Serum levels of soluble adhesion molecules intercellular adhesion molecule 1, vascular cell adhesion molecule 1, and E-selectin in patients with Wegener's granulomatosis. Relationship to disease activity and relevance during followup

Phenazine methosulphate-treated red blood cells activate NF-κB and upregulate endothelial ICAM-1 expression

Although enhanced Red Blood Cell (RBC) - Endothelial Cell (EC) interaction, as well as RBC induced EC activation, have been extensively studied in several RBC-linked pathologies, the specific individual effects of oxidatively modified RBC on EC activation has not yet been documented. However, increasing evidence in both experimental and clinical studies suggests that oxidatively modified RBC could be considered potential pathogenic determinants in several acute and chronic diseases displaying systemic oxidative stress. Therefore, the present study aimed to explore the specific effects of oxidized RBC interaction with endothelial cells on intracellular signaling pathways that promote EC activation. RBC were exposed to oxidative stress induced by phenazine methosulphate (PMS). It is shown that the interaction of oxidatively modified RBC with cultured human umbilical vein endothelial cells (HUVEC) results in: a) EC activation as indicated by the increased surface expression of intercellular adhesion molecule -1 (ICAM-1); b) the activation of transcription factor NF-κB, an indicator of cellular oxidant stress. These results emphasize the specific contribution of oxidatively modified RBC interaction to EC activation and their possible pathological role in vascular diseases and oxidative stress.

Accelerated atherosclerosis in ANCA-associated vasculitis

OBJECTIVES

Cardiovascular disease, including myocardial infarction and stroke, is a major cause of mortality in ANCA-associated vasculitis (AAV). Although AAV affects small vessels, an accelerated atherosclerosis not explained by traditional cardiovascular risk factors (CVRF) has been demonstrated. We aimed to investigate the association of atherosclerosis measured by carotid intima-media thickness (CIMT) and cerebral small vessel disease in AAV-patients.

MATERIALS & METHODS

Twenty-three AAV-patients in complete remission were recruited. Carotid ultrasonography (US), transcranial Doppler (TCD), brain magnetic resonance imaging (MRI), and SPECT after intravenous administration of tracer 99mTc-HMPAO (dose: 720MBq) were performed.

RESULTS

AAV-patients presented higher CIMT compared to normative population. Multivariate linear regression analysis demonstrated an association of higher CIMT with increased pulsatility index in middle cerebral artery (PI-MCA) (P=.011), higher lesion load on ARWMC scale (P=.011) and abnormal SPECT (P=.008). No association between higher CIMT and CVRF (diabetes or hypertension) was demonstrated. Increasing internal carotid artery pulsatility index (PI-ICA) was associated with decreasing mean flow velocity (MFV)-MCA (P=.038), increasing PI-MCA (P=.008) and increasing white matter lesions on MRI (P=.011).

CONCLUSIONS

Our study adds weight to the presence of increased atherosclerosis in AAV-patients. The association observed between CIMT and PI-ICA with small vessel cerebral disease, points the possible association of easy to use carotid US in predicting microvascular brain injury.

Tissue-specific microvascular endothelial cells show distinct capacity to activate NK cells: implications for the pathophysiology of granulomatosis with polyangiitis

The relevance of tissue specificity of microvascular endothelial cells (MECs) in the response to inflammatory stimuli and sensitivity to immune cell-mediated injury is not well defined. We hypothesized that such MEC characteristics might shape their interaction with NK cells through the use of different adhesion molecules and NK cell receptor ligands or the release of different soluble factors and render them more or less vulnerable to NK cell injury during autoimmune vasculitis, such as granulomatosis with polyangiitis (GPA). To generate a comprehensive expression profile of human MECs of renal, lung, and dermal tissue origin, we characterized, in detail, their response to inflammatory cytokines and to proteinase 3, a major autoantigen in GPA, and analyzed the effects on NK cell activation. In this study, we show that renal MECs were more susceptible than lung and dermal MECs to the effect of inflammatory signals, showing upregulation of ICAM-1 and VCAM-1 on their surface, as well as release of CCL2, soluble fractalkine, and soluble VCAM-1. Proteinase 3-stimulated renal and lung MECs triggered CD107a degranulation in control NK cell. Notably, NK cells from GPA patients expressed markers of recent in vivo activation (CD69, CD107a), degranulated more efficiently than did control NK cells in the presence of renal MECs, and induced direct killing of renal MECs in vitro. These results suggest that, upon inflammatory conditions in GPA, renal MECs may contribute to the recruitment and activation of NK cells in the target vessel wall, which may participate in the necrotizing vasculitis of the kidney during this disease.

Levels of soluble VCAM-1, soluble ICAM-1, and soluble E-selectin in patients with tuberculous pleuritis

Tuberculosis is characterized by the presence of activated mononuclear cells both in the peripheral circulation and in pleural fluid. Expression and up-regulation of adhesion molecules is the basis of cell-cell adhesion in granuloma formation and in leukocyte migration to the inflammatory site. Soluble isoforms of adhesion molecules have been described, and their expression at high levels indicated an activated state. The purpose of this study was to evaluate levels of soluble adhesion molecules in serum and pleural fluid from patients with tuberculous pleural effusions, compared with non-tuberculous pleural effusions. We analysed levels of soluble vascular cell adhesion molecule-1 (s.VCAM-1), soluble intercellular adhesion molecule-1 (s.ICAM-1), and soluble E-selectin (sE-selectin) in serum and pleural fluid from patients with tuberculous pleuritis, by sandwich ELISA. Serum levels of s.ICAM-1 and s.VCAM-1 in patients with tuberculosis were higher than those in healthy controls (p < 0.001). Levels of sE-selectin levels were in the normal range compared with control groups. In pleural fluid, levels of s.VCAM-1 and s.ICAM-1 were increased in pleural effusions. Patients with tuberculous pleural effusion exhibited high levels of s.ICAM-1 compared with patients with neoplastic pleural involvement. Up-regulation of s.VCAM-1 and s.ICAM-1 in serum, along with increased levels of sE-selectin in pleural effusions from tuberculous patients, may result in transmigration of activated inflammatory cells inducing pleural damage, which may contribute to the pathological processes involved.

