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.

Autoantibody-Mediated Depletion of IL-1RA in Still's Disease and Potential Impact of IL-1 Targeting Therapies.

BACKGROUND: Adult-onset Still's disease (AOSD) and systemic juvenile idiopathic arthritis (sJIA) resemble a continuum of a rare, polygenic IL-1ß-driven disease of unknown etiology. OBJECTIVE: In the present study we sought to investigate a potential role of recently described autoantibodies neutralizing the interleukin-1(IL-1)-receptor antagonist (IL-1-Ra) in the pathogenesis of Still's disease. METHODS: Serum or plasma samples from Still's disease patients (AOSD, n = 23; sJIA, n = 40) and autoimmune and/or inflammatory disease controls (n = 478) were analyzed for autoantibodies against progranulin (PGRN), IL-1Ra, IL-18 binding protein (IL-18BP), and IL-36Ra, as well as circulating IL-1Ra and IL-36Ra levels by ELISA. Biochemical analyses of plasma IL-1Ra were performed by native Western blots and isoelectric focusing. Functional activity of the autoantibodies was examined by an in vitro IL-1ß-signaling reporter assay. RESULTS: Anti-IL-1-Ra IgG were identified in 7 (27%) out of 29 Still's disease patients, including 4/23 with AOSD and 3/6 with sJIA and coincided with a hyperphosphorylated isoform of endogenous IL-1Ra. Anti-IL-36Ra antibodies were found in 2 AOSD patients. No anti-PGRN or anti-IL-18BP antibodies were detected. Selective testing for anti-IL-1Ra antibodies in an independent cohort (sJIA, n = 34) identified 5 of 34 (14.7%) as seropositive. Collectively, 8/12 antibody-positive Still's disease patients were either new-onset active disease or unresponsive to IL-1 blocking drugs. Autoantibody-seropositivity associated with decreased IL-1Ra plasma/serum levels. Seropositive plasma impaired in vitro IL-1Ra bioactivity, which could be reversed by anakinra or canakinumab treatment. CONCLUSION: Autoantibodies neutralizing IL-1Ra may represent a novel patho-mechanism in a subgroup of Still's disease patients, which is sensitive to high-dose IL-1 blocking therapy.

Secukinumab is not associated with cancer recurrence or progression in patients with spondyloarthritis and history of neoplastic disease.

Secukinumab is a monoclonal antibody directed against interleukin-17 approved for the treatment of psoriasis and spondyloarthritis. The favorable oncological profile of secukinumab in patients with a history of malignancy has been shown in patients with psoriasis. However, systematic data to this regard have not been published yet for patients with spondyloarthritis. The objective of the present study was to evaluate the oncological safety of secukinumab in patients affected by this group of diseases. We performed a retrospective study in which we identified from our cohort patients with spondyloarthritis treated with secukinumab and with a history of malignancy. These patients' baseline demographic, treatment, rheumatological, and oncological data were collected. The neoplastic outcome (i.e., cancer recurrence or progression) after secukinumab start was then analyzed. Our study included 22 patients with spondyloarthritis. The most frequently reported oncological diagnosis was breast cancer (9 [41%] patients). Secukinumab was started after a median of 24 months following cancer diagnosis. At this time point, all but three patients were in oncological remission. No case of cancer relapse or progression was recorded over a median follow-up of 30 months. In the largest cohort reported to date to this regard, secukinumab was not associated with oncological recurrence or progression in patients with spondyloarthritis with a history of malignancy. Secukinumab may, therefore, represent a safe option in this clinical scenario.

Validation of the 2022 American College of Rheumatology/EULAR classification criteria for Takayasu arteritis.

