Restricted usage of T-cell receptor Valpha-Vbeta genes in infiltrating cells in aortic tissue of patients with Takayasu's arteritis

Biomarkers in Takayasu arteritis

Takayasu arteritis (TA) is a rare large vasculitis with unknown etiology, which affects the aorta and its primary branches, as well as the pulmonary and coronary arteries. Cellular and humoral immunity, chronic inflammation, and genetic factors are involved into TA pathogenesis. Several biomarkers, such as MMPs, TIMPs, cytokines, cell adhesion molecules, autoantibodies, complements, PTX3, sRAGE, NT-proBNP, 8-isoPGF_2α, NO₂^-, acute-phase and immunology-related proteins, thrombogenicity markers, ghrelin leptin and adipokines, endothelial damage and repair factors, genetic markers etc., related to the pathogenesis could be observed in patients with TA. These biomarkers have revealed great values in early diagnosis, evaluating disease activity, guiding clinical treatment options, and thus demonstrated significant clinical application values in TA. The combination of biomarkers assay and imaging examination may detect TA more accurately. The aim of this review is to systemically observe the clinical significance of these biomarkers in TA.

Intravenous tocilizumab for Takayasu arteritis with aortic aneurysms, bilateral renal artery stenosis, and atypical aortic coarctation in a 2-year-old girl

Takayasu arteritis (TAK) is classified as large vessel vasculitis, and continuous inflammation of the vessel results in aneurysm or stenosis, which leads to various serious complications. Recently, a TAKT [TAK treated with tocilizumab (TCZ)] study showed that subcutaneous TCZ, a humanised anti-interleukin-6 receptor monoclonal antibody, is an effective treatment in patients with TAK above 12 years of age; however, the effectiveness of TCZ for juvenile TAK under 12 years old remains unclear. Here, we described the case of a 2-year-old girl with TAK, which was successfully treated with intravenous TCZ. She was diagnosed with TAK type V (Numano's angiographic classification system) with aortic aneurysms, bilateral renal arteries stenosis, and atypical descending aortic coarctation based on contrast-enhanced computed tomography findings. Treatment was started with 2 mg/kg/day prednisolone (PSL) and methotrexate instead of methylprednisolone pulse due to renovascular hypertension. She was immediately afebrile and her C-reactive protein level decreased, although it was elevated 4 weeks after starting PSL. Intravenous TCZ of 8 mg/kg/2 weeks was added because the progression of aneurysms or stenosis might lead to a poor prognosis. PSL was steadily reduced under intravenous TCZ. Magnetic resonance imaging showed that aortic aneurysms, renal arteries stenosis, and aortic coarctation ameliorated 4 months after starting TCZ, with the amelioration maintained at 1 year after starting TCZ. Aneurysms and stenosis improved; therefore, TCZ may be effective for the treatment of inflammation of vessels, aneurysms, and stenosis. It is desirable to examine the effect of TCZ on TAK patients under 12 years of age.

Advances in Takayasu arteritis: An Asia Pacific perspective

Takayasu Arteritis (TA) is a rare form of chronic granulomatous large vessel vasculitis that is more common in Asia compared to other parts of the world. There have been several developments in the field of Takayasu arteritis in relation to genetics, classification, clinical features, imaging, disease activity assessment and management and much of these works have been done in the Asia Pacific region. We will be discussing selected few in the current review.

Genome-Wide DNA Methylation Profiling in CD8 T-Cells and Gamma Delta T-Cells of Asian Indian Patients With Takayasu Arteritis

Background: Takayasu’s Arteritis (TA) is a chronic inflammatory disease that affects aorta and its main branches at their origin. Genetic, pathological and functional studies have shown that CD8 and Gamma delta (γ/δ) T-lymphocytes are involved in inflammatory processes in affected regions of arteries causing vascular damage. The molecular function of these lymphocytes remains unclear and currently no epigenetic studies are available in TA. We primarily performed genome wide methylation analysis in CD8 T cells and γδ T cells of patients with TA and compared with healthy controls.

Methods: We recruited 12 subjects in each group namely TA patient and healthy controls. Blood samples were collected after obtaining informed written consent. CD8 T cells and γδ T cells were separated from whole blood. DNA extracted from these cells and were subjected to bisulfite treatment. Finally, bisulfite treated DNA was loaded in Infinium Methylation EPIC array. Bioinformatics analysis was used to identify differential methylation regions which were then mapped to genes.

Results: Interleukin (IL)-32 and Lymphotoxin-A were genes significantly hypomethylated in CD8 T-cells. Anti-inflammatory cytokine genes, IL-10, IL-1RN and IL-27 were hypomethylated in γδ T cells of TA patients as compared to healthy controls. Gene enrichment analysis using Gene Ontology (GO) database and Kyoto Encyclopaedia of Genes and Genomes (KEGG) identified that genes involved in T-cell receptor signalling pathways were hypomethylated in CD8 T-cells and hypermethylated in γδ T cells of TA patients.

Conclusion: CD8 T-cells might play a major role in immunopathogenesis of inflammation in TA, whereas γδ T cells may play a regulatory role.

