Genetics of vasculitis.

Systemic vasculitis encompasses a wide range of conditions characterized by varying degrees of inflammation in blood vessels. Although the etiology of vasculitis remains unclear, accumulated data suggest that it is triggered in genetically predisposed individuals by the concurrence of certain environmental factors. The importance of the genetic component has been consistently supported by evidence of familial aggregation, differential prevalence by ethnicity, and multiple genetic associations with disease susceptibility and severity reported in recent years. The strongest association signals in most vasculitides correspond to genetic variants within the HLA region, suggesting an important role of the immune system in its pathophysiology. However, each type of vasculitis has distinct defining HLA association markers, likely due to disease-specific differences in antigenic drivers. Furthermore, other genetic polymorphisms located outside the HLA region play an important role in susceptibility to different vasculitides. More recent research has assessed the shared genetic susceptibility evident across different vasculitides. Future studies should focus on the identification of genetic markers that can serve as reliable biomarkers for early diagnosis, prognosis, and treatment response in systemic vasculitis.

Impact of conventional and biological disease-modifying anti-rheumatic drugs on arterial lesions in Takayasu arteritis.

BACKGROUND: The definition of Takayasu arteritis (TAK) remission and disease activity is still unclear. Vascular imaging is an essential tool for following-up patients. Herein, we aimed to compare the evolution of vascular lesions (ie vessel wall thickening and stenosis) under conventional disease-modifying anti-rheumatic drugs (cDMARDs) relatively to biological DMARDs (bDMARDs) in TAK patients followed with the same CT angiography modalities. METHOD: We compared 75 lines of therapy in TAK patients who received cDMARDs (n = 40 lines) and bDMARDs (n = 35 lines) using CT angiography. We established 1-3 main target vessels with vessel wall thickening and/or stenosis. Every targeted vessel had its thickness and its lumen diameter measured at the initiation of immunosuppressive treatment and at 12 months. RESULTS: We observed an overall reduction of arterial wall thickness in 73% of cases and 31% had >25% of wall thickness relative decrease. Using a linear mixed effects model, first line immunosuppressive therapy (p= 0.012) and bDMARDs relatively to cDMARDs (p= 0.026) were independently associated with vessel wall thickness reduction in TAK. Thirty-eight percent of the stenotic vessels had a > 25% relative increase in lumen diameter under immunosuppressive therapy. The relative increase >25% in lumen diameter was noted in 56% vs 17% with bDMARDs compared with cDMARDs. CONCLUSION: Immunosuppressive treatments can reduce arterial wall thickness and widen lumen diameter in TAK. bDMARDs seems to be more effective than cDMARDs to improve arterial lesions in TAK.

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

BACKGROUND: Vascular fibrosis directly causes vascular thickening in Takayasu arteritis (TAK), in which sustained transforming growth factor beta (TGF-ß) activation is critical. Understanding TGF-ß 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-ß activation and vascular fibrosis development. METHODS: In TAK patients, PCSK5 and TGF-ß 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-ß 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-ß 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-ß (pro-TGF-ß) to the mature form by binding the pro-TGF-ß cleavage site. Leflunomide inhibited PCSK5 and pro-TGF-ß binding, decreasing TGF-ß 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-ß and downstream SMAD2/3 pathway activation. Leflunomide might be anti-fibrotic by disrupting PCSK5 and pro-TGF-ß binding, presenting a new TAK treatment approach.

Role of Optical Coherence Tomography in Vasculitis-Associated Pulmonary Hypertension and Chronic Thromboembolic Pulmonary Hypertension.

