Identification of susceptibility loci for Takayasu arteritis through a large multi-ancestral genome-wide association study.

Takayasu arteritis is a rare inflammatory disease of large arteries. We performed a genetic study in Takayasu arteritis comprising 6,670 individuals (1,226 affected individuals) from five different populations. We discovered HLA risk factors and four non-HLA susceptibility loci in VPS8, SVEP1, CFL2, and chr13q21 and reinforced IL12B, PTK2B, and chr21q22 as robust susceptibility loci shared across ancestries. Functional analysis proposed plausible underlying disease mechanisms and pinpointed ETS2 as a potential causal gene for chr21q22 association. We also identified >60 candidate loci with suggestive association (p < 5 × 10-5) and devised a genetic risk score for Takayasu arteritis. Takayasu arteritis was compared to hundreds of other traits, revealing the closest genetic relatedness to inflammatory bowel disease. Epigenetic patterns within risk loci suggest roles for monocytes and B cells in Takayasu arteritis. This work enhances understanding of the genetic basis and pathophysiology of Takayasu arteritis and provides clues for potential new therapeutic targets.

Assessment of Damage in Takayasu's Arteritis.

OBJECTIVES: To evaluate damage and clinical characteristics associated with damage in Takayasu's arteritis (TAK). METHODS: Patients with TAK enrolled in a multicentre, prospective, observational study underwent standardized damage assessment every 6 months using the Vasculitis Damage Index (VDI) and the Large-Vessel Vasculitis Index of Damage (LVVID). RESULTS: The study included 236 patients with TAK: 92% female, 81% Caucasian; median (25th, 75th percentile) disease duration = 2.6 (0.12, 6.9) years. Eighty-four percent had follow-up: median (25th, 75th) duration 4.1 (1.9, 7.5) years.Items of damage were present in 89% on VDI, 87% on LVVID, in the peripheral vascular (76% VDI, 74% LVVID), cardiac (40% VDI, 45% LVVID) systems. During follow-up, 42% patients had new damage;, including major vessel stenosis/arterial occlusion (8%), limb claudication (6%), hypertension (7%), aortic aneurysm (4%), and bypass surgery (4%). Disease-specific damage accounted for >90% new items. Older age, relapse, and longer duration of follow-up were associated with new damage items; a higher proportion of patients without new damage were on methotrexate (p< 0.05). Among 48 patients diagnosed with TAK within 180 days of enrolment, new damage occurred in 31% on VDI and 52% on LVVID. History of relapse was associated with new damage in the entire cohort while in patients with a recent diagnosis, older age at diagnosis was associated with new damage. CONCLUSION: Damage is present in > 80% of patients with TAK even with recent diagnosis and >40% of patients accrue new, mainly disease-specific damage. Therapies for TAK that better control disease activity and prevent damage should be prioritized.

Axial Spondyloarthritis: Does Magnetic Resonance Imaging Classification Improve Report Interpretation.

OBJECTIVE: The interpretation of magnetic resonance imaging (MRI) reports is crucial for the diagnosis of axial spondyloarthritis, but the subjective nature of narrative reports can lead to varying interpretations. This study presents a validation of a novel MRI reporting system for the sacroiliac joint in clinical practice. METHODS: A historical review was conducted on 130 consecutive patients referred by 2 rheumatologists for initial MRI assessment of possible axial spondyloarthritis. The original MRI reports were interpreted by the rheumatologists and the radiologist who originally read the images and then categorized according to the novel system. Two musculoskeletal radiologists then reinterpreted the original MRI scans using the new system, and the resulting reports were interpreted and categorized by the same rheumatologists. The quality of the new framework was assessed by comparing the interpretations of both reports. RESULTS: Ninety-two patients met the study criteria. The rheumatologists disagreed on the categorization of the original MRI reports in 12% of cases. The rheumatologists and original radiologists disagreed on the categorization of the initial report in 23.4% of cases. In contrast, there was 100% agreement between the rheumatologists and radiologists on the categorization of the new MRI report. CONCLUSION: The new MRI categorization system significantly improved the agreement between the clinician and radiologist in report interpretation. The system provided a standard vocabulary for reporting, reduced variability in report interpretation, and may therefore improve clinical decision-making.