Using the co-expression network of T cell-activation-related genes to assess the disease activity in Takayasu's arteritis patients

Background

There have been lacking reliable serum biomarkers in assessing the disease activity of Takayasu’s arteritis (TAK). This study aimed to assess the disease activity of TAK by assayed gene expression levels in peripheral mononuclear cells (PBMCs).

Methods

The expression level of genes that essential in T cell activation in PBMCs in active TAK patients, inactive TAK patients, and healthy controls were detected by real-time fluorescence quantitative polymerase chain reaction, including TCR, CD28, CD40, CD40L, PD-1, PD-L1, PD-L2, CTLA4, TIGIT, TIM3, LAG3, CCL5, T-bet, RORC, and FOXP3. Gene co-expression network was established, and the signature of the topology structure in active TAK patients compared to the inactive TAK patients were extracted and described by formulas. Respectively, the disease activity was assessed by the routine serum biomarkers, including ESR, CRP, IL-6, and TNF-α, the gene expression level of TCR, CD28, T-bet, and RORC, as well as the signature of the topology structure, and the diagnostic efficacies were compared.

Results

Compared with the inactive TAK patient group, the active TAK patient group had a greater clustering coefficient in the network consisting of genes that essential in T cell activation. When assessing the disease activity used this signature of topology structure, the sensitivity was 90.9%, the specificity was 100%, and the AUC was 0.98, which was greater than the AUCs of these biomarkers.

Conclusions

The signature of the topology structure could distinguish the active TAK patients from inactive TAK patients. This maybe is a novel evaluation algorithm of disease activity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02636-2.

Coronary Vasculitis

The term coronary “artery vasculitis” is used for a diverse group of diseases with a wide spectrum of manifestations and severity. Clinical manifestations may include pericarditis or myocarditis due to involvement of the coronary microvasculature, stenosis, aneurysm, or spontaneous dissection of large coronaries, or vascular thrombosis. As compared to common atherosclerosis, patients with coronary artery vasculitis are younger and often have a more rapid disease progression. Several clinical entities have been associated with coronary artery vasculitis, including Kawasaki’s disease, Takayasu’s arteritis, polyarteritis nodosa, ANCA-associated vasculitis, giant-cell arteritis, and more recently a Kawasaki-like syndrome associated with SARS-COV-2 infection. This review will provide a short description of these conditions, their diagnosis and therapy for use by the practicing cardiologist.

Blood Biomarkers for Monitoring and Prognosis of Large Vessel Vasculitides

PURPOSE OF REVIEW

Large vessel vasculitides (LVVs) are inflammatory conditions of the wall of large-sized arteries, mainly represented by giant cell arteritis (GCA) and Takayasu arteritis (TA). The inflammatory process within the vessel wall can lead to serious consequences such as development of aneurysms, strokes and blindness; therefore, early diagnosis and follow-up of LVV are fundamental. However, the arterial wall is poorly accessible and blood biomarkers are intended to help physicians not only in disease diagnosis but also in monitoring and defining the prognosis of these conditions, thus assisting therapeutic decisions and favouring personalised management. The field is the object of intense research as the identification of reliable biomarkers is likely to shed light on the mechanisms of disease progression and arterial remodelling. In this review, we will discuss the role of blood biomarkers in LVVs in the light of the latest evidence.

RECENT FINDINGS

In clinical practice, the most widely performed laboratory investigations are the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). However, these indices may be within normal limits during disease relapse and they are not reliable in patients receiving interleukin-6 (IL-6) receptor inhibitors. New biomarkers struggle to gain traction in clinical practice and no molecule with good accuracy has been identified to date. IL-6, a pro-inflammatory cytokine that drives CRP synthesis and increases the ESR, is one of the most promising biomarkers in the field. IL-6 analysis is increasingly performed, and serum levels are more sensitive than ESR for active GCA and might reflect persistent inflammation with high risk of relapse in patients on IL-6 receptor inhibitors. A future with biomarkers that reflect different disease features is an important aspiration. Accordingly, intense effort is being made to identify IL-6-independent inflammatory biomarkers, such as S100 proteins, pentraxin-3 and osteopontin. Moreover, metalloproteinases such as MMP2/9 and angiogenic modulators such as VEGF, YLK-40 and angiopoietins are being studied as markers of arterial remodelling. Lastly, biomarkers indicating organ damage may guide prognostic stratification as well as emergency therapeutic decisions: the most promising biomarkers so far identified are NT-proBNP, which reflects myocardial strain; pentraxin-3, which has been associated with recent optic nerve ischemia; and endothelin-1, which is associated with ischaemic complications. Currently, the use of these molecules in clinical practice is limited because of their restricted availability, lack of sufficient studies supporting their validity and associated costs. Further evidence is required to better interpret their biological and clinical value.

