity provide the best prognostic indicator in IPF. Potential biomarkers for diagnosing IPF include KL-6, MMP1 and MMP7. Brain naturetic peptide shows promise as a non-invasive screening tool for the diagnosis of IPF-associated pulmonary hypertension.

Evidence of vascular damage in dengue disease: demonstration of high levels of soluble cell adhesion molecules and circulating endothelial cells

Clinical evidence suggests that vascular damage plays a key role in the pathophysiology of dengue hemorrhagic fever (DHF). In this study, the authors tested this hypothesis by examining the levels of soluble intercellular adhesion molecule and vascular cell adhesion molecule (sICAM-1 and sVCAM-1), and the presence of circulating endothelial cells (CECs), as evidence of vascular damage, in peripheral blood from DHF patients (n=13). A significant increase in plasma levels of sICAM-1 (n=12) and sVCAM-1 (n=13) was detected by enzyme-linked immunosorbent assay (ELISA) in DHF patients, compared with healthy individuals. Increased numbers of CECs, as detected by the expression of endothelial cell markers (ICAM-1, platelet cell adhesion molecule [PCAM]-1, and CD36) with flow cytometry, were observed in DHF patients (n=4), compared to healthy subjects. The high levels of sICAM-1 and sVCAM-1, together with the presence of CECs in DHF patients, provide further evidence of endothelium damage and activation in DHF patients.

Levels of soluble forms of ICAM and VCAM in patients with myelodysplastic syndromes and their prognostic significance

The aim of this study was to assess circulating soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), and interleukin-1beta (IL-1beta) in myelodysplastic syndromes (MDS) in order to evaluate their clinical significance. Seventy patients with untreated MDS [21 refractory anemia (RA), nine RA with ringed sideroblasts (RARS), 17 RA with excess of blasts (RAEB), 11 RAEB in transformation (RAEBt), and 12 chronic myelomonocytic leukemia (CMML)] were included in this study. Serum levels of sICAM, sVCAM, and IL-1beta were determined at diagnosis using commercially available immunoassays. In addition, 15 healthy volunteers were studied as a control group. sICAM, sVCAM, and IL-1beta serum levels were significantly higher in MDS patients in comparison with the control group (P <0.001). Patients with CMML showed the highest sICAM, sVCAM, and IL-1beta levels in comparison with other MDS-related subtypes. Furthermore significantly elevated levels of the studied parameters were detected in high-risk MDS patients (RAEB, RAEB-t, and CMML) in comparison with low-risk MDS (RA and RARS). IL-1beta was strongly correlated both to sICAM and sVCAM. In conclusion we have provided evidence that increased sICAM and sVCAM serum levels are related to MDS severity.

ICAM-1, ICAM-2 and ICAM-3 in the Sera of Patients with Idiopathic Pulmonary Fibrosis

In order to test the serum levels of ICAM-1, ICAM-2 and ICAM-3 in patients with idiopathic pulmonary fibrosis (IPF), twenty patients with IPF and eleven with secondary interstitial fibrosis (SIF), as well as forty healthy volunteers (HV) were studied. Serum intracellular adhesion molecules (ICAM) 1, 2 and 3 were assessed by ELISA. Functional respiratory tests, which included spirometry and lung diffusing capacity were simultaneously performed. Median values of serum ICAM-1 and ICAM-2 were higher in the patients' than in the healthy volunteers' (HV) group: IPF group: 946.60 ng/ml and 400.14 ng/ml; SIF group: 901.58 ng/ml and 378.27 ng/ml; HV group: 308.40 ng/ml and 217.55 ng/ml, respectively (p<0.05). ICAM-3 serum levels were equal between the three groups. ICAM-2 negatively correlated to DLCO values. (p<0.005). It can be concluded that ICAM 1 and 2 are elevated in the sera of patients with pulmonary fibrosis. ICAM-2 might be associated with a more impaired clinical status.

Elevated levels of circulating adhesion molecules in patients with active pulmonary tuberculosis

OBJECTIVE

Recent studies have indicated the importance of cell adhesion molecules in the pathogenesis of various inflammatory lung diseases. Our study was designed to determine whether five soluble adhesion molecules including soluble L-, E- and P-selectin (sL-, sE- and sP-selectin), intercellular adhesion molecule-1 (sICAM-1), and vascular cell adhesion molecule-1 (sVCAM-1) in serum reflect the severity of active pulmonary tuberculosis (TB), and whether there is a distinct profile of these soluble molecules in this disease.

METHODOLOGY

Using enzyme-linked immunosorbent assays, we measured the serum levels of these five soluble adhesion molecules in 31 patients with active TB and 11 healthy volunteers.

RESULTS

Serum levels of sE-selectin, sP-selectin and sICAM-1, but not sL-selectin or sVCAM-1, were significantly higher in patients with active TB than in the control subjects (P < 0.001, each). Significant correlations were detected only between serum levels of sE-selectin and sP-selectin, sE-selectin and sICAM-1, and sP-selectin and sICAM-1. There was a significant correlation between the Gaffky scale result (a scale assessing the number of mycobacteria bacilli present) and all of the above adhesion molecules, except for sL-selectin. Serum levels of sE-selectin, sL-selectin and sICAM-1 also correlated with the CXR radiological score. Higher levels of sL-selectin and sICAM-1 were detected in the serum of patients with radiological cavity formation compared to those without. The ESR, C-reactive protein and circulating neutrophil counts all correlated significantly with sE-selectin, sP-selectin, sICAM-1 and sVCAM-1.

CONCLUSION

The results suggest that there is a distinct profile of soluble adhesion molecules in active pulmonary TB and that sE-selectin, sP-selectin, and especially sICAM-1 appear to be the most sensitive clinical measures of disease severity.