Mitochondrial-mediated inflammation and platelet activation in giant cell arteritis.

Markers of extracellular mitochondria are present in giant cell arteritis (GCA) patients. However, their role in promoting inflammation and platelet activation is no known. To investigate this, isolated mitochondria were opsonized with plasma from GCA patients or healthy individuals and incubated with peripheral blood mononuclear cells (PBMCs) or platelets and assessed for inflammatory cytokine production and platelet activation. Plasma from GCA patients promoted increased mitochondrial-mediated cytokine production by PBMCs as compared to healthy controls (p < 0.05). Mitochondria opsonized with plasma factors from patients with GCA induced higher platelet activation as compared to mitochondria opsonized with plasma factors from healthy individuals (p = 0.0015). Platelet levels of P-selectin were associated with disease activity in GCA (r = 0.34, p = 0.01). GCA patients have impaired ability to regulate the clearance of extracellular mitochondria, possibly contributing to excessive inflammation and platelet activation. Targeting key drivers of mitochondrial extrusion and/or their clearance could lead to new therapeutic interventions in GCA.

Neutrophil extracellular trap formation in anti-neutrophil cytoplasmic antibody-associated and large-vessel vasculitis.

Levels of neutrophil extracellular traps (NETs) were measured in plasma of healthy controls (HC, n = 30) and patients with granulomatosis with polyangiitis (GPA, n = 123), microscopic polyangiitis (MPA, n = 61), Takayasu's arteritis (TAK, n = 58), and giant cell arteritis (GCA, n = 68), at times of remission or activity and correlated with levels of the platelet-derived thrombospondin-1 (TSP-1). Levels of NETs were elevated during active disease in patients with GPA (p < 0.0001), MPA (p = 0.0038), TAK (p < 0.0001), and GCA (p < 0.0001), and in remission for GPA, p < 0.0001, MPA, p = 0.005, TAK, p = 0.03, and GCA, p = 0.0009. All cohorts demonstrated impaired NET degradation. Patients with GPA (p = 0.0045) and MPA (p = 0.005) had anti-NET IgG antibodies. Patients with TAK had anti-histone antibodies (p < 0.01), correlating with presence of NETs. Levels of TSP-1 were increased in all patients with vasculitis, and associated with NET formation. NET formation is a common process in vasculitides. Targeting NET formation or degradation could be potential therapeutic approaches for vasculitides.

Plasma Exchange and Glucocorticoids in Severe ANCA-Associated Vasculitis.

BACKGROUND: More effective and safer treatments are needed for antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. METHODS: We conducted a randomized trial with a 2-by-2 factorial design to evaluate the use of plasma exchange and two regimens of oral glucocorticoids in patients with severe ANCA-associated vasculitis (defined by an estimated glomerular filtration rate of <50 ml per minute per 1.73 m2 of body-surface area or diffuse pulmonary hemorrhage). Patients were randomly assigned to undergo plasma exchange (seven plasma exchanges within 14 days after randomization) or no plasma exchange (control group). Patients were also randomly assigned to follow either a standard-dose regimen or a reduced-dose regimen of oral glucocorticoids. Patients were followed for up to 7 years for the primary composite outcome of death from any cause or end-stage kidney disease (ESKD). RESULTS: Death from any cause or ESKD occurred in 100 of 352 patients (28.4%) in the plasma-exchange group and in 109 of 352 patients (31.0%) in the control group (hazard ratio, 0.86; 95% confidence interval [CI], 0.65 to 1.13; P = 0.27). The results were similar in subgroup analyses and in analyses of secondary outcomes. We also assessed the noninferiority of a reduced-dose regimen of glucocorticoids to a standard-dose regimen, using a noninferiority margin of 11 percentage points. Death from any cause or ESKD occurred in 92 of 330 patients (27.9%) in the reduced-dose group and in 83 of 325 patients (25.5%) in the standard-dose group (absolute risk difference, 2.3 percentage points; 90% CI, -3.4 to 8.0), which met the criterion for noninferiority. Serious infections at 1 year were less common in the reduced-dose group than in the standard-dose group (incidence rate ratio, 0.69; 95% CI, 0.52 to 0.93), but other secondary outcomes were similar in the two groups. CONCLUSIONS: Among patients with severe ANCA-associated vasculitis, the use of plasma exchange did not reduce the incidence of death or ESKD. A reduced-dose regimen of glucocorticoids was noninferior to a standard-dose regimen with respect to death or ESKD. (Funded by the U.K. National Institute for Health Research and others; PEXIVAS Current Controlled Trials number, ISRCTN07757494; ClinicalTrials.gov number, NCT00987389.).