BACKGROUND: Identifying and understanding the microstructural changes within the wall of the pulmonary artery (PA) is crucial for elucidating disease mechanisms and guiding treatment strategies. We assessed the utility of optical coherence tomography (OCT) in identifying such changes within segmental/subsegmental PAs and compared the morphological variations in WHO group 4 pulmonary hypertension associated with Behcet Disease (BD), Takayasu arteritis (TA) and chronic thromboembolic pulmonary hypertension (CTEPH). Idiopathic pulmonary arterial hypertension (IPAH) patients served as controls.Methods and Results: A total of 197 cross-sectional images were analyzed from 20 consecutive patients. BD patients exhibited lower %wall area and mean wall thickness (MWT) compared with CTEPH, TA and, IPAH patients. TA patients showed a notably higher %wall area, which was significant in IPAH and BD patients. Variations in %wall area measurements were observed across distinct cross-sectional segments of the PA within individual patients (22% in CTEPH, 19% in BD, 16% in TA, 23% in IPAH patients). Intravascular webs, bands, and thrombi were observed in BD and CTEPH patients. OCT provided clear delineation of vascular wall calcifications and adventitial vasa vasorum. No procedure-related complications were observed. CONCLUSIONS: PA involvement differs among the various etiologies of PH, with the PA being heterogeneously affected. OCT offers promise in elucidating microstructural vascular wall changes and providing insights into disease mechanisms and treatment effects.

Ultrasound Examination of Common Carotid Adventitial Thickness Can Differentiate Takayasu Arteritis and Large Vessel Giant Cell Arteritis.

Pathological studies have demonstrated that the adventitial layer is markedly thickened in Takayasu (TAK) as compared to large vessel giant cell arteritis (LV-GCA). An ultrasound (US) examination of the arterial vessels allows the determination of intima media thickness (IMT) and of adventitial layer thickness (extra media thickness (EMT)). No previous study has evaluated if there are differences in EMT thickness between TAK and LV-GCA. In this cross-sectional retrospective study of stored ultrasound (US) imaging, we have compared common carotid artery (CCA) EMT and IMT in a series of consecutive TAK and LV-GCA patients. US examination CCA IMT and EMT were significantly higher in TAK as compared to LV-GCA. With ROC curve analysis, we have found that an EMT > 0.76 mm has high sensitivity and specificity for TAK CCA examination. The percentage of CCA at EMT > 0.76 mm and the total arterial wall thickening were significantly higher in TAK group examinations. EMT thickness correlated with disease duration and IMT in the TAK group, as well as with the IMT and ESR values in the LV-GCA group. Upon multivariate logistic regression analysis, factors independently associated with TAK CCA were EMT > 0.76 mm and age. No significant variation in IMT and EMT could be demonstrated in subsequent US CCA examinations.

High estrogen induces trans-differentiation of vascular smooth muscle cells to a macrophage-like phenotype resulting in aortic inflammation via inhibiting VHL/HIF1a/KLF4 axis.

Estrogen is thought to have a role in slowing down aging and protecting cardiovascular and cognitive function. However, high doses of estrogen are still positively associated with autoimmune diseases and tumors with systemic inflammation. First, we administered exogenous estrogen to female mice for three consecutive months and found that the aorta of mice on estrogen develops inflammatory manifestations similar to Takayasu arteritis (TAK). Then, in vitro estrogen intervention was performed on mouse aortic vascular smooth muscle cells (MOVAS cells). Stimulated by high concentrations of estradiol, MOVAS cells showed decreased expression of contractile phenotypic markers and increased expression of macrophage-like phenotypic markers. This shift was blocked by tamoxifen and Krüppel-like factor 4 (KLF4) inhibitors and enhanced by Von Hippel-Lindau (VHL)/hypoxia-inducible factor-1α (HIF-1α) interaction inhibitors. It suggests that estrogen-targeted regulation of the VHL/HIF-1α/KLF4 axis induces phenotypic transformation of vascular smooth muscle cells (VSMC). In addition, estrogen-regulated phenotypic conversion of VSMC to macrophages is a key mechanism of estrogen-induced vascular inflammation, which justifies the risk of clinical use of estrogen replacement therapy.

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.

Assessment of Damage in Takayasu's Arteritis.

