Value of whole-body contrast-enhanced magnetic resonance angiography with vessel wall imaging in quantitative assessment of disease activity and follow-up examination in Takayasu’s arteritis

Multimodality imaging to assess diagnosis and evaluate complications of large vesselarteritis

Different types of vasculitis can be distinguished according to the blood vessel's size that is preferentially affected: large-vessel, medium-vessel, and small-vessel vasculitides. Giant cell arteritis (GCA) and Takayasu's arteritis (TAK) are the main forms of large-vessel vasculitis, and may lead to lumen narrowing. Clinical manifestations of arterial narrowing on the short- and long term include vision loss, stroke, limb ischemia, and heart failure. Imaging tools are well established diagnostic tests for large-vessel vasculitis and may aid therapy monitoring in selected cases while providing important information regarding the occurrence of vascular damage, tissue and organ complications. This review aims to provide the current status of multimodality imaging for the diagnosis and identification of vascular complications in the field of large vessel vasculitis.

Chinese guideline for the diagnosis and treatment of Takayasu's arteritis (2023)

Takayasu's arteritis (TAK) is a chronic granulomatous inflammatory disease that involves aorta and its primary branches. It is characterized by wall thickening, stenosis/obliteration or aneurysm formation of the involved arteries. In order to standardize the diagnosis and treatment of TAK in China, a clinical practice guideline with an evidence-based approach is developed under the leadership of National Clinical Medical Research Center for Dermatologic and Immunologic Diseases (NCRC-DID). Eleven recommendations for 11 clinical questions that are important to the diagnosis and treatment of TAK are developed based on the latest evidence and expert opinions combined with real clinical practice in China.

The role of plateletcrit in Takayasu arteritis: A potential biomarker for disease activity and 6-month treatment response

OBJECTIVES

To determine the role of plateletcrit as a potential biomarker for disease activity and treatment response in Takayasu arteritis (TAK).

METHODS

Totally, 215 newly diagnosed TAK patients were consecutively enrolled. Demographic data, clinical manifestations, laboratory and imaging examinations, and treatment strategy were recorded at baseline and at each visit during the 6-month treatment period. Normal plateletcrit (0.1%-0.4%) and hyper-plateletcrit (>0.4%) observed at baseline were used as group criteria.

RESULTS

At baseline, the overall plateletcrit was 0.32 (0.24-0.38)%, with a normal and high level observed in 172 (80.00%) and 43 (20.00%) patients, respectively. Baseline plateletcrit was significantly higher in patients with active disease and associated with inflammatory biomarkers, including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and interleukin (IL)-6 (all p < .01). At 6 months, complete remission was achieved in 171 (79.53%) patients, and a significant decrease in plateletcrit was observed in these cases (p < .01). Patients with a normal baseline plateletcrit were more likely to achieve complete remission compared to those with a high baseline plateletcrit (HR = 4.65, 95% CI: 2.38-19.08, p < .01). In addition, ESR (p = .01) and IL-6 (p = .02) levels were still higher in patients with a high baseline plateletcrit at 6 months. Progression of vascular lesions was indicated in 18 (8.37%) patients at 6 months, and these patients also had significantly higher baseline plateletcrit (p = .03).

CONCLUSION

Plateletcrit levels were positively related to disease activity and inflammatory index in TAK. Importantly, patients with high baseline plateletcrit levels may show a worse treatment response at 6 months.

The Role of Imaging in Diagnosis and Monitoring of Large Vessel Vasculitis

Technological advances and increased recognition of the prevalence and implications of large vessel vasculitis have led to robust research into various imaging techniques. Although there is still debate about which modality to choose in specific clinical scenarios, Ultrasound, PET/CT, MRI/A, and CT/A offer complementary information regarding diagnosis, disease activity, and vascular complication monitoring. Recognition of the strengths and limitations of each technique is important for appropriate application in clinical practice.