Circulating angiopoietin-2 as a biomarker in ANCA-associated vasculitis

The endothelial-specific Angiopoietin-Tie2 ligand-receptor system is an important regulator of endothelial activation. Binding of angiopoietin-2 (Ang-2) to Tie2 receptor renders the endothelial barrier responsive to pro-inflammatory cytokines. We previously showed that circulating Ang-2 correlated with disease severity in a small cohort of critically ill patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis. The current study reassessed Ang-2 as a biomarker of disease activity and relapse in AAV. Circulating Ang-2 was measured in 162 patients with severe AAV (BVAS/WG≥3, with or without glomerulonephritis) in a clinical trial. Ang-2 levels during active AAV were compared to levels in the same patients during remission (BVAS/WG = 0). Levels in clinical subsets of AAV were compared, and association with future disease course was assessed. Ang-2 levels were elevated in severe disease (median 3.0 ng/ml, interquartile range 1.9–4.4) compared to healthy controls (1.2, 0.9–1.5). However, they did not reliably decline with successful treatment (median 2.6 ng/ml, interquartile range 1.9–3.8, median change −0.1). Ang-2 correlated weakly with BVAS/WG score (r = 0.17), moderately with markers of systemic inflammation (r = 0.25–0.41), and inversely with renal function (r = −0.36). Levels were higher in patients with glomerulonephritis, but levels adjusted for renal dysfunction were no different in patients with or without glomerulonephritis. Levels were higher in patients with newly diagnosed AAV and lower in patients in whom treatment had recently been started. Ang-2 levels during active disease did not predict response to treatment, and Ang-2 levels in remission did not predict time to flare. Thus, Ang-2 appears to have limited practical value in AAV as a biomarker of disease activity at time of measurement or for predicting future activity.

Biomarkers of endothelial cell activation: candidate markers for drug-induced vasculitis in patients or drug-induced vascular injury in animals

There is a pressing need for vascular biomarkers for studies of drug-induced vasculitis in patients and drug-induced vascular injury (DIVI) in animals. We previously reviewed a variety of candidate biomarkers of endothelial cell (EC) activation (Zhang et al., 2010). Now we update information on EC activation biomarkers from animal data on DIVI and clinical data of vasculitic patients, particularly patients with primary antineutrophil cytoplasmic autoantibody (ANCA)-associated small vessel vasculitis (primary AAVs), including Wegener's granulomatosis, microscopic polyangiitis, Churg-Strauss syndrome and necrotizing crescentic glomerulonephritis. Drug-associated ANCA-positive small vessel vasculitis (drug-AAVs) can closely resemble primary AAVs, suggesting the large overlap between primary idiopathic systemic vasculitis and drug-induced vasculitis. AAVs in patients and DIVI in animals vary considerably; however, there is close resemblance between AAVs and DIVI in some respects: (1) the immunopathogenetic mechanisms (activation of primed neutrophils, ECs and T cells by ANCA in patients and activation of ECs, mast cells, and macrophages by drugs in animals); (2) the morphologic changes (fibrinoid necrosis of the vessel wall and neutrophilic infiltration); (3) the preferable sites (small arteries, arterioles, capillaries and venules); and (4) elevation of vascular biomarkers suggestive of an endothelial origin. The present review discusses soluble and cell component biomarkers and provides a rationale for the potential utility of EC activation biomarkers in nonclinical and clinical studies during new drug development. Further investigation, however, is needed to assess their potential utility.

The effect of aggressive versus conventional lipid-lowering therapy on markers of inflammatory and oxidative stress

Purpose

Recent trial results are in favor of aggressive lipid lowering using high dose statins in patients needing secondary prevention. It is unclear whether these effects are solely due to more extensive lipid lowering or the result of the potentially anti-inflammatory properties of statins. We aimed to determine whether aggressive compared with conventional statin therapy is more effective in reducing systemic markers of inflammation and oxidative stress.

Materials and methods

This was a multi-centre, double-blind, placebo-controlled trial. Patients with previous cardiovascular disease, who did not achieve low density lipoprotein (LDL) cholesterol levels <2.6 mmol/l on conventional statin therapy (simvastatin 40 mg) were randomized to continue with simvastatin 40 mg or to receive atorvastatin 40 mg for 8 weeks and thereafter atorvastatin 80 mg for the final 8 weeks (aggressive treatment). Lipids, C-reactive protein, soluble cellular adhesion molecules, neopterin, von Willebrand Factor, and antibodies against oxidized LDL were measured at baseline and after 16 weeks.

Results

Lipid levels decreased significantly in the aggressive treatment group (LDL-C reduction 20.8%; P < 0.001), whereas a slight increase was observed in the conventional group (LDL-C increase 3.7%; P = 0.037). A significant reduction in antibodies against oxidized LDL was seen in the aggressive (13.4%; P < 0.001) and the conventional (26.8%; P < 0.001) group, but there was no difference between groups (P = 0.25). Furthermore, no significant differences in change in other biomarkers was observed between both groups.

Conclusions

This study does not support the hypothesis that a more profound reduction in inflammatory and oxidative stress contributes to the benefits of aggressive statin therapy.

Anti-Neutrophil Cytoplasmic Autoantibodies: A Renewed Paradigm in Periodontal Disease Pathogenesis?

In the past, various models including the autoimmunity model have been proposed to explain the pathogenesis of periodontal diseases. The aim of this review is to introduce the pathogenic role of anti-neutrophil cytoplasmic autoantibodies (ANCAs) in various autoimmune diseases and compare these conditions with periodontal disease to elucidate common pathogenic mechanisms. Also, a novel model to explain the pathogenesis of periodontal disease based on the concept of ANCA-associated autoimmunity is proposed. This encompasses a wide array of biochemical mediators that range from direct and indirect initiators of ANCA production and eventual release of proinflammatory mediators and free radicals, all of which have been implicated in periodontal tissue destruction in the past. In addition, specific links between the typical ANCA-associated diseases and periodontal disease are discussed. Finally, a new paradigm in the periodontal disease-associated destruction is proposed that includes the currently accepted mechanism, namely, the genetic-microbial-host interactions.

