Serum levels of soluble adhesion molecules ICAM-1, VCAM-1 and E-selectin in patients with Wegener's granulomatosis

Alterations of serum levels of plasminogen, TNF-α, and IDO in granulomatosis with polyangiitis patients

BACKGROUND

Granulomatosis with polyangiitis (GPA) is a representative of vasculitides associated with anti-neutrophil cytoplasmic autoantibodies. "Classical" antibodies directed against proteinase 3 are involved in the pathogenesis and are part of the GPA diagnosis at the same time. Along with them, however, antibodies against Lysosomal-Associated Membrane Protein-2 (LAMP-2) and antibodies directed against plasminogen have been described in GPA.Objectives and methodology: We performed a cross-sectional study enrolling 34 patients diagnosed with GPA. Our study was aimed at looking for correlations between serum levels of LAMP-2 and plasminogen and the clinical manifestations of the GPA. Furthermore, we examined serum levels of tumor necrosis factor-alpha (TNF-α) and its associated indoleamine-pyrrole 2,3-dioxygenase (IDO), as well as we looked for a correlation between these cytokines and the clinical manifestations of GPA.

RESULTS

The results showed that in GPA, serum plasminogen levels were negatively associated with renal involvement (receiver operating characteristic (ROC) area under the curve (AUC) of 0.78) (95% CI 0.53-0.91), p = 0.035, and the extent of proteinuria, Spearman's Rho = -0.4, p = 0.015. Increased levels of TNF-α and IDO correlated with disease activity, Spearman's Rho =0.62, p = 0.001 and Spearman's Rho = 0.4, p = 0.022, respectively, whereas only TNF-α was increased in severe forms of GPA with lung involvement (ROC AUC of 0.8) (95% CI 0.66-0.94), p = 0.005.

CONCLUSIONS

In this study, we demonstrate the alteration of soluble factors, which play an important role in the pathogenesis of GPA and their relationship with the clinical manifestations of the disease. Our main results confirm the associations of increased secretory TNF-α and some clinical manifestations, and we describe for the first time decreased serum plasminogen levels and their association with renal involvement.

Interleukin-6 in ANCA-associated vasculitis: Rationale for successful treatment with tocilizumab

OBJECTIVE

Microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) are systemic, necrotizing, small-vessel vasculitis associated with circulating anti-neutrophil cytoplasmic autoantibodies (ANCA), and thus called ANCA-associated vasculitides (AAV). The aim of the present study is to evaluate a potential role of interleukin (IL)-6 and its pathway in the pathogenesis of AAV and to review previous evidence of IL-6 in MPA and GPA.

METHODS

Blood and histological samples from 10 untreated myeloperoxidase (MPO)-ANCA/proteinase 3 (PR3)-ANCA-positive patients with active AAV were studied. Serum levels of cytokines/chemokines were evaluated by means of a Bio-Plex Multiple Cytokine Assay. IL-6 production at sites of active vasculitis was assessed by means of both immunohistochemistry and in situ hybridization techniques. We also treated a patient with MPA who was resistant or allergic to conventional treatments with a 12-month course of the IL-6 inhibitor tocilizumab and followed him up for 24 additional months. We also reviewed all the published cases in the English literature of histologically confirmed MPA or GPA, in which elevated IL-6 serum levels or intralesional IL-6 expression were reported.

RESULTS

IL-6 serum levels were significantly increased in patients with AAV as compared to controls (median = 51.96pg/mL; range: 34.11-84.30; versus 0.68pg/mL; range: 0.01-1.81; P < 0.005). Also, IL-6 was expressed and produced at sites of active vasculitis. Treatment with tocilizumab was able to induce a complete and sustained disease remission in a patient with severe multisystemic MPA, as well as normalization of circulating levels of IL-6-associated pro-inflammatory cytokines and chemokines. Previous evidence of IL-6 pathway activation in AAV is scarce. Increased serum levels of IL-6 were reported in seven clinical studies for a total of approximately 120 patients, mainly affected by GPA.

CONCLUSION

The finding of an activated IL-6 pathway in patients with AAV, together with the observed effects of tocilizumab monotherapy, provides evidence for a possible central role of IL-6 in the pathogenesis of AAV and suggests its targeting as a potential treatment.

Aortic aneurysm rupture as a rare complication of granulomatosis with polyangiitis: a case report

Introduction

Granulomatosis with polyangiitis is characterized by systemic inflammation of medium and small blood vessels. Aortic involvement in granulomatosis with polyangiitis is extremely rare. As far as we know this is the first reported case of successful treatment in a patient with granulomatosis with polyangiitis complicated with aortic aneurysm rupture.

Case presentation

We describe a case of granulomatosis with polyangiitis in a 38-year-old Japanese man who developed an aortic aneurysm rupture 22 years after disease onset. The patient was operated on and a J-graft was inserted. He recovered uneventfully.