OBJECTIVES: The present study validates the 2022 ACR/European Alliance of Associations for Rheumatology (EULAR) classification criteria for Takayasu's arteritis (TAK), compared with the 1990 ACR TAK classification criteria. METHODS: The fulfilment of 2022 ACR/EULAR and 1990 ACR TAK criteria from four referral centres was assessed for TAK compared with extracranial giant cell arteritis (EC-GCA) and other controls. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), likelihood ratio of a positive test (LR+) or negative test (LR-), and area under receiver operating characteristics curve (AUC) were calculated. RESULTS: Among 504 patients with TAK (404 females) and 222 controls (151 females, 144 patients with EC-GCA), the 2022 ACR/EULAR criteria had better sensitivity (95.83% vs 82.94%) and NPV, but poorer specificity (63.51% vs 90.54%), PPV, LR+, LR- and AUC at the pre-determined cut-offs than the 1990 ACR criteria. The 2022 ACR/EULAR criteria had greater specificity (76.06% vs 57.62%) and AUC (0.845 vs 0.771), with similar sensitivity (93% vs 96.53%) in males as in females. The 2022 ACR/EULAR criteria performed similarly with only EC-GCA as controls (sensitivity 95.83%, specificity 60.42%, AUC 0.781). Sensitivity remained similar, whereas specificity was higher for 40-60 years vs <40 years. Cut-offs of ≥6 (sensitivity 91.87%, specificity 82.88%) and ≥7 (sensitivity 86.71%, specificity 86.49%), or removing the point for female sex (sensitivity 92.64%, specificity 81.08%) greatly improved the balance between sensitivity and specificity. CONCLUSION: The poor specificity of the 2022 ACR/EULAR TAK criteria in real-life settings was improved by increasing the cut-off to 6 or 7, or removing the point for female sex.

Myelomonocytic cells in giant cell arteritis activate trained immunity programs sustaining inflammation and cytokine production.

OBJECTIVE: Trained immunity (TI) is a de facto memory program of innate immune cells, characterized by immunometabolic and epigenetic changes sustaining enhanced production of cytokines. TI evolved as a protective mechanism against infections; however, inappropriate activation can cause detrimental inflammation and might be implicated in the pathogenesis of chronic inflammatory diseases. In this study, we investigated the role of TI in the pathogenesis of giant cell arteritis (GCA), a large-vessel vasculitis characterized by aberrant macrophage activation and excess cytokine production. METHODS: Monocytes from GCA patients and from age- and sex-matched healthy donors were subjected to polyfunctional studies, including cytokine production assays at baseline and following stimulation, intracellular metabolomics, chromatin immunoprecipitation-qPCR, and combined ATAC/RNA sequencing. Immunometabolic activation (i.e. glycolysis) was assessed in inflamed vessels of GCA patients with FDG-PET and immunohistochemistry (IHC), and the role of this pathway in sustaining cytokine production was confirmed with selective pharmacologic inhibition in GCA monocytes. RESULTS: GCA monocytes exhibited hallmark molecular features of TI. Specifically, these included enhanced IL-6 production upon stimulation, typical immunometabolic changes (e.g. increased glycolysis and glutaminolysis) and epigenetic changes promoting enhanced transcription of genes governing pro-inflammatory activation. Immunometabolic changes of TI (i.e. glycolysis) were a feature of myelomonocytic cells in GCA lesions and were required for enhanced cytokine production. CONCLUSIONS: Myelomonocytic cells in GCA activate TI programs sustaining enhanced inflammatory activation with excess cytokine production.

Efficacy and safety of TNF-α antagonists and tocilizumab in Takayasu arteritis: multicentre retrospective study of 209 patients.

OBJECTIVE: To assess the safety and the efficacy of TNF-α antagonists and tocilizumab in patients with Takayasu arteritis (TAK). METHODS: A total of 209 patients with TAK [median age 29 years (interquartile range 7-62)], 186 (89%) females] were included. They received either TNF-α antagonists [n = 132 (63%) with 172 lines; infliximab (n = 109), adalimumab (n = 45), golimumab (n = 8), certolizumab (n = 6) and etanercept (n = 5)] or tocilizumab [n = 77 (37%) with 121 lines; i.v. and s.c. in 95 and 26 cases, respectively]. RESULTS: A complete response at 6 months was evidenced in 101/152 (66%) patients on TNF-α antagonists and 75/107 (70%) patients on tocilizumab. Age ≥30 years [odds ratio 2.09 (95% CI 1.09, 3.99)] was associated with complete response, whereas vascular signs [OR 0.26 (95% CI 0.1, 0.65)], baseline prednisone ≥20 mg/day [OR 0.51 (95% CI 0.28, 0.93)] were negatively associated with the complete response to TNF-α antagonists or tocilizumab. During a median follow-up of 36 months, 103 relapses were noted. Supra-aortic branches and thoracic aorta involvement [HR 2.44 (95% CI 1.06, 5.65) and 3.66 (1.18, 11.4), respectively] and systemic signs at baseline [HR 2.01 (95% CI 1.30, 3.11)] were significantly associated with relapse. The cumulative incidence of treatment discontinuation and relapse were similar in TNF-α antagonists and tocilizumab. Fifty-eight (20%) adverse effects occurred on biologic targeted therapies [37 (21%) on TNF-α antagonists and 21 (17%) on tocilizumab (P = 0.4), respectively]. CONCLUSION: This large multicentre study shows high efficacy of biologic targeted treatments in refractory TAK. Efficacy, relapse and drug retention rate were equivalent with TNF-α antagonists and tocilizumab.