A novel molecular mechanism of vascular fibrosis in Takayasu arteritis: macrophage-derived GPNMB promoting adventitial fibroblast extracellular matrix production in the aorta

Takayasu arteritis (TAK) is a chronic large vessel disease characterized by aortic fibrotic thickening, which was mainly mediated by activation of aorta adventitial fibroblasts (AAFs). Our previous genetic study demonstrated that TAK-associated locus IL6 rs2069837 regulated glycoprotein non-metastatic melanoma protein B (GPNMB) expression. Thus, this study aimed to investigate the pathogenic role of GPNMB in TAK. Through pathological staining, we find that GPNMB was mainly expressed in vascular adventitia and positively correlated with adventitial extracellular matrix (ECM) expression in TAK vascular lesion. Specifically, GPNMB was increased in adventitial CD68⁺ macrophages, which were closely located with CD90⁺ adventitial fibroblasts. In in-vitro cell culture, THP-1-derived macrophages with GPNMB overexpression promoted ECM expression in AAFs. This effect was also confirmed in aortic tissue or AAFs culture with GPNMB overexpression or active GPNMB protein stimulation. Mechanistically, Co-IP assay and siRNA or inhibitor intervention demonstrated that integrin αVβ1 receptor mediated GPNMB effect on AAFs, which also activated downstream Akt and Erk pathway in AAFs. Furthermore, we showed that leflunomide treatment inhibited GPNMB-mediated fibrosis in AAFs, as well as GPNMB expression in macrophages, which were also partially validated in leflunomide-treated patients. Taken together, these data indicated that macrophage-derived GPNMB promotes AAFs ECM expression via the integrin αVβ1 receptor and Akt/Erk signaling pathway and leflunomide might play an anti-fibrotic role in TAK by interfering with the macrophage-derived GPNMB/AAFs axis. This study provides evidence that targeting GPNMB is a potential therapeutic strategy for treating vascular fibrosis in TAK.

Outcome Measures and Biomarkers for Disease Assessment in Takayasu Arteritis

Takayasu arteritis (TAK) is a less common large vessel vasculitis where histopathology of involved arteries is difficult to access except during open surgical procedures. Assessment of disease activity in TAK, therefore, relies on surrogate measures. Clinical disease activity measures such as the National Institutes of Health (NIH) score, the Disease Extent Index in TAK (DEI.TAK) and the Indian TAK Clinical Activity Score (ITAS2010) inconsistently associate with acute phase reactants (APRs). Computerized tomographic angiography (CTA), magnetic resonance angiography (MRA), or color Doppler Ultrasound (CDUS) enables anatomical characterization of stenosis, dilatation, and vessel wall characteristics. Vascular wall uptake of 18-fluorodeoxyglucose or other ligands using positron emission tomography computerized tomography (PET-CT) helps assess metabolic activity, which reflects disease activity well in a subset of TAK with normal APRs. Angiographic scoring systems to quantitate the extent of vascular involvement in TAK have been developed recently. Erythrocyte sedimentation rate and C-reactive protein have a moderate performance in distinguishing active TAK. Numerous novel biomarkers are under evaluation in TAK. Limited literature suggests a better assessment of active disease by combining APRs, PET-CT, and circulating biomarkers. Validated damage indices and patient-reported outcome measures specific to TAK are lacking. Few biomarkers have been evaluated to reflect vascular damage in TAK and constitute important research agenda.

ACR Appropriateness Criteria® Noncerebral Vasculitis

Noncerebral vasculitis is a wide-range noninfectious inflammatory disorder affecting the vessels. Vasculitides have been categorized based on the vessel size, such as large-vessel vasculitis, medium-vessel vasculitis, and small-vessel vasculitis. In this document, we cover large-vessel vasculitis and medium-vessel vasculitis. Due to the challenges of vessel biopsy, imaging plays a crucial role in diagnosing this entity. While CTA and MRA can both provide anatomical details of the vessel wall, including wall thickness and enhancement in large-vessel vasculitis, FDG-PET/CT can show functional assessment based on the glycolytic activity of inflammatory cells in the inflamed vessels. Given the size of the vessel in medium-vessel vasculitis, invasive arteriography is still a choice for imaging. However, high-resolution CTA images can depict small-caliber aneurysms, and thus can be utilized in the diagnosis of medium-vessel vasculitis. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Vessel Wall MR Imaging in the Pediatric Head and Neck

Vessel wall MR imaging (VWI) is a technique that progressively has gained traction in clinical diagnostic applications for evaluation of intracranial and extracranial vasculopathies, with increasing use in pediatric populations. The technique has shown promise in detection, differentiation, and characterization of both inflammatory and noninflammatory vasculopathies. In this article, optimal techniques for intracranial and extracranial VWI as well as applications and value for pediatric vascular disease evaluation are discussed.