OBJECTIVES: To evaluate damage and clinical characteristics associated with damage in Takayasu's arteritis (TAK). METHODS: Patients with TAK enrolled in a multicentre, prospective, observational study underwent standardized damage assessment every 6 months using the Vasculitis Damage Index (VDI) and the Large-Vessel Vasculitis Index of Damage (LVVID). RESULTS: The study included 236 patients with TAK: 92% female, 81% Caucasian; median (25th, 75th percentile) disease duration = 2.6 (0.12, 6.9) years. Eighty-four percent had follow-up: median (25th, 75th) duration 4.1 (1.9, 7.5) years.Items of damage were present in 89% on VDI, 87% on LVVID, in the peripheral vascular (76% VDI, 74% LVVID), cardiac (40% VDI, 45% LVVID) systems. During follow-up, 42% patients had new damage;, including major vessel stenosis/arterial occlusion (8%), limb claudication (6%), hypertension (7%), aortic aneurysm (4%), and bypass surgery (4%). Disease-specific damage accounted for >90% new items. Older age, relapse, and longer duration of follow-up were associated with new damage items; a higher proportion of patients without new damage were on methotrexate (p< 0.05). Among 48 patients diagnosed with TAK within 180 days of enrolment, new damage occurred in 31% on VDI and 52% on LVVID. History of relapse was associated with new damage in the entire cohort while in patients with a recent diagnosis, older age at diagnosis was associated with new damage. CONCLUSION: Damage is present in > 80% of patients with TAK even with recent diagnosis and >40% of patients accrue new, mainly disease-specific damage. Therapies for TAK that better control disease activity and prevent damage should be prioritized.

Exceptional multisite aneurysms in Takayasu arteritis: A unique and challenging case.

This case describes a rare and complex presentation of Takayasu arteritis, a large vessel vasculitis primarily affecting young females. Unlike typical Takayasu arteritis cases characterized by arterial stenosis, this 34-year-old male presented with an unusually high number of aneurysms affecting the aorta, subclavian arteries, and other segments. This unique abundance of aneurysms complicates diagnosis and management. This disease typically manifests as arterial stenosis, with aneurysms occurring in a minority of cases. The most common site for aneurysms is the ascending aorta, making multifocal aneurysms, as seen in this case, exceptionally rare. Managing multiple aneurysms in Takayasu arteritis is complex, necessitating careful consideration of factors like aneurysm size, morphology, and risk of complications. This case underscores the unique challenges posed by multifocal aneurysms in this condition, highlighting the need for a comprehensive approach to treatment.

Mini-access ascending aorto-bifemoral bypass surgery for the treatment of aortic steno-occlusive disease.

Objectives: Mid-aortic syndrome is a rare condition characterized by severe aortic narrowing, leading to high upper body blood pressure and organ hypoperfusion, necessitating surgical intervention. Although central bypassing is considered ideal, it involves extensive incisions. To overcome these limitations, less-invasive approaches have been developed. This study aims to introduce a mini-access approach using video-endoscopy and to evaluate the feasibility and outcomes of mini-access ascending aorto-bifemoral bypass surgery. Methods: From November 2020 to May 2022, we performed ascending aorta to bifemoral artery bypass operations on 7 patients to treat steno-occlusive diseases in the downstream aorta. A Y-graft was created, and procedures were conducted under general anesthesia using video-endoscopy with limited skin incisions. Results: Intraoperatively, there were no major complications, and none of the patients required cardiopulmonary bypass support. Furthermore, there were no postoperative mortalities or major complications. Postoperatively, the mean ankle-brachial index significantly improved from 0.59/0.59 to 0.96/0.92 (P = .004), and the mean glomerular filtration rate increased from 61.1 to 85.3 mL/min/1.73 mm2 (P = .012). Additionally, symptoms of claudication resolved in all patients. Conclusions: Videoscope-assisted mini-access aortic bypass surgery not only provides favorable early postoperative outcomes but also represents a technically feasible alternative to traditional surgical approaches for the treatment of steno-occlusive aortic diseases.

Diagnosing vasculitis with ultrasound: findings and pitfalls.

