The association of serum interleukin-6 levels with clinical outcomes in antineutrophil cytoplasmic antibody-associated vasculitis.

OBJECTIVE: To investigate serum IL-6 (sIL-6) levels during active disease, complete remission (CR), and relapse in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), and to explore the association of changes in sIL-6 with clinical outcomes. METHODS: sIL-6 levels were measured at baseline and longitudinally over 18 months, in 78 patients with AAV enrolled in a randomized controlled trial comparing treatment with either rituximab (RTX) or cyclophosphamide (CYC)/azathioprine (AZA). Outcome variables included baseline clinical features, ANCA specificity, disease activity (active disease versus CR), time to relapse events, B cell repopulation, and ANCA titer increases. RESULTS: At baseline, sIL6 levels were detectable in 81% of patients; 73% (n = 57) of subjects were proteinase 3 (PR3)-ANCA positive, sIL-6 levels were higher in subjects with PR3-ANCAs and positively correlated with their levels (rs = 0.36,p < 0.01), but not with levels of myeloperoxidase (MPO)-ANCA (rs = -0.17,p = 0.47). Higher baseline sIL-6 levels were associated with PR3-ANCA positivity, fever, pulmonary nodules/cavities, conductive deafness, and absence of urinary red blood cell casts (p < 0.05). Baseline sIL6 levels did not predict CR at month 6 (p = 0.71), and the median sIL-6 level declined from baseline with induction therapy, regardless of CR achievement. An increase in sIL-6 during CR was a predictor for subsequent severe relapse in RTX-treated patients (hazard ratio (HR):7.24,p = 0.01), but not in CYC/AZA-treated patients (HR:0.62,p = 0.50). In contrast, a sIL-6 increase did not predict B cell repopulation or ANCA titer increase in either treatment arm (p > 0.05). CONCLUSION: At baseline, sIL-6 concentrations correlate with PR3-ANCA titers and are associated with specific clinical manifestations of AAV. Baseline sIL6 concentrations do not predict CR at 6 months, but the increase in sIL-6 concentrations during CR is associated with subsequent severe relapse among RTX-treated patients. Further investigation into the mechanistic role of IL6 in AAV might lead to identifying this pathway as a potential therapeutic target in this disease.

The net effect of ANCA on neutrophil extracellular trap formation.

The formation of neutrophil extracellular traps induced by antineutrophil cytoplasmic autoantibodies has been implicated in the pathogenesis of antineutrophil cytoplasmic autoantibody-associated vasculitis. Kraaij et al. now provide evidence that excessive neutrophil extracellular trap formation in vitro induced by sera from patients with antineutrophil cytoplasmic autoantibody-associated vasculitis is associated with active disease but is not dependent on the presence of antineutrophil cytoplasmic autoantibodies.

Towards precision medicine in ANCA-associated vasculitis.

ANCA-associated vasculitis (AAV) is characterized by inflammation and destruction of small and medium-sized vessels. Current management strategies for AAV have been validated in large groups of patients. However, recent insights indicate that distinct patient subsets may actually exist within AAV, thereby justifying the development of more personalized treatment strategies. In this review, we discuss current evidence for a better classification of AAV based on ANCA type. We describe how thus defined categories of AAV patients may differ in genetic background, clinical presentation, immune pathology, response to treatment and disease outcome. We also explore how these insights may provide a rationale for targeted treatments in different categories of AAV patients. Finally, we provide recommendations on how to further establish precision medicine in AAV.

Pharmacokinetics of rituximab and clinical outcomes in patients with anti-neutrophil cytoplasmic antibody associated vasculitis.

Objectives: To study the determinants of the pharmacokinetics (PK) of rituximab (RTX) in patients with ANCA-associated vasculitis (AAV) and its association with clinical outcomes. Methods: This study included data from 89 patients from the RTX in AAV trial who received the full dose of RTX (four weekly infusions of 375 mg/m2). RTX was quantified at weeks 2, 4, 8, 16 and 24, and summarized by computing the trapezoidal area under the curve. We explored potential determinants of the PK-RTX, and analysed its association with clinical outcomes: achievement of remission at 6 months, duration of B-cell depletion and time to relapse in patients who achieved complete remission. Results: RTX serum levels were significantly lower in males and in newly diagnosed patients, and negatively correlated with body surface area, baseline B-cell count and degree of disease activity. In multivariate analyses, the main determinants of PK-RTX were sex and new diagnosis. Patients reaching complete remission at month 6 had similar RTX levels compared with patients who did not reach complete remission. Patients with higher RTX levels generally experienced longer B-cell depletion than patients with lower levels, but RTX levels at the different time points and area under the curve were not associated with time to relapse. Conclusion: Despite the body-surface-area-based dosing protocol, PK-RTX is highly variable among patients with AAV, its main determinants being sex and newly diagnosed disease. We did not observe any relevant association between PK-RTX and clinical outcomes. The monitoring of serum RTX levels does not seem clinically useful in AAV.