FABP3 overexpression promotes vascular fibrosis in Takayasu's arteritis via enhancing fatty acid oxidation in aorta adventitial fibroblasts

OBJECTIVE

To identify the role of fatty acid-binding protein-3 (FABP3) in vascular fibrosis in Takayasu's arteritis (TAK) and to explore the underlying molecular mechanism.

METHODS

The expression of FABP3 and extracellular matrix proteins (ECMs) were detected in aorta tissues from TAK patients (n = 12) and healthy controls (n = 8) by immunohistochemistry. The concentration of serum proteins was determined by ELISA. CCK8 and Ki67 staining were used to measure aorta adventitial fibroblasts (AAFs) proliferation. Widely-targeted lipidomic profiling was used to screen for associated metabolic pathways. Changes in ECMs and fatty acid oxidation (FAO) related enzymes were determined by RT-qPCR and Western blot. The interactions between FABP3 and these enzymes were explored with Co-immunoprecipitation (Co-IP) assay.

RESULTS

The expression of FABP3 was increased in the thickened adventitia of TAK patients, and was positively correlated with the serum expression of ECMs. FABP3 knockdown inhibited AAF proliferation and ECMs production, whereas FABP3 overexpression enhanced these processes. Further analysis revealed that FABP3 upregulation promoted carnitine palmitoyltransferase 1A (CPT1A) and carnitine/acylcarnitine carrier protein (CACT) expressions, two key enzymes in FAO, as well as ATP levels. FABP3 and CACT were co-localized in the adventitia and bound to each other in AAFs. Etomoxir reversed the enhanced FAO, ATP production, AAF proliferation, and ECM production mediated by FABP3 upregulation. Treatment with 60 g/day curcumin granules for three months reduced the level of serum FABP3. Curcumin also inhibited vascular fibrosis by reducing FABP3-enhanced FAO in AAFs.

CONCLUSION

Elevated FABP3 expression accelerated vascular fibrosis in TAK, which was likely mediated by promoting FAO in AAFs.

Application progress of multiple imaging modalities in Takayasu arteritis

Takayasu arteritis (TA) is a chronic, idiopathic, granulomatous large vessel vasculitis of unknown etiology. The clinical manifestations of TA are incredibly variable, mainly depending on the location of the lesions. In the light of its insidious progress and the diversity of clinical manifestations, a substantial proportion of patients might experience a considerable delay in diagnosis, which leads to irreversible malignant complications, highlighting the importance of early diagnosis. There has been accumulating evidence that early identification of disease is pivotal to initiate timely therapy and ameliorate the prognosis. Therefore, this review discusses and summarizes the latest evidence on the application progress of multiple imaging modalities.

Multimodality Imaging of Large Vessel Vasculitis, From the AJR Special Series on Inflammation

Large vessel vasculitis (LVV) is a non-infectious inflammation of the large vessels, including the aorta and its main branches. Imaging plays an essential role in diagnosing LVV, given the challenges of tissue biopsy. This article reviews the types of LVV, and the multimodality imaging tools available to establish the diagnosis in patients with LVV. The cornerstone of imaging diagnosis is morphologic assessment using grey-scale ultrasound, combined grey-scale US with color Doppler US, CTA, or MRA. In the last decade, substantial progress has been made in functional and molecular imaging with FDG PET/CT for the diagnosis of LVV. Investigation is ongoing to develop novel MRA techniques and new PET tracers to assess disease activity and to differentiate the various vasculitides. An algorithm is provided to guide imaging technique selection based on the patient's specific clinical presentation.

