Efficacy and safety of tofacitinib versus leflunomide with glucocorticoids treatment in Takayasu arteritis: A prospective study

Difficult-to-treat Takayasu arteritis: a case-based review

Takayasu arteritis is a rare chronic inflammatory large vessel vasculitis which affects the aorta and its large branches. The diagnosis is based on the 2022 ACR/EULAR classification criteria for Takayasu arteritis. The management of this vasculitis is challenging. Although it is corticosteroid-responsive, relapses and disease progression are common. Thus, it is possible to resort to alternative conventional synthetic disease-modifying anti-rheumatic drugs and biologics, as second-line such as tumor necrosis factor-alpha inhibitors, tocilizumab, or JAK inhibitors as second-line agents is possible. Nevertheless, in some complex cases, the vasculitis remains active despite different proposed therapeutic lines, and a multitarget approach could induce sustained remission. We report herewith a case of 33-female patient with a refractory Takayasu arteritis which remained active after three different therapeutic lines with tocilizumab, then infliximab, then Upadacitinib. Finally, we consider a successful multitarget approach with a combination of infliximab, Upadacitinib, and methotrexate.

Current Immunosuppressive Treatment for Takayasu Arteritis

Takayasu arteritis (TAK) is a rare disease characterized by inflammation of large blood vessels, which results in vascular stenosis, occlusion, and aneurysm formation. The principal treatment has been glucocorticoids, but the recent emergence of biological disease-modifying anti-rheumatic drugs (bDMARDs), represented by tocilizumab (TCZ), has significantly changed the treatment landscape. Both cardiologists and cardiovascular surgeons will encounter patients receiving these drugs who require catheterization, other invasive procedures, or surgery. Several bDMARDs have shown promise against TAK in clinical studies and their use is expected to increase in the future. Janus kinase inhibitors may also be effective. Here, we review the evidence supporting the use of TCZ and other immunosuppressants in TAK and provides an update on their status as well as the relevant guidelines.

[News on the treatment of large vessel vasculitis]

Large vessel vasculitis, such as giant cell arteritis (GCA) and Takayasu arteritis (TAK) are primarily manifested on large and medium-sized arteries. While GCA mainly affects older people after the 6th decade of life onwards, TAK mainly affects young women under the age of 40 years. Glucocorticoids (GC) are still the standard treatment for both diseases. Refractory courses and relapses in particular often lead to long-term treatment with high cumulative doses of GC, which can lead to increased morbidity and mortality. To date, only the interleukin 6 (IL-6) receptor blocker tocilizumab has been approved for the treatment of GCA. The data on methotrexate and other conventional immunosuppressants are incomplete and in some cases contradictory. The early use of steroid-sparing immunosuppressants is recommended for TAK, although the number of randomized placebo-controlled trials is limited and no steroid-sparing treatment has yet been approved for TAK. For both diseases there is still a great need for modern and safe steroid-sparing treatment that effectively treats vasculitis, prevents damage and enables adequate disease monitoring. This article provides an overview of the current study situation and possible future treatment options for GCA and TAK.

Pro-fibrotic effect of the susceptible gene PCSK5 in vascular fibrosis of Takayasu arteritis via TGF-β and SMAD3 signaling pathway activation

BACKGROUND

Vascular fibrosis directly causes vascular thickening in Takayasu arteritis (TAK), in which sustained transforming growth factor beta (TGF-β) activation is critical. Understanding TGF-β activation regulation and blocking it might yield a therapeutic effect in TAK. Proprotein convertase subtilisin/kexin type 5 (PCSK5) rs6560480 (T/C) is associated with TAK development. In this study, we assessed the association between the PCSK5 rs6560480 genotype and PCSK5 expression in TAK and explored its molecular role in TGF-β activation and vascular fibrosis development.

METHODS

In TAK patients, PCSK5 and TGF-β expression in plasma and aortic tissue was examined by ELISA and immunohistochemical staining, and PCSK5 rs6560480 was genotyped. The correlation between PCSK5 and extracellular matrix (ECM) expression was examined by Western blotting (WB) and immunohistochemistry staining. Detection by co-immunoprecipitation was performed to detect the interaction between PCSK5 and TGF-β in adventitial fibroblasts (AAFs). Downstream signaling pathways were detected by WB and validated with appropriate inhibitors. Potential immunosuppressive agents to inhibit the effects of PCSK5 were explored in cell culture and TAK patients.