Proteome-wide analysis and CXCL4 as a biomarker in systemic sclerosis.

BACKGROUND: Plasmacytoid dendritic cells have been implicated in the pathogenesis of systemic sclerosis through mechanisms beyond the previously suggested production of type I interferon. METHODS: We isolated plasmacytoid dendritic cells from healthy persons and from patients with systemic sclerosis who had distinct clinical phenotypes. We then performed proteome-wide analysis and validated these observations in five large cohorts of patients with systemic sclerosis. Next, we compared the results with those in patients with systemic lupus erythematosus, ankylosing spondylitis, and hepatic fibrosis. We correlated plasma levels of CXCL4 protein with features of systemic sclerosis and studied the direct effects of CXCL4 in vitro and in vivo. RESULTS: Proteome-wide analysis and validation showed that CXCL4 is the predominant protein secreted by plasmacytoid dendritic cells in systemic sclerosis, both in circulation and in skin. The mean (±SD) level of CXCL4 in patients with systemic sclerosis was 25,624±2652 pg per milliliter, which was significantly higher than the level in controls (92.5±77.9 pg per milliliter) and than the level in patients with systemic lupus erythematosus (1346±1011 pg per milliliter), ankylosing spondylitis (1368±1162 pg per milliliter), or liver fibrosis (1668±1263 pg per milliliter). CXCL4 levels correlated with skin and lung fibrosis and with pulmonary arterial hypertension. Among chemokines, only CXCL4 predicted the risk and progression of systemic sclerosis. In vitro, CXCL4 down-regulated expression of transcription factor FLI1, induced markers of endothelial-cell activation, and potentiated responses of toll-like receptors. In vivo, CXCL4 induced the influx of inflammatory cells and skin transcriptome changes, as in systemic sclerosis. CONCLUSIONS: Levels of CXCL4 were elevated in patients with systemic sclerosis and correlated with the presence and progression of complications, such as lung fibrosis and pulmonary arterial hypertension. (Funded by the Dutch Arthritis Association and others.).

FSAP-mediated nucleosome release from late apoptotic cells is inhibited by autoantibodies present in SLE.

Inefficient clearance of apoptotic cells and the subsequent exposure of the immune system to nuclear contents are crucially involved in the pathogenesis of systemic lupus erythematosus (SLE). Factor VII-activating protease (FSAP) is activated in serum upon contact with dead cells, and releases nucleosomes from late apoptotic cells into the extracellular environment. We investigated whether FSAP-mediated nucleosome release from late apoptotic cells is affected in SLE patients. Nucleosome release in sera of 27 SLE patients and 30 healthy controls was investigated by incubating late apoptotic Jurkat cells with serum and analyzing the remaining DNA content by flow cytometry. We found that nucleosome release in sera of SLE patients with high disease activity was significantly decreased when compared with that in SLE sera obtained during low disease activity or from healthy individuals. Upon removal of IgG/IgM antibodies from SLE sera, nucleosome release was restored. Similarly, monoclonal antinuclear antibodies inhibited nucleosome release in healthy donor serum or by plasma-purified FSAP. This inhibition was lost when Fab fragments were used, suggesting that antigen cross-linking is involved. In conclusion, FSAP-mediated nucleosome release from late apoptotic cells is greatly impaired in SLE patient sera, possibly hampering the clearance of these cells and thereby propagating inflammation.

Interstitial Immunostaining and Renal Outcomes in Antineutrophil Cytoplasmic Antibody-Associated Glomerulonephritis.