Effect of hydroxychloroquine on angiographic progression in routine treatment of Takayasu arteritis

OBJECTIVES

Hydroxychloroquine (HCQ), an anti-malarial drug, is widely used in the treatment of rheumatic diseases. However, the benefits of HCQ in the treatment of Takayasu arteritis (TA) remain unclear, especially in terms of alleviation of vascular progression.

METHODS

This longitudinal observational retrospective study was based on the East China TA cohort. Patients received routine treatment with prednisone and immunosuppressants. Fifty TA patients who underwent magnetic resonance angiography two times within a 1.5-year follow-up period of monitoring vascular changes were divided into HCQ and non-HCQ groups according to whether HCQ was prescribed. Changes in angiographic features were compared. Multivariate Cox regression analysis was employed to further validate the results.

RESULTS

Of 50 TA patients, 21 were prescribed HCQ. The two groups shared a similar disease course, vascular types, prednisone with immunosuppressants intervention strategy, globin level, and disease remission rate at 6 months. The HCQ group showed greater reduction in the inflammatory indices erythrocyte sedimentation rate and C-reactive protein (CRP) level (p < .05), and a significantly lower incidence of angiographic progression than the non-HCQ group (19.0% vs. 51.7%, p = .035). After adjustment for age and usage of tocilizumab, angiographic progression was found to be independently associated with CRP (hazard ratio [95% confidence interval], HR [95% CI]: 1.102 [1.000-1.024], p = .046), and the usage of HCQ (HR [95% CI]: 0.266 [0.075-0.940], p = .040).

CONCLUSION

HCQ enhanced the anti-inflammatory effect of routine treatment strategies with prednisone and immunosuppressants, and alleviated angiographic progression in TA.

Efficacy and safety of leflunomide versus cyclophosphamide for initial-onset Takayasu arteritis: a prospective cohort study

BACKGROUND

Leflunomide (LEF) has been considered as an alternative treatment for Takayasu arteritis (TA); however, data on its efficacy are still scanty.

OBJECTIVE

To investigate the efficacy and safety of LEF versus cyclophosphamide (CYC) for initial-onset TA.

METHODS

Initial-onset TA patients with active disease were enrolled in this research. Patients enrolled from 1 January 2009 to 31 December 2015 were treated with glucocorticoids and CYC, while patients enrolled from 1 January 2016 to 31 October 2018 received glucocorticoids and LEF. Treatment response including complete remission (CR), partial remission (PR), and effectiveness rate (ER) and side effects were evaluated at 6 and 12 months.

RESULTS AND CONCLUSION

In total, 92 patients were enrolled. A total of 47 patients were treated with LEF, while 45 patients were treated with CYC. The CR and ER rates were 75.55%, and 88.89% at 6 months, and 85.37% and 95.12% at 12 months in the LEF group. The CR and ER rates were 39.02% and 70.73% at 6 months, and 56.41% and 82.05% at 12 months in the CYC group. The CR rate was significantly higher in the LEF group than in the CYC group both at 6 months (75.61% versus 38.24%, p < 0.01) and 12 months (77.42% versus 53.33%, p < 0.05) after adjustment for propensity scores. The incidence of side effects in the LEF group was much lower than that in the CYC group (21.28% versus 44.44%). In conclusion, LEF provided a better treatment response, along with lower reproductive toxicity, compared with CYC in initial-onset TA.

Fully integrated 18F-FDG PET/MR in large vessel vasculitis

BACKGROUND

To evaluate the usefulness of [18F] fluorodeoxyglucose (FDG) positron emission tomography (PET)/magnetic resonance (MR) in large vessels vasculitis (LVV) patients.

METHODS

We performed an observational retrospective study based on our records. Images were acquired on a PET/MR scanner using 18F-FDG-PET whole body imaging. For each PET scan, a qualitative analysis and a semi-quantitative measure using the maximum of the standardized uptake value (SUVMax) were performed. SUVMax measurements normalized to the liver uptake were categorized using a grading scale. Vessel's wall thickness (WT) was measured at five fixed points (inferior margin of T5, T9, T12, L3, thickest area-max WT).