The role of inflammatory and immunological mediators in periodontitis and cardiovascular disease

Epidemiological studies have implicated periodontitis (PD) as a risk factor for development of cardiovascular disease (CVD). Persistent infections such as periodontitis induce inflammatory and immune responses which may contribute to coronary atherogenesis, and, in conjunction with other risk factors, may lead to coronary heart disease (CHD). In this review, mechanisms are described that may help explain the association between periodontal infections and CHD. Periodontal diseases are bacterial infections associated with bacteremia, inflammation, and a strong immune response, all of which may represent significant risk factors for the development of atherogenesis, CHD, and myocardial infarction (MI). Several mechanisms may participate in this association, including those induced by oral organisms, and those associated with host response factors. This review will focus on host factors. Oral pathogens and inflammatory mediators (such as interleukin [IL]-1 and tumor necrosis factor [TNF]-alpha) from periodontal lesions intermittently reach the bloodstream inducing systemic inflammatory reactants such as acute-phase proteins, and immune effectors including systemic antibodies to periodontal bacteria. This review will describe the potential role of various inflammatory as well as immunologic factors that may play a role in periodontitis as a possible risk factor for CHD.

The role of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and regulated on activation, normal T-cell expressed and secreted (RANTES) in the relationship between air pollution and asthma among children

To evaluate the role of adhesion molecules and chemokines in the relationship between air pollution and asthma, the authors determined the following in 230 children who lived in 4 communities in Japan that had different levels of air pollution: serum concentrations of soluble intercellular adhesion molecule-1 (sICAM-1); soluble vascular cell adhesion molecule-1 (sVCAM-1); regulated on activation, normal T-cell expressed and secreted (RANTES); and total immunoglobulin E (IgE). Children with asthma or who exhibited wheezing (n = 115) and nonasthmatic children (n = 115) were studied. Serum concentrations of sICAM-1, sVCAM-1, and RANTES were increased significantly in asthmatic children, compared with nonasthmatic children. Nonasthmatic children with serum IgE levels that were greater than or equal to 250 IU/ml had significantly lower concentrations of sICAM-1 and sVCAM-1 than the other children. The geometric means of sICAM-1 increased as air pollution increased. The results of this study suggest that adhesion molecules or chemokines are associated with asthma and that ICAM-1 may play an important role in the relationship between air pollution and the occurrence of asthma.

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.

Does soluble intercellular adhesion molecule-1 (ICAM-1) affect neutrophil activation and adhesion following ischaemia-reperfusion?

OBJECTIVES

To examine the effect of reperfusion plasma and sICAM-1 on neutrophil integrin expression and neutrophil adhesion to determine if sICAM-1 has a potential role in the regulation of neutrophil adhesion.

MATERIALS

Twenty-seven patients, 17 men and 10 women undergoing femorodistal surgery. Blood was taken preoperatively and from the femoral vein following the release of the cross-clamp. Neutrophils were obtained from five volunteers and incubated with phosphate buffered saline (PBS), preoperative plasma or reperfusion plasma with and without sICAM-1. Neutrophil expression of CD11b and adhesion were measured.

MAIN RESULTS

Neutrophil CD11b expression did not change following incubation in the three media. Neutrophil adhesion increased significantly following exposure to reperfusion plasma compared to PBS or preoperative plasma (45.5 adhesion vs. 12.75%, p < 0.01 Mann-Whitney U-test). Soluble ICAM-1 decreased CD11b expression and adhesion in neutrophils exposed to reperfusion plasma only (CD11b expression fell from 15.9 to 3.4 mcf, p < 0.01 Mann-Whitney U-test and adhesion fell to 11.6% cells adhered, p < 0.01).

CONCLUSION

An increase in CD11b expression is not required for an increase in neutrophil adhesion. The change in neutrophil adhesion produced by reperfusion plasma can be blocked by sICAM-1. Soluble ICAM-1 may have a physiological role in the regulation of neutrophil adhesion.

Increased levels of soluble forms of adhesion molecules in Takayasu arteritis

The present series of experiments were designed to determine if soluble forms of vascular cell adhesion molecule-1 and inter cellular adhesion molecule-1 are elevated in the setting of Takayasu arteritis. Plasma levels of these soluble adhesion molecules were measured by enzyme-linked immunosorbent assay in 73 Takayasu arteritis and 36 age-matched normal controls and examined with respect to the age of patients. Soluble vascular cell adhesion molecule-1 levels were significantly higher in Takayasu arteritis (mean 871.4 ng/ml, P<0.01) compared with controls (mean 607.9 ng/ml). No difference was found in soluble inter cellular adhesion molecule-1 levels between these two groups. Comparison of soluble vascular cell adhesion molecule-1 and inter cellular adhesion molecule-1 in these patients subdivided by age into three groups indicated significantly higher levels of these molecules in individuals over 50 years old compared to those under 39 years old (P<0.05). These data suggest that the measurement of soluble vascular cell adhesion molecule-1 may be clinically important in Takayasu arteritis. The correlation of soluble vascular cell adhesion molecule-1 and inter cellular adhesion molecule-1 levels with age may indicate some relationship with progression of this disease.

Elevated levels of soluble adhesion molecules in serum of patients with diffuse panbronchiolitis

STUDY OBJECTIVE

Adhesion molecules have been implicated in the pathogenesis of inflammatory diseases. This study was designed to determine whether soluble adhesion molecules in serum reflect the disease activity in diffuse panbronchiolitis (DPB).

PATIENTS AND METHODS

Using an enzyme-linked immunosorbent assay, we measured the serum levels of soluble L-, E-, and P-selectin (sL-, sE-, and sP-selectin), intercellular adhesion molecule-1, and vascular cell adhesion molecule-1 in 27 patients with DPB, 13 with bronchiectasis, and 15 normal adults. BAL was also performed, and the levels of interleukin (IL)-8 and IL-1 beta in BAL fluid (BALF) were measured.