Diagnostic Value of HLA Typing in Pathogenesis of Cardiomyopathy

Development of cardiomyopathy (CM) is dependent upon several factors. However, the reaction of the immune response against myocardial tissue due to microbial and viral infections plays an important role in this disease. Therefore, the purpose of this study is to investigate the relationship between HLAs and their pathogenic mechanisms in the incidence of CM. Relevant literature was identified by a PubMed search (1989-2017) of English-language papers using the terms "Cardiomyopathy", "Human leukocyte antigen or HLA", "immune response", and "polymorphism". If CM patients are afflicted with viral and microbial infections, HLA class II molecules, which are not expressed on myocardial tissue in normal conditions, are mainly expressed on it. As a result, these HLAs present self- antigens and provoke autoimmune responses against myocardial tissue. On the other hand, the occurrence of polymorphism as well as disrupted expression of miRNAs can affect HLA expression, leading to hypertrophy and fibrosis of cardiac muscle. Finally, it is inferred that the expression evaluation of HLAs as well as identification of polymorphisms in their coding genes can be effective diagnostic factors in the detection of people susceptible to CM.

Discrepancies between vascular and systemic inflammation in large vessel vasculitis: an important problem revisited

A lack of absolute correlation between systemic inflammation parameters and ongoing vascular disease activity is an important problem in some patients with large vessel vasculitis, especially Takayasu arteritis (TAK). Systemic and vascular wall inflammation in TAK are obviously interrelated, but sometimes they may act independently. There are clear discrepancies between these two types of inflammation, including cytokine patterns and responses to treatment. Vascular and systemic inflammation may also be discordant in two subgroups of giant cell arteritis. The first subgroup is mainly characterized by severe systemic inflammation mostly associated with IL-6-driven immunity, while in the second subgroup there is less systemic inflammation but prominent neuro-ophthalmic ischaemic complications characterized mostly by IFN-γ-mediated effects. Although no definite boundaries exist, it may be suggested that the IL-6/Th17/IL-17 pathway primarily drives systemic inflammation while the IL-12/Th1/IFN-γ pathway dominates in vascular wall inflammation both in TAK and giant cell arteritis. Immunosuppressive treatment of TAK (especially corticosteroids) initially suppresses systemic inflammation, while longer treatment duration is required for the suppression of vascular inflammation. Therefore, evaluating only the systemic inflammation may be misleading. Vascular wall inflammation is currently evaluated using expensive imaging methods, which are not feasible for repetitive use. Although pentraxin-3 is superior to erythrocyte sedimentation rate and CRP, we need more reliable biomarkers to reflect vascular wall inflammation in patients with TAK.

Tocilizumab and refractory Takayasu disease: Four case reports and systematic review

BACKGROUND

Relapses upon corticosteroids tapering and immunosuppressive agents are frequent in Takayasu arteritis (TA). Interleukin-6 is highly involved in physiopathology of TA. Many reports showed efficacy of tocilizumab (TCZ) in refractory TA cases. We report four cases and an updated literature review on the TCZ efficacy and safety in patients with TA.

METHODS

Patients with TA defined by ACR 1990 criteria were included. Clinical, biological and imaging data were retrospectively reported. Disease activity was analyzed before TCZ and during the follow-up. Medline database was searched for systematic literature review.

RESULTS

One hundred and five patients (median age 28years [22-38]) were included, mostly refractory cases (76 patients, 72%). Median TCZ duration was 12months [6-20]. Among 105 patients, 90 patients (85.7%) had an initial clinical response within three months [3-6] and 43/66 patients (65.2%) had a radiological improvement. Only seven patients (9%) showed relapse on therapy. Corticosteroid dose reduction was obtained in 75/83 patients (90.4%). Relapse after TCZ discontinuation was observed in six patients (46%), with a median time of five months [2-9]. Twenty-four side-effects were noted in 18 patients (18%), with TCZ interruption in seven cases (7%): 10 infections, five cytopenia, six hepatitis, one pancreatitis, one cutaneous rash and one breast cancer.

CONCLUSIONS

This review confirms that TCZ is safe and effective in refractory cases of TA and TCZ is a corticosteroid-sparing therapy in patients with or without previous TNFα blockers therapy. However relapses after TCZ discontinuation are frequent.

Investigational drugs in systemic vasculitis

INTRODUCTION

Treatment of systemic vasculitis is based on glucocorticoids (GC) in association with immunosuppressive therapy. There are still unmet needs, including earlier onset of response, more targeted therapies, reduction of relapse-risk and decrease of long-term GC and classic immunosuppressants toxicities. Areas covered: In this review, we discuss investigational drugs in early phase clinical trials for induction of remission in vasculitis. We focus on ANCA-associated vasculitis, Behçet's disease, giant cell arteritis, Takayasu arteritis, and cryoglobulinemic vasculitis. We performed a comprehensive review of articles published on pubmed and a review of clinical trials registered online ( https://clinicaltrials.gov ) for each vasculitis. Expert opinion: Recent progress in the pathogenesis identifies new therapeutic targets. Some of these therapies are promising in GC sparing effects, in reducing relapse rate, and for their safety profile. These results need to be confirmed in large-scale phase III studies.