RESULTS

23 LVV patients were included, 56.5% giant cells arteritis, 34.8% Takayasu's arteritis and 8.7% isolated aortitis, all Caucasian, mostly females (82%). We considered 32 PET scans for the LVV group (from min. 1 to max. 3 scans/patient) mainly during follow-up (29/32 scans), and 23 PET scans from a control group of non-metastatic malignancies patients. We found higher SUVMax compared to controls, in all sites, irrespective of clinical disease activity. Mean WT resulted higher in patients than in controls but was not correlated to SUVMax. Mean WT positively correlated with age in both cohorts, inversely correlated to disease duration, while no correlation with SUVMax was observed. The concordance between clinically active disease and PET hypermetabolism was poor (K Cohen 0.33).

CONCLUSIONS

PET/MR is a safe imaging technique capable of detecting inflammation in aortic wall. Low radiological exposure of PET/MR should be considered especially in young women receiving follow-up studies.

EULAR recommendations for the use of imaging in large vessel vasculitis in clinical practice summary

Large vessel vasculitis (LVV) is the most common form of primary vasculitis comprising of giant cell arteritis (GCA), Takayasu's arteritis (TAK) and idiopathic aortitis. Early diagnosis and treatment of LVV are paramount to reduce the risk of ischemic complications such as visual loss and strokes, vascular stenosis and occlusion, and aortic aneurysm formation. Use of imaging modalities [ultrasound (US), magnetic resonance imaging (MRI), computed tomography (CT) and [18F]-fluorodeoxyglucose positron emission tomography (PET)] has steadily increased to enable assessment of cranial and extracranial arteries, as well as the aorta. These imaging modalities are less invasive, more sensitive and readily available compared to temporal artery biopsy (TAB). Modern imaging methods have changed the role of TAB in diagnosing GCA and have replaced diagnostic angiography. Over the last two decades, several studies have evaluated the use of US, MRI, CT and PET in LVV. However, these various imaging tools are not yet uniformly used in routine clinical practice and controversy exists as to which imaging modality best provides meaningful assessments of disease activity and damage in LVV. In January 2018, evidence-based recommendations for the use of imaging modalities in LVV were published. The aim of this review is to summarize the current evidence of imaging in patients with or suspected of having LVV, and to highlight the clinical implications of the EULAR recommendations.

Childhood-Onset Takayasu Arteritis (c-TA): Current and Future Drug Therapy

Childhood-onset Takayasu arteritis (c-TA) is the third most common systemic vasculitic disorder in children. Vascular stenosis is the main complication, and aneurysms are reported in 19-65% of cases, often in combination with stenotic lesions. Management of patients with c-TA is largely based on studies involving predominantly patients with adult-onset TA (a-TA). More widely used criteria for patients with c-TA have been devised by the joint European League Against Rheumatism, Pediatric Rheumatology International Trials Organization, and Pediatric Rheumatology European Society. Of the available imaging modalities, those that do not use radiation (color Doppler ultrasound and magnetic resonance angiogram) are preferred over ¹⁸F-labeled fluoro-2-deoxyglucose (¹⁸F-FDG) positron-emission tomography, computed tomography (CT), and CT angiogram in children. Remission rates have been reported to be lower in c-TA than in a-TA, and published mortality rates in c-TA range from 16 to 40%, which is much higher than reported in patients with a-TA. The usual drug therapy options include steroids plus steroid-sparing second-line immunosuppressants, such as mycophenolate, azathioprine, methotrexate, cyclophosphamide, and cyclosporine, along with antiplatelet agents. Interleukin-6 inhibitors such as tocilizumab, as well as the tumor necrosis factor inhibitors, are other aggressive therapeutic options. As yet, no randomized controlled trials have been conducted in c-TA.

Contrast-enhanced Ultrasonography for Monitoring Arterial Inflammation in Takayasu Arteritis

OBJECTIVE

To evaluate the utility of contrast-enhanced ultrasound (CEUS) compared with 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) in assessing vessel inflammation of Takayasu arteritis (TA).

METHODS

This is a retrospective analysis of 71 patients with TA who had undergone carotid CEUS. Twenty-two of 71 patients underwent FDG-PET after CEUS. Clinical disease activity was assessed by Kerr criteria and the Indian Takayasu Clinical Activity Score 2010 (ITAS2010). We investigated the correlation between carotid vascularization on CEUS and clinical data. The consistency of carotid CEUS and PET data has been analyzed for TA disease activity.