Rituximab versus azathioprine for maintenance of remission for patients with ANCA-associated vasculitis and relapsing disease: an international randomised controlled trial.

OBJECTIVE: Following induction of remission with rituximab in anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) relapse rates are high, especially in patients with history of relapse. Relapses are associated with increased exposure to immunosuppressive medications, the accrual of damage and increased morbidity and mortality. The RITAZAREM trial compared the efficacy of repeat-dose rituximab to daily oral azathioprine for prevention of relapse in patients with relapsing AAV in whom remission was reinduced with rituximab. METHODS: RITAZAREM was an international randomised controlled, open-label, superiority trial that recruited 188 patients at the time of an AAV relapse from 29 centres in seven countries between April 2013 and November 2016. All patients received rituximab and glucocorticoids to reinduce remission. Patients achieving remission by 4 months were randomised to receive rituximab intravenously (1000 mg every 4 months, through month 20) (85 patients) or azathioprine (2 mg/kg/day, tapered after month 24) (85 patients) and followed for a minimum of 36 months. The primary outcome was time to disease relapse (either major or minor relapse). RESULTS: Rituximab was superior to azathioprine in preventing relapse: HR 0.41; 95% CI 0.27 to 0.61, p<0.001. 19/85 (22%) patients in the rituximab group and 31/85 (36%) in the azathioprine group experienced at least one serious adverse event during the treatment period. There were no differences in rates of hypogammaglobulinaemia or infection between groups. CONCLUSIONS: Following induction of remission with rituximab, fixed-interval, repeat-dose rituximab was superior to azathioprine for preventing disease relapse in patients with AAV with a prior history of relapse. TRIAL REGISTRATION NUMBER: NCT01697267; ClinicalTrials.gov identifier.

Added diagnostic yield of temporal artery magnetic resonance angiography in the evaluation of giant cell arteritis.

OBJECTIVES: Temporal artery magnetic resonance angiography (TAMRA) is a useful tool to investigate possible diagnoses of GCA. As acquired images also reveal other local structures, they may assist in finding alternative diagnoses when assessing for possible GCA. We sought to assess the utility of TAMRA in identifying other significant abnormalities either associated with a diagnosis of GCA or potentially mimicking a clinical presentation of GCA. METHODS: A retrospective cohort study was undertaken at St Joseph's Healthcare in Hamilton, Ontario, Canada between February 2007 and April 2020 and included patients who underwent TAMRA for a possible diagnosis of GCA. Patient demographics, diagnosis and imaging findings were extracted, and descriptive analysis of findings was performed. RESULTS: We included 340 individuals who underwent TAMRA for assessment of a potential diagnosis of GCA and had clinical information available; there were 126 (37.1%) diagnoses of GCA. Fourteen (4.1%) patients had findings on TAMRA that demonstrated an alternative diagnosis, findings were predominantly in the temporomandibular joint, orbit and meninges. Eighteen (14.3%) patients with GCA had intracranial vascular changes that were demonstrative of intracranial vasculitis; one stroke was attributed to intracranial GCA. CONCLUSIONS: TAMRA has proven utility in diagnosing GCA, and these data suggest that it also has utility in identifying alternative diagnoses to rule out the disease. Intracranial vasculitis was also seen in 14.3% of patients; the clinical impact of these findings is currently poorly understood and requires further study.

Ocular manifestations of ANCA-associated vasculitis.