Improvement of Arterial Wall Lesions in Parallel with Decrease of Plasma Pentraxin-3 Levels in a Patient with Refractory Takayasu Arteritis after Treatment with Tocilizumab

A 19-year-old Japanese woman with active Takayasu arteritis despite multiple conventional immunosuppressive therapies with glucocorticoids in combination with intravenous cyclophosphamide, azathioprine, or infliximab with methotrexate and tacrolimus was successfully treated by switching from infliximab to intravenous tocilizumab. Worsening of claudication of the legs and elevated acute phase reactants, including plasma pentraxin-3 levels, were observed during combination therapy with infliximab. Computed tomography demonstrated increased wall thickening with contrast enhancement in the preexisting lesion of the descending aorta and the femoral arteries. After switching from infliximab to tocilizumab, plasma pentraxin-3 levels gradually decreased to the normal range in parallel with the improvement of claudication. Follow-up computed tomographic scans confirmed the marked improvement of these arterial lesions. Moreover, plasma pentraxin-3 level was increased in response to the worsening of claudication that occurred just after switching to a subcutaneous tocilizumab injection. Measurements of plasma pentraxin-3 might be useful for evaluation of the vascular wall inflammation and therapeutic efficacy even during biologic therapy targeting tumor necrosis factor α and interleukin-6.

Standard and biological treatment in large vessel vasculitis: guidelines and current approaches

INTRODUCTION

Giant cell arteritis and Takayasu arteritis are the two major forms of idiopathic large vessel vasculitis. High doses of glucocorticoids are effective in inducing remission in both conditions, but relapses and recurrences are common, requiring prolonged glucocorticoid treatment with the risk of the related adverse events. Areas covered: In this article, we will review the standard and biological treatment strategies in large vessel vasculitis, and we will focus on the current approaches to these diseases. Expert commentary: The results of treatment trials with conventional immunosuppressive agents such as methotrexate, azathioprine, mycophenolate mofetil, and cyclophosphamide have overall been disappointing. TNF-α blockers are ineffective in giant cell arteritis, while observational evidence and a phase 2 randomized trial support the use of tocilizumab in relapsing giant cell arteritis. Observational evidence strongly supports the use of anti-TNF-α agents and tocilizumab in Takayasu patients with relapsing disease. However biological agents are not curative, and relapses remain common.

Updates in Pathophysiology, Diagnosis and Management of Takayasu Arteritis

BACKGROUND

Takayasu arteritis (TA) is a rare, systemic, inflammatory vasculitis of granulomatous nature, and still of unknown etiology. It mainly involves the aorta and its major branches and is more commonly seen in women of childbearing age and Asians. TA leads to stenosis, occlusion, or aneurysmal degeneration of large arteries, and its pathogenesis seems to be mainly due to an abnormal cell-mediated immunity, although other molecular and genetic abnormalities may contribute. The diagnosis and treatments lie on clinical and arteriographic findings. Because of its fluctuating course, both clinical scores and biomarkers are currently evaluated. The aim of this review is to report a comprehensive and methodologically robust state of the art about Takayasu arteritis, including the latest data and evidences in the definition, epidemiology, pathogenesis and etiology, clinical manifestations and classification, diagnosis, assessment of disease activity and progression, biomarkers, and treatment.

METHODS

We searched all publications addressing definition, epidemiology, pathogenesis, etiology, classification, diagnosis, biomarkers, and treatment of TA. Randomized trials, cohort studies, and reviews were contemplated to give a breadth of clinical data. PubMed and Scopus were searched from August 2010 to November 2015.

RESULTS

Of the 3,056 records found, 267 matched our inclusion criteria. After reading the full-text articles, we decided to exclude 169 articles because of the following reasons: (1) no innovative or important content; (2) no multivariable analysis; (3) insufficient data; (4) no clear potential biases or strategies to solve them; (5) no clear end-points; and (6) inconsistent or arbitrary conclusions. The final set included 98 articles.

CONCLUSIONS

This review presents the last updates in all fields of Takayasu arteritis. Still today, large areas of TA pathogenesis and disease-activity assessment need to be further investigated to better treat patients with TA.

Isolation of vascular smooth muscle antigen-reactive CD4(+)αβTh1 clones that induce pulmonary vasculitis in MRL/Mp-Fas(+/+) mice

Here, we established CD4(+)αβTh1 clones specific for rat vascular smooth muscle antigen (VSMAg) that induced vasculitis lesions in the lungs of MRL/Mp-Fas(+/+) mice following adoptive transfer. Six different T cell clones, MV1b1 (Vβ1), MV1b4 (Vβ4), MV1b8.3 (Vβ8.3), MV1b61 (Vβ6), MV1b62 (Vβ6), and MV1b63 (Vβ6), were isolated from the MV1 T cell line from the regional lymph nodes of immunized MRL/Mp-Fas(+/+) mice; the three (Vβ6) clones had unique CDR3 amino acid sequences. Following stimulation with VSMAg-pulsed antigen presenting cells, MV1b61 and MV1b62 failed to secrete interferon-γ and tumor necrosis factor-α, although the other four clones secreted high levels of both cytokines. In adoptive transfer experiments, MV1b61 and MV1b62 did not induce organ involvement including pulmonary vasculitis. In contrast, MV1b1, MV1b4, MV1b8.3, and MV1b63 induced perivascular mononuclear cell infiltration in pulmonary small arteries. These clones may provide useful tools for investigating the underlying mechanisms of vasculitis syndromes and for developing therapeutic strategies.