Rheumatologists are increasingly utilizing ultrasound for suspected giant cell arteritis (GCA) or Takayasu arteritis (TAK). This enables direct confirmation of a suspected diagnosis within the examination room without further referrals. Rheumatologists can ask additional questions and explain findings to their patients while performing ultrasound, preferably in fast-track clinics to prevent vision loss. Vascular ultrasound for suspected vasculitis was recently integrated into rheumatology training in Germany. New European Alliance of Associations for Rheumatology recommendations prioritize ultrasound as the first imaging tool for suspected GCA and recommend it as an imaging option for suspected TAK alongside magnetic resonance imaging, positron emission tomography and computed tomography. Ultrasound is integral to the new classification criteria for GCA and TAK. Diagnosis is based on consistent clinical and ultrasound findings. Inconclusive cases require histology or additional imaging tests. Robust evidence establishes high sensitivities and specificities for ultrasound. Reliability is good among experts. Ultrasound reveals a characteristic non-compressible 'halo sign' indicating intima-media thickening (IMT) and, in acute disease, artery wall oedema. Ultrasound can further identify stenoses, occlusions and aneurysms, and IMT can be measured. In suspected GCA, ultrasound should include at least the temporal and axillary arteries bilaterally. Nearly all other arteries are accessible except the descending thoracic aorta. TAK mostly involves the common carotid and subclavian arteries. Ultrasound detects subclinical GCA in over 20% of polymyalgia rheumatica (PMR) patients without GCA symptoms. Patients with silent GCA should be treated as GCA because they experience more relapses and require higher glucocorticoid doses than PMR patients without GCA. Scores based on intima-thickness (IMT) of temporal and axillary arteries aid follow-up of GCA, particularly in trials. The IMT decreases more rapidly in temporal than in axillary arteries. Ascending aorta ultrasound helps monitor patients with extracranial GCA for the development of aneurysms. Experienced sonologists can easily identify pitfalls, which will be addressed in this article.

Diagnosing vasculitis with ultrasound Rheumatologists use ultrasound to diagnose two types of blood vessel inflammation: giant cell arteritis (GCA) or Takayasu arteritis (TAK). They can do this right in their office during the examination, without sending patients elsewhere. During the ultrasound, rheumatologists can talk with patients about what they see. This is especially helpful in fast-track clinics to prevent vision loss. In Germany, doctors training to become rheumatologists learn how to use ultrasound to check for problems like these. An organization called 'European Alliance of Associations for Rheumatology (EULAR)' recommends using ultrasound as the main way to look for GCA and, if needed, for TAK. Ultrasound is also an important part of the new classification criteria for GCA and TAK. However, doctors do not rely on ultrasound alone. They also look what patients are feeling and do other medical tests. If ultrasound is not clear enough, doctors might need to do more tests like taking a small piece of tissue (biopsy) or using other kinds of imaging like MRI or CT scans. Ultrasound can show some characteristic signs of blood vessel inflammation, like a 'halo sign,' which tells doctors that the blood vessel walls are thicker than normal. It can also spot other problems like blockages or bulges in the blood vessels. When doctors suspect GCA, they should at least examine the arteries at the forehead and at the armpit. Most of the time, these areas are easy to see with ultrasound, but some areas might be harder to reach. Sometimes, people can have blood vessel inflammation without feeling any typical symptoms. Ultrasound can still find this silent inflammation in more than 20% of people with a condition called polymyalgia rheumatica (PMR). Even though these patients do not have typical symptoms of GCA, it is important to treat them the same way as those with GCA. Otherwise, they may have more flare-ups and need higher doses of glucocorticoids. Doctors may measure the thickness of the artery walls over time in research studies. This helps them to see if treatments are working well. The wall thickness decreases faster in arteries of the head than in larger arteries outside the head. Ultrasound of the aorta close to heart helps to find out if a widening of the aorta develops. This can be dangerous because of rupture.

Takayasu arteritis presenting with large cerebral infarction in a 39-year-old Syrian woman: a case report.

