The effectiveness of tocilizumab and its comparison with tumor necrosis factor alpha inhibitors for Takayasu Arteritis: A systematic review and meta-analysis

Association between premature vascular smooth muscle cells senescence and vascular inflammation in Takayasu's arteritis

OBJECTIVES

Arterial wall inflammation and remodelling are the characteristic features of Takayasu's arteritis (TAK). It has been proposed that vascular smooth muscle cells (VSMCs) are the main targeted cells of inflammatory damage and participate in arterial remodelling in TAK. Whether VSMCs are actively involved in arterial wall inflammation has not been elucidated. Studies have shown that cellular senescence in tissue is closely related to local inflammation persistence. We aimed to investigate whether VSMCs senescence contributes to vascular inflammation and the prosenescent factors in TAK.

METHODS

VSMCs senescence and senescence-associated secretory phenotype were detected by histological examination, bulk RNA-Seq and single-cell RNA-seq conducted on vascular surgery samples of TAK patients. The key prosenescent factors and the downstream signalling pathway were investigated in a series of in vitro and ex vivo experiments.

RESULTS

Histological findings, primary cell culture and transcriptomic analyses demonstrated that VSMCs of TAK patients had the features of premature senescence and contributed substantially to vascular inflammation by upregulating the expression of senescence-associated inflammatory cytokines. IL-6 was found to be the critical cytokine that drove VSMCs senescence and senescence-associated mitochondrial dysfunction in TAK. Mechanistically, IL-6-induced non-canonical mitochondrial localisation of phosphorylated STAT3 (Tyr705) prevented mitofusin 2 (MFN2) from proteasomal degradation, and subsequently promoted senescence-associated mitochondrial dysfunction and VSMCs senescence. Mitochondrial STAT3 or MFN2 inhibition ameliorated VSMCs senescence in ex vivo cultured arteries of TAK patients.

CONCLUSIONS

VSMCs present features of cellular senescence and are actively involved in vascular inflammation in TAK. Vascular IL-6-mitochondrial STAT3-MFN2 signalling is an important driver of VSMCs senescence.

EULAR recommendations for the use of imaging in large vessel vasculitis in clinical practice: 2023 update

OBJECTIVES

To update the EULAR recommendations for the use of imaging modalities in primary large vessel vasculitis (LVV).

METHODS

A systematic literature review update was performed to retrieve new evidence on ultrasound, MRI, CT and [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) for diagnosis, monitoring and outcome prediction in LVV. The task force consisted of 24 physicians, health professionals and patients from 14 countries. The recommendations were updated based on evidence and expert opinion, iterating until voting indicated consensus. The level of agreement was determined by anonymous votes.

RESULTS

Three overarching principles and eight recommendations were agreed. Compared to the 2018 version, ultrasound is now recommended as first-line imaging test in all patients with suspected giant cell arteritis, and axillary arteries should be included in the standard examination. As an alternative to ultrasound, cranial and extracranial arteries can be examined by FDG-PET or MRI. For Takayasu arteritis, MRI is the preferred imaging modality; FDG-PET, CT or ultrasound are alternatives. Although imaging is not routinely recommended for follow-up, ultrasound, FDG-PET or MRI may be used for assessing vessel abnormalities in LVV patients with suspected relapse, particularly when laboratory markers of inflammation are unreliable. MR-angiography, CT-angiography or ultrasound may be used for long-term monitoring of structural damage, particularly at sites of preceding vascular inflammation.

CONCLUSIONS

The 2023 EULAR recommendations provide up-to-date guidance for the role of imaging in the diagnosis and assessment of patients with LVV.

Pediatric-onset Takayasu arteritis is associated with greater risk of mortality than adult-onset Takayasu arteritis-A systematic review with meta-analysis of observational cohort studies

A subset of Takayasu arteritis (TAK) has onset in the pediatric age group (≤18 years). The differences in mortality between pediatric-onset and adult-onset TAK are unclear. Therefore, we undertook a systematic review with meta-analysis to compare mortality risk in pediatric-onset with adult-onset TAK. Scopus, Pubmed (MEDLINE and Pubmed Central), recent conference abstracts, clinicaltrials.gov, and the Cochrane database were searched up to August 2023 for relevant studies. Five studies (all of moderate or high quality on the Newcastle Ottawa scale) were identified which had compared mortality between 151 pediatric-onset and 499 adult-onset TAK. Pediatric-onset TAK was associated with a significantly higher risk of death than adult-onset TAK (pooled risk ratio 2.27, 95% confidence interval 1.05 - 4.85, I2=0%). Cardiovascular disease and infections were the major causes of death in both pediatric-onset and adult-onset TAK. Sub-group analyses identified a greater mortality risk with pediatric-onset TAK in retrospective (but not prospective) studies and in studies of high quality (but not in those of moderate quality). Meta-regression did not reveal a significant influence of differences in sex distribution or age or the proportions of patients with pediatric-onset or adult-onset TAK on the pooled mortality risk. An increased mortality risk with pediatric-onset TAK on meta-analysis is consistent with more frequent severe organ manifestations of pediatric-onset TAK (heart failure, renal failure) when compared with adult-onset TAK. Future studies should systematically evaluate differences in the pathogenesis between pediatric-onset and adult-onset to understand the reasons for such observed differences in the mortality risk.