[Pathogenesis of large vessel vasculitis]

Giant cell arteritis (GCA) and Takayasu's arteritis (TA) are two granulomatous vasculitis affecting large arteries that present specific epidemiological and clinical features. Their pathogenesis is not fully understood but major advances have been obtained during the last years, thus allowing the emergence of new therapeutic strategies. GCA and TA develop on a specific genetic background but share some similarities regarding the immunological pathways involved in their pathogenesis. The trigger of these diseases is not clearly identified but it is thought that an infectious agent could activate and lead to the maturation of dendritic cells that are localized in the adventitia of arteries. Then, the cells of the adaptative immune response are recruited and activated: CD4 T cells that polarize into Th1 and Th17 cells, cytotoxic CD8 T cells and Natural Killer cells. Furthermore, the T regulatory cells (Treg) are decreased both in GCA and TA. Humoral immune response seems also to be involved, especially in TA. Then, the cytokines produced by T lymphocytes (especially IL-17 and IFN-γ) trigger the recruitment and activation of monocytes and their differentiation into macrophages and multinuclear giant cells that produce IL-1β and IL-6 that are responsible for general symptoms of GCA and TA, and cytotoxic mediators and growth factors that trigger the remodeling of the arterial wall leading to aneurysms and ischemic manifestations of GCA an TA.

Recent advances in the medical management of Takayasu arteritis: an update on use of biologic therapies

PURPOSE OF REVIEW

To critically review recent advances in medical management of Takayasu arteritis, with a special focus on the rationale and evidence to support the use of biologic agents in this disease.

RECENT FINDINGS

Multiple case series and observational studies support the use of anti-tumor necrosis factor (TNF) medications, in particular infliximab, in patients who relapse upon tapering steroids and/or adding nonbiologic immunosuppressive agents. However, these medications must be continued to maintain effect, and often patients require increased doses over time. Tocilizumab and rituximab have been shown to lead to improved disease activity in small numbers of Takayasu's patients, including those refractory to anti-TNF treatment.

SUMMARY

Anti-TNF agents are recommended for the treatment of Takayasu's patients who are unable to taper prednisone despite treatment with a nonbiologic immunosuppressive medication. Whether these biologic agents should be considered earlier in the treatment algorithm of these complicated patients remains an area of interest. Tocilizumab and rituximab may also be of benefit in refractory patients. Prospective randomized controlled trials are needed to confirm these findings.

Anti-cytokine treatment for Takayasu arteritis: State of the art

Takayasu arteritis (TA) is a rare and idiopathic large-vessel arteritis typically affecting young women which has important morbidity and mortality. There are no animal models of TA and pathogenesis is still mysterious. Clinical assessment lacks accurate activity indexes and is based on the integration of clinical, laboratory and radiological data. TA rarity has hampered randomized clinical trials and the achievement of high-quality evidence to guide clinical activity. Prevention of vascular progression, with progressive vessel wall remodelling and hyperplasia, is the main therapeutic goal. Medical therapy remains the mainstay of management and comprises traditional immunosuppressive agents and anti-inflammatory drugs, such as steroids and blockers of pivotal cytokines, TNF-α and IL-6. These strategies however only partially limit vascular progression, indicating that local molecular events are involved. Here we discuss recent data suggesting that selected cellular components of TA lesions should be evaluated as novel therapeutic targets.

Treatment of refractory Takayasu arteritis with tocilizumab: 7 Italian patients from a single referral center

OBJECTIVE

The aim of our study was to evaluate the safety and the efficacy of tocilizumab (TCZ) for refractory Takayasu arteritis (TA).

METHODS

We retrospectively assessed the outcome of blocking interleukin (IL)-6 with TCZ in 7 consecutive patients with refractory TA using a combination of clinical and imaging assessment.

RESULTS

During a median followup visit at 14 months, 4 patients taking TCZ [including 2 nonresponders to tumor necrosis factor (TNF) inhibitors] achieved clinical response, suggesting a nonredundant role for IL-6 in TA. Inflammatory markers normalized in all patients treated with TCZ. However, vascular progression occurred in 4 patients, suggesting the involvement of other inflammatory pathways and confirming the limitations of erythrocyte sedimentation rate and C-reactive protein for disease activity assessment while taking TCZ. Three patients experienced adverse events and 2 suspended TCZ.

CONCLUSION

TCZ may be effective in a subset of patients with refractory TA, even in cases of unresponsiveness to TNF inhibitors. Inflammatory markers are not valid markers of TA activity on TCZ. Further studies are needed to confirm these preliminary observations.

Tocilizumab: a new therapy for large vessel vasculitis

Large vessel vasculitis represents mainly two main diseases: giant cell arteritis and Takayasu arteritis. Recent advancements in the treatment for different rheumatic diseases refractory to disease-modifying antirheumatic agents with biologic agents have resulted in remarkable efficacy and tolerability. However, treatments for large vessel vasculitis (LVV) with tumor necrosis factor-α inhibitors have yielded conflicting results. Recently, very promising results have been reported in patients treated with tocilizumab. The purpose of this review is to summarize the current treatment strategies of LVV and the recent evidence on the use of tocilizumab in LVV.