BACKGROUND: Immunopathologic features predict renal function at baseline and follow-up in antineutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis (GN). The interstitial infiltrate consists predominantly of T lymphocytes, but their pathophysiologic significance is unclear, especially in light of the success of B-cell-directed therapy. METHODS: Renal biopsies from 33 patients treated with cyclophosphamide (CYC; n = 17) or rituximab (RTX; n = 16) in the RTX in ANCA-associated vasculitis (RAVE) trial were classified according to the new ANCA GN classification. T- and B-cell infiltration in the interstitium was assessed by immunostaining for CD3 and CD20. Correlations of clinical and histologic parameters with renal function at set time points were examined. RESULTS: The mean (SD) baseline estimated glomerular filtration rate was 36 (20) mL/min/1.73 m2. ANCA GN class distribution was 46% focal, 33% mixed, 12% sclerotic and 9% crescentic. The interstitial infiltrate consisted of >50% CD3 positive cells in 69% of biopsies, but >50% CD20 positive cells only in 8% of biopsies. In a multiple linear regression model, only baseline glomerular filtration rate (GFR) correlated with GFR at 6, 12, and 18 months. Interstitial B- and T-cell infiltrates had no significant impact on long-term prognosis, independent of the treatment limb. A differential effect was noted only at 6 months, where a dense CD3 positive infiltrate predicted lower GFR in the RTX group and a CD20 positive infiltrate predicted higher GFR in the CYC group. CONCLUSIONS: In ANCA-associated GN, the interstitial infiltrate contains mainly T lymphocytes. However, it is neither reflecting baseline renal function nor predictive of response to treatment, regardless of the immunosuppression regimen employed.

Ig gene analysis reveals altered selective pressures on Ig-producing cells in parotid glands of primary Sjögren's syndrome patients.

In this study, we sought to understand the selective pressures shaping the Ig-producing cell repertoire in the parotid glands of primary Sjögren's syndrome (pSS) patients before and after rituximab treatment (RTX). In particular, we evaluated the role of potential N-glycosylation motifs acquired by somatic hypermutation (ac-Nglycs) within Ig H chain V region (IGHV) genes as alternative selective pressures for B cells in pSS. Five pSS patients received RTX. Sequential parotid salivary gland biopsies were taken before RTX, at 12 wk and at 36-52 wk after treatment. Parotid biopsies from four non-pSS patients served as controls. Sequence analysis was carried out on the IgA and IgG RNA transcripts expressing IGHV3 genes in all parotid biopsies. Both IgG and IgA sequences from pSS patients exhibited no evidence for positive Ag-driven selection pressure in their CDRs in contrast to non-pSS controls. The prevalence of IgG sequences with ac-Nglycs was significantly higher in pSS patients than in non-pSS controls. Selection pressures shaping the IgG and IgA repertoire within pSS patients' parotid glands are distinct from those in non-pSS controls, with very little evidence for positive (auto)antigen selection. The higher prevalence of ac-Nglycs on pSS-IgG compared with non-pSS IgG indicates that ac-Nglycs could be an alternative form of selection pressure. We speculate that B cell hyperproliferation within parotid glands of pSS patients may result from Ag-independent interactions such as that between glycosylated B cell receptors and lectins within the microenvironment rather than (auto)antigen-specific stimulation. Our study brings a new perspective into research on pSS.

Usefulness of antineutrophil cytoplasmic autoantibodies in diagnosing and managing systemic vasculitis.

PURPOSE OF REVIEW: Antineutrophil cytoplasmic autoantibodies (ANCAs) are considered important diagnostic tests in the work-up of patients suspected of vasculitis. Here we discuss new developments in the methodology of testing, the pitfalls in using these tests as diagnostic tools, and the value of serial ANCA testing for the follow-up of patients with ANCA-associated vasculitis including treatment decisions. RECENT FINDINGS: Both the indirect immunofluorescence (IIF) test and antigen-specific assays should be performed. New methodologies include automated reading in the IIF test and third-generation assays (anchor ELISA and bead-based multiplex assay) for the antigenic-specific assays. ANCA testing should be done in the right clinical context as positive results for PR3-ANCA and MPO-ANCA do occur in other conditions than vasculitis as well. These ANCAs develop in about 10% of patients with infective endocarditis. The occurrence of drug-induced ANCA and ANCA, also directed against elastase, following use of levamisole-adulterated cocaine should be recognized. In the right clinical context, ANCA are highly sensitive and specific for their associated disease. The value of serial ANCA testing for the follow-up of patients with ANCA-associated vasculitis is still under discussion but may be relevant in patients with renal involvement and in patients treated with rituximab. SUMMARY: The techniques for ANCA testing improve further but new tests should be standardized and validated. Their diagnostic value in the right clinical context is undisputed. Their value for the follow-up of patients is still under discussion.

