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.

Identification of susceptibility loci for Takayasu arteritis through a large multi-ancestral genome-wide association study.

Takayasu arteritis is a rare inflammatory disease of large arteries. We performed a genetic study in Takayasu arteritis comprising 6,670 individuals (1,226 affected individuals) from five different populations. We discovered HLA risk factors and four non-HLA susceptibility loci in VPS8, SVEP1, CFL2, and chr13q21 and reinforced IL12B, PTK2B, and chr21q22 as robust susceptibility loci shared across ancestries. Functional analysis proposed plausible underlying disease mechanisms and pinpointed ETS2 as a potential causal gene for chr21q22 association. We also identified >60 candidate loci with suggestive association (p < 5 × 10-5) and devised a genetic risk score for Takayasu arteritis. Takayasu arteritis was compared to hundreds of other traits, revealing the closest genetic relatedness to inflammatory bowel disease. Epigenetic patterns within risk loci suggest roles for monocytes and B cells in Takayasu arteritis. This work enhances understanding of the genetic basis and pathophysiology of Takayasu arteritis and provides clues for potential new therapeutic targets.

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 six 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.

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.

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.

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.

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.

Fibroblast Activation Protein Inhibitor-Positron Emission Tomography in Aortitis: Fibroblast pathology in active inflammation and remission.

OBJECTIVES: Epigenetically modified fibroblasts contribute to chronicity in inflammatory diseases. Reasons for the relapsing character of large vessel vasculitis (LVV) remain obscure, including the role of fibroblasts, in part due to limited access to biopsies of involved tissue.68Ga FAPI-46 (FAPI)-PET/CT detects activated fibroblasts in vivo. In this exploratory pilot study, we tested the detection of fibroblast activation in vessel walls using FAPI-PET/CT in LVV with aortitis. METHODS: 8 LVV patients with aortitis and 8 age- and gender-matched controls were included. Distribution of FAPI uptake was evaluated in the aorta and large vessels. FAPI-uptake was compared with MRI inflammatory activity scores. Imaging results were compared with clinical parameters such as serum inflammatory markers, time of remission and medication. RESULTS: Three aortitis patients were clinically active, five in remission. Irrespective of activity, FAPI uptake was significantly enhanced in aortitis compared with controls. Patients in remission had a mean duration of remission of 2.8 years (range 1-4 years), yet significant FAPI uptake in the vessel wall was found.In remitted aortitis, MRI inflammatory scores were close to be negative, while in 4/5 patients visually identifiable FAPI uptake was observed. CONCLUSIONS: This pilot feasibility study shows significant tracer uptake in the aortic walls in LVV. FAPI positivity indicates ongoing fibroblast pathology in clinically remitted LVV.

Aneurysmal Disease in Patients With Takayasu Arteritis.

OBJECTIVE: Takayasu arteritis (TA) leads to stenotic disease. Aneurysmal lesions are rarer. This study assessed the main characteristics of aneurysmal disease in a Canadian cohort of patients with TA. METHODS: This monocentric retrospective study included patients with TA followed at the Mount Sinai Hospital Vasculitis Clinic in Toronto. Diagnosis of TA was based on clinical findings and/or satisfied the 1990 American College of Rheumatology classification criteria. RESULTS: Seventy-four patients were included. At any time, aneurysmal disease was found in 23 (31%) patients. Median disease duration was 9.0 (IQR 7.0-19.0) years. Prior hypertension (P = 0.02), fever (P = 0.04), and seizure disorders (P = 0.03) were more common. Limb claudication was less frequent (P = 0.01). Persistent and/or new aneurysms were demonstrated in 22/23 patients at follow-up. Thoracic aorta aneurysm (13/22) was most common, followed by abdominal aorta (8/22), subclavian (7/22), and carotid (6/22) artery disease. Aortic valve regurgitation was more frequent (9/23 vs 3/48; P = 0.001). Twenty-one patients had been treated with glucocorticoids (median 6.1 years [IQR 3.7-8.1]). Methotrexate, azathioprine, and leflunomide were repeatedly used. Infliximab (7/23) was used more often (P = 0.04), whereas tocilizumab was received by only 4 patients with aneurysmal disease (P = 0.01). Patients with aneurysms suffered more frequent relapses (2.0 [IQR 0.0-4.0] vs 1.0 [IQR 0.0-2.0], P = 0.04). CONCLUSION: Aneurysmal disease was found in a significant proportion of patients with TA. Given that aneurysms may carry a risk of rupture, and are associated with a higher rate of relapse, this finding should be reported systematically in TA studies.

Organ Damage and Quality of Life in Takayasu Arteritis　- Evidence From a National Registry Analysis.

BACKGROUND: Takayasu arteritis, affecting primarily young women, damages large arteries and organs. We examined the impact of disease duration and sex on organ damage and quality of life using Japan's Intractable Disease Registry.Methods and Results: After refining data, 2,013 of 2,795 patients were included in the study. Longer disease duration was related to a lower prevalence of disease activity symptoms, a higher prevalence of organ damage, and a higher proportion of patients requiring nursing care. Compared with men, women tended to have an earlier onset age, exhibiting longer disease duration. A higher proportion of women had aortic regurgitation and required nursing care. The proportion of female patients in employment was lower than that of the general female population, whereas no difference was observed between male patients and the general male population. Logistic regression analysis revealed that age at surveillance, brain ischemia, visual impairment/loss, and ischemic heart disease were significant factors associated with high nursing care needs (Level ≥2, with daily activity limitations). CONCLUSIONS: Early diagnosis and effective treatment, particularly to prevent brain ischemia, visual impairment, and ischemic heart disease, may improve the quality of life of patients with Takayasu arteritis, especially women.