RESULTS

The serum levels of these molecules were significantly elevated in DPB patients compared with the control subjects. DPB patients also had significant high levels of circulating sE- and sP-selectin compared with patients with bronchiectasis. There was a significant correlation between serum sE-selectin and the percentage of neutrophils in BALF in all patients. There was a significant inverse correlation between serum sE-selectin and percent vital capacity in DPB patients. In the same patients, the relationships between serum sE-selectin and BALF concentrations of IL-1 beta as well as between serum sL-selectin and BALF IL-8 were also significant. Treatment of DPB patients with macrolides significantly reduced the serum levels of these soluble adhesion molecules and BALF concentrations of IL-1 beta and IL-8.

CONCLUSIONS

Our results suggest that these soluble adhesion molecules, particularly selectins, may reflect the disease activity of DPB, and that their levels may be regulated by cytokines produced in the lungs.

Clinical validity of intercellular adhesion molecule-1 (ICAM-1) and TSH receptor antibodies in sera from patients with Graves' disease

We compared the concentrations of soluble intercellular adhesion molecule-1 (sICAM-1) and the activities of thyroid-stimulating antibodies (TSAb) and thyrotropin-receptor antibodies (TBIAb) as measured with a commercial kit (TRAK). Sera were obtained from patients with Graves' disease (GD) before, during and after therapy with carbimazole (1-methyl-2-thio-3-carbethoxyimidazole). In all the situations, TSAb method was more sensitive than TBIAb. These two parameters dropped during therapy and were not correlated at any stage of measurement. sICAM-1 levels increased in 56.4% of patients before treatment, remained elevated at the beginning of treatment and decreased after twelve months of therapy. TSAb levels were significantly different between patients in relapse (78%) and those in remission (18%) (Z = -2.250, P = 0.025), with a relapse rate depending on the TSAb positivity (chi 2 = 7.103, P = 0.0077). Positive sICAM-1 values were found in 3 of the 9 (33.3%) patients who relapsed after discontinuing the drug but were negative in all the patients remaining in remission with a significant difference (Z = -1.982, P = 0.0475). The relapse rate was also dependent on positive sICAM-1 values (chi 2 = 3.958, P = 0.0466). No correlation was found between sICAM-1 levels and anti-TSH receptor antibodies TSAb or TBIAb. We conclude that the TBIAb technique is too insensitive to explore GD. TSAb and sICAM-1 assays in patients with GD are good markers of immune process after treatment withdrawal. Because of its rapid implementation, the sICAM-1 assay may advantageously replace TSAb measurement for forming a prognosis of GD.

Localization of intercellular adhesion molecule-1 (ICAM-1) in the lungs of silica-exposed mice

Intercellular adhesion molecule-1 (ICAM-1) is expressed on a variety of cells including endothelial cells, alveolar epithelial cells, and alveolar macrophages. Endothelial/epithelial cell ICAM-1 participates in the migration of leukocytes out of the blood in response to pulmonary inflammation, whereas alveolar macrophage ICAM-1 may represent cell activation. Our previous studies have shown that there is increased expression of ICAM-1 in lung tissue during acute inflammation following intratracheal injection with silica particles (2 mg/mouse). This increased expression was shown to play a role, in part, in the migration of neutrophils from the circulation into the tissue parenchyma. The aim of the current work is to localize expression of ICAM-1 during acute inflammation in lungs of mice exposed to either silica or the nuisance dust, titanium dioxide. In silica-exposed mice, a significant increase in ICAM-1 was detected on day-1 and localized by immunohistochemistry to aggregates of pulmonary macrophages and to type II epithelial cells. Areas of the lung with increased ICAM-1 expression also showed increased tumor necrosis factor alpha expression. Immunocytochemical staining of bronchoalveolar lavage (BAL) cells demonstrated increased ICAM-1 expression associated with alveolar macrophages 3, 5, and 7 days following silica exposure. Finally, soluble ICAM-1 levels in the BAL fluid were significantly increased in mice exposed to silica on the same days. Titanium dioxide exposure elicited a minimal increase in expression of ICAM-1 in the lungs. These data demonstrate that exposure to the toxic particle silica specifically increases ICAM-1 expression localized to pulmonary macrophages and type II epithelial cells.

Soluble Markers of Leucocyte Adhesion in Patients with Venous Disease

Objective:

To measure soluble CD54 (ICAM-1) and CD62E (E-selectin) as markers of neutrophil adhesion in four groups of patients with varying severity of venous disease and compare the values obtained with those in age- and sex-matched control subjects.

Design:

Prospective study of patients with varicose veins compared with a group of control subjects with no history or clinical findings of varicose veins.

Setting:

The Middlesex Hospital Vascular Laboratory, London.

Patients:

Patients referred to the Middlesex Hospital Vascular Laboratory for investigation of venous disease. Neither patients nor controls had arterial disease, any other systemic illness, or were on any medication known to alter white cell activity.

Interventions:

Ten millimetres of blood taken from an arm vein into EDTA for a neutrophil count and soluble CD54 and CD62E, measured using an ELISA.

Results:

Similar levels of soluble CD54 and CD62E were found in all four groups of patients compared with their controls ( p = 0.71 for soluble CD54 for all patients compared with all controls, and p = 0.65 for soluble CD62E, Mann–Whitney U-test). There was no difference in the neutrophil count between the controls and patients in any group ( p = 0.74 for all subjects, Mann–Whitney U-test).

Conclusion:

This study shows no evidence of increased soluble CD54 or CD2E or CD62E in patients with venous disease, despite previous work showing increased CD54 and neutrophil degranulation in patients with venous disease. The reason for this is currently unknown.