Efficacy of remission-induction regimens for ANCA-associated vasculitis.

BACKGROUND: The 18-month efficacy of a single course of rituximab as compared with conventional immunosuppression with cyclophosphamide followed by azathioprine in patients with severe (organ-threatening) antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis is unknown. METHODS: In a multicenter, randomized, double-blind, double-dummy, noninferiority trial, we compared rituximab (375 mg per square meter of body-surface area administered once a week for 4 weeks) followed by placebo with cyclophosphamide administered for 3 to 6 months followed by azathioprine for 12 to 15 months. The primary outcome measure was complete remission of disease by 6 months, with the remission maintained through 18 months. RESULTS: A total of 197 patients were enrolled. As reported previously, 64% of the patients in the rituximab group, as compared with 53% of the patients in the cyclophosphamide-azathioprine group, had a complete remission by 6 months. At 12 and 18 months, 48% and 39%, respectively, of the patients in the rituximab group had maintained the complete remissions, as compared with 39% and 33%, respectively, in the comparison group. Rituximab met the prespecified criteria for noninferiority (P<0.001, with a noninferiority margin of 20%). There was no significant difference between the groups in any efficacy measure, including the duration of complete remission and the frequency or severity of relapses. Among the 101 patients who had relapsing disease at baseline, rituximab was superior to conventional immunosuppression at 6 months (P=0.01) and at 12 months (P=0.009) but not at 18 months (P=0.06), at which time most patients in the rituximab group had reconstituted B cells. There was no significant between-group difference in adverse events. CONCLUSIONS: In patients with severe ANCA-associated vasculitis, a single course of rituximab was as effective as continuous conventional immunosuppressive therapy for the induction and maintenance of remissions over the course of 18 months. (Funded by the National Institute of Allergy and Infectious Diseases and others; RAVE ClinicalTrials.gov number, NCT00104299.)

Using Mass Spectrometry to Quantify Rituximab and Perform Individualized Immunoglobulin Phenotyping in ANCA-Associated Vasculitis.

Therapeutic monoclonal immunoglobulins (mAbs) are used to treat patients with a wide range of disorders including autoimmune diseases. As pharmaceutical companies bring more fully humanized therapeutic mAb drugs to the healthcare market analytical platforms that perform therapeutic drug monitoring (TDM) without relying on mAb specific reagents will be needed. In this study we demonstrate that liquid-chromatography-mass spectrometry (LC-MS) can be used to perform TDM of mAbs in the same manner as smaller nonbiologic drugs. The assay uses commercially available reagents combined with heavy and light chain disulfide bond reduction followed by light chain analysis by microflow-LC-electrospray ionization-quadrupole-time-of-flight mass spectrometry (ESI-Q-TOF MS). Quantification is performed using the peak areas from multiply charged mAb light chain ions using an in-house developed software package developed for TDM of mAbs. The data presented here demonstrate the ability of an LC-MS assay to quantify a therapeutic mAb in a large cohort of patients in a clinical trial. The ability to quantify any mAb in serum via the reduced light chain without the need for reagents specific for each mAb demonstrates the unique capabilities of LC-MS. This fact, coupled with the ability to phenotype a patient's polyclonal repertoire in the same analysis further shows the potential of this approach to mAb analysis.

Toll-like receptor 9 activation enhances B cell activating factor and interleukin-21 induced anti-proteinase 3 autoantibody production in vitro.