OBJECTIVES: ANCA-associated vasculitis (AAV) is a group of multisystem diseases that can have several ocular manifestations. There are published data on ocular manifestations of granulomatosis with polyangiitis (GPA), but few for eosinophilic granulomatosis with polyangiitis (EGPA) or microscopic polyangiitis (MPA). There is little information concerning chronicity, complications, and association with other cranial manifestations of AAV. METHODS: This study retrospectively analysed longitudinal multicentre cohorts of individuals with AAV followed between 2006 and 2022. Data included diagnosis, demographics, cranial manifestations of disease, presence of manifestations at onset of disease and/or follow-up, and ocular complications of disease. Univariate and multivariable logistic regression analysis assessed associations across disease manifestations. RESULTS: Data from 1441 patients were analysed, including 395 with EGPA, 876 with GPA, and 170 with MPA. Ocular manifestations were seen within 23.1% of patients: 39 (9.9%) with EGPA, 287 (32.7%) with GPA, and 12 (7.1%) with MPA at any time in the disease course. There were more ocular manifestations at onset (n = 224) than during follow-up (n = 120). The most common disease-related manifestations were conjunctivitis/episcleritis and scleritis. In multivariable analysis, dacryocystitis, lacrimal duct obstruction, and retro-orbital disease were associated with sinonasal manifestations of GPA; ocular manifestations were associated with hearing loss in MPA. The most common ocular complications and/or damage seen were cataracts (n = 168) and visual impairment (n = 195). CONCLUSION: Ocular manifestations occur in all forms of AAV, especially in GPA. Clinicians should be mindful of the wide spectrum of ocular disease in AAV, caused by active vasculitis, disease-associated damage, and toxicities of therapy.

CanVasc consensus recommendations for the use of avacopan in antineutrophil cytoplasm antibody-associated vasculitis: 2022 addendum.

OBJECTIVE: In 2020, the Canadian Vasculitis Research Network (CanVasc) published their updated recommendations for the management of ANCA-associated vasculitides (AAV). The current addendum provides further recommendations regarding the use of avacopan in AAV based on a review of newly available evidence. METHODS: An updated systematic literature review on avacopan (formerly, CCX168) using Medline, Embase, and the Cochrane Library was performed for publications up to September 2022. New recommendations were developed and categorized according to the EULAR grading levels, as done for previous CanVasc recommendations. A modified Delphi procedure and videoconferences were used to reach ≥80% consensus on the inclusion, wording and grading of each recommendation. RESULTS: Three new recommendations were developed. They focus on avacopan therapy indication and duration, as well as timely glucocorticoid tapering. CONCLUSION: These 2022 addended recommendations provide rheumatologists, nephrologists and other specialists caring for patients with AAV with guidance for the use of avacopan, based on current evidence and consensus from Canadian experts.

Airway autoantibodies are determinants of asthma severity.

BACKGROUND: Local airway autoimmune responses may contribute to steroid dependence and persistent eosinophilia in severe asthma. Auto-IgG antibodies directed against granule proteins such as eosinophil peroxidase (EPX), macrophage scavenger receptor with collagenous structure (MARCO) and nuclear/extranuclear antigens (antinuclear antibodies (ANAs)) have been reported. Our objective was to describe the prevalence and clinical characteristics of asthmatic patients with airway autoreactivity, and to assess if this could be predicted from clinical history of autoreactivity. METHODS: We analysed anti-EPX, anti-MARCO and ANAs in 218 sputum samples collected prospectively from 148 asthmatic patients, and evaluated their association with lung function parameters, blood/airway inflammation, severity indices and exacerbations. Additionally, 107 of these patients consented to fill out an autoimmune checklist to determine personal/family history of systemic autoimmune disease and symptoms. RESULTS: Out of the 148 patients, 59 (40%) were anti-EPX IgG+, 53 (36%) were anti-MARCO IgG+ and 64 out of 129 (50%) had ≥2 nuclear/extranuclear autoreactivities. A composite airway autoreactivity score (CAAS) demonstrated that 82 patients (55%) had ≥2 airway autoreactivities (considered as CAAS+). Increased airway eosinophil degranulation (OR 15.1, 95% CI 1.1-199.4), increased blood leukocytes (OR 3.5, 95% CI 1.3-10.1) and reduced blood lymphocytes (OR 0.19, 95% CI 0.04-0.84) predicted CAAS+. A third of CAAS+ patients reported an exacerbation, associated with increased anti-EPX and/or anti-MARCO IgG (p<0.05). While no association was found between family history or personal diagnosis of autoimmune disease, 30% of CAAS+ asthmatic patients reported sicca symptoms (p=0.02). Current anti-inflammatory (inhaled/oral corticosteroids and/or adjunct anti-interleukin-5 biologics) treatment does not attenuate airway autoantibodies, irrespective of eosinophil suppression. CONCLUSION: We report 55% of moderate-severe asthmatic patients to have airway autoreactivity that persists despite anti-inflammatory treatment and is associated with exacerbations.