Conclusion

Recommendations in regard to, and consideration of, aortic involvement should be kept in mind in the long-term careful follow up of granulomatosis with polyangiitis.

Cysteine, histidine and glycine exhibit anti-inflammatory effects in human coronary arterial endothelial cells

The activation of nuclear factor-kappa B (NF-κB) in vascular endothelial cells may be involved in vascular pathogeneses such as vasculitis or atherosclerosis. Recently, it has been reported that some amino acids exhibit anti-inflammatory effects. We investigated the inhibitory effects of a panel of amino acids on cytokine production or expression of adhesion molecules that are involved in inflammatory diseases in various cell types. The activation of NF-κB was determined in human coronary arterial endothelial cells (HCAECs) because NF-κB modulates the production of many cytokines and the expression of adhesion molecules. We examined the inhibitory effects of the amino acids cysteine, histidine and glycine on the induction of NF-κB activation, expression of CD62E (E-selectin) and the production of interleukin (IL)-6 in HCAECs stimulated with tumour necrosis factor (TNF)-α. Cysteine, histidine and glycine significantly reduced NF-κB activation and inhibitor κBα (IκBα) degradation in HCAECs stimulated with TNF-α. Additionally, all the amino acids inhibited the expression of E-selectin and the production of IL-6 in HCAECs, and the effects of cysteine were the most significant. Our results show that glycine, histidine and cysteine can inhibit NF-κB activation, IκBα degradation, CD62E expression and IL-6 production in HCAECs, suggesting that these amino acids may exhibit anti-inflammatory effects during endothelial inflammation.

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.

Relationship between markers of platelet activation and inflammation with disease activity in Wegener's granulomatosis

OBJECTIVE

There remains a need for biomarkers to guide therapy in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. Our objective was to determine whether measures of platelet activation or inflammation are associated with disease activity in Wegener's granulomatosis (WG).

METHODS

Study subjects were participants in a clinical trial. Soluble CD40 ligand (sCD40L), C-reactive protein, interleukin 6 (IL-6), IL-8, monocyte chemoattractant protein 1 (MCP-1), P-selectin, vascular endothelial growth factor, and proteinase 3 (PR3)-specific ANCA were measured by ELISA using plasma samples obtained at baseline (active disease), at remission, and prior to, during, and after first flares. Disease activity was assessed by the Birmingham Vasculitis Activity Score for WG (BVAS/WG). Association of biomarkers with disease activity was determined with conditional logistic and linear regression.

RESULTS

Over a mean followup of 27 months, 180 subjects underwent 2044 visits; markers were measured in 563 samples. Longitudinally, all markers other than IL-6 were associated with disease activity. The strongest associations for active disease at baseline versus remission were observed for sCD40L (OR 4.72, 95% CI 2.47-9.03), P-selectin (OR 6.26, 95% CI 2.78-14.10), PR3-ANCA (OR 9.41, 4.03-21.99), and inversely for MCP-1 (OR 0.36, 95% CI 0.22-0.57). BVAS/WG increased by 0.80 (95% CI 0.44-1.16), 0.83 (95% CI 0.42-1.25), and 0.81 (95% CI 0.48-1.15) per unit-increase in PR3-ANCA, sCD40L, and P-selectin, respectively; and decreased by 1.54 (95% CI 0.96-2.12) per unit-increase in MCP-1.

CONCLUSION

Cytokines arising from within the circulation, including those of platelet activation, correlate with disease activity in WG.

Screening of serum samples from Wegener's granulomatosis patients using antibody microarrays

Wegener's Granulomatosis (WG) is an idiopathic granulomatosis autoimmune vasculitis that primarily affects small vessels and is associated with glomerulonephritis and pulmonary granulomatous vasculitis. Anti-neutrophil cytoplasmic auto-antibodies (cANCA) against proteinase-3 are used to identify WG, but ANCA titers are not present in some patients with the localized disease. The objective of this study was to develop an antibody array to help identify protein expression patterns in serum from patients with WG as compared to normals. The arrays were tested for limits of detection, background, and cross reactivity using standard proteins. The arrays were hybridized with either normal patient serum (n = 30) or with serum samples from a population of WG patients (n = 26) that were age and sex matched. Data analysis and curve fitting of the standard dilution series calculated r(2) values and determined a sensitivity of <50 pg/mL for the majority of proteins. A total of 24 proteins were assessed. Several statistically significant increases (p<0.05) were seen in the expression of: angiotensin converting enzyme-I, IFN-γ, IL-8, s-ICAM-1 and s-VCAM in WG patients as compared to controls. Utilizing the antibody microarray technology has led to the identification of potential biomarkers of vascular injury in the serum of WG patients.

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)