Effectiveness and safety of infliximab dose escalation in patients with refractory Takayasu arteritis: A real-life experience from a monocentric cohort.

OBJECTIVES: To evaluate effectiveness and safety of infliximab dose escalation in Takayasu arteritis (TAK) patients. To identify factors associated with refractoriness to standard-dose infliximab. METHODS: Medical records of infliximab-treated TAK patients from a large single-centre observational cohort were reviewed. Infliximab therapy duration, concomitant therapies, and reasons for dose escalation and therapy suspension were evaluated. Occurrence of adverse events was recorded. A comparison between patients who maintained infliximab standard-dose and those who needed dose-escalation was performed. Factors associated with refractoriness to standard dose were analysed. RESULTS: Forty-one patients were included. Starting infliximab dose was 5 mg/kg 6-weekly and 28 patients (68%) needed dose escalation. Persistence/recurrence of clinical symptoms was the most frequent reason for escalation. Median therapy duration was 39 (IQR, 26-61) months in the standard-dose group and 68 (38-87) months in the intensified-dose group. In the intensified-dose-group, infliximab was suspended in eight patients (29%) after a median of 38 (31-71) months, due to loss of response (n = 7) or patient's request (n = 1). Patients in the intensified-dose group had a higher number of relapses (3.4 vs 0.8 events/patient) and received a higher cumulative steroid dose (1.7 [1.6-2.3] vs 1.3 [1-1.6] g/month of prednisone). Three patients from the intensified-dose group had serious infections; one patient from the standard-dose group developed paradoxical psoriasis. At univariate analysis, age at diagnosis and age at infliximab start were associated with infliximab escalation. CONCLUSION: In TAK, dose escalation is safe and allows to optimise infliximab durability in refractory patients. Younger patients seem to be more refractory to standard dosages.

Failure of first anti-TNF agent in Takayasu's arteritis: to switch or to swap?

OBJECTIVES: Biologic drugs (bDMARD), especially TNF-α-inhibitors (TNFi), are used in refractory Takayasu's arteritis (TAK) patients. Up to 23% of patients are switched to a different bDMARD because of inefficacy. No data are available on which strategy is more efficient after TNFi failure. The aim of our study is to evaluate whether a switch or swap strategy should be preferred in TAK patients failing TNFis. METHODS: TAK patients treated with a second bDMARD after the failure of the first TNFi were identified from 3 referral centres. Patients were classified as switch if treated with a different TNFi, and swap if treated with a non-TNFi bDMARD. Baseline features were evaluated. Efficacy and safety of the second bDMARD at 6 and 12 months were assessed and a comparison between switch and swap patients was made. RESULTS: Twenty-four TAK patients were identified. Eleven patients (46%) were switched and 13 patients (54%) were swapped (12 to tocilizumab, 1 to ustekinumab). Baseline features of patients in the 2 groups were comparable. At 12 months, the second bDMARD was suspended in 4 switch (36%) and in 5 swap (42%) patients. Second biologic drug survival and relapse-free survival were equivalent between the two groups at 6 and 12 months. A vascular worsening was observed in 4 switch (40%) and 2 swap (25%) patients. Severe infections, myocardial infarction, ischemic stroke or cancer were recorded in no patient. CONCLUSIONS: Our retrospective study suggests that in first-line TNFi failure TAK patients both switch and swap strategies can be considered suitable approaches.

18F-FDG PET reveals unique features of large vessel inflammation in patients with Takayasu's arteritis.