Accelerated atherosclerosis in patients with Wegener's granulomatosis

BACKGROUND

Several autoimmune disorders are complicated by excess cardiovascular disease. In addition to traditional risk factors, non-traditional risk factors such as endothelial activation and excessive vascular remodelling might be determinants of the progression of atherosclerosis in patients with an autoimmune disease.

OBJECTIVE

To evaluate whether patients with Wegener's granulomatosis (WG) have an increased prevalence of atherosclerosis and to determine predisposing factors.

METHODS

29 WG patients (19 men; mean (SD) age, 53 (14) years) with inactive disease and 26 controls (16 men; age 53 (15) years) were studied. Common carotid intima-media thickness (IMT) was measured by ultrasound. In all individuals traditional risk factors for cardiovascular disease were determined. High sensitivity C reactive protein (hsCRP) was measured. Endothelial activation was assessed by measuring thrombomodulin, vascular cell adhesion molecule-1, and von Willebrand factor. As a marker of vascular remodelling matrix metalloproteinases (MMP-3 and MMP-9) and TIMP-1 were measured.

RESULTS

IMT was increased in WG patients compared with controls (p<0.05). No differences in traditional risk factors and endothelial activation markers between patients and controls were found. Levels of hsCRP, MMPs, and TIMP-1 were increased in WG patients (p<0.05).

CONCLUSIONS

Increased IMT found in WG patients cannot be explained by an increased prevalence of traditional risk factors. Although endothelial activation markers in WG patients with inactive disease were not increased, the raised levels of hsCRP, MMPs, and TIMP-1 suggest that enhanced inflammation and excessive vascular remodelling are contributing factors in the development of accelerated atherosclerosis in WG.

Levels of soluble E-selectin in patients with active Behcet's disease

Behcet's disease is a systemic vasculitis of unknown aetiology. Endothelial cell injury plays an important role in the pathogenesis and immunopathology of Behcet's disease. E-selectin is expressed by activated endothelial cells. Because the selectin adhesion molecules are shed from activated cells, soluble forms of these proteins can be used as activation markers of endothelium (E-selectin). The pathogenesis of Behcet's disease (BD) is closely related to endothelial cells, leucocyte functions and immunity. The aim of this study was to investigate circulating E-selectin adhesion molecules, which are known to play a significant part in the immune response especially by regulating interaction of the leucocytes with endothelium in BD. Plasma E-selectin concentrations were evaluated in 23 patients with BD and 20 healthy control subjects. The disease activity was evaluated by clinical manifestations (oral aphthous ulcer, genital ulceration, positive pathergy test, skin lesions, eye involvement, thrombophlebitis and arthritis) and by laboratory investigations [erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)]. The patients were newly or previously diagnosed cases not taking any drug for BD. Levels of E-selectin were measured with commercially available sandwich enzyme-linked immunosorbent assay (ELISA) kits using human sE-selectin (cat. no: BMS 205). Plasma E-selectin concentrations of patients and controls were compared with the Mann-Whitney U test. Statistical significance was assigned to p values lower than 0.05. Serum levels (mean+/-SD) of soluble E-selectin (sE-selectin) were significantly higher in 23 patients with BD than in 20 healthy controls (53.2+/-18.2 ng/ml vs 33.8+/-7.5 ng/ml, p<0.0001). A statistically significant positive correlation was observed between sE-selectin levels and CRP and ESR in patients with BD (r=0.78, p<0.001 and r=0.56, p<0.01, respectively). Increases in the E-selectin in BD may be a direct consequence of the leucocyte and endothelium activations observed during the disease process. The noninvasive investigations can be used as biochemical markers for inflammation. This may provide additional information regarding disease activity along with the traditional indices such as ESR and CRP.

Pathogenesis of diseases associated with antineutrophil cytoplasm autoantibodies

Little is known about the etiologies of diseases associated with circulating antineutrophil cytoplasm autoantibodies (ANCA), such as primary vasculitides and inflammatory bowel diseases. However, the understanding of immune mechanisms supposedly involved in the pathogenesis of these diseases is still growing. In the present review, we first focus on the mechanisms triggering the development of ANCA, including the potential role of microbial superantigens and the possible defect(s) in the progression of apoptosis or in the removal of apoptotic cells. We next concentrate on the contribution of ANCA to the clinical symptoms and on the pathogenic role of ANCA, including the accessibility of ANCA antigens as targets for circulating antibodies and the mode of action of ANCA. Mechanisms of neutrophil activation by ANCA include the engagement of Fcgamma receptors, the possible mechanisms of neutrophil-mediated tissue damage, and the neutrophil-endothelial interaction.

Circulating cellular adhesion molecules ICAM-1, VCAM-1, P- and E-selectin in the prediction of cardiovascular disease in diabetes mellitus

BACKGROUND: Macrovascular disease in diabetes mellitus is a multifactorial process resulting in part from accelerated atherosclerosis and increased thrombosis. The resultant cardiovascular mortality is up to five times that of an age-matched non-diabetic population. Recently, cell adhesion molecules (CAMs) have been demonstrated in atherosclerotic plaques and implicated in the initiation and development of atherosclerosis. METHODS: To assess circulating CAMs as potential predictors of the development of macrovascular disease in diabetes mellitus, we carried out a 5-year prospective study in 28 diabetic patients without manifest macrovascular disease at entry. Circulating CAMs [intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), P-selectin and E-selectin] were measured at baseline and at follow-up. RESULTS: Except for neuropathy, no patient had other microvascular diabetic complications (retinopathy or nephropathy) or clinically manifest macrovascular disease. Eleven patients developed macrovascular disease at follow-up (seven coronary heart disease, two cerebrovascular disease, two peripheral vascular disease). At baseline, systolic blood pressure and serum creatinine were higher (but within normal range) in patients developing macrovascular disease. Baseline ICAM-1 was significantly higher in the patients who developed macrovascular disease than in those who did not, and it remained so even after adjusting for age, systolic blood pressure, creatinine and glycaemic control (P=0.0007). However, baseline VCAM-1, P-selectin and E-selectin were not found to be associated with macrovascular disease. The risk of developing macrovascular disease was associated with increasing baseline concentrations of ICAM-1 [odds ratios 1.04 (95% CI 1.01-1.07); P=0.01]. No correlation was seen between ICAM-1, HbA(1) and cholesterol. CONCLUSION: This study suggests that ICAM-1 may predict development of macrovascular disease in diabetes mellitus.