Takayasu arteritis: diagnosis, treatment and prognosis

Takayasu arteritis (TA) is a chronic nonspecific granulomatous vasculitis affecting aorta and its main branches, coronary and pulmonary arteries. TA often occurs in young women and has a characteristic heterogeneity depending on ethnicity and geographical location. Although the pathogenesis of TA remains unclear, the interaction of many factors, such as autoimmunity, inflammation, genetic and environmental factors and so on, is involved in the occurrence and development of TA. Angiography, which is recognized as the gold standard in evaluating vascular lesions in TA, combined with computer tomography angiography (CTA), magnetic resonance angiography (MRA), ultrasonography, (18)Fluorodeoxyglucose positron emission tomography ((18)F-FDG-PET) could not only provide important information for early diagnosis but also detect disease activity, and thus further guide the treatment in TA. In addition, beside the commonly used corticosteroids, immunosuppressive agents, percutaneous transluminal angioplasty (PTA) and surgical revascularization, anti-tumor necrosis factor (TNF) agent has been more widely used in refractory cases of TA. The objective of this review is to systemically describe the pathogenesis, clinical characteristics, diagnosis, treatment and prognosis of TA.

The interleukin-1 gene cluster polymorphisms are associated with Takayasu's arteritis in Mexican patients

Takayasu's arteritis (TA) is a chronic inflammatory arteritis of unknown etiology involving mainly the aorta and its major branches. The interleukin (IL) 1β and IL-1 receptor antagonist have been playing an important role as regulators of inflammation. We investigated whether the polymorphisms at the IL-1B and IL-1RN gene cluster were associated with the genetic susceptibility to develop TA. We analyzed the IL-1B, IL-1F10.3, and IL-1RN polymorphisms in a sample of 58 TA patients, and 248 clinically healthy unrelated Mexican individuals by 5' exonuclease TaqMan polymerase chain reaction. Polymorphic haplotypes were constructed after linkage disequilibrium analysis. We found increased frequencies of different polymorphisms (C allele and TC genotype of IL-1F10.3; TT genotype of IL-1RN.4; C allele and TC genotype of IL-1RN6.1; G allele of IL-1RN6.2 and haplotypes "1T" and "1C" of IL-RN VNTR and IL-1RN6.1) in the group of TA when compared to healthy controls. On the other hand, decreased frequency of IL-1-511 TC genotype was found in the TA group compared to controls. IL-1B and IL-1RN gene polymorphisms could be involved in the risk of developing TA in the Mexican population. These associations were independent of the affected vessels.

Tocilizumab: An Updated Review of Its Use in the Treatment of Rheumatoid Arthritis and Its Application for Other Immune-Mediated Diseases

Interleukin-6 (IL-6), produced by a variety of cells, is a typical cytokine featuring redundancy and pleiotropic activity. IL-6 is promptly and transiently synthesized in response to infections or injuries, and participates in host defense by inducing immune responses, hematopoiesis, and acute-phase reactions. However, since its abnormal persistent production of mostly unknown etiology plays an important pathological role in the development of various immune-mediated diseases, a humanized anti-IL-6 receptor monoclonal antibody, tocilizumab, was developed and is now used as an innovative biologic for rheumatoid arthritis in more than 90 countries. Several factors strongly suggest that a IL-6 blockade strategy may have a broad application for the treatment of various immune-mediated diseases. These factors include favorable results of pilot or case studies with off-label use of tocilizumab, pathological analyses of the contribution of IL-6 to the development of immune-mediated diseases, and the potential capability of tocilizumab to both repair an imbalance of effector T cell subsets and to suppress pathologic autoantibody production. However, clinical trials to evaluate the efficacy and safety of tocilizumab for these diseases are essential. Furthermore, clarification of the cell source of IL-6 production and of the mechanisms through which dysregulated continuous IL-6 synthesis is induced constitutes an important issue for future studies into the pathogenesis of diseases.

Coronary artery involvement in pediatric Takayasu's arteritis: Case report and literature review

Takayasu's arteritis (TA) is a form of chronic vasculitis that typically occurs in young adult Asian females, but it can also present in younger patients not fitting this classic profile. In these cases, the sequelae are generally similar to those found in adults. The disease predominantly affects the aorta and its primary branches. However, the coronary arteries are also affected in up to 20% of cases, which may precipitate myocardial infarction. Imaging of the coronary arteries therefore becomes critically important in the evaluation of a patient with possible Takayasu's arteritis. We present a case of a pediatric patient with TA who had no symptoms of angina but who was found to have significant coronary artery involvement on diagnostic imaging. This necessitated tailoring of traditional management.

Tocilizumab for the treatment of large-vessel vasculitis (giant cell arteritis, Takayasu arteritis) and polymyalgia rheumatica

OBJECTIVE

The interleukin-6 pathway is up-regulated in giant cell arteritis (GCA), Takayasu arteritis (TA), and polymyalgia rheumatica (PMR). We retrospectively assessed the outcomes of 10 patients with relapsing/refractory GCA, TA, or PMR treated with tocilizumab (TCZ).