PURPOSE: The object of this study was to assess whether 18F-fluorodeoxyglucose PET/CT (FDG PET/CT) provides novel information in patients with Takayasu's arteritis (TA) in addition to that provided by current activity assessment, to analyse the effects of possible confounders, such as arterial grafts, and to verify whether PET/CT could be informative in lesions <4 mm thick. METHODS: We studied 30 patients with TA, evaluated from October 2010 to April 2014 by both PET/CT and magnetic resonance imaging (MRI). All arterial lesions were evaluated by PET both qualitatively (positive/negative) and semiquantitatively (maximum standardized uptake value, SUVmax), and the thickness of lesions in the MRI field of view was evaluated. In a per-patient analysis, the relationships between the PET data and acute-phase reactants and NIH criteria for active TA were evaluated. In a per-lesion analysis, the relationships between the PET features of each lesion and MRI morphological data were evaluated. The effects of the presence of arterial grafts were also evaluated. RESULTS: Increased FDG uptake was seen in 16 of 30 patients (53%) and in 46 of 177 vascular lesions (26%). Significant periprosthetic FDG uptake was seen in 6 of 7 patients (86%) with previous vascular surgery and in 10 of 11 of grafts (91%). Graft-associated uptake influenced the PET results in three patients (10%) and the SUVmax values in five patients (17%). Of 39 lesions with significant FDG uptake, 15 (38%) were <4 mm thick. Lesion thickness was correlated with lesion SUVmax in FDG-avid lesions only. FDG arterial uptake was not associated with systemic inflammation or NIH criteria. CONCLUSIONS: PET/CT reveals unique and fundamental features of arterial involvement in TA. PET/CT may be useful in the assessment of local inflammatory and vascular remodelling events independent of systemic inflammation during follow-up, even in lesions in which the arterial wall is <4 mm. The presence of arterial grafts is a potential confounder. Prospective studies are required to correlate PET findings with relevant clinical outcomes.

Anti-TNFα agents curb platelet activation in patients with rheumatoid arthritis.

BACKGROUND: Cardiovascular disease is important in rheumatoid arthritis (RA). Tissue factor (TF) is expressed upon platelet activation and initiates coagulation. Anti-tumour necrosis factor-α (TNFα) agents seem to decrease RA-associated cardiovascular events. We investigated whether (1) TNFα activates human platelets and (2) TNFα pharmacological blockade modulates the platelet-leucocyte reciprocal activation in RA. DESIGN: The expression of platelet TNFα receptors has been assessed by flow cytometry and immunogold electron microscopy. Platelet and leucocyte activation has been assessed also in the presence of antibodies against the TNFα receptors 1 and 2 and of infliximab. TF expression, binding to fibrinogen and phosphatidylserine exposure, has been assessed by flow cytometry, TF activity by coagulation time and by endogenous thrombin generation. Markers of platelet and leucocyte activation have been assessed in 161 subjects: 42 patients with RA, 12 with osteoarthritis, 37 age-matched and sex-matched patients with chronic stable angina and 70 age-matched and sex-matched healthy subjects. RESULTS: TNFα elicited the platelet activation and the expression of TF, which in turn prompted thrombin generation and clot formation. Inhibition of the TNFα-induced activation restricted platelet ability to activate leucocytes and to induce leucocyte TF. TNFα inhibition did not influence platelet activation induced by collagen, ADP or thrombin receptor activating peptide-6. Platelets of patients with RA were more activated than those of controls. Activation was reduced in patients treated with TNFα inhibitors. CONCLUSIONS: TNFα-dependent pathways control platelet activation and TF expression in RA. Further studies will verify whether the protective effect of TNFα inhibitors on cardiovascular events involves their ability to modulate platelet function.

Prospectively-followed pregnancies in patients with inflammatory arthritis taking biological drugs: an Italian multicentre study.