OBJECTIVES: Granulomatosis with polyangiitis (GPA) is a relapsing small-vessel vasculitis characterized by circulating ANCA against PR3. The mechanisms that trigger PR3-ANCA production are unknown. The aim of this study was to determine whether endogenous factors [B cell activating factor (BAFF) and IL-21] and exogenous factors [oligodeoxynucleotides containing CpG motifs (CpG-ODN)] synergize in stimulating PR3-ANCA production in GPA patients. METHODS: Peripheral blood mononuclear cells from GPA patients and healthy controls (HCs) were cultured in the presence of BAFF and IL-21, with or without CpG-ODN, for 12 days. PR3-ANCA production in culture supernatants was quantified by Phadia EliA. Phenotypic characterization and the influence of CpG-ODN treatment on IL-21 receptor (IL-21R), transmembrane activator and calcium-modulator and cyclophilin ligand interactor (TACI) and BAFF receptor (BAFF-R) expression on B cells was analysed by flow cytometry. RESULTS: Stimulation with BAFF and IL-21 significantly increased ANCA production in patient samples, which could be augmented further by addition of CpG-ODN. Stimulation with CpG-ODN increased the percentage of IL-21R(+) and TACI(+) B cells but did not affect BAFF-R expression. GPA patients had an increased percentage of circulating IL-21R(+) and a decreased percentage of TACI(+) circulating memory B cells when compared with HCs. Additionally, patients had decreased expression of BAFF-R on B cells, which was inversely correlated with BAFF concentrations in plasma. CONCLUSION: Our data demonstrate that endogenous and exogenous factors can synergize to promote PR3-ANCA production. Mechanistically, CpG-ODN up-regulated IL-21R and TACI expression on B cells, possibly sensitizing these cells for IL-21- and BAFF-mediated signals. Agents inhibiting Toll-like receptor 9, BAFF and IL-21 signalling pathways may serve as potential therapeutics for intervention in GPA patients.

Pro: Cyclophosphamide in lupus nephritis.

Based on efficacy and toxicity considerations, both low-dose pulse cyclophosphamide as part of the Euro-Lupus Nephritis protocol and mycophenolate mofetil (MMF) with corticosteroids may be considered for induction of remission in patients with proliferative lupus nephritis. The long-term follow-up data available for low-dose pulse cyclophosphamide, the fact that compliance is guaranteed with this regimen and economic issues all favour the Euro-Lupus regimen in this author's opinion. For maintenance treatment, either azathioprine (AZA) or MMF may be used; AZA is preferred in case pregnancy is planned, while MMF is preferred when the disease relapses during use of AZA and, possibly, after successful induction of remission with MMF.

Extended versus standard azathioprine maintenance therapy in newly diagnosed proteinase-3 anti-neutrophil cytoplasmic antibody-associated vasculitis patients who remain cytoplasmic anti-neutrophil cytoplasmic antibody-positive after induction of remission: a randomized clinical trial.

BACKGROUND: Cytoplasmic anti-neutrophil cytoplasmic antibody (C-ANCA) positivity at remission has been associated with an increased relapse rate in patients with proteinase 3 anti-neutrophil cytoplasmic antibody-associated vasculitis (PR3-AAV) after a switch to azathioprine maintenance therapy. We therefore hypothesized that extended azathioprine maintenance therapy could reduce the incidence of relapse in this setting. METHODS: Patients newly diagnosed with PR3-AAV at 12 centres in The Netherlands during 2003-11 who received a standardized induction regimen consisting of oral cyclophosphamide and corticosteroids were enrolled (n = 131). Patients were randomized to standard or extended azathioprine maintenance therapy when C-ANCA was positive at the time of stable remission. Standard maintenance treatment consisted of azathioprine (1.5-2.0 mg/kg) until 1 year after diagnosis and subsequent tapering to 25 mg every 3 months. Extended azathioprine maintenance therapy (1.5-2.0 mg/kg) was continued until 4 years after diagnosis and tapered thereafter. The primary endpoint was relapse-free survival at 4 years after diagnosis. RESULTS: In patients with PR3-AAV who were C-ANCA positive at the time of stable remission, relapse-free survival at 4 years after diagnosis did not differ significantly between standard azathioprine (n = 24) and extended azathioprine (n = 21) maintenance therapy (P = 0.40). There was also no significant difference in relapse-free survival between patients receiving standard azathioprine (n = 106) versus extended azathioprine maintenance therapy (n = 21; P = 0.94). In addition, there was no difference in the relapse rate between patients with PR3-AAV who were C-ANCA positive (n = 45) at the time of remission versus patients who became C-ANCA negative at the time of remission (n = 82; P = 0.62). CONCLUSIONS: This randomized trial suggests that extended azathioprine maintenance therapy has only a limited effect on the prevention of relapse in patients with PR3-AAV at 4 years after diagnosis. Moreover, positive C-ANCA status at stable remission was not associated with an increased rate of relapse. TRIAL REGISTRATION: ClinicalTrials.gov NCT 00128895.