Subthreshold hyperoxia potentiates TNF-alpha-induced ICAM-1 expression on cultured pulmonary microvascular endothelial cells

The effects of combined exposure to subthreshold hyperoxia and the inflammatory cytokine tumor necrosis factor alpha (TNF-alpha) on the expression of intercellular adhesion molecule-1 (ICAM-1) were examined in bovine lung microvascular endothelial cells (BLuEC). The expression of total ICAM-1 was not affected by 50% hyperoxia conditions alone, indicating that this level is subthreshold for BLuEC. In the presence of 5 ng/mL TNF-alpha, which has minimal influence on BLuEC alone, the amount of total ICAM-1 expression under 50% hyperoxia was higher than that in normoxic conditions (approximately 30%) throughout the culture period. The amount of soluble ICAM-1 that has been released into the culture medium increased after joint exposure to hyperoxia and TNF-alpha. These results suggest that exposure to subthreshold hyperoxia, which does not by itself cause damage to the endothelial cells or induce ICAM-1 expression, potentiates the effects of low-level TNF-alpha exposure.

New indices of ischemic heart disease and aging: studies on the serum levels of soluble intercellular adhesion molecule-1 (ICAM-1) and soluble vascular cell adhesion molecule-1 (VCAM-1) in patients with hypercholesterolemia and ischemic heart disease

It is known that the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on the surface of vascular endothelial cells is closely related to the formation of early atherosclerotic lesions. In this study, serum soluble ICAM-1(sICAM-1) and soluble VCAM-1(sVCAM-1) were determined by sandwich ELISA both in normal healthy individuals (n = 114) and in patients with hypercholesterolemia (HC, n = 112) or ischemic heart disease (IHD, n = 38) to clarify the significance of the soluble forms of the adhesion molecules in the development of atherosclerotic diseases. IHD patients, not HC patients, showed significant elevation of sICAM-1, but not of sVCAM-1, compared with controls in age and sex-matched subjects. In addition, multiple linear regression analysis showed that sICAM-1 was correlated only to the presence of IHD but not to age and lipids. Multiple logistic regression analysis revealed that sICAM-1 was the most powerful independent predictor of the presence of IHD. On the other hand, sVCAM-1, not sICAM-1, was positively correlated to age. Multiple linear regression analysis showed that age was the most powerful independent predictor of the level of sVCAM-1. These data suggest that sICAM-1 and sVCAM-1 are useful as indices of clinical manifestations of atherosclerosis and aging, respectively.

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.

Effect of antioxidants on hyperoxia-induced ICAM-1 expression in human endothelial cells

The regulating mechanism of hyperoxia-induced ICAM-1 expression has not been elucidated. We studied the effect of antioxidants, including superoxide dismutase (SOD), catalase and N-acetylcysteine (NAC), on hyperoxia-induced ICAM-1 expression in human pulmonary artery endothelial cells (HPAEC) and human umbilical vein endothelial cells (HUVEC). Cells were cultured to confluence and exposed to either hyperoxic or normoxic gas with or without various kinds of antioxidants. The levels of ICAM-1 expression in the endothelial cells and the concentrations of reduced (GSH) and oxidized glutathione (GSSG) in the media were examined by flow cytometry and by spectrophotometry, respectively. After 48-hour exposure to hyperoxia, ICAM-1 expression was increased (HPAEC; 161 +/- 21% and HUVEC; 163 +/- 16%) and total glutathione concentration in the media was decreased as compared with normoxia. SOD did not change the GSH and GSSG concentrations in the media. Catalase dose-dependently decreased the supernatant GSSG concentration in both HPAEC and HUVEC, while the GSH concentration was nearly constant. NAC dose-dependently increased the supernatant GSH concentrations in both HPAEC and HUVEC. There was no difference in the supernatant GSSG concentrations between the NAC-treated HPAEC and HUVEC. There was no difference in ICAM-1 expression in either HPAEC or HUVEC with SOD treatment. ICAM-1 expressions in 100 U/ml (236 +/- 20%) and 1,000 U/ml (315 +/- 36%) of catalase were increased in HPAEC, and that in 1,000 U/ml (440 +/- 209%) of catalase was increased in HUVEC. Five and 10 U/ml of NAC decreased ICAM-1 expression in HPAEC (141 +/- 26% and 113 +/- 11%) and HUVEC (119 +/- 23% and 106 +/- 7%), respectively. These results suggest that extracellular glutathione may play a role in regulating hyperoxia-induced ICAM-1 expression in HPAEC and HUVEC.

The effects of treatment with chemotherapy on energy metabolism and inflammatory mediators in small-cell lung carcinoma

A disturbed energy balance has been demonstrated in lung cancer patients. Both an enhanced resting energy expenditure (REE) and a decreased energy intake contribute to weight loss. Enhanced systemic levels of inflammatory mediators were found to be related to the enhanced REE in lung cancer. The aim of the present study was to investigate energy metabolism and systemic levels of inflammatory mediators in small-cell lung carcinoma (SCLC) patients before and after treatment with chemotherapy. Hypermetabolism and an enhanced inflammatory response have already been demonstrated in SCLC by our group before. Twelve newly diagnosed SCLC patients were consecutively included in the study. REE was measured by indirect calorimetry and body composition was determined by bioelectrical impedance (BIA) before and 1 month after treatment. To assess the inflammatory state the acute-phase proteins, C-reactive protein (CRP) and lipopolysaccharide-binding protein (LBP), both soluble tumour necrosis factor (TNF) receptors, (sTNF-R)-55 and sTNF-R75, and soluble intercellular adhesion molecule (sICAM)-1 were measured in plasma before and 1 month after treatment. CRP was assessed by turbidemetry, whereas the other inflammatory parameters were measured by enzyme-linked immunosorbent assay (ELISA). A significant reduction in REE was found irrespective of therapeutic outcome, whereas body weight and body composition remained stable. The acute-phase proteins CRP and LBP were reduced significantly after treatment with chemotherapy, whereas both sTNF receptors and sICAM-1 remained enhanced. No correlation, however, existed between the decrease in REE and the decrease in the acute-phase proteins. In conclusion, chemotherapeutic treatment attenuates the tumour-related metabolic derangements and acute-phase response.