Hypothyroidism in vasculitis.

OBJECTIVE: To study the prevalence, risk and clinical associations of hypothyroidism among several forms of vasculitis. METHODS: Patients with GCA, Takayasu's arteritis (TAK), PAN and the three forms of ANCA-associated vasculitis [AAV; granulomatosis with polyangiitis (GPA), microscopic polyangiitis and eosinophilic granulomatosis with polyangiitis (EGPA)] enrolled in a prospective, multicentre, longitudinal study were included. RESULTS: The study included data on 2085 patients [63% female, 90% White] with a mean age of 54.6 years (s.d. 17.2). Diagnoses were GCA (20%), TAK (11%), PAN (5%), GPA (42%), microscopic polyangiitis (8%) and EGPA (14%). Hypothyroidism was present in 217 patients (10%) (83% female), with a mean age 59.8 years (s.d. 14.5). Age- and sex-adjusted risk of hypothyroidism was GCA, odds ratio (OR) 0.61 (95% CI 0.41, 0.90); TAK, OR 0.57 (95% CI 0.31, 1.03); PAN, OR 0.59 (95% CI 0.25, 1.38); GPA, OR 1.51 (95% CI 1.12, 2.05); microscopic polyangiitis, OR 1.81 (95% CI 1.18, 2.80) and EGPA, OR 0.82 (95% CI 0.52, 1.30). Among patients with AAV, age- and sex-adjusted risk of hypothyroidism was higher with positive MPO-ANCA [OR 1.89 (95% CI 1.39, 2.76)]. The clinical manifestations of vasculitis were similar in patients with and without hypothyroidism, except transient ischaemic attacks, which were more frequently observed in patients with GCA and hypothyroidism (12% vs 2%; P = 0.001). CONCLUSIONS: Differences in the risk of hypothyroidism among vasculitides may be due to genetic susceptibilities or immune responses. This study confirms an association of hypothyroidism with MPO-ANCA.

Infliximab therapy in refractory sarcoidosis: a multicenter real-world analysis.

BACKGROUND: Infliximab is a monoclonal antibody that binds and neutralizes circulating tumor necrosis factor-alpha, a key inflammatory cytokine in the pathophysiology of sarcoidosis. Despite the paucity of randomized clinical trials, infliximab is often considered a therapeutic option for refractory disease. Our study aimed to investigate the effectiveness of infliximab in patients with refractory sarcoidosis. METHODS: Sarcoidosis patients from three tertiary centres were retrospectively identified by pharmacy records based on treatment with infliximab. Treatment with Infliximab was initiated in patients who failed first and second line immunomodulators as determined by a multidisciplinary team of Respirologists, Dermatologists, ENT specialists, Rheumatologists, and Neurologists. Participants were characterized by the primary organ for which infliximab was initiated and the total number of organs involved. Clinical outcomes were categorized as treatment success versus failure. We defined treatment success as (A) improvement of cutaneous, upper airway, lymph node, gastrointestinal, eye, or joint manifestations; or (B) improvement or no change in central nervous system (CNS) or pulmonary manifestations. RESULTS: 33 patients with refractory sarcoidosis were identified. The proportion of treatment success was 100% (95% CI 54.1-100) in CNS, 91.7% (95% CI 61.5-99.8) in cutaneous, 78.6% (95% CI 49.2-95.3) in pulmonary and 71.5% (95% CI 29.0-96.3) in upper airway disease. The use of infliximab was associated with a reduction prednisone dose by 50%. CONCLUSION: Infliximab is possibly an effective therapy for refractory sarcoidosis, with the greatest value in neurologic and cutaneous manifestations. Across all disease presentations, infliximab facilitated a clinically relevant reduction in corticosteroid dose. Relapse is common after discontinuation of infliximab.