Rituximab versus cyclophosphamide for ANCA-associated vasculitis with renal involvement.

Rituximab (RTX) is non-inferior to cyclophosphamide (CYC) followed by azathioprine (AZA) for remission-induction in severe ANCA-associated vasculitis (AAV), but renal outcomes are unknown. This is a post hoc analysis of patients enrolled in the Rituximab for ANCA-Associated Vasculitis (RAVE) Trial who had renal involvement (biopsy proven pauci-immune GN, red blood cell casts in the urine, and/or a rise in serum creatinine concentration attributed to vasculitis). Remission-induction regimens were RTX at 375 mg/m(2) × 4 or CYC at 2 mg/kg/d. CYC was replaced by AZA (2 mg/kg/d) after 3-6 months. Both groups received glucocorticoids. Complete remission (CR) was defined as Birmingham Vasculitis Activity Score/Wegener's Granulomatosis (BVAS/WG)=0 off prednisone. Fifty-two percent (102 of 197) of the patients had renal involvement at entry. Of these patients, 51 were randomized to RTX, and 51 to CYC/AZA. Mean eGFR was lower in the RTX group (41 versus 50 ml/min per 1.73 m(2); P=0.05); 61% and 75% of patients treated with RTX and 63% and 76% of patients treated with CYC/AZA achieved CR by 6 and 18 months, respectively. No differences in remission rates or increases in eGFR at 18 months were evident when analysis was stratified by ANCA type, AAV diagnosis (granulomatosis with polyangiitis versus microscopic polyangiitis), or new diagnosis (versus relapsing disease) at entry. There were no differences between treatment groups in relapses at 6, 12, or 18 months. No differences in adverse events were observed. In conclusion, patients with AAV and renal involvement respond similarly to remission induction with RTX plus glucocorticoids or CYC plus glucocorticoids.

Does reduction of disease activity improve early markers of cardiovascular disease in newly diagnosed rheumatoid arthritis patients?

OBJECTIVE: The incidence of cardiovascular disease (CVD) is increased in RA. This study was designed to evaluate whether a reduction in disease activity influences early markers of CVD. METHODS: In a prospective longitudinal study, 58 newly diagnosed RA patients and 58 age- and sex-matched healthy controls (HCs) were included. Endothelial dysfunction was measured by small artery elasticity (SAE) and endothelial cell activation was assessed by measuring soluble vascular cellular activation molecule 1(sVCAM-1) and von Willebrand factor (vWF). Advanced glycation end products (AGEs) were quantified by skin autofluorescence. After 1 year, measurements were repeated in all RA patients. RESULTS: At entry, SAE was decreased in RA vs HCs [median 3.4 ml/mmHg100 (range 1.2-9.0) vs 6.1 (range 5.0-15.3), P < 0.0001] and sVCAM-1 and vWF were increased: 391 ng/ml (range 256-680) vs 341 (range 223-691) (P = 0.0015) and 120 ng/ml (range 26.5-342) vs 99 (range 22-298) (P = 0.02), respectively. SAE was inversely correlated with the 28-joint DAS (DAS28; r = -0.31, P = 0.016). AGEs were increased by 2.55 arbitrary units (range 1.29-4.65) vs 2.12 (range 1.32-3.82) in HCs (P = 0.003). In multivariate analysis, the presence of RA, age and systolic blood pressure were independently and inversely related to SAE. After 1 year, SAE had significantly improved in RA, from 3.4 (range 1.2-9.0) to 3.8 (range 1.5-10.3) (P = 0.03). CONCLUSION: Endothelial dysfunction is present in newly diagnosed RA patients, independently of traditional risk factors and is inversely correlated with disease activity. By reducing disease activity, endothelial dysfunction improves, although not to normal values. Also, a reduction in disease activity targeting traditional risk factors remains important in preventing CVD in RA.

High mobility group box 1 serum levels are increased in Behçet's disease, but not associated with disease activity or disease manifestations.