Circulating intercellular adhesion molecule-1 and its cellular expression in head and neck non-Hodgkin's lymphomas, including lethal midline granuloma

Extranodal non-Hodgkin's lymphoma in the head and neck, especially T-cell lymphoma of the lethal midline granuloma (LMG) type, has unique clinical and histologic features differentiating it from other lymphomas. The authors measured soluble intercellular adhesion molecule-1 (ICAM-1) in sera from 12 patients with T-cell lymphoma of the LMG type and from 52 patients with other head and neck non-Hodgkin's lymphomas, by double-determinant immunoassay. The expression of ICAM-1 in lymphoma tissue was examined in 26 patients by the avidin-biotin immunoperoxidase method. The serum ICAM-1 levels were significantly higher in T-cell lymphoma of the LMG type than in other head and neck lymphomas or in healthy adult controls. Elevated levels of serum ICAM-1 were associated with increased levels of serum lactate dehydrogenase, poor prognosis, and impaired T-cell-dependent immune functions, both in T-cell lymphoma of the LMG type and in other head and neck lymphomas. When we monitored serum ICAM-1 levels in individual patients, the level decreased in the complete remission interval compared to before treatment and went up again when the lymphoma relapsed. Although the staining intensities of ICAM-1 in lymphoma cells were not related to serum ICAM-1 levels, a markedly intense expression of ICAM-1 was found on the angiocentric or angiodestructive lymphoreticular infiltrate region in the tissues from T-cell lymphoma of the LMG type. A higher serum ICAM-1 level and its tissue expression in T-cell lymphoma of the LMG type may be one of the clues to understanding this particular lymphoma. The serum ICAM-1 level could be an efficient parameter for monitoring the clinical course of head and neck non-Hodgkin's lymphomas.

Longitudinal analysis of soluble intercellular adhesion molecule 1 in retinal vasculitis patients

Increased levels of soluble intercellular adhesion molecule 1 (sICAM-1) in serum have been demonstrated in several human disease conditions. We have previously shown, in a point-prevalence study, a positive correlation between sICAM-1 levels and disease relapse in patients with idiopathic retinal vasculitis. We now report a longitudinal study over 1 year in which sICAM-1 levels were compared with clinical disease status in order to determine this relationship further. Serum samples from 11 patients with idiopathic retinal vasculitis were tested for the presence of sICAM-1 by enzyme linked immunosorbent assay. Eight control subjects were also tested. Five out of 11 patients presented with relapse and had raised sICAM-1 levels compared with quiescent periods of their disease. Five out of 11 patients showed no relapse over 1 year and also no increase in sICAM-1 levels. One patient showed increased levels of sICAM-1, but no clinical signs of relapse. These results indicate that sICAM-1 is associated with disease activity in retinal vasculitis patients and could indicate dysfunction of the blood-retina barrier.

Circulating intercellular adhesion molecule 1 in rheumatoid arthritis--relationship to systemic vasculitis and microvascular injury in nailfold capillary microscopy

Intercellular adhesion molecule-1 (ICAM-1) is a membrane bound molecule that plays an important role in the pathogenic inflammatory responses observed in vasculitis. The aim of this study was to determine whether levels of soluble ICAM-1 sICAM-1) shedding into the circulation reflect the vascular injury found in nailfold capillaroscopy as well as systemic vasculitis in RA patients. We determined serum levels of sICAM-1 and soluble interleukin-2 receptor (sIL-2R) by an enzyme-linked immunosorbent assay in 79 RA patients. Serum levels of sICAM-1 were significantly increased in RA patients compared to 30 healthy controls. RA patients with clinical signs of systemic vasculitis showed significantly higher levels of sICAM-1 than those without vascular involvement. Although no significant correlation between sICAM-1 levels and the capillaroscopy findings were found, 75% of the patients with severe vascular changes in capillaroscopy exceeded normal sICAM-1 cut off value. Serum sICAM-1 concentrations correlated significantly with the erythrocyte sedimentation rate and serum sIL-2R, but not with the duration of RA, radiological stages, Ritchie index, age or type of treatment. These findings suggest that increased levels of sICAM-1 in serum of RA patients reflect systemic vascular involvement rather than a local vascular injury.

Increased plasma concentrations of circulating intercellular adhesion molecule-1 (cICAM-1) in patients with necrotizing pancreatitis

The intercellular adhesion molecule-1 (ICAM-1), a membrane glycoprotein, is important in the adhesion of cytokine-stimulated leukocytes to the endothelium of microvessels and their transendothelial migration. Circulating isoforms of ICAM-1 (cICAM-1) are known to be elevated in human serum as an indirect consequence of inflammatory responses. The aim of this study was to investigate whether cICAM-1 levels are elevated in patients with acute pancreatitis within 48 h of the onset of abdominal pain and whether cICAM-1 levels correlate with the severity of the tissue damage. Twenty-five consecutive patients admitted to a medical ICU had elevated cCAM-1 concentrations of 548 +/- 68 ng/ml, significantly different when compared to a control group of 18 healthy subjects (343 +/- 29; p = 0.018). According to the findings of contrast-enhanced CT or laparotomy patients were further divided in a group with acute edematous pancreatitis and a group with acute necrotizing pancreatitis. Pancreatic necrosis was associated with cICAM-1 levels of 729 +/- 106 ng/ml, significantly different from patients with mild disease (367 +/- 48) and controls (p < 0.001). Plasma cICAM-1 levels were not significantly different between healthy subjects and patients with mild pancreatitis. A significant correlation was found between cICAM-1 and C-reactive protein, an acute phase reactant and marker of necrotizing pancreatitis (r = 0.62; p < 0.01). The sensitivity and specificity for the detection of edematous or necrotizing pancreatitis of cICAM-1 plasma concentrations (cutoff point at 500 ng/ml) were 75% and 85%, respectively. These results suggest an enhanced release of ICAM-1 into plasma in the early stage of acute necrotizing pancreatitis. Leukocyte-endothelial cell adhesion may be associated with the inflammatory process of necrotizing tissue damage in acute pancreatitis. It could thus serve as a marker or predictor of a severe clinical course of pancreatitis.