OBJECTIVES: Information on new drugs does not include their possible effects on pregnancy because pregnant women are excluded from clinical trials. Although not classified as teratogenic in animals, limited data is available on biological anti-rheumatic agents and their safety in human pregnancy. The aim of the study is to evaluate the safety of biological drugs in pregnant patients with chronic arthritis. METHODS: Pregnancy outcome and maternal disease variations were prospectively followed in six Italian Rheumatology Centres. Patients exposed to biological agents during the periconceptional period or during pregnancy were included in the study. The occurrence of congenital malformations as well as the obstetric and neonatal outcomes were assessed. RESULTS: Between 1999 and 2013 we identified 79 exposed pregnancies in 67 women affected by different rheumatic diseases with peripheral chronic arthritis. At the time of the start of pregnancy, 56 patients were taking etanercept, 13 adalimumab, 3 infliximab, 2 each certolizumab-pegol and rituximab, 1 each golimumab, anakinra and abatacept. Biological treatment was stopped after a mean of 41 days since documented pregnancy. Live births were reported in 66% of pregnancies. The rate of spontaneous pregnancy loss was 20%. Only one congenital malformation was reported. CONCLUSIONS: TNF-alpha inhibitors can be considered safe in the periconception period, representing a possible therapeutic choice also in young women affected by an aggressive form of chronic arthritis and hoping for a pregnancy. Reports of exposure during 2nd/3rd trimester are still limited and suggest caution. Experience with abatacept, tocilizumab, anakinra and rituximab in pregnancy is insufficient.

Histone-Specific CD4+ T Cell Plasticity in Active and Quiescent Systemic Lupus Erythematosus.

OBJECTIVE: The aim of this study was to assess whether circulating histone-specific T cells represent tools for precision medicine in systemic lupus erythematosus (SLE). METHODS: Seroprevalence of autoantibodies and HLA-DR beta (DRB) 1 profile were assessed among 185 patients with SLE and combined with bioinformatics and literature evidence to identify HLA-peptide autoepitope couples for ex vivo detection of antigen-specific T cells through flow cytometry. T cell differentiation and polarization was investigated in patients with SLE, patients with Takayasu arteritis, and healthy controls carrying HLA-DRB1*03:01 and/or HLA-DRB1*11:01. SLE Disease Activity Index 2000 and Lupus Low Disease Activity State were used to estimate disease activity and remission. RESULTS: Histone-specific CD4+ T cells were selectively detected in patients with SLE. Among patients with a history of anti-DNA antibodies, 77% had detectable histone-specific T cells, whereas 50% had lymphocytes releasing cytokines or upregulating activation markers after in vitro challenge with histone peptide antigens. Histone-specific regulatory and effector T helper (Th) 1-, Th2-, and atypical Th1/Th17 (Th1*)-polarized cells were significantly more abundant in patients with SLE with quiescent disease. In contrast, total Th1-, Th2-, and Th1*-polarized and regulatory T cells were similarly represented between patients and controls or patients with SLE with active versus quiescent disease. Histone-specific effector memory T cells accumulated in the blood of patients with quiescent SLE, whereas total effector memory T cell counts did not change. Immunosuppressants were associated with expanded CD4+ histone-specific naive T (TN) and terminally differentiated T cells. CONCLUSION: Histone-specific T cells are selectively detected in patients with SLE, and their concentration in the blood varies with disease activity, suggesting that they represent innovative tools for patient stratification and therapy.

Effectiveness of a two-year tapered course of tocilizumab in patients with giant cell arteritis: A single-centre prospective study.

OBJECTIVE: To evaluate the feasibility of tocilizumab tapering and withdrawal in patients with giant cell arteritis (GCA). METHODS: GCA patients eligible for tocilizumab were prospectively enrolled. Tocilizumab was administered weekly for the first 12 months, every-other-week for an additional 12 months, then discontinued. Relapses on tocilizumab were managed with temporary increases in systemic glucocorticoids or addition of methotrexate. Primary outcome was relapse-free survival at month 6 after tocilizumab suspension. Relapse-free survival on tocilizumab, imaging response, and adverse events were evaluated. RESULTS: 23 GCA patients were enrolled. Reasons for tocilizumab start were relapse (n = 14), persistence of activity (n = 5), or steroid-related adverse events (n = 4). At tocilizumab start, two patients were on methotrexate, which was maintained. Fourteen patients had extracranial vascular involvement on 18FDG-PET/CT. During the first 12 months, four patients (17%) had clinical relapse. At every-other-week tocilizumab start, all patients were in clinical remission, two patients had active vasculitis on 18FDG-PET/CT; two patients were on steroid therapy, and four patients were taking methotrexate. Two patients (9%) relapsed while on every-other-week tocilizumab. At tocilizumab suspension, no patient was on steroid therapy and no patient had signs of active vasculitis on 18FDG-PET/CT. In the 6 months after tocilizumab discontinuation, six patients (26%) relapsed. No new or unexpected safety findings were identified. CONCLUSION: Tocilizumab tapered over a two-year period was effective to induce and maintain remission in GCA. Relapses on tocilizumab were minor and responded to incremental changes in therapy. A significant proportion of patients relapsed in the 6 months after therapy suspension.