Introduction and importance: Takayasu Arteritis (TA) is a rare chronic inflammatory disease of unknown etiology that primarily affects large vessels, such as the aorta and its major branches. The disease typically presents with diverse symptoms, depending on the site and degree of arterial lesions. Delayed diagnosis is common, especially in younger populations. Case presentation: A 39-year-old Syrian female presented with an initial stroke. She had no prior medical history and was otherwise healthy. On examination, she had an absent left radial pulse, a carotid bruit, and muscle weakness. Blood tests showed an elevated ESR and CRP. Computed tomography of the brain revealed a right large cerebral infarction. Multislice computed tomography angiography showed diffuse arterial wall thickening, stenosis, and occlusion of several major vessels, including the left internal carotid artery, right internal carotid artery, and left subclavian artery. Clinical discussion: The patient was diagnosed with TA based on the American College of Rheumatology criteria. She was treated with prednisolone, methotrexate, and aspirin, and her symptoms improved significantly. Conclusion: This case highlights the importance of considering TA in the differential diagnosis of ischemic stroke, especially in young patients with atypical presentations. Early identification and management are essential to preclude critical sequelae.

Unravelling a Triad: A Rare Case of Takayasu Arteritis, Hashimoto's Thyroiditis, and Psoriasis in a Young Female With Heart Failure.

Takayasu arteritis (TA) is an autoimmune entity of unknown aetiology causing granulomatous thickening of large and medium-sized arteries. Common symptoms include claudication, headaches, dizziness, syncope, visual changes, and palpitations. Diverse cardiac manifestations, such as ischemic heart disease, significant aortic regurgitation, and pulmonary hypertension, are associated with TA, although they rarely manifest as congestive heart failure. Radio-imaging, including CT angiography and MR angiography, along with more invasive procedures such as conventional angiography, are often used for diagnosis. Treatment is done with corticosteroids, steroid-sparing agents, biologics, and revascularization procedures. Here, we have a case of a 17-year-old Indian female who presented to us with a complaint of abdominal pain. She was diagnosed with Hashimoto's thyroiditis a few years ago, along with a history of congestive heart failure. On general examination, blood pressure was asymmetrical in the upper limbs with the presence of bilateral carotid bruit. There was also the presence of extensive scaly lesions on the extensor surface of all four limbs, suggestive of psoriasis. Radio-imaging confirmed the diagnosis of TA. CT angiography also showed total occlusion of the celiac trunk and proximal left gastric artery, which was likely the cause of her symptoms. The patient received treatment with corticosteroids in conjunction with methotrexate, along with other supportive drugs. TA with congestive heart failure has been occasionally described in the literature, while the association of TA with psoriasis is much rarer. The simultaneous occurrence of various autoimmune diseases is common, but the triad of Hashimoto thyroiditis, psoriasis, and TA with an initial presentation of heart failure is unique. Due to the common co-occurrence of autoimmune conditions, early and thorough patient evaluation with comprehensive studies is imperative for optimal health outcomes.

A pilot study of childhood-onset Takayasu arteritis using whole exome sequencing suggests oligogenic inheritance involving classical complement, collagen, and autoinflammatory pathways.