Effectiveness and safety of adalimumab compared with leflunomide in patients with Takayasu arteritis: a retrospective cohort study

OBJECTIVE

This study aims to evaluate the effectiveness and safety of adalimumab (ADA) compared with leflunomide (LEF) in patients with Takayasu arteritis (TAK).

METHOD

A retrospective cohort study was performed with the following inclusion criteria: the fulfilment of the 2022 American College Classification/European Alliance of Associations for Rheumatology criteria for TAK, age ≥18 years, and written informed consent. Forty-four patients were treated with LEF (n=28) or ADA (n=16) therapy due to relapsing/refractory disease or toxicity from previous therapy. Patients were evaluated at baseline (T0), at a median of 7.0 months (T1) and at 15.0 months of follow-up (T2). Data regarding disease activity, daily dose of prednisone, side effects and angiographic progression were analysed.

RESULTS

LEF and ADA groups had similar features on the baseline visit. However, intravenous methylprednisolone was more frequently prescribed for the ADA group (p=0.019). On T1 and T2 visits, complete response rates were similar for ADA and LEF groups (75.0% and 88.5%; p=0.397 and 62.5% vs 78.3%; p=0.307), respectively. The differences remained non-significant after adjusting for baseline variables by propensity score matching. Although the ADA group had a higher median daily prednisone on visit T1 (p=0.004), it was similar on visit T2 (p=0.595). Similar rates of angiographic progression were observed in ADA and LEF groups (40% vs 25%; p=0.467). Mild-to-moderate adverse events were observed only in the LEF group (17.9%).

CONCLUSION

LEF and ADA had comparable outcomes after a median of 15.0 months of follow-up. However, withdrawal from therapy and mild-to-moderate adverse events were only observed in the LEF group.

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.

New Therapeutic Approaches to Large-Vessel Vasculitis

Giant cell arteritis (GCA) and Takayasu arteritis (TAK) are large-vessel vasculitides affecting the aorta and its branches. Arterial damage from these diseases may result in ischemic complications, aneurysms, and dissections. Despite their similarities, the management of GCA and TAK differs. Glucocorticoids are used frequently but relapses are common, and glucocorticoid toxicity contributes to significant morbidity. Conventional immunosuppressive therapies can be beneficial in TAK, though their role in the management of GCA remains unclear. Tumor necrosis factor inhibitors improve remission rates and appear to limit vascular damage in TAK; these agents are not beneficial in GCA. Tocilizumab is the first biologic glucocorticoid-sparing agent approved for use in GCA and also appears to be effective in TAK. A better understanding of the pathogenesis of both conditions and the availability of targeted therapies hold much promise for future management.

Arterial wall fibrosis in Takayasu arteritis and its potential for therapeutic modulation

Arterial wall damage in Takayasu arteritis (TAK) can progress despite immunosuppressive therapy. Vascular fibrosis is more prominent in TAK than in giant cell arteritis (GCA). The inflamed arterial wall in TAK is infiltrated by M1 macrophages [which secrete interleukin-6 (IL-6)], which transition to M2 macrophages once the inflammation settles. M2 macrophages secrete transforming growth factor beta (TGF-β) and glycoprotein non-metastatic melanoma protein B (GPNMB), both of which can activate fibroblasts in the arterial wall adventitia. Mast cells in the arterial wall of TAK also activate resting adventitial fibroblasts. Th17 lymphocytes play a role in both TAK and GCA. Sub-populations of Th17 lymphocytes, Th17.1 lymphocytes [which secrete interferon gamma (IFN-γ) in addition to interleukin-17 (IL-17)] and programmed cell death 1 (PD1)-expressing Th17 (which secrete TGF-β), have been described in TAK but not in GCA. IL-6 and IL-17 also drive fibroblast activation in the arterial wall. The Th17 and Th1 lymphocytes in TAK demonstrate an activation of mammalian target organ of rapamycin 1 (mTORC1) driven by Notch-1 upregulation. A recent study reported that the enhanced liver fibrosis score (derived from serum hyaluronic acid, tissue inhibitor of metalloproteinase 1, and pro-collagen III amino-terminal pro-peptide) had a moderate-to-strong correlation with clinically assessed and angiographically assessed vascular damage. In vitro experiments suggest the potential to target arterial wall fibrosis in TAK with leflunomide, tofacitinib, baricitinib, or mTORC1 inhibitors. Since arterial wall inflammation is followed by fibrosis, a strategy of combining immunosuppressive agents with drugs that have an antifibrotic effect merits exploration in future clinical trials of TAK.

Management of Takayasu arteritis

This review overviews the challenges in the assessment of disease activity, damage, and therapy of Takayasu arteritis (TAK). Recently developed disease activity scores for TAK are more useful for follow-up visits and require validation of cut-offs for active disease. A validated damage score for TAK is lacking. Computed tomography angiography (CTA), magnetic resonance angiography (MRA), and ultrasound enable the evaluation of vascular anatomy and arterial wall characteristics of TAK. 18-fluorodeoxyglucose (18-FDG) positron emission tomography (PET) visualizes arterial wall metabolic activity and complements the information provided by circulating C-reactive protein (CRP) levels. ESR and CRP alone moderately reflect TAK disease activity. TAK is corticosteroid-responsive but relapses upon tapering corticosteroids. Conventional synthetic disease-modifying anti-rheumatic drugs (DMARDs) are the first-line maintenance agents, and tumor necrosis factor-alpha inhibitors, tocilizumab, or tofacitinib are second-line agents for TAK. Revascularization procedures for TAK should be used judiciously during periods of inactive disease.