OBJECTIVES: High mobility group box 1 (HMGB1) is a nuclear protein that acts as an alarmin when released into the extracellular milieu. HMGB1 is a biomarker of active disease in several systemic autoimmune diseases. Behçet's disease (BD) is a systemic inflammatory disorder with a waxing/waning course. The objective of this study is to evaluate serum HMGB1 levels as a possible biomarker for disease activity in BD. METHODS: A cross-sectional study measuring serum HMGB1 levels was performed in 26 BD patients and 20 healthy controls. The Brazilian version of the simplified BD Current Activity Form (BR-BDCAFs) was used to measure disease activity. RESULTS: Serum HMGB1 levels were higher in patients with active disease [3.82 (2.54-6.11) ng/ml], in patients with BD without active disease but still on therapy [2.76 (1.89-5.78) ng/ml] and in patients in remission without treatment [2.66 (1.86-4.70) ng/ml] than in healthy controls [0.96 (0.59-1.39) ng/ml], P < 0.001. Levels were comparable between BD patients with active disease, BD without active disease but still on therapy and those in remission without treatment (P = 0.432). There was no correlation between serum HMGB1 levels and BR-BDCAF(s) (ρ = 0.195; P = 0.339). No association could be found between serum HMGB1 levels and specific disease involvement or therapy. So serum HMGB1 levels cannot be used as a biomarker in BD. CONCLUSION: Serum HMGB1 levels are increased in patients with BD as compared with healthy controls. However, no association was found with disease activity, specific organ involvement or therapy in BD.

B-cell therapy in antineutrophil cytoplasmic antibody-associated vasculitis.

Until recently, standard of care for patients with generalized or severe antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) has consisted of an induction regimen with cyclophosphamide (CYC) and corticosteroids followed by maintenance treatment with azathioprine. This regimen is associated with significant toxicity resulting in considerable morbidity and mortality whereas relapses are still not infrequent. In two controlled trials, the Rituximab in ANCA-associated Vasculitis study (RAVE) and the RITUXVAS trial of the European Vasculitis Study Group (EUVAS), rituximab (RTX) proved non-inferior to CYC for induction of remission. In addition, outcome at 18 months for the RAVE trial and 12 months for the RITUXVAS trial showed that RTX without maintenance treatment was as efficacious as CYC followed by azathioprine maintenance. To prevent relapses, which occur particularly in patients positive for PR3-ANCA, 500 mg RTX given every 6 months was shown to be superior to azathioprine in a French study. Thus, RTX is a new and promising therapeutic armamentarium for AAV although long-term safety has still to be established.

Pathogenesis and treatment of ANCA-associated vasculitides.

Recent studies have increased our insight into the pathogenesis of ANCA-associated vasculitis (AAV). Although many data from in vitro and in vivo experimental studies support the pathogenic role of the autoantibodies, cellular immunity seems involved as well. Besides, an amplification loop via the alternative pathway of complement is apparent. These new insights make a more targeted therapeutic approach possible. In particular, the B-cell depleting antibody rituximab has been shown non-inferior to cyclophosphamide for induction of remission, and even superior in patients with relapsing disease being positive for PR3-ANCA. Rituximab is also superior to cyclophosphamide for maintaining remission. Blocking the C5a-receptor seems promising as well as an alternative for high dose corticosteroids during induction of remission.

Is B-cell depletion first choice in antineutrophil cytoplasmic antibody-associated vasculitis?

PURPOSE OF REVIEW: To discuss in detail the efficacy and safety of rituximab (RTX) for induction and maintenance of remission in patients with antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) who are either treatment naive, relapsing or refractory to standard of care. RECENT FINDINGS: In treatment naive AAV patients, RTX without maintenance treatment is as effective as cyclophosphamide (CYC) followed by azathioprine (AZA) for maintenance for up to 18 months. RTX is superior to CYC for induction of remission in patients with relapsing AAV. Nevertheless, long-term follow-up shows relapsing disease in up to 50% of patients with proteinase 3-ANCA, irrespective of the induction regimen. RTX is useful in patients with refractory AAV, but percentages of patients achieving complete remission differ between series. RTX seems more effective than AZA for maintaining remission, but detailed results from prospective studies are being awaited. Adverse events do not differ between RTX and classical induction regimens, but infections related to hypogammaglobulinemia and neutropenia could be items of concern with repeated administration of RTX. SUMMARY: RTX is an alternative for CYC for induction of remission in generalized AAV and could be first choice for relapsing patients and patients refractory to CYC. RTX is promising for maintenance of remission, but long-term safety should be awaited.