RESULTS

Patients with PCSK5 rs6560480 TT patients had significantly higher PCSK5 levels and more thickened vascular lesions than patients with PCSK5 rs6560480 CT. PCSK5 expression was significantly increased in alpha smooth muscle actin (α-SMA)-positive myofibroblasts in TAK vascular lesions. Overexpressing PCSK5 facilitated TGF-β and downstream SMAD2/3 activation and ECM expression in AAFs and aorta in in-vitro culture. The mechanistic study supported that PCSK5 activated precursor TGF-β (pro-TGF-β) to the mature form by binding the pro-TGF-β cleavage site. Leflunomide inhibited PCSK5 and pro-TGF-β binding, decreasing TGF-β activation and ECM expression, which was also partially validated in leflunomide-treated patients.

CONCLUSION

The findings revealed a novel pro-fibrotic mechanism of PCSK5 in TAK vascular fibrosis via TGF-β and downstream SMAD2/3 pathway activation. Leflunomide might be anti-fibrotic by disrupting PCSK5 and pro-TGF-β binding, presenting a new TAK treatment approach.

A Glimpse into Humoral Response and Related Therapeutic Approaches of Takayasu's Arteritis

Takayasu's arteritis (TAK) manifests as an insidiously progressive and debilitating form of granulomatous inflammation including the aorta and its major branches. The precise etiology of TAK remains elusive, with current understanding suggesting an autoimmune origin primarily driven by T cells. Notably, a growing body of evidence bears testimony to the widespread effects of B cells on disease pathogenesis and progression. Distinct alterations in peripheral B cell subsets have been described in individuals with TAK. Advancements in technology have facilitated the identification of novel autoantibodies in TAK. Moreover, emerging data suggest that dysregulated signaling cascades downstream of B cell receptor families, including interactions with innate pattern recognition receptors such as toll-like receptors, as well as co-stimulatory molecules like CD40, CD80 and CD86, may result in the selection and proliferation of autoreactive B cell clones in TAK. Additionally, ectopic lymphoid neogenesis within the aortic wall of TAK patients exhibits functional characteristics. In recent decades, therapeutic interventions targeting B cells, notably utilizing the anti-CD20 monoclonal antibody rituximab, have demonstrated efficacy in TAK. Despite the importance of the humoral immune response, a systematic understanding of how autoreactive B cells contribute to the pathogenic process is still lacking. This review provides a comprehensive overview of the biological significance of B cell-mediated autoimmunity in TAK pathogenesis, as well as insights into therapeutic strategies targeting the humoral response. Furthermore, it examines the roles of T-helper and T follicular helper cells in humoral immunity and their potential contributions to disease mechanisms. We believe that further identification of the pathogenic role of autoimmune B cells and the underlying regulation system will lead to deeper personalized management of TAK patients. We believe that further elucidation of the pathogenic role of autoimmune B cells and the underlying regulatory mechanisms holds promise for the development of personalized approaches to managing TAK patients.

Treatment efficacy and safety of adalimumab versus tocilizumab in patients with active and severe Takayasu arteritis: an open-label study

OBJECTIVE

This study aimed to compare the efficacy and safety of adalimumab (ADA) vs tocilizumab (TCZ) in patients with Takayasu arteritis (TAK).

METHODS

This was a randomized, controlled, open-label study. Forty patients with active and severe TAK were enrolled. They were treated with ADA (n = 21) combined with glucocorticoids (GCs) and MTX or TCZ (n = 19) combined with GCs and MTX. The planned follow-up duration was 12 months. The primary end point was the efficacy rate (ER) at 6 months. The secondary end points included ER at 9 and 12 months, relapse rate, GC tapering, adverse effects, and life quality changes during treatment.