Contextualizing temporal arterial magnetic resonance angiography in the diagnosis of giant cell arteritis: a retrospective cohort study.

OBJECTIVES: Imaging modalities have become common in evaluating patients for a possible diagnosis of GCA. This study seeks to contextualize how temporal arterial magnetic resonance angiography (TA-MRA) can be used in facilitating the diagnosis of GCA. METHODS: A retrospective cohort study was performed on patients who had been previously referred to a rheumatologist for evaluation of possible GCA in Hamilton, Ontario, Canada. Data including clinical features, inflammatory markers, imaging, and biopsy results were extracted. Multivariable logistic regression model to predict the diagnosis of GCA. Using these models, the utility of TA-MRA in series with or in parallel to clinical evaluation was demonstrated across the cohort as well as in subgroups defined by biopsy and imaging status. RESULTS: In total 268 patients had complete data. Those diagnosed with biopsy- and/or imaging-positive GCA were more likely to demonstrate classic features including jaw claudication and vision loss. Clinical multivariable modelling allowed for fair discriminability [receiver operating characteristic (ROC) 0.759, 95% CI: 0.703, 0.815] for diagnosing GCA; there was excellent discriminability in facilitating the diagnosis of biopsy-positive GCA (ROC 0.949, 0.898-1.000). When used in those with a pre-test probability of 50% or higher, TA-MRA had a positive predictive value of 93.0%; in those with a pre-test probability of 25% or less TA-MRA had a negative predictive value of 89.5%. CONCLUSION: In those with high disease probability, TA-MRA can effectively rule in disease (and replace temporal artery biopsy). In those with low to medium probability, TA-MRA can help rule out the disease, but this continues to be a challenging diagnostic population.

Efficacy of leflunomide in the treatment of vasculitis.

OBJECTIVES: Only a few small case series, case reports, and one small clinical trial suggested some benefit of leflunomide (LEF) in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis and other vasculitides. We analysed the clinical efficacy and tolerability of LEF in a large cohort of patients with various vasculitides. METHODS: This was a retrospective analysis of patients who received LEF for treatment of their vasculitis enrolled in the Vasculitis Clinical Research Consortium (VCRC) Longitudinal Study and in 3 additional centres from the Canadian vasculitis research network (CanVasc). RESULTS: Data for 93 patients were analysed: 45 had granulomatosis with polyangiitis (GPA), 8 microscopic polyangiitis (MPA), 12 eosinophilic granulomatosis with polyangiitis (EGPA), 14 giant-cell arteritis (GCA), 9 Takayasu's arteritis (TAK), and 5 polyarteritis nodosa (PAN). The main reason for initiation of LEF was active disease (89%). LEF was efficacious for remission induction or maintenance at 6 months for 62 (67%) patients (64% with GCA, 89% with TAK, 80% with PAN, 69% with GPA, 75% with MPA, 33% with EGPA); 20% discontinued LEF before achieving remission because of persistent disease activity. Overall, 22 adverse events (gastrointestinal symptoms being the most common) led to drug discontinuation in 18 (19%) patients, of which 12 stopped LEF before month 6, before showing any benefit in 8/12 of these patients. CONCLUSIONS: Leflunomide can be an effective therapeutic option for various vasculitides, especially for non-severe refractory or relapsing ANCA-associated vasculitis or large-vessel vasculitis. No new safety signals for LEF were identified in this population.

A Genome-wide Association Study Identifies Risk Alleles in Plasminogen and P4HA2 Associated with Giant Cell Arteritis.

Giant cell arteritis (GCA) is the most common form of vasculitis in individuals older than 50 years in Western countries. To shed light onto the genetic background influencing susceptibility for GCA, we performed a genome-wide association screening in a well-powered study cohort. After imputation, 1,844,133 genetic variants were analyzed in 2,134 case subjects and 9,125 unaffected individuals from ten independent populations of European ancestry. Our data confirmed HLA class II as the strongest associated region (independent signals: rs9268905, p = 1.94 × 10-54, per-allele OR = 1.79; and rs9275592, p = 1.14 × 10-40, OR = 2.08). Additionally, PLG and P4HA2 were identified as GCA risk genes at the genome-wide level of significance (rs4252134, p = 1.23 × 10-10, OR = 1.28; and rs128738, p = 4.60 × 10-9, OR = 1.32, respectively). Interestingly, we observed that the association peaks overlapped with different regulatory elements related to cell types and tissues involved in the pathophysiology of GCA. PLG and P4HA2 are involved in vascular remodelling and angiogenesis, suggesting a high relevance of these processes for the pathogenic mechanisms underlying this type of vasculitis.