Assessing disease activity in the systemic vasculitides

The improvement in survival of the systemic vasculitides with the use of current immunosuppression has heightened awareness of their poor long-term outcome in terms of chronic morbidity and relapse. Assessment of systemic vasculitis is an essential part of its management. Better understanding of the underlying pathophysiology of the antineutrophil cytoplasmic antibody-related vasculitides has resulted in improved assays and may result in more precise serologic assessment of disease. Clinical assessment tools for accurately measuring disease activity and damage have been developed and are reviewed in this article. It is becoming increasingly clear that these clinical tools are practical, effective measures that can assist in the treatment of individual patients and play an important role in clinical trials of systemic vasculitis.

PTX3 in small-vessel vasculitides: an independent indicator of disease activity produced at sites of inflammation

OBJECTIVE

To verify whether the prototypical long pentraxin PTX3 represents an indicator of the activity of small-vessel vasculitis.

METHODS

Concentrations of PTX3, a pentraxin induced in endothelium by cytokines, were measured by enzyme-linked immunosorbent assay in the sera of 43 patients with Churg-Strauss syndrome, Wegener's granulomatosis, and microscopic polyangiitis. PTX3 was also measured in the sera of 28 patients with systemic lupus erythematosus (SLE), 22 with rheumatoid arthritis, and 16 with CREST syndrome (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasias). Serum concentrations of C-reactive protein (CRP) were measured by immunoturbidimetry. The cells involved in PTX3 production in vivo were identified in skin biopsy samples.

RESULTS

Patients with active vasculitis had significantly higher concentrations of PTX3 than did those with quiescent disease (P < 0.001). PTX3 levels in the latter group were similar to those in healthy controls. PTX3 levels were higher in patients with untreated vasculitis and lower in patients who underwent immunosuppressive treatments (P < 0.005). In contrast, patients with active SLE had negligible levels of the pentraxin. PTX3 levels did not correlate with CRP levels in vasculitis patients. Endothelial cells produced PTX3 in active skin lesions.

CONCLUSION

PTX3 represents a novel acute-phase reactant produced at sites of active vasculitis.

Secondary prevention with fluvastatin decreases levels of adhesion molecules, neopterin and C-reactive protein

BACKGROUND

Treatment of hypercholesterolaemia with HMG-CoA reductase inhibitors results in an earlier reduction of morbidity and mortality than expected from trials using conventional cholesterol-lowering therapies. Possible explanations for this effect include stimulation of angiogenesis, improvement of endothelial function, plaque stabilisation, inhibition of coagulation and/or thrombocyte aggregation and inhibition of the inflammatory response associated with atherosclerosis.

METHODS

We investigated whether statins exert their effects by inhibition of endothelial activation, inflammation and/or monocyte/macrophage activation by measuring plasma levels of soluble cell adhesion molecules, neopterin and C-reactive protein upon treatment with fluvastatin for a period of 12 months in patients with established atherosclerosis and hypercholesterolaemia.

RESULTS

Blood samples were taken at baseline and at 3 and 12 months after starting treatment with fluvastatin 80 mg daily. Upon treatment, a reduction of s-ICAM-1 (956.3+/-123.6 vs. 745.4+/-127.4 vs. 674.9+/-70.8 ng/ml, P<0.05) and s-E-selectin (58.6+/-6.7 vs. 47.0+/-6.1 vs. 44.9+/-3.2 ng/ml, P<0.01) was observed. In addition, levels of neopterin decreased, albeit transiently (7.1+/-0.7 vs. 6.0+/-0.5 vs. 6.5+/-0.8 nmol/l, P=0.02), suggesting a reduction in monocyte/macrophage activity. Moreover, we found a decrease in levels of C-reactive protein during follow-up (5.21+/-2.0 vs. 3.18+/-0.7 vs. 1.95+/-0.3 mg/l, P<0.05), compatible with a reduction in inflammatory activity.

CONCLUSION

We conclude that statins have a combined beneficial effect on monocyte/macrophage activity, endothelial function and systemic inflammatory activity.

Proteinase 3 enhances endothelial monocyte chemoattractant protein-1 production and induces increased adhesion of neutrophils to endothelial cells by upregulating intercellular cell adhesion molecule-1

Wegener's granulomatosis is an autoimmune disease that is characterized by systemic vasculitis and granuloma formation. Early influx of polymorphonuclear neutrophils (PMN), followed at a later stage by mononuclear cells, contributes to the granulomatous inflammation. Previous studies have shown that proteinase 3 (PR3), the major autoantigen in Wegener's granulomatosis, specifically binds to endothelial cells and plays a possible role in activation of these cells by enhancing interleukin-8 production, thus providing a chemotactic and activating stimulus for PMN. The present study demonstrated that PR3 enhances the production of monocyte chemoattractant protein-1 (MCP-1) by human umbilical vein endothelial cells (HUVEC) in a dose- and time-dependent manner. The PR3-induced increase in MCP-1 production was demonstrated at both the protein and the mRNA levels and was chemotactic for monocytes. In addition, it was demonstrated that PR3 induces a dose- and time-dependent increase in the expression of intercellular adhesion molecule-1 (ICAM-1) as determined by fluorescence-activated cell sorter analysis. The PR3-induced increase in expression of ICAM-1 was also demonstrated at the mRNA level. PR3 induced a slight increase in vascular cell adhesion molecule-1 expression and had no effect on the expression of both P- and E-selectin. Incubation of HUVEC for 24 h in the presence of PR3 resulted in a significant increase in adhesion of PMN, which was reduced to baseline levels in the presence of blocking monoclonal antibody anti-ICAM-1 or anti-CD18 or a combination of both. Monocytes showed a slight but statistically not significant increase in adhesion. Incubation of HUVEC with PR3 for 4 h did not result in enhanced adhesion of either PMN or monocytes. It was hypothesized that PR3, which may be released locally at inflammatory sites after activation of cytokine primed PMN, plays a role in endothelial cell activation by enhancing both interleukin-8 and MCP-1 production, thus providing a chemotactic and activating stimulus for both PMN and monocytes. In addition, PR3 may contribute to the ongoing inflammation by enhancing the adhesion of PMN to endothelial cells by upregulating ICAM-1 expression.