RESULTS

In the intention-to-treat (ITT) population, the ER at 6 months was higher in the ADA group (85.71% vs 52.63%, P = 0.02). A similar direction of effect was noted in the per-protocol set (89.47% vs 62.50%, P = 0.06). The percentages of patients who achieved a GC dose of ≤10 mg/day at 6 months were similar between the ADA and TCZ groups (47.37% vs 43.75%, P = 0.83). The ERs at 9 and 12 months were similar between the two groups (P > 0.05). During the first 12 months of treatment, the relapse rate and adverse event incidence were comparable between the two groups (ADA vs TCZ: 9.52% vs 10.53%, P = 0.96; 38.10% vs 47.37%, P = 0.55, respectively).

CONCLUSION

ADA combined with GCs and MTX may be more efficacious than TCZ combined with GCs and MTX among patients with active and severe TAK.

TRIAL REGISTRATION

Clinicaltrials.gov; NCT04300686.

Baricitinib for refractory Takayasu arteritis: a prospective cohort study in a tertiary referral centre

OBJECTIVE

To investigate the treatment efficacy and safety of baricitinib in patients with refractory Takayasu arteritis (TAK).

METHODS

We performed a prospective cohort study in which baricitinib 4 mg daily was prescribed to patients with refractory TAK, combined with oral glucocorticoids (GCs).

RESULTS

10 patients with refractory TAK were enrolled with a median age of 28 (IQR=22-37) years, median disease duration of 50 (IQR=24-65) months. The median dose of GCs was 10 (IQR=8.1-22.5) mg prednisone or equivalence dosage at baseline. At 6 months of baricitinib treatment, 6/10 (60%) patients had an overall treatment response. During an average follow-up of 15.3 (range 4-31) months, 4/10 (40%) patients maintained overall treatment response. 8/10 (80%) patients tapered or maintained the same dose of GCs with no change of the combined classical synthetic disease-modifying antirheumatic drugs. Two patients discontinued GCs at 18 and 24 months and were in continuous remission till the end of the study. One patient withdrew baricitinib due to liver dysfunction.

CONCLUSION

Baricitinib 4 mg daily is effective for refractory TAK and is well tolerated.

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.

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.

Advances and challenges in management of large vessel vasculitis

Glucocorticoids (GC) remains the mainstay for management of large vessel vasculitis (LVV). Recent introduction of interleukin-6 signaling blocker, tocilizumab has substantially changed the practice in management of patients with LVV, in particular, giant cell arteritis (GCA). Benefit of tocilizumab to patients with Takayasu arteritis (TAK) is supported by observational studies, but randomized clinical trials are lacking. Addition of tocilizumab enables reduction of the total amount of GC in patients with GCA, but GC burden remains high and to be further reduced. Ongoing studies aim at minimal use of GC or even GC-free. Tumor necrosis factor inhibitors appear to be beneficial to TAK despite their ineffectiveness to GCA. Randomized clinical trials are undergoing to target other inflammatory cytokines in both GCA and TAK. Janus kinase inhibitors alone or in combination with conventional disease modifying anti-rheumatic drugs showed promising results in treatment of TAK.

Efficacy and safety of leflunomide in the management of large vessel vasculitis: A systematic review and metaanalysis of cohort studies

OBJECTIVE

The search for new glucocorticoid-sparing disease-modifying anti-rheumatic drugs continues to be an unmet need in large vessel vasculitis (LVV). This report aims to assess the effectiveness and safety of leflunomide (LEF) in Takayasu arteritis (TA) and giant cell arteritis (GCA).

METHODS

We systematically reviewed the literature, searching for studies evaluating the efficacy of LEF in LVV. A meta-analysis was conducted using the random-effects method.

RESULTS

The literature search identified eight studies that assessed LEF in TAK and seven in GCA. All were uncontrolled observational studies with a high risk of bias, implying a low or very-low certainty of evidence. In TAK, the pooled proportion of patients achieving at least a partial remission was 75% (95% CI: 0.64-0.84), angiographic stabilization was observed in 86% (0.77-0.94) and relapses in 12% (0.05-0.21). The mean reduction in the prednisolone dose (MRPD) after LEF treatment was 15.7 mg/d (10.28-21.16). Adverse events were observed in 8% of patients (0.02-0.16). Comparison of LEF with methotrexate (MTX) or cyclophosphamide revealed LEF to be superior in terms of remission induction, relapse prevention, and tolerance. When compared with tofacitinib, both drugs demonstrated comparable efficacy. In GCA, the pooled proportion of patients achieving at least a partial remission was 60% (0.17-0.95). The MRPD after LEF treatment was 15.63 mg/d (1.29-32.55) and 53% of the patients were able to discontinue glucocorticoids (0.25 - 0.80). Relapses were observed in 21% of cases (0.14- 0.28) and adverse events in 28% (0.12-0.46). Comparison of LEF with MTX showed similar efficacy and tolerance.