TNF-alpha, IL-8, soluble ICAM-1, and neutrophils in sputum of cystic fibrosis patients

The cytokines tumor necrosis factor-alpha (TNF-alpha), interleukin-8 (IL-8), and intercellular adhesion molecule-1 (ICAM-1) have important roles in regulating neutrophil migration and the inflammatory response. To determine whether the concentration of these cytokines and soluble ICAM-1 (sICAM-1) in sputum was increased in patients with cystic fibrosis during acute exacerbations, we conducted (1) a cross-sectional study of 40 patients, 22 who were clinically well and 18 with acute pulmonary exacerbations; and (2) an 11 months longitudinal study of 16 patients. Significant differences in clinical scores, pulmonary function, and sputum neutrophil density were found between the acutely ill and the well group. There was a strong linear relationship (P < 0.0005) between TNF-alpha and IL-8 concentrations in sputum, but no association between clinical status and cytokine concentrations. The concentration of sICAM-1 was lower in acutely ill compared with well patients in the cross-sectional study. Recovery of exogenous IL-8 added to sputum was complete, while recovery of TNF-alpha averaged 70%. Recovery of exogenous sICAM-1 was only 43%, and the recoveries were lower in sputum samples from acutely ill patients than those from stable patients (P = 0.018). These data indicate that in cystic fibrosis patients, sputum concentrations of TNF-alpha and IL-8 are not increased during acute exacerbations of pulmonary inflammation.

Circulating intercellular adhesion molecule-1 (ICAM-1) as an early and sensitive marker for virus-induced T cell activation

The effect of systemic virus infection on the level of circulating ICAM-1 (cICAM-1) in serum, and the role of virus-activated T cells in this context, were studied using the murine lymphocytic choriomeningitis virus infection as primary model system. A marked virus-induced elevation in cICAM-1 in serum was revealed, the presence of which coincided with the phase of virus-induced T cell activation. However, high levels of cICAM-1 in serum were observed well before maximal T cell activation could be demonstrated. No increase in cICAM-1 was observed in the serum of infected T cell-deficient nude mice, clearly demonstrating that T cells were mandatory. Analysis of MHC class I and MHC class II-deficient mice revealed that either CD4+ or CD8+ T cells alone are sufficient, despite a markedly reduced inflammatory exudate in the former animals. These results indicate that virus-activated T cells induce shedding of ICAM-1 into the circulation, and this parameter may be used as an early and sensitive marker for immune activation.

Prognostic value of plasma soluble intercellular adhesion molecule-1 and endothelin-1 concentration in patients with chronic congestive heart failure

We tested the hypothesis that plasma endothelin-1 (ET-1) and soluble intercellular adhesion molecule-1 (sICAM-1) in patients with congestive heart failure (CHF) are related to subsequent survival, and assessed whether the measurements of these substances provide additional prognostic information to that obtained from clinical and biochemical variables previously known to be associated with high mortality. Plasma levels of sICAM-1 and ET-1 were measured in 102 patients with CHF (left ventricular ejection fraction [LVEF] < 0.45), and patients were followed up for > 18 months. The plasma level of sICAM-1 increased with the severity of CHF (normal, 149 +/- 10 ng/ml, mild CHF [New York Heart Association functional class II], 207 +/- 9.4 ng/ml, severe CHF [functional class III or IV], 293 +/- 18 ng/ml). The plasma level of ET-1 also increased with the severity of CHF (normal, 1.5 +/- 0.2 pg/ml, mild CHF, 2.1 +/- 0.1 pg/ml, severe CHF, 4.0 +/- 0.4 pg/ml). Plasma levels of both sICAM-1 and ET-1 decreased after treatment in 14 patients, with improvements in symptoms (from functional class IV to II) during the follow-up period. There was a significant positive correlation between the plasma level of ET-1 and plasma sICAM-1 (r = 0.44, p < 0.001). A significant negative correlation was observed between LVEF and plasma ET-1 (r = -0.34, p < 0.001), and plasma sICAM-1 (r = -0.36, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Soluble intercellular adhesion molecule-1 (ICAM-1) in sera and bronchoalveolar lavage (BAL) fluids of extrinsic allergic alveolitis

ICAM-1 plays an important role in inflammatory diseases. We analysed ICAM-1 expression on BAL fluid cells and measured soluble ICAM-1 (sICAM-1) concentrations in sera and BAL fluids from patients with extrinsic allergic alveolitis (EAA). We found significantly increased cellular ICAM-1 expression on BAL fluid lymphocytes and alveolar macrophages, and significantly increased values of circulating and BAL fluid sICAM-1 in EAA patients compared with controls. Successive measurement showed prompt decrease of both sICAM-1 values in EAA patients during periods when antigen exposure was prevented. In BAL fluids from EAA patients, sICAM-1 values significantly correlated to neutrophil and ICAM-1+ lymphocyte counts. In EAA patients, circulating and BAL fluid sICAM-1 values has significant negative correlations to values of carbon monoxide diffusing capacity and to time intervals between last episode and sample collection. However, these values had significant positive correlation to values of alveolar-arterial oxygen pressure difference. In EAA, antigen exposure appears to induce cellular ICAM-1 expression on BAL fluid cells, and also appears to up-regulate shedding of ICAM-1 in the alveolar lining fluid and in the circulation. The sICAM values appear to reflect disease activity of EAA.