Intravenous versus subcutaneous tocilizumab in Takayasu arteritis: multicentre retrospective study.

OBJECTIVES: In this large multicentre study, we compared the effectiveness and safety of tocilizumab intravenous versus subcutaneous (SC) in 109 Takayasu arteritis (TAK) patients. METHODS: We conducted a retrospective multicentre study in referral centres from France, Italy, Spain, Armenia, Israel, Japan, Tunisia and Russia regarding biological-targeted therapies in TAK, since January 2017 to September 2019. RESULTS: A total of 109 TAK patients received at least 3 months tocilizumab therapy and were included in this study. Among them, 91 and 18 patients received intravenous and SC tocilizumab, respectively. A complete response (NIH <2 with less than 7.5 mg/day of prednisone) at 6 months was evidenced in 69% of TAK patients, of whom 57 (70%) and 11 (69%) patients were on intravenous and SC tocilizumab, respectively (p=0.95). The factors associated with complete response to tocilizumab at 6 months in multivariate analysis, only age <30 years (OR 2.85, 95% CI 1.14 to 7.12; p=0.027) and time between TAK diagnosis and tocilizumab initiation (OR 1.18, 95% CI 1.02 to 1.36; p=0.034). During the median follow-up of 30.1 months (0.4; 105.8) and 10.8 (0.1; 46.4) (p<0.0001) in patients who received tocilizumab in intravenous and SC forms, respectively, the risk of relapse was significantly higher in TAK patients on SC tocilizumab (HR=2.55, 95% CI 1.08 to 6.02; p=0.033). The overall cumulative incidence of relapse at 12 months in TAK patients was at 13.7% (95% CI 7.6% to 21.5%), with 10.3% (95% CI 4.8% to 18.4%) for those on intravenous tocilizumab vs 30.9% (95% CI 10.5% to 54.2%) for patients receiving SC tocilizumab. Adverse events occurred in 14 (15%) patients on intravenous route and in 2 (11%) on SC tocilizumab. CONCLUSION: In this study, we confirm that tocilizumab is effective in TAK, with complete remission being achieving by 70% of disease-modifying antirheumatic drugs-refractory TAK patients at 6 months.

Takayasu arteritis: intravascular contrast medium for MR angiography in the evaluation of disease activity.

OBJECTIVE: Takayasu arteritis is difficult to diagnose, and the evaluation of disease activity is even more challenging. Laboratory, clinical, and radiologic criteria are limited indicators of disease activity. Gadofosveset trisodium is a recently introduced intravascular contrast agent. In this study we sought to investigate a correlation between clinical activity and enhancement of vascular wall thickening in patients with Takayasu arteritis who underwent MR angiography with gadofosveset. SUBJECTS AND METHODS: Twenty-three consecutively registered patients (21 women, two men) with Takayasu arteritis underwent MR angiography of the supraaortic trunks, aorta, and visceral vessels. Intravascular contrast medium was used to correlate thickened vessel wall enhancement with clinical criteria of disease activity. ECG-triggered black-blood first-pass high-resolution steady-state imaging was performed for all patients. RESULTS: Before MR angiography, 14 patients were considered to have active disease. Heterogeneous structural involvement of the vascular tree was found. Twenty of 23 patients (87.0%) had supraaortic trunk involvement, including 12 of the 14 patients (85.7%) with active disease. Seventeen of the 23 patients (73.9%) had aortic and visceral vessel involvement, including 12 of the 14 patients (85.7%) with active disease. On steady state images in the active disease group, the mean signal-to-noise-ratio increased from 17.4 to 35.3 after gadofosveset injection (p > 0.0001), while in the nonactive disease group it increased from 52.8 to 69.6 (p = 0.08). A cutoff of 40% was best for differentiating active from inactive disease (sensitivity, 100%; specificity, 89%; positive predictive value, 92%; negative predictive value, 100%). CONCLUSION: Use of intravascular contrast medium significantly increases the effectiveness of MR angiography in differentiating active and inactive disease.