CONCLUSION

LEF is well tolerated and might be effective for patients with TAK and GCA.

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.

Leflunomide: Traditional immunosuppressant with concurrent antiviral effects

Leflunomide is a classic disease-modifying anti-rheumatic drug that is widely used to treat autoimmune diseases. Studies also show its antiviral effects in in vitro and/or in vivo experiments. Considering glucocorticoids, immunosuppressants and newly emerged antibodies commonly used in autoimmune diseases and autoinflammatory disorders bring risk of infection such as viral infection, leflunomide with combination of anti-viral and immunosuppressive features to maintain the balance between infection and anti-inflammation are attractive. Here we summarize the actions and mechanisms of leflunomide in immunoregulatory and antiviral effects.

Diagnostik und Therapie der Großgefäßvaskulitiden – Wo stehen wir aktuell?

Die beiden Großgefäßvaskulitiden unterscheiden sich in mehrfacher Hinsicht, vor allem aber durch das Alter der betroffenen Patienten bei Erstmanifestation. Die Riesenzellarteriitis (RZA) ist eine Erkrankung des älteren Patienten wohingegen die Takayasu Arteriitis per definitionem vor dem 40 Lebensjahr auftritt. Die Diagnosen sind in den letzten Jahren durch verbesserte Bildgebung und Therapieoptionen mehr ins Bewusstsein gerückt. Neben der klassischen Steroidtherapie – welche bis heute Mittel der ersten Wahl ist – steht uns mit Tocilizumab, einem monoklonalen Antikörper gegen IL6-Rezeptor, zumindest für die RZA, eine zusätzliche hocheffektive Therapie zur Verfügung. Andere vielversprechende Substanzen befinden sich derzeit in Erprobung. Dieser Artikel soll einen Überblick zu Diagnostik und Therapie, aber auch einen Ausblick zu möglicherweise kommenden medikamentösen Optionen bieten.

Presentation and clinical course of pediatric-onset versus adult-onset Takayasu arteritis-a systematic review and meta-analysis

Takayasu arteritis (TAK) is a less common large-vessel vasculitis which can occur in either children or adults. However, differences between pediatric-onset and adult-onset TAK have not been systematically analyzed. We undertook a systematic review (pre-registered on PROSPERO, identifier CRD42022300238) to analyze differences in clinical presentation, angiographic involvement, treatments, and outcomes between pediatric-onset and adult-onset TAK. We searched PubMed (MEDLINE and PubMed Central), Scopus, major recent international rheumatology conference abstracts, Cochrane database, and clinicaltrials.gov, and identified seven studies of moderate to high quality comparing pediatric-onset and adult-onset TAK. Meta-analysis of 263 pediatric-onset and 981 adult-onset TAK suggested that constitutional features (fever, and in subgroup analyses, weight loss), hypertension, headache, and sinister features of cardiomyopathy, elevated serum creatinine, and abdominal pain were more frequent in pediatric-onset TAK, whereas pulse loss/pulse deficit and claudication (particularly upper limb claudication) were more frequent in adult-onset TAK. Hata's type IV TAK was more common in pediatric-onset TAK, and Hata's type I TAK in adult-onset TAK. Children with TAK also appeared to require more intense immunosuppression with more frequent use of cyclophosphamide, biologic DMARDs, tumor necrosis factor alpha inhibitors, and, in subgroup analyses, tocilizumab in pediatric-onset TAK than in adult-onset TAK. Surgical or endovascular procedures, remission, and risk of mortality were similar in both children and adults with TAK. No studies had compared patient-reported outcome measures between pediatric-onset and adult-onset TAK. Distinct clinical features and angiographic extent prevail between pediatric-onset and adult-onset TAK. Clinical outcomes in these subgroups require further study in multicentric cohorts.