METHODS

Patients with GCA (n = 7), TA (n = 2), and PMR (n = 1) received TCZ. Seven subjects had failed at least 1 second-line agent. The outcomes evaluated were symptoms of disease activity, inflammatory markers, ability to taper glucocorticoids, and cross-sectional imaging when indicated clinically.

RESULTS

The mean followup time of this cohort since diagnosis was 27 months (range 16-60 months). The patients were treated with TCZ for a mean period of 7.8 months (range 4-12 months). Before TCZ therapy, the patients experienced an average of 2.4 flares/year. All patients entered and maintained clinical remission during TCZ therapy. The mean daily prednisone dosages before and after TCZ initiation were 20.8 mg/day (range 7-34.3 mg/day) and 4.1 mg/day (range 0-10.7 mg/day), respectively (P = 0.0001). The mean erythrocyte sedimentation rate declined from 41.5 mm/hour (range 11-68 mm/hour) to 7 mm/hour (range 2.2-11.3 mm/hour; P = 0.0001). The adverse effects of TCZ included mild neutropenia (n = 4) and transaminitis (n = 4). One patient flared 2 months after TCZ discontinuation. An autopsy on 1 patient who died from a postoperative myocardial infarction following elective surgery revealed persistent vasculitis of large and medium-sized arteries.

CONCLUSION

TCZ therapy led to clinical and serologic improvement in patients with refractory/relapsing GCA, TA, or PMR. The demonstration of persistent large-vessel vasculitis at autopsy of 1 patient who had shown a substantial response requires close scrutiny in larger studies.

Successful tocilizumab treatment in a child with refractory Takayasu arteritis

Takayasu arteritis (TA) in the child remains a therapeutic challenge because corticosteroids and conventional immunosuppressive agents are not always safe or efficacious. The complex formed by interleukin-6 (IL-6) and soluble IL-6 receptor appears to play a pivotal role in the pathogenesis of TA. We describe a favorable response to the anti-IL-6 receptor antibody tocilizumab (TCZ) in a child with aggressive and refractory TA including an assessment of the proinflammatory cytokine profile. A 3-year-old girl with TA consisting of thickening of the aortic arch wall, severe obstruction of the supra-aortic branches, and complete occlusion of both common carotid arteries failed to respond to corticosteroids, methotrexate, tumor necrosis factor α blockade, cyclophosphamide, and mycophenolate mofetil, and 3 years later, the disease remained active with severe manifestations (brain ischemia). The patient underwent percutaneous angioplasty, although significant restenosis was soon documented. After a severe relapse, the patient started TCZ infusions (8 mg/kg for 2 weeks), and a rapid clinical remission was observed, associated with a drastic reduction of inflammatory markers and IL-6 levels. Corticosteroids were withdrawn, the patient's weight and height improved, and bone mineral density values returned to normal. Two years later, TCZ infusions were extended, with no significant side effects. Cerebral ischemia resolved, and recanalization of the previously occluded supra-aortic branches was performed.

Successful treatment with tocilizumab in a case of Cogan's syndrome complicated with aortitis

A 69-year-old man with sensorineural hearing loss and iritis was diagnosed with atypical Cogan's syndrome. He had several systematic manifestations: aortitis, meningitis, panniculitis and seronegative arthritis. Remission induced by treatment with high doses of prednisolone was followed by relapse within 1 year. Although his condition was resistant to various immunosuppressive drugs, including methotrexate, cyclosporine, azathioprine and adalimumab, his symptoms, inflammatory response and quality of life measures were successfully improved by tocilizumab, a humanized anti-interleukin-6 receptor antibody.

Immunotherapeutic implication of IL-6 blockade

IL-6 is a cytokine featuring redundancy and pleiotropic activity. While IL-6 contributes to host defense against acute environmental stress, continuous IL-6 production plays a significant pathological role in various autoimmune and chronic inflammatory diseases. To counter this drawback, tocilizumab, a humanized anti-IL-6 receptor antibody, was developed. Clinical trials have verified the efficacy of tocilizumab for patients with rheumatoid arthritis, Castleman's disease and systemic juvenile idiopathic arthritis, resulting in approval of this innovative biologic for their treatment. Moreover, a considerable number of case reports and pilot studies have indicated the beneficial effects of tocilizumab on other autoimmune and chronic inflammatory diseases. Further clinical studies to evaluate the efficacy and safety of tocilizumab for these diseases are essential.

Takayasu's arteritis is associated with HLA-B*52, but not with HLA-B*51, in Turkey

Introduction

HLA-B*51 and HLA-B*52 are two close human leukocyte antigen (HLA) allele groups with minor amino acid differences. However, they are associated with two different vasculitides (HLA-B*51 in Behçet's disease and HLA-B*52 in Takayasu's arteritis (TAK)) and with major clinical and immunological differences. In this study, we aimed to screen a large cohort of TAK patients from Turkey for the presence of HLA-B*51 and HLA-B*52 as susceptibility and severity factors.