Rituximab as therapy to induce remission after relapse in ANCA-associated vasculitis.

OBJECTIVES: Evaluation of rituximab and glucocorticoids as therapy to induce remission after relapse in ANCA-associated vasculitis (AAV) in a prospective observational cohort of patients enrolled into the induction phase of the RITAZAREM trial. METHODS: Patients relapsing with granulomatosis with polyangiitis or microscopic polyangiitis were prospectively enrolled and received remission-induction therapy with rituximab (4×375 mg/m2) and a higher or lower dose glucocorticoid regimen, depending on physician choice: reducing from either 1 mg/kg/day or 0.5 mg/kg/day to 10 mg/day by 4 months. Patients in this cohort achieving remission were subsequently randomised to receive one of two regimens to prevent relapse. RESULTS: 188 patients were studied: 95/188 (51%) men, median age 59 years (range 19-89), prior disease duration 5.0 years (range 0.4-34.5). 149/188 (79%) had previously received cyclophosphamide and 67/188 (36%) rituximab. 119/188 (63%) of relapses had at least one major disease activity item, and 54/188 (29%) received the higher dose glucocorticoid regimen. 171/188 (90%) patients achieved remission by 4 months. Only six patients (3.2% of the study population) did not achieve disease control at month 4. Four patients died in the induction phase due to pneumonia (2), cerebrovascular accident (1), and active vasculitis (1). 41 severe adverse events occurred in 27 patients, including 13 severe infections. CONCLUSIONS: This large prospective cohort of patients with relapsing AAV treated with rituximab in conjunction with glucocorticoids demonstrated a high level of efficacy for the reinduction of remission in patients with AAV who have relapsed, with a similar safety profile to previous studies.

Derivation of an angiographically based classification system in Takayasu's arteritis: an observational study from India and North America.

OBJECTIVES: To develop and replicate, using data-driven methods, a novel classification system in Takayasu's arteritis based on distribution of arterial lesions. METHODS: Patients were included from four international cohorts at major academic centres: India (Christian Medical College Vellore); North America (National Institutes of Health, Vasculitis Clinical Research Consortium and Cleveland Clinic Foundation). All patients underwent whole-body angiography of the aorta and branch vessels, with categorization of arterial damage (stenosis, occlusion or aneurysm) in 13 territories. K-means cluster analysis was performed to identify subgroups of patients based on pattern of angiographic involvement. Cluster groups were identified in the Indian cohort and independently replicated in the North American cohorts. RESULTS: A total of 806 patients with Takayasu's arteritis from India (n = 581) and North America (n = 225) were included. Three distinct clusters defined by arterial damage were identified in the Indian cohort and replicated in each of the North American cohorts. Patients in cluster one had significantly more disease in the abdominal aorta, renal and mesenteric arteries (P < 0.01). Patients in cluster two had significantly more bilateral disease in the carotid and subclavian arteries (P < 0.01). Compared with clusters one and two, patients in cluster three had asymmetric disease with fewer involved territories (P < 0.01). Demographics, clinical symptoms and clinical outcomes differed by cluster. CONCLUSION: This large study in Takayasu's arteritis identified and replicated three novel subsets of patients based on patterns of arterial damage. Angiographic-based disease classification requires validation by demonstrating potential aetiological or prognostic implications.

Urinary soluble CD163 and monocyte chemoattractant protein-1 in the identification of subtle renal flare in anti-neutrophil cytoplasmic antibody-associated vasculitis.