Takayasu arteritis (TA) is a chronic granulomatous inflammatory disease affecting the aorta and its branches. Paediatric TA (pTA) may present from 6 months after birth till the adolescent age group. Genetics and pathogenesis of pTA are not fully understood. Earlier studies reported monogenic mutation in NOD2, XIAP, and STAT1 genes in patients with pTA. TA, a relatively rare disease, is more common in geographical pockets, including India. We hypothesized that South Asian patients with pTA, namely, those of Indian subcontinent origin, may have clinically relevant and unique pathogenic variants involving one or more genes, especially those linked to genetically driven vasculitic illnesses, including autoinflammatory pathologies. Children with pTA fulfilling EULAR/PRINTO/PReS classification criteria and presenting with clinical symptoms to the Paediatric Rheumatology clinic of Christian Medical College, Vellore, were included. Blood samples were collected after getting informed consent from parents or guardians and assent forms from children. DNA was extracted from whole blood using the Qiagen DNA extraction kit. Initially, the common variant in Indian population, namely, ADA2 c.139G > A; p.Gly47Arg, was screened, followed by whole exome sequencing. Fourteen children were recruited for the study. Median age of patients was 11 years (4 months-14 years) with a male-to-female ratio of 4:10. Distribution of angiographic subsets by Numano's classification of included children were as follows: type 5 (n = 7), type 4 (n = 5), and type 3 (n = 2). We identified novel variants in ten different genes. This include variants in genes of classical complement pathway, namely, C2, C3, C6, C7, and C9, and other genes, namely, CYBA, SH3BP2, GUCY2C, CTC1, COL5A1, and NLPR3. Two of 14 patients have heterozygous pathogenic variants; this implies that combination of heterozygous variants in C3 and COL5A1 might lead to disease development, suggesting digenic inheritance. One patient has a homozygous variant in CYBA. None of the patients were identified to have ADA2 variants. Whole exome sequencing reveals combination of rare variants in genes C3, COL5A1, and CYBA associated with disease development in children with Takayasu Arteritis. Key Points • We identified novel variants in genes of classical complement pathway, namely, C2, C3, C6, C7, and C9, and other genes, namely, CYBA, SH3BP2, GUCY2C, CTC1, COL5A1, and NLPR3. • Two of 14 patients have heterozygous pathogenic variants in C3 and COL5A1; this may have implications in disease development, suggesting digenic inheritance. • One patient has homozygous variant in CYBA. • None of the patients were identified to have ADA2 variants.

Anterior ST-Segment Elevation Myocardial Infarction in a Teenager: A Diagnostic Dilemma.

This study presents an unusual manifestation of Takayasu arteritis in a 16-year-old girl with significant left main and right coronary artery vasculitis. The distinct clue on the diagnosis was cardiac magnetic resonance findings of increased periaortic tissue enhancement in late gadolinium enhancement sequences. Cardiac magnetic resonance has high accuracy in the diagnosis of patients with Takayasu arteritis.

Asymptomatic Takayasu Arteritis With Critical Multivessel Stenosis.

Takayasu arteritis is characterized by blood vessel inflammation involving the aorta and its branches. We describe a patient with Takayasu arteritis with severe multivessel involvement and classic physical examination findings but virtually no symptoms because of the presence of extensive collateral circulation seen on computed tomography angiography and magnetic resonance angiography imaging.

Current evidence on the role of fibroblasts in large-vessel vasculitides: From pathogenesis to therapeutics.

Large-vessel vasculitides (LVV) comprise a group of chronic inflammatory diseases of the aorta and its major branches. The most common forms of LVV are giant cell arteritis (GCA) and Takayasu arteritis (TAK). Both GCA and TAK are characterized by granulomatous inflammation of the vessel wall accompanied by a maladaptive immune and vascular response that promotes vascular damage and remodeling. The inflammatory process in LVV starts in the adventitia where fibroblasts constitute the dominant cell population. Fibroblasts are traditionally recognized for synthesizing and renewing the extracellular matrix thereby being major players in maintenance of normal tissue architecture and in tissue repair. More recently, fibroblasts have emerged as a highly plastic cell population exerting various functions, including the regulation of local immune processes and organization of immune cells at the site of inflammation through production of cytokines, chemokines and growth factors as well as cell-cell interaction. In this review, we summarize and discuss the current knowledge on fibroblasts in LVV. Furthermore, we identify key questions that need to be addressed to fully understand the role of fibroblasts in the pathogenesis of LVV.

Effector CD4+ T cell subsets in Takayasu arteritis - Differences between the peripheral blood and the aorta.