Measurement of soluble adhesion molecules in primary Raynaud's phenomenon and in Raynaud's phenomenon secondary to connective tissue diseases

Adhesion molecules play a role in the inflammation and pathogenesis of vascular diseases. In 13 patients with primary Raynaud's phenomenon, 19 with Raynaud's phenomenon associated with connective tissue disease, and 16 control subjects, we measured plasma levels of soluble forms of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin, and von Willebrand factor. Patients with secondary Raynaud's phenomenon had plasma levels of soluble forms of intercellular adhesion molecule- 1, vascular cell adhesion molecule-1, E-selectin, and von Willebrand factor which were significantly higher than in those with primary Raynaud's phenomenon and controls, while no difference was observed between patients with primary Raynaud's phenomenon and controls. Within the group with secondary Raynaud's phenomenon, the strongest correlations were between soluble forms of intercellular adhesion molecule-1 and both E-selectin, (r=0.67, P<0.001) and von Willebrand factor (r=0.58, P<0.01). In none of the three groups were the levels of soluble adhesion molecules and von Willebrand factor changed by exposure of hands to cold, although all patients had a definite vasospasm. In conclusion, this study indicates that primary Raynaud's phenomenon is not associated with elevation of soluble adhesion molecules and von Willebrand factor. Prospective studies are now required to investigate the role of these molecules as predictors of secondary diseases.

Circulating soluble adhesion molecules in ANCA-associated vasculitis

BACKGROUND

To evaluate whether changes in concentrations of soluble (s) E-selectin, sP-selectin, sL-selectin, intercellular adhesion molecule 1 (sICAM-1), and vascular cell adhesion molecule 1 (sVCAM-1) reflect disease activity in patients with ANCA-associated vasculitis and whether serum levels of these adhesion molecules are related to the degree of renal failure in patients with chronic renal failure (CRF).

SUBJECTS AND METHODS

A sandwich ELISA was used to measure these soluble adhesion molecules in (i) sera from 20 patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (10 patients with Wegener's granulomatosis (WG) and 10 patients with microscopic polyangiitis (MPA)), obtained at the time of diagnosis and during the remission period; (ii) sera from 40 patients with CRF not undergoing haemodialysis.

RESULTS

At the time of diagnosis, serum levels of sE-selectin, sICAM-1 and sVCAM-1 (88+/-42 ng/ml, 437+/-184 ng/ml, 1720+/-1174 ng/ml respectively) were significantly higher in patients with ANCA-associated vasculitis than in healthy controls (P<0.0001, P=0.002 and P=0.001 respectively). Serum sP-selectin values did not differ from those obtained in normal donors. In contrast, sL-selectin levels (940+/-349 ng/ml) were significantly lower in patients than those recorded in healthy controls (P<0.0001). A significant decrease in concentrations of sE-selectin, sP-selectin, sICAM-1, and sVCAM-1 was observed between active and remission phases (P<0.0001, P=0.002, P=0.001 and P=0.001 respectively). No significant differences were observed in sL-selectin levels between active and remission phases. sL-selectin concentrations (802+/-306 ng/ml) during the remission phase remained lower than those observed in healthy controls (P<0.0001). No correlation was observed between serum creatinine and sE-selectin, sP-selectin, sICAM-1 and sVCAM-1 in patients of the CRF group. A slight negative correlation was established between creatinine and sL-selectin concentration.

CONCLUSIONS

Increased serum levels of sE-selectin, sICAM-1, and sVCAM-1 and decreased levels of sL-selectin in active ANCA-associated vasculitis, and the normalization of sE-selectin, sICAM-1, and sVCAM-1 during the remission phase suggest that the concentration of soluble levels of these adhesion molecules reflects disease activity. The decrease in sP-selectin levels between active and inactive phases also suggest that this receptor may reflect clinical activity. The lack of correlation between serum levels of sE-selectin, sP-selectin, sICAM-1, and sVCAM-1 and the degree of renal failure in patients with CRF suggests that the mechanism of clearance of these molecules is not renal.

Increased serum levels of soluble L-selectin (CD62L) in patients with active systemic lupus erythematosus (SLE)

The adhesion molecule L-selectin (CD62L) mediates lymphocyte recirculation and leucocyte rolling on vascular endothelium at sites of inflammation. Serum levels of soluble L-selectin (sL-selectin) were measured in patients with SLE in order to relate these levels to clinical activity and immunological parameters. An ELISA was used to detect the soluble form of human L-selectin (CD62L) in 42 patients with SLE and in 33 healthy individuals. The mean +/- s.e.m. values of sL-selectin were 1285 +/- 121 ng/ml for patients with SLE and 986 +/- 180 ng/ml for healthy blood donors, but there was no significant difference. When patients with active SLE were analysed, higher levels of circulating sL-selectin were found when compared with patients without activity (1497 +/- 167 ng/ml versus 941 +/- 150 ng/ml; P = 0.028). We found a significant correlation between the levels of sL-selectin and of dsDNA antibodies (r = 0.36, P = 0. 044) and between levels of sL-selectin and SLE Disease Activity Index (SLEDAI) score (r = 0.42, P = 0.003). Patients with active SLE studied cross-sectionally showed significant elevations of sL-selectin (CD62L) compared with controls. Thus, the levels of this soluble adhesion molecule correlated with active disease and levels of anti-dsDNA antibodies.

Leukocyte proteinases in wound healing: roles in physiologic and pathologic processes

Leukocytes express a number of proteinases which play critical roles in physiologic processes during wound healing. However, if the activity of these proteinases is uncontrolled, they can contribute to devastating tissue injury that can affect most organ systems. Until recently, little was known about the mechanisms by which leukocytes retain the activity of their proteinases within the extracellular space which contains highly effective proteinase inhibitors. Studies of the cell biology of leukocyte proteinases have begun to identify the mechanisms by which proteinases can circumvent the effects of physiologic proteinase inhibitors. Herein, we will review the cell biology of leukocyte proteinases, and we will discuss the mechanisms by which leukocyte proteinases can contribute to physiologic processes occurring during wound healing, as well as their roles in pathologic processes.