BACKGROUND: Prior work has shown that urinary soluble CD163 (usCD163) displays excellent biomarker characteristics for detection of active renal vasculitis using samples that included new diagnoses with highly active renal disease. This study focused on the use of usCD163 in the detection of the more clinically relevant state of mild renal flare and compared results of usCD163 testing directly to testing of urinary monocyte chemoattractant protein-1 (uMCP-1). METHODS: Patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV, n = 88) were identified within a serially sampled, longitudinal and multicentre cohort. Creatinine-normalized usCD163 and uMCP-1 levels were measured by enzyme-linked immunosorbent assay and, both alone and in combination, were compared between times of active renal AAV and during remission and/or active non-renal AAV. RESULTS: Samples from 320 study visits included times of active renal vasculitis (n = 39), remission (n = 233) and active extrarenal vasculitis (n = 48). Median creatinine levels were 0.9 mg/dL [interquartile range (IQR) 0.8-1.2] in remission and 1.4 mg/dL (IQR 1.0-1.8) during renal flare. usCD163 levels were higher in patients with active renal vasculitis compared with patients in remission and those with active extrarenal vasculitis, with median values of 162 ng/mmol (IQR 79-337), 44 (17-104) and 38 (7-76), respectively (P < 0.001). uMCP-1 levels were also higher in patients with active renal vasculitis compared with patients in remission and those with active extrarenal vasculitis, with median values of 10.6 pg/mmol (IQR 4.6-23.5), 4.1 (2.5-8.4) and 4.1 (1.9-6.8), respectively (P < 0.001). The proposed diagnostic cut-points for usCD163 and uMCP-1 were 72.9 ng/mmol and 10.0 pg/mmol, respectively. usCD163 and uMCP-1 levels were marginally correlated (r2 = 0.11, P < 0.001). Combining novel and existing biomarkers using recursive tree partitioning indicated that elevated usCD163 plus either elevated uMCP-1 or new/worse proteinuria improved the positive likelihood ratio (PLR) of active renal vasculitis to 19.2. CONCLUSION: A combination of usCD163 and uMCP-1 measurements appears to be useful in identifying the diagnosis of subtle renal vasculitis flare.

Sputum Antineutrophil Cytoplasmic Antibodies in Serum Antineutrophil Cytoplasmic Antibody-Negative Eosinophilic Granulomatosis with Polyangiitis.

RATIONALE: Eosinophilic granulomatosis with polyangiitis (eGPA) is a small-vessel vasculitis where 40% of patients present with serum antineutrophil cytoplasmic antibodies (ANCAs). We examined the presence and clinical relevance of sputum ANCAs in the serum ANCA- patients with eGPA. METHODS: ANCA was investigated in matched sputum and blood samples collected from 23 patients with eGPA (n = 10, serum ANCA+), 19 patients with eosinophilic asthma (prednisone dependent), and 13 healthy volunteers. IgG reactivity to common target antigens and cytokine profiles in sputum samples were examined. Pathogenicity of detected sputum ANCA was assessed using in vitro degranulation assays. MEASUREMENTS AND MAIN RESULTS: Most patients with eGPA (17 of 23, 74%) showed significantly increased sputum ANCAs compared with patients with eosinophilic asthma (P = 0.002) and healthy controls (P < 0.0001), irrespective of their serum ANCA status. In addition, 16 of 17 (94%) of sputum ANCA+ patients had clinical manifestations of severe asthma compared with 3 of 6 (50%) in the sputum ANCA- subset (P = 0.04). Microarray analysis of 123 common antigens failed to reveal a specific target for the ANCA IgG. However, immunoprecipitated immunoglobulins from ANCA+ sputum allowed extensive extracellular trap formations from both neutrophils and eosinophils in vitro, indicating pathogenicity of detected IgG autoantibodies. Cytokine analysis showed lung-localized increases in CXCL8 (neutrophil/eosinophil chemotaxis), CCL24 (eosinophil recruitment), and CXCL12 (lymphocyte recruitment) in the sputa from ANCA+ patients (P < 0.01). CONCLUSIONS: We report a novel finding of ANCA reactivity in the sputa of patients with eGPA in whom disease severity is driven by respiratory complications. Investigating localized autoimmunity may lead to the discovery of novel pathomechanisms, therapeutic targets, and optimal biomarkers for diagnosing and managing eGPA.