RESULTS

There was a statistically significant correlation between the results of CEUS and ITAS2010 (p = 0.004) or Kerr criteria (p < 0.001). According to ITAS2010, thirty-four of 71 patients with TA were clinically inactive. Assessment of 34 TA patients with clinically inactive disease yielded 11 CEUS scans that showed active lesions (visual grade ≥ 2) in the left or right carotid artery. In 22 cases that underwent CEUS and FDG-PET, 12 were active and 10 were inactive on the basis of ITAS2010. Moreover, bilateral carotid CEUS vascularization score positively correlated with vascular FDG uptake in these patients with TA (p = 0.004). When vascular inflammation was defined as FDG uptake with visual grade ≥ 2, carotid CEUS showed sensitivity of 100% and specificity of 80%.

CONCLUSION

For TA patients with clinically inactive disease, CEUS could help clinicians to identify active lesions in the carotid vascular region. Carotid CEUS may be a rapid and cost-effective imaging tool in the followup of patients with TA.

Imaging in diagnosis, outcome prediction and monitoring of large vessel vasculitis: a systematic literature review and meta-analysis informing the EULAR recommendations

Objectives

To perform a systematic literature review on imaging techniques for diagnosis, outcome prediction and disease monitoring in large vessel vasculitis (LVV) informing the European League Against Rheumatism recommendations for imaging in LVV.

Methods

Systematic literature review (until 10 March 2017) of diagnostic and prognostic studies enrolling >20 patients and investigating ultrasound, MRI, CT or positron emission tomography (PET) in patients with suspected and/or established primary LVV. Meta-analyses were conducted, whenever possible, obtaining pooled estimates for sensitivity and specificity by fitting random effects models.

Results

Forty-three studies were included (39 on giant cell arteritis (GCA), 4 on Takayasu arteritis (TAK)). Ultrasound ('halo' sign) at temporal arteries (8 studies, 605 patients) and MRI of cranial arteries (6 studies, 509 patients) yielded pooled sensitivities of 77% (95% CI 62% to 87%) and 73% (95% CI 57% to 85%), respectively, compared with a clinical diagnosis of GCA. Corresponding specificities were 96% (95% CI 85% to 99%) and 88% (95% CI 81% to 92%). Two studies (93 patients) investigating PET for GCA diagnosis reported sensitivities of 67%-77% and specificities of 66%-100% as compared with clinical diagnosis or temporal artery biopsy. In TAK, one study each evaluated the role of magnetic resonance angiography and CT angiography for diagnostic purposes revealing both a sensitivity and specificity of 100%. Studies on outcome prediction and monitoring disease activity/damage were limited and mainly descriptive.

Conclusions

Ultrasound and MRI provide a high diagnostic value for cranial GCA. More data on the role of imaging for diagnosis of extracranial large vessel GCA and TAK, as well as for outcome prediction and monitoring in LVV are warranted.

Imaging in Giant Cell Arteritis

Much progress has been made in the use of imaging as a diagnostic tool in giant cell arteritis (GCA), which assists in the management of patients where the initial diagnosis is unclear. This includes patients with atypical cranial symptoms, or with predominantly systemic, constitutional or limb symptoms. Ultrasound and magnetic resonance imaging are capable of visualising both the cranial and extracranial large vessel circulation, with vessel wall thickening and stenotic lesions being visualised. Computed tomographic angiography is helpful in visualising the aorta for aneurysm complicating GCA but can also detect vessel wall thickening in established large vessel vasculitis. PET-CT is a very sensitive test for early vascular inflammation in extracranial large vessel vasculitis, before aneurysmal or stenotic lesions have developed, of use in the patient with unexplained constitutional symptoms. The place of imaging in the follow-up of GCA is being investigated, and repeated imaging may be useful in select cases. Generally, vascular abnormalities become less defined once glucocorticoid treatment has been started, and therefore, imaging studies must be conducted early as part of a GCA fast-track assessment.