Monocyte activation in patients with Wegener's granulomatosis

OBJECTIVE

Wegener's granulomatosis (WG) is an inflammatory disorder characterised by granulomatous inflammation, vasculitis, and necrotising vasculitis and is strongly associated with anti-neutrophil cytoplasmic antibodies (ANCA). Activated monocytes/macrophages are present in renal biopsy specimens and participate in granuloma formation by synthesising and secreting a variety of chemoattractants, growth factors, and cytokines. In view of these findings, in vivo monocyte activation was evaluated in patients with WG and the findings related to parameters of clinical disease activity.

METHODS

Monocyte activation was analysed by measuring plasma concentrations of soluble products of monocyte activation, that is neopterin and interleukin 6 (IL6), by ELISA, and by quantitating the surface expression of activation markers on circulating monocytes by flow cytometry.

RESULTS

Twenty-four patients with active WG were included in this study. Ten of these patients were also analysed at the time of remission. Twelve patients with sepsis served as positive controls, and 10 healthy volunteers as negative controls for monocyte activation. Patients with active disease had increased monocyte activation compared with healthy controls as shown by increased concentrations of neopterin (p < 0.0001) and increased surface expression of CD11b (p < 0.05) and CD64 (p < 0.05). In those patients with increased concentrations of IL6 during active disease plasma concentrations of IL6 decreased during follow up when patients went into remission (p < 0.0001). In addition, neopterin (r = 0.37, r = 0.44), IL6 (r = 0.37, r = 0.60) and CD63 expression (r = 0.39, r = 0.45) correlated significantly with disease activity as measured by the Birmingham Vasculitis Activity Score and C reactive protein values, respectively. Compared with patients with sepsis, all markers of monocyte activation in patients with vasculitis were lower.

CONCLUSION

It is concluded that disease activity in WG correlates with the extent of activation of monocytes, compatible with their role in the pathophysiology of this disease.

Vascular cell adhesion molecule-1 (VCAM-1) and leukocyte activation in pre-eclampsia and eclampsia

OBJECTIVE

To evaluate the levels of VCAM-1 in pre-eclampsia/eclampsia as a possible marker of leukocyte activation and endothelial damage.

METHODS

We performed a case-control study on 25 healthy pregnant women and 35 patients diagnosed as pre-eclampsia or eclampsia which were randomly selected. Peripheral venous blood samples were obtained and serum levels of VCAM-1 were measured by enzyme-linked immunoassay (ELISA).

RESULTS

In pre-eclampsia/eclampsia, VCAM-1 levels were higher than in normal pregnancy. Serum concentrations of VCAM-1 were significantly higher in severe pre-eclampsia and eclampsia compared to mild pre-eclampsia or healthy controls. ROC analysis detected that VCAM-1 > or = 450 ng/ml had a sensitivity of 0.79 and a specificity of 0.90 in detecting severe pre-eclampsia and eclampsia.

CONCLUSION

This is the first study to correlate VCAM-1 levels with severity of disease in pre-eclampsia. Our findings indicate that increasing levels of soluble VCAM-1 are present in the circulation of patients with severe pre-eclampsia/eclampsia compared to mild pre-eclampsia or healthy pregnant women. Elevated VCAM-1 levels may represent a possible mechanism by which endothelial cells attract leukocytes and cause endothelial cell damage.

Active Wegener’s Granulomatosis Is Associated with HLA-DR+ CD4+ T Cells Exhibiting an Unbalanced Th1-Type T Cell Cytokine Pattern: Reversal with IL-10

Wegener’s granulomatosis (WG) is a granulomatous vasculitis that affects the upper respiratory tract, lung, and kidney. Since T cells make up a significant proportion of cells infiltrating granulomatous lesions in WG, we investigated the proliferative response and cytokine profile of T cells from these patients. PBMCs were isolated from 12 patients with active WG, 7 patients with inactive disease, and 12 healthy normal donors. PBMCs from clinically active WG patients exhibited increased proliferation following stimulation with either PMA/ionomycin or anti-CD2 and anti-CD28, when compared with normal donors. In addition, these PBMCs exhibited increased secretion of IFN-γ, but not of IL-4, IL-5, or IL-10. Furthermore, TNF-α production from PBMCs and CD4+ T cells isolated from patients with WG was elevated, when compared with healthy donors. In further studies, we investigated the ability of WG patients’ monocytes to produce IL-12 and showed that both inactive and active patients produced increased amounts of IL-12. Finally, the in vitro IFN-γ production by WG PBMC is inhibited in a dose-dependent manner by exogenous IL-10. These data suggest that T cells from WG patients overproduce IFN-γ and TNF-α, probably due to dysregulated IL-12 secretion, and that IL-10 may therefore have therapeutic implications for this disease.

Assessment of disease activity in systemic vasculitis

The systemic vasculitides are a group of inflammatory disorders characterised by relapses and remission. Before the introduction of immunosuppressive drugs, mortality was unacceptably high. Immunosuppressive therapy has had a therapeutic impact, but at the cost of increased risk of infection and other adverse effects. Differentiating infection from active disease can be difficult, and the inappropriate prescription of immunosuppressive drugs can be fatal. Hence disease indices which can aid physicians to identify the active phase of disease and enable early treatment, will be valuable in the management of this group of disorders.

Laboratory findings in the vasculitides

The primary vasculitides are diseases of unknown aetiology. They are characterized by inflammation of blood vessel walls. Measuring non-specific laboratory markers of inflammation is useful in the monitoring of patients with vasculitis. The diagnostic specificity of these markers is, however, restricted. In the last decade, autoantibodies reacting with myeloid granule proteins have been detected in the sera from patients with Wegener's granulomatosis, microscopic polyangiitis, Churg-Strauss syndrome, and the renal limited form of these vasculitides (i.e. idiopathic rapidly progressive glomerulonephritis). Anti-neutrophil cytoplasmic antibodies (ANCA) in the aforementioned disorders react with proteinase 3 (Pr3) or myeloperoxidase (MPO), and only incidentally to other antigens such as elastase and bactericidal-permeability increasing protein. The presence of ANCA alone, in particular perinuclear ANCA, as detected by indirect immunofluorescence, has a low specificity for those vasculitides. However, in combination with the presence of anti-Pr3 or anti-MPO antibodies as detected by enzyme-linked immunosorbent assay, sensitivity and specificity for the vasculitides is high. Several in vitro and in vivo data have suggested a pathophysiological role for anti-Pr3 and anti-MPO in the associated disorders. Measuring levels of the autoantibodies seems useful for the follow-up of patients with these vasculitides. The sensitivity and specificity of rises in ANCA levels for ensuing relapses appears somewhat lower than previously suggested. Refinement of the assays, for example, by measuring subclasses and functional characteristics of the autoantibodies, may improve their value in monitoring patients with vasculitides.