Methods

TAK patients (n = 330) followed at a total of 15 centers were included in the study. The mean age of the patients was 37.8 years, and 86% were women. DNA samples from the patients and healthy controls (HC; n = 210) were isolated, and the presence of HLA-B*51 or HLA-B*52 was screened for by using PCR with sequence-specific primers.

Results

We found a significant association of HLA-B*52 with TAK (20.9% vs HC = 6.7%, P = 0.000, OR = 3.7, 95% CI = 2.02 to 6.77). The distribution of HLA-B*51 did not differ between TAK patients and HCs (22.7% vs 24.8%, OR = 0.9, 95% CI = 0.60 to 1.34). The presence of HLA-B*52 decreased in late-onset patients (> 40 years of age; 12.0%, P = 0.024, OR = 0.43, 95% CI = 0.20 to 0.91). Patients with angiographic type I disease with limited aortic involvement also had a lower presence of HLA-B*52 compared to those with all other disease subtypes (13.1% vs 26%, P = 0.005, OR = 0.43, 95% CI = 0.23 to 0.78).

Conclusions

In this study, the previously reported association of TAK with HLA-B*52 in other populations was confirmed in patients from Turkey. The functional relevance of HLA-B*52 in TAK pathogenesis needs to be explored further.

Tocilizumab for the treatment of rheumatoid arthritis and other systemic autoimmune diseases: current perspectives and future directions

Interleukin (IL)-6 is a cytokine featuring redundancy and pleiotropic activity. While IL-6, when transiently produced, contributes to host defense against acute environmental stress, continuous dysregulated IL-6 production plays a significant pathological role in several systemic autoimmune diseases. In response to the expectation that IL-6 blockade would constitute a novel therapeutic strategy for the treatment of these diseases, tocilizumab, a humanized anti-IL-6 receptor antibody, was developed. Clinical trials have verified the efficacy and the safety of tocilizumab for patients with rheumatoid arthritis, resulting in approval of this innovative biologic for the treatment of rheumatoid arthritis in more than 90 countries worldwide. Pathological analyses of the effect of IL-6 on the development of autoimmune diseases and a considerable number of case reports and pilot studies have also indicated the beneficial effects of this antibody on other systemic autoimmune diseases, including systemic lupus erythematosus, systemic sclerosis, polymyositis, and large-vessel vasculitis.

New indications for biological therapies

Biological agents have originally been developed to treat refractory arthritis, but evidence has been accruing, supporting their use in vasculitis as well. In the large-vessel vasculitides giant cell arteritis and Takayasu arteritis, TNF-α inhibitors have shown some efficacy in patients with relapsing disease. In contrast, in patients with recent onset of giant cell arteritis, TNF-α inhibitors failed to provide a significant benefit over and above that conferred by glucocorticoids alone. More recent, preliminary data suggest a role for the interleukin-6 receptor antagonist tocilizumab in both resistant and treatment-naïve giant cell arteritis and Takayasu arteritis. Biological agents have also been proposed to treat difficult anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis. Uncontrolled observations suggest that the TNF-α inhibitor infliximab might be beneficial in resistant cases. On the contrary, a randomized controlled trial did not show superiority of the recombinant human soluble TNF-α p75 receptor fusion protein etanercept over placebo in maintaining remission in granulomatosis with polyangiitis. Two randomized controlled trials have demonstrated that the anti-CD20 monoclonal antibody rituximab was as effective as the standard-of-care agent cyclophosphamide in inducing remission. In addition, rituximab appeared to be superior to cyclophosphamide in inducing remission in the subset of patients with relapsing disease. These findings prove that biological therapy has a role in vasculitis. Research is investigating novel therapies as well as focusing on how to best use the available drugs.

Pathogenesis of Takayasu's arteritis: a 2011 update

While our knowledge of the pathogenesis of Takayasu's arteritis (TA) has considerably improved during the last decade, the exact pathogenic sequence remains to be elucidated. It is now hypothesised that an unknown stimulus triggers the expression of the 65kDa Heat-shock protein in the aortic tissue which, in turn, induces the Major Histocompatibility Class I Chain-Related A (MICA) on vascular cells. The γδ T cells and NK cells expressing NKG2D receptors recognize MICA on vascular smooth muscle cells and release perforin, resulting in acute vascular inflammation. Pro-inflammatory cytokines are released and increase the recruitment of mononuclear cells within the vascular wall. T cells infiltrate and recognize one or a few antigens presented by a shared epitope, which is associated with specific major Histocompatibility Complex alleles on the dendritic cells, these latter being activated through Toll-like receptors. Th1 lymphocytes drive the formation of giant cells through the production of interferon-γ, and activate macrophages with release of VEGF resulting in increased neovascularisation and PDGF, resulting in smooth muscle migration and intimal proliferation. Th17 cells induced by the IL-23 microenvironnement also contribute to vascular lesions through activation of infiltrating neutrophils. Although still controversial, dendritic cells may cooperate with B lymphocytes and trigger the production of anti-endothelial cell auto-antibodies resulting in complement-dependent cytotoxicity against endothelial cells. In a near future, novel drugs specifically designed to target some of the pathogenic mechanisms described above could be expanding the physician's therapeutic arsenal in Takayasu's arteritis.