Intercellular adhesion molecule-1 (ICAM-1) in the sera of patients with Graves' disease: correlation with disease activity and treatment status

Intercellular adhesion molecule (ICAM-1), a ligand for lymphocyte function-associated antigen-1 (LFA-1), plays an important role in a variety of immune-mediated mechanisms such as lymphocyte attachment to cultured Graves' thyroid cells. We report the detection of a soluble form of the ICAM-1 molecule (sICAM-1) in sera from patients with Graves' disease (GD) and other thyroid disorders. The mean (+/- SD) sICAM-1 concentration in 28 euthyroid control subjects was 1931 +/- 681 pmol/L. The mean sICAM-1 concentration in 25 untreated hyperthyroid patients with GD was significantly elevated (3065 +/- 890 pmol/L), and decreased significantly (2489 +/- 845 pmol/L) after treatment with antithyroid drugs and/or 131I. Of 14 GD patients who had been in remission following administration of antithyroid drugs, 12 had recurrent disease. In 10 of the 12 patients in whom GD recurred, the sICAM-1 concentration (3807 +/- 796 pmol/L) increased significantly. The mean sICAM-1 concentration in patients with hypothyroidism due to chronic thyroiditis (n = 15:2895 +/- 569 pmol/L) was significantly elevated over that of control subjects, and not different from untreated hyperthyroid patients. The mean sICAM-1 concentration in patients with subacute thyroiditis (n = 13: 3036 +/- 441 pmol/L) was significantly elevated, while the mean sICAM-1 concentration in patients with nodular goiter (n = 10: 2318 +/- 490 pmol/L) was within the normal range. These results indicate that mean serum sICAM-1 concentration was significantly elevated in patients with untreated GD, and it decreased after treatment and increased at the time of recurrence. Therefore, the elevated serum concentration of sICAM-1 in patient with GD probably reflects ongoing immune processes.

Potential therapeutic initiatives for fibrogenic lung diseases

Fibrotic process affecting the lung and other tissues is characterized by stimulation of fibroblast proliferation and connective tissue deposition. Conventional therapy consisting of glucocorticoids or cytotoxic agents is usually ineffective in blocking progression of disease. Potential new therapies have emerged from the use of animal models of pulmonary fibrosis and recent advances in the cellular and molecular biology of inflammatory reactions. Such therapies involve the use of substances directed against the action of certain growth factors, cytokines, or oxidants that are elaborated during the fibrotic reaction. In this article, we review possible therapeutic applications of these advances.

Elevated levels of soluble intercellular adhesion molecule-1 correlate with disease activity in Behçet's disease

The objective of this study was to measure soluble intercellular adhesion molecule-1 (sICAM-1) in patients with Behçet's disease (BD) and to analyse the relationship of sICAM-1 levels with clinical and some laboratory measures of disease activity. Forty patients with BD fulfilling the International Study Group Criteria for the diagnosis of BD and 20 healthy controls were studied. Twenty patients had active, and 20 patients had inactive disease. Serum sICAM-1 was determined by a sandwich ELISA. The mean (+/- SD) sICAM-1 level was significantly higher in the whole BD group (297.3 +/- 86.6 ng/ml) than in the healthy controls (213 +/- 83.5 ng/ml; P < 0.05). The mean sICAM-1 levels in active and inactive BD patients were 315.7 +/- 76.3 ng/ml and 258.3 +/- 73.3 ng/ml, respectively. The mean sICAM-1 level in active patients was significantly higher than in inactive patients and healthy controls (P < 0.02 and P < 0.001, respectively). No statistically significant difference in mean sICAM-1 levels was found between inactive BD patients and healthy controls (P > 0.05). There was no statistically significant difference between the mean sICAM-1 levels of active patients with (351.3 +/- 77.2 ng/ml) or without vascular lesions (292 +/- 68.8; P > 0.05). In spite of a positive correlation between disease activity and both erythrocyte sedimentation rate and C-reactive protein (CRP; P < 0.01), we found no correlation between sICAM-1 and either of them (P > 0.05). The elevated levels of sICAM-1 may be due to endothelial cell activation and/or damage or may be the result of inflammation.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of cell adhesion molecules in the lungs of patients with idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic inflammatory disorder restricted to the lungs. Leukocyte entry into the area of inflammation is regulated, at least partly, by endothelial expression of leukocyte-selective cell adhesion molecules (CAMs). To investigate the relevance of these CAMs to the accumulation of leukocytes in IPF, we examined the expression of E-selectin (endothelial leukocyte adhesion molecule-1; ELAM-1), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) by immunohistochemistry in lung tissue from nine patients with IPF and five nonsmoking normal subjects. The results demonstrated that in normal lungs, ICAM-1 was weakly expressed on endothelial cells, but neither E-selectin nor VCAM-1 was detected. In the lungs of patients with IPF, E-selectin expression on endothelial cells was restricted to honeycombing regions. Endothelial expression of ICAM-1 was increased throughout the tissue, but VCAM-1 was not detected in IPF. The distribution of leukocytes in lungs with IPF consisted of mostly lymphocyte accumulation in the interstitium and neutrophil accumulation within the airspaces of honeycomb regions. These results suggest that E-selectin may play a role in the recruitment of neutrophils in regions of honeycombing and that ICAM-1 may play a role in lymphocyte recruitment into the interstitium in addition to contributing to neutrophil recruitment in regions of honeycombing in patients with IPF.

Soluble endothelium-associated adhesion molecules in patients with Graves' disease

The targeting and recruitment of inflammatory cells to vascular endothelium in Graves' disease (GD) is mediated by intercellular adhesion molecule-1 (ICAM-1), endothelial leucocyte adhesion molecule-1 (ELAM-1), and vascular cell adhesion molecule-1 (VCAM-1). We have studied serum levels of soluble ICAM-1 (sICAM-1), soluble ELAM-1 (sELAM-1), and soluble VCAM-1 (sVCAM-1) in patients with GD (n = 21) and in patients with iodine-deficient goitre (IDG) (n = 23). The serum levels of sICAM-1 were markedly elevated in patients with GD before treatment with thiamazole (median 560 ng/ml versus 185 ng/ml in patients with IDG). In addition, elevated serum concentrations of sELAM-1 (median 85 ng/ml versus 33 ng/ml, respectively) and sVCAM-1 (median 42 ng/ml versus 15 ng/ml, respectively) were observed in patients with GD (P < 0.01 for all). The serum levels of sELAM-1 and sVCAM-1 dropped significantly after initiation of therapy and were within the normal range after 4, and 8 weeks of therapy, respectively. Serum levels of sICAM-1 were elevated even after 8 weeks of therapy. Serum levels of sVACM-1 and sICAM-1 correlated with the serum concentrations of anti-thyroid-stimulating hormone (TSH)-receptor antibodies (TSHR-R) (n = 21; r = 0.929 and r = 0.810, respectively) and anti-thyroid peroxidase antibodies (TPO-Ab) (n = 21; r = 0.673 and r = 0.750, respectively). However, no correlation between sELAM-1 and TPO-Ab, TSHR-R, and anti-thyroglobulin antibodies (Tg-Ab), respectively, could be found. In addition to thyroid hormones and autoantibodies, serum concentrations of sELAM-1 and sVCAM-1, but not sICAM-1, could be useful as clinical markers for disease activity.