Clinical relevance of elevated serum thrombomodulin and soluble E-selectin in patients with Wegener's granulomatosis and other systemic vasculitides

PURPOSE

Vascular injury plays an important pathophysiological role in vasculitis. Soluble serum thrombomodulin (sTM), a promising marker of endothelial cell injury, is released into the circulating blood following cell damage and was therefore investigated as a parameter of disease activity in patients with Wegener's granulomatosis (WG) and various other vasculitides.

PATIENTS AND METHODS

One hundred and ninety-seven sera of 102 patients with histologically proven WG of different disease activity and 41 sera of patients with other vasculitides at their active stage were investigated (12 Takayasu arteritis [TA], 7 giant cell arteritis [GCA], 10 polyarteritis nodosa [PAN], 12 Behcet's disease [BD]). The sera were examined for the levels of sTM and sE-selectin (CD62E) by enzyme-linked immunosorbent assay (ELISA) and for the presence of classical anti-neutrophil cytoplasmic antibodies (cANCA) by indirect immunofluorescence (IIF). The disease activity was evaluated according to the clinical symptoms and organ involvement.

RESULTS

A significant increase of sTM levels compared with control values (26 +/- 2 ng/ml) was found in active WG, TA, GCA, PAN, and BD: limited active WG: 63 +/- ng/ml; generalized active WG: 119 +/- 15 ng/ml; limited WG, partial remission: 60 +/- 5 ng/ml; generalized WG, partial remission: 75 +/- 7 ng/ml; active TA: 36 +/-; active GCA: 36 +/- 4 ng/ml, active PAN: 33 +/- 2 ng/ml, active BD: 40 +/- 4 ng/ml. Limited and generalized WG in complete remission did not have elevated levels of sTM. sTM values closely reflected relapses and therapy-induced remissions of WG. Elevated cANCA titers were correlated as well with the disease activity in WG but more weakly than sTM levels. In contrast, sE-selectin values were not significantly correlated with the disease activity and the course of disease.

CONCLUSIONS

sTM is a promising serological marker of disease activity and progression in active limited and generalized WG and other vasculitides reflecting the degree of endothelial cell damage. sTM might prove to be a clinically useful marker for therapeutic considerations.

Anti-endothelial cell IgG antibodies from patients with Wegener's granulomatosis bind to human endothelial cells in vitro and induce adhesion molecule expression and cytokine secretion

OBJECTIVE

To elucidate the role of anti-endothelial cell antibodies (AECA) in vascular inflammation in patients with Wegener's granulomatosis (WG).

METHODS

IgG fractions from 3 AECA-positive WG patients, IgG from 3 AECA-negative WG patients, and IgG from healthy donors were tested for their ability to: a) bind to endothelial cells and to display complement-dependent or antibody-dependent cellular cytotoxicity, b) modulate cell membrane expression of adhesion molecules, as evaluated by cytofluorometry and by immunoenzymatic assay, and c) induce the secretion of interleukin-1 beta (IL-1 beta), IL-6, IL-8, and monocyte chemotactic protein 1 (MCP-1).

RESULTS

We found that AECA IgG from WG patients do not display any significant cytotoxicity but are able to up-regulate the expression of E-selectin, intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 and to induce the secretion of IL-1 beta, IL-6, IL-8, and MCP-1.

CONCLUSION

AECA in patients with WG could play a potential pathogenetic role by activating endothelial cells, and thus facilitating leukocyte recruitment and adhesion to endothelial surfaces, rather than by displaying a cytotoxic activity.

Antineutrophil cytoplasmic antibodies: major autoantigens, pathophysiology, and disease associations

Antineutrophil cytoplasmic antibodies (ANCA) are important serological markers for the primary systemic vasculitides, including microscopic polyarteritis and necrotizing crescentic glomerulonephritis. Numerous reports have established the clinical utility of ANCA titer in monitoring disease activity, relapses, and response to treatment. ANCA, detected by indirect immunofluorescence (IIF) assays using patient's serum and ethanol-fixed human neutrophils, produce two common fluorescent staining patterns: cytoplasmic (C-ANCA), involving a 29-kD neutral serine protease termed proteinase 3 (PR3), and perinuclear (P-ANCA), the result mainly of myeloperoxidase (MPO), but occasionally by other components of the azurophilic granules including lysozyme, elastase, cathepsins, and lactoferrin. Some sera contain granulocyte-specific antinuclear antibodies (GS-ANA), which require formaldehyde fixation of neutrophils to cross link cytoplasmic antigens for distinguishing between ANCA and the GS-ANA by IIF. Positive IIF is confirmed by Western blot analysis or specific enzyme-linked immunosorbent assay for PR3, MPO, and other neutrophil granule antigens. The C-ANCA pattern is highly specific for Wegener's granulomatosis, a disease characterized by granulomatous inflammation, necrotizing and crescentic glomerulonephritis, and vasculitis; P-ANCA is found in sera of individuals with vasculitis, glomerulonephritis, and several other diseases. ANCA are predominantly immunoglobulin (Ig)G isotype, but may be IgM and IgA. Various pathophysiologic mechanisms have been proposed involving ANCA-mediated neutrophil activation in a hypothetical model of vasculitic diseases: positive signals via the FcgammaRII (CD32) receptor after IgG-ANCA binding to membrane-associated PR3, relevant cytokines, production of adhesion molecules on both activated neutrophils and endothelial cells, and the release of neutrophil reactive oxygen species and degranulation causing endothelial cell damage. Interference of C-ANCA with PR3 proteolysis and PR3 inhibition physiologically by the alpha1-proteinase inhibitor may have a pathogenic role. No convincing data have been reported for the existence of autoreactive T lymphocytes reactive to any degree with the neutrophil azurophilic enzymes. Studies of various drug- and infectious agent-related diseases and ANCA may contribute to understanding the mechanism(s) involved in some vasculitides.