Takayasu arteritis (TAK) is a granulomatous vasculitis that affects large arteries. T cells are important in TAK pathophysiology as these cells orchestrate granulomatous infiltration in arteries. This study aims to evaluate effector CD4+ T cells in the peripheral blood and the aortic wall of TAK patients and to analyze associations with disease activity and therapy. We performed a longitudinal study including 30 TAK patients and 30 controls. CD3+ T cells, CD3+CD4- T cells, CD4+ T cells, and Th1, Th2, and Th17 cells were evaluated in peripheral blood by flow cytometry, and the expression of CD4, CD8, Tbet, GATA-3, and RORγT was analyzed in the aorta of 6 patients by immunohistochemistry. TAK patients presented lower CD3+ T cells and CD4+ T cells (p=0.031 and p=0.039, respectively) than controls. Patients with active disease and those in remission had higher proportions of Th17 cells than controls (p=0.016 and p=0.004, respectively). Therapy for TAK did not result in significant differences concerning CD4+ effector T cell subpopulations. Disease duration correlated with the number and percentage of Th2 cells (rho=-0.610 and rho=-0.463, respectively) and with Th17 cells (rho=-0.365 and rho=-0.568). In the aorta, the expression of CD8 was higher than CD4, whereas GATA-3, Tbet and RORγT were expressed in this order of frequency. In conclusion, TAK patients present an increased Th17 response in the peripheral blood regardless of disease activity, whereas in the aortic tissue CD8 cells and the Th2 response were predominant.

Serum osteoprotegerin and its gene polymorphisms in patients with Takayasu's arteritis: a bicentric cross-sectional study.

INTRODUCTION: Takayasu's arteritis (TAK) patients are at an elevated risk of metabolic syndrome and cardiovascular diseases (CVD). Currently, there are no well-validated biomarkers to assess this risk in this population. Previous research in different cohorts has linked serum levels of osteoprotegerin (OPG) and its polymorphisms to accelerated atherosclerosis and a marker of poor prognosis in CVD. Thus, we assessed this protein as a potential biomarker of CVD in TAK patients. OBJECTIVES: To evaluate the serum levels of OPG and its SNPs (single nucleotide polymorphisms) in TAK patients and healthy controls, and to associate these parameters with clinical data. METHODS: This bicentric cross-sectional study included TAK patients who were compared with healthy individuals (control group). The serum levels of OPG and the frequency of OPG SNPs [1181G > C (rs2073618), 245 A > C (rs3134069), 163T > C (rs3102735), and 209 C > T (rs3134070)] were compared between the both groups and associated with clinical data. RESULTS: In total, 101 TAK patients and 93 controls were included in the study. The serum levels of OPG (3.8 ± 1.9 vs. 4.3 ± 1.8pmol/L, respectively; P = 0.059), and its four polymorphisms were comparable between both groups. In an additional analysis of only TAK patients, serum OPG levels and its four genes were not associated with any CVD parameters, except for higher OPG levels among patients without dyslipidemia. CONCLUSION: No significant differences were observed in serum OPG levels or in the genotype frequencies of OPG SNPs between the patient and control groups. Similarly, no correlation was found between laboratory parameters and clinical data on CVD risk in TAK patients.

Outcome and prognosis of isolated carotid vasculitis.

OBJECTIVE: To assess the prognosis and outcome of patients with isolated carotid vasculitis. METHODS: We performed a retrospective multicenter study of 36 patients (median age at diagnosis was 37 [IQR 27-45] years and 11 [31 %] patients were men) with initial presentation as isolated carotid vasculitis. Study endpoints included vascular complications, relapses, and progression to large vessel vasculitis (i.e. Giant cell arteritis or Takayasu). RESULTS: The most frequent involvement was the left internal carotid artery (39 %), and 81 % had stenosis. After a median follow-up of 32 months [IQR 12-96], 21 (58 %) patients had a vascular event, including 31 % of new onset vascular lesions and 25 % of stroke/transient ischemic attack. Patients with stroke had less carotidynia at diagnosis (33 % vs 74 %, p = 0.046), higher significant carotid stenosis (i.e. > 50 %) (89 % vs. 30 %, p = 0.026) and higher severe carotid stenosis (i.e. >70 %) (67 % vs 19 %, p = 0.012), compared to those without stroke. Twenty (52 %) patients experienced relapses. High CRP at diagnosis was associated with relapses (p = 0.022). At the end of follow-up, 21 (58 %) patients were classified as having Takayasu arteritis, 13 (36 %) as isolated carotid vasculitis, and two (6 %) as giant cell arteritis. CONCLUSION: Carotid vasculitis may occur as a topographically limited lesion and is associated with significant rate of vascular complications.