Intercellular adhesion molecule-1 (ICAM-1) expression and soluble ICAM-1 (sICAM-1) production by cytokine-activated human aortic endothelial cells: a possible role for ICAM-1 and sICAM-1 in atherosclerotic aortic aneurysms

The interactions of inflammatory cells, cytokines, and cell adhesion molecules (CAM) may be important in the pathogenesis of vascular diseases such as abdominal aortic aneurysms (AAA), in which inflammation plays a role. The aim of this study was to investigate the pathogenic role of ICAM-1, a molecule involved in leucocyte-endothelial interactions, in vascular inflammation. ELISA of human explant culture supernatants revealed a four-fold increase in sICAM-1 production by AAA (n = 9) versus normal (n = 8) aortic explants. Human aortic endothelial cell (hAEC) culture was used for further studies as an in vitro model for aortic inflammatory conditions. Tumour necrosis factor-alpha (TNF-alpha) or IL-1 beta treatment of hAEC resulted in an up to 1.8-fold significant increase in sICAM-1 production compared with resting cells. In addition, the expression of ICAM-1 on cytokine-stimulated versus resting hAEC was measured by radioimmunoassay. TNF-alpha significantly induced ICAM-1 expression on these cells. These results suggest that different forms of ICAM-1, present on or released by the activated aortic endothelium, may be involved in leucocyte adhesion to and migration into the vessel wall.

Soluble intercellular adhesion molecule-1 (sICAM-1) in atopic dermatitis

The serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) were determined by enzyme-linked immunosorbent assay, in 88 patients with atopic dermatitis (AD), 29 patients with eczematous dermatitis (ED) and in 33 healthy controls. The sICAM-1 levels were significantly higher in both AD and ED patients than in normal individuals. The longitudinal study of patients with AD revealed a significant decrease in the levels of sICAM-1 (P < 0.05) with improvements in disease activity. In AD patients, the sICAM-1 level correlated significantly with the total numbers of leukocytes and lymphocytes (P < 0.01 and P < 0.05, respectively), whereas no such correlation was found in patients with ED. Our studies show that the levels of sICAM-1 may be a useful immunologic parameter for monitoring disease activity in some of the individuals with AD.

Upregulation of ICAM-I by Plasmodium falciparum: in vitro and in vivo studies

AIMS

To monitor the expression of intercellular adhesion molecule I (ICAM-I) in vitro after stimulation of human macrophages with Plasmodium falciparum antigens, as well as the plasma concentrations of soluble ICAM-I (SICAM-I) in vivo in malarial patients.

METHODS

Human mononuclear leucocytes were cultured and stimulated for four hours with 300 ng/ml exogenous P falciparum antigens. CD14 and CD54 (ICAM-I) expression was monitored using flow cytometry. Soluble ICAM-I (s ICAM-I) was also measured in the blood of 122 outpatients with malaria before and after treatment (Rio Branco, Acre, Brazil).

RESULTS

ICAM-I expression increased from 15% to 375% after four hours of stimulation. When sICAM-I was analysed in the plasma of 122 patients with P falciparum or Plasmodium vivax malaria by enzyme immunoassay, significant increases were found. These were more pronounced in patients with P falciparum malaria, compared with healthy controls, and with the same patients four weeks after treatment.

CONCLUSION

ICAM-I expression may also be upregulated in human macrophages by exogenous Plasmodium antigens as well as by cytokines during the acute phase of malaria. sICAM-I concentrations are downregulated after treatment, probably caused by the absence of circulating Plasmodium antigens.

Pulmonary expression of ICAM-1 and LFA-1 in experimental Goodpasture's syndrome

The functional importance of ICAM-1 and its ligands, the beta 2-integrins, in leukocytic accumulation in pulmonary injury has been recently demonstrated in experimental models of lung disease. However, the exact location of these adhesion molecules remains unknown. In the current study we have used immunogold ultrastructural techniques to define the precise location of ICAM-1 in the lung and its interaction with beta 2-integrin expressing leukocytes in the early stages of experimental Goodpasture's (GP) syndrome in the rat. In normal animals there is strong constitutive ICAM-1 expression on the luminal surface of the alveolar epithelium that is confined to type I cells and completely absent from type II cells. Constitutive expression of ICAM-1 on the pulmonary capillary endothelium is comparatively weak. In GP syndrome there is an increase in ICAM-1 expression, which is still confined to the alveolar type I epithelial cells and capillary endothelium. This is associated with an early (1.5 hours) influx of CD18 expressing polymorphonuclear leukocytes, which are seen migrating into alveoli and the pulmonary interstitium. There is a later (6-12 hours) influx of CD11a/CD18 expressing macrophages which are present in the interstitium and in large numbers in the alveolar spaces, where they are very closely apposed to and adherent to the alveolar epithelium. This is the first study to demonstrate the precise ultrastructural location of ICAM-1 in the normal rat lung and in disease. In vivo administered antibody to ICAM-1 gains access to the extravascular sites within the lung, in particular the surface of alveolar type I epithelial cells, and this raises the possibility that beneficial effects of such antibodies may extend beyond their ability to inhibit interactions between leukocytes and endothelial cells.