Elevation of serum soluble vascular cell adhesion molecule-1 (sVCAM-1) levels in bronchial asthma

We have previously shown the elevation of serum soluble intercellular adhesion molecule-1 (sICAM-1) and soluble E-selectin (sE-selectin) in patients with bronchial asthma during asthma attacks. In the present study, we extended our earlier study by measuring serum sVCAM-1 levels by ELISA in 45 patients with bronchial asthma (23 atopic and 22 non-atopic) during asthma attacks and in stable conditions in order to assess further the state of adhesion molecules in allergic inflammation of bronchial asthma. The levels of sVCAM-1 in sera obtained during bronchial asthma attacks were higher than those in sera obtained in stable conditions. These findings were observed regardless of atopic status. To examine the regulatory mechanism in the elevation of serum sVCAM-1 levels, serum tumor necrosis factor-alpha (TNF-alpha) levels were measured by ELISA. TNF-alpha levels in sera obtained during bronchial asthma attacks were higher than those in sera obtained in stable conditions. The nature of change in serum TNF-alpha levels correlated with the nature of change in serum sVCAM-1 levels, but serum TNF-alpha levels did not correlate with serum sVCAM-1 levels. These results suggest that higher levels of sVCAM-1 during asthma attacks may reflect the up-regulation of VCAM-1 expression in allergic inflammation, and that a soluble form of VCAM-1 molecules may be useful markers for the presence of allergic inflammation. TNF-alpha is shown to enhance the expression and release of VCAM-1 in vitro, however; the regulatory mechanism in the elevation of serum sVCAM-1 levels remains to be clarified.

Soluble cell adhesion molecules and von Willebrand factor in children with Kawasaki disease

Fifty-nine children with acute Kawasaki disease (KD), a childhood vasculitis, were compared with 35 children with fever due to infection and 48 healthy children. Levels of soluble E-selectin (sE-selectin), soluble intercellular adhesion molecule-1 (sICAM-1), and soluble vascular cell adhesion molecule-1 (sVCAM-1) in the healthy children were double those found in adults. All three soluble cell adhesion molecules and von Willebrand factor (vWF) were higher in the children with KD than in the healthy children, but only sE-selectin, a marker for activated endothelial cells, and sICAM-1 were higher than in the febrile children. The high levels of vWF in KD appear to reflect the prominent acute-phase reaction. This information can help us to understand further the complex interactions between cytokines, circulating inflammatory cells and the vascular endothelium, and may lead to new therapeutic avenues in KD and other inflammatory diseases and vasculitides.

Birmingham Vasculitis Activity Score (BVAS) in systemic necrotizing vasculitis

The continuing morbidity of patients with vasculitis, despite the improved prognosis with aggressive therapy, underlines the need for accurate disease assessment. We have devised a clinical index of disease activity, and evaluated its use in several forms of necrotizing vasculitis. The weighted score is based on symptoms and signs in nine separate organ systems. Disease features are only scored if they are attributable to active vasculitis. The Birmingham Vasculitis Activity Score (BVAS) was compared with two other published vasculitis activity scores, with the physician's global assessment (PGA), with outcome, and with serological markers of disease activity. In a cross-sectional study of 213 consecutive patients with different forms of vasculitis, all 107 vasculitis patients who were judged completely well on clinical assessment had a BVAS score of 0. Twenty-two patients with active vasculitis prior to treatment had a median score of 7.5 (range 4-30) and 69 with active disease on treatment had a median score of 10 (1-29). Of the 12 who died, median score immediately prior to death was 20.5 (9-30). In a serial prospective study, 30 cases had documented episodes of active disease. During periods of disease activity, the median BVAS values were significantly higher than in remission (15 [range 3-32] vs. 0 [0-2], p < 0.001); the same was true for CRP values (80 [9-361] vs. 13.5 [5-68], p < 0.001). This was not true for erythrocyte sedimentation rate (ESR), haemoglobin (Hb) or von Willebrand factor (VWF).(ABSTRACT TRUNCATED AT 250 WORDS)

Levels of soluble VCAM-1, soluble ICAM-1, and soluble E-selectin during disease exacerbations in patients with systemic lupus erythematosus (SLE); a long term prospective study

Active SLE is characterized by immune deposits and subsequent vascular inflammation in many organs. Expression and up-regulation of adhesion molecules is basic to migration of inflammatory cells into the tissues. Recently, soluble isoforms of these molecules have been described which might be an expression of their up-regulation in the tissues and, as such, of disease activity. The purpose of this study was to evaluate whether changes in levels of soluble adhesion molecules reflect disease activity. We analysed serial sera in a 6-month period preceding 22 consecutive exacerbations of SLE for levels of soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1), and sE-selectin. Levels were related to clinical disease activity (SLEDAI), and levels of anti-dsDNA and complement. At the time of maximal disease activity, levels of sVCAM-1 in patients with SLE were higher than those in controls (P < 0.0001), levels in patients with renal involvement being higher than in those without (P < 0.02). Levels of sVCAM-1 correlated with SLEDAI scores (P < 0.05) and, inversely, with levels of C3 (P = 0.01). In addition, in the presence of anti-dsDNA, levels of sVCAM-1 tended to correlate with levels of these autoantibodies (P < 0.1). Levels of sICAM-1 were normal and sE-selectin levels even decreased compared with controls. Levels of sVCAM-1 were higher at the moment of relapse (P = 0.001) than at 6 months before this time point. This rise correlated with the rise in SLEDAI score (P < 0.02). Levels of sICAM-1 and sE-selectin did not rise, and remained in the normal range in all exacerbations studied. In conclusion, in contrast to sICAM-1 and sE-selectin, levels of sVCAM-1 are increased, rise parallel to disease activity during exacerbations in SLE, and are associated with decreasing levels of complement factors. This favours the hypothesis of immune deposit formation, activation of the complement cascade and activation of endothelial cells. Concurrent up-regulation of vascular adhesion molecules may thus result in transmigration of activated inflammatory cells inducing tissue damage.