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.

Vasa vasorum interna in the carotid wall of active forms of Takayasu arteritis evidenced by ultrasound localization microscopy.

Introduction: Takayasu arteritis (TA) is associated with microvascularization of the wall of large arteries and is related to inflammation. Ultrasound localization microscopy (ULM), combining ultrafast ultrasound imaging with microbubble (MB) injection, can track the path of MBs within the arterial wall and thus provide imaging of the vasa vasorum. From the analysis of MB tracks in the common carotid arteries of patients with active TA, we report the presence of microvessels in connection with the carotid lumen (i.e., vasa vasorum interna [VVI]). Methods: ULM maps were obtained on five patients with active disease in the observational single-center series of the TAK-UF study. MB tracks connected to the carotid lumen were automatically identified, allowing the reconstruction of VVI. Results: MB tracking allows us to observe a microvascular network on the inner part of the wall, with some vessels in communication with the carotid lumen. This type of vessel was identified in all patients with active TA (n = 5) with a median of 2.2 [1.1-3.0] vessels per acquisition (2D longitudinal view of 3 cm of the common carotid artery). The blood flow within these vessels is mainly centrifugal; that is, toward the adventitia (88% [54-100] of MB tracks with flow directed to the outer part of the wall). Conclusion: VVI are present in humans in the case of active TA and emphasize the involvement of the intima in the pathological process. ClinicalTrials.gov Identifier: NCT03956394.

Poor obstetric outcomes in women with takayasu arteritis: a retrospective cohort study.

The objective of this study was to assess the pregnancy outcomes in a cohort of patients who experienced pregnancies before and/or after being diagnosed with Takayasu's arteritis (TA). The present investigation encompassed a total of 88 pregnancies seen in a cohort of 35 patients who met the criteria outlined by the American College of Rheumatology in 1990 for the classification of Takayasu arteritis (TA). Pregnancies were classified into two categories. 1. Pregnancies that occurred before the diagnosis (pre-d or pre-TA) 2. Pregnancies that happened following a diagnosis (post-d or post-TA). Fifty-nine pregnancies (67.0%) occurred in 21 TA patients before the diagnosis with and a complication rate of 15.2%, and twenty-nine pregnancies (33.0%) occurred in 14 patients concomitant with or after TA diagnosis and complication rate 100%. Although the hypertension rate was higher in the pre-d group than in the post-d group, it was not significant (32.2% vs. 10.3%, p = 0.160). However, preeclampsia (20.6% vs. 0%, p = 0.001), low birth weight (27.5% vs. 1.6%, p = 0.001), and prematurity (24.1% vs. 1.6%, p = 0.035) were observed more frequently in the post-d group compared to the pre-d group. The frequency of abortions and in-utero deaths were similar in both groups (p > 0.05). Patients with hypertension had significantly higher rates of preeclampsia (p = 0.003), preterm birth (p = 0.036), low birth weight (p = 0.250), abortion (p = 0.018), in utero death (p = 0.128), and cesarean section (p = 0.005) than those without hypertension. Renal artery involvement was detected in 15 (42.8%) patients. All patients with renal artery involvement had hypertension, and they had significantly more pregnancy complications than the other group (p = 0.001). TA negatively affects pregnancy outcomes. A good control of arterial hypertension before conception and during pregnancy is critical to improve both maternal and fetal outcomes. In addition, detecting renal artery stenosis before pregnancy is important in reducing possible negative pregnancy outcomes.

Diagnostic delays in systemic vasculitides.

Systemic vasculitides are among the less common disorders encountered in routine rheumatology practice. The low incidence and heterogeneous presentation at onset can potentially lead to delayed diagnosis. Not recognizing these in the early phase may prove detrimental, as some vasculitis may progress to a catastrophic course with major morbidity or mortality. The causes of diagnostic delay may vary among different types of vasculitis and may also be disease-, patient-, or physician-related. Disease-related factors include the myriad presentations with diverse and non-specific symptoms, mimicking other conditions like infections. In addition, some forms have prolonged prodromal phases before evident organ damage. Limited awareness among healthcare professionals, particularly outside rheumatology, and a lack of readily available diagnostic tools contribute to missed diagnoses. Delays in seeking care due to non-specific symptoms or lack of access to specialist care can worsen outcomes. The economic burden also increases with delayed diagnosis and damage accrual when the disease remains unrecognized or untreated for prolonged periods. Although the causes of vasculitis are numerous, including secondary causes, in this review, we focus on diagnostic delays in primary vasculitides and suggest potential steps to identify and treat these diseases early. These include educating both healthcare professionals and the public about the signs and symptoms of vasculitis; expanding the rheumatology workforce and facilitating timely referrals; implementing readily available and reliable tests for early detection; and streamlining care and diagnostic pathways. Such measures have the potential to improve the overall outcomes of the disease, with prolonged remission, minimal damage accrual, and improved quality of life.

Trends in health care of patients with vasculitides, including giant cell arteritis, Takayasu arteritis, ANCA-associated vasculitis and Behçet's disease: cross-sectional data of the German National Database 2007-2021.

The aim of this study is to present the current care situation of patients with giant cell arteritis (GCA), Takayasu arteritis (TAK), ANCA-associated vasculitis (AAV) and Behçet's disease (BD). Trends over the last 15 years will reflect improvements and remaining deficits in the management of vasculitides. Consecutive cross-sectional data from patients with vasculitides from the German National Database (NDB) of the Collaborative Arthritis Centres between 2007 and 2021 were included. Medication, physician- and patient-reported outcomes on disease activity and disease burden, inpatient stays and occupational participation are compared for different vasculitis entities and over time. Employment rates were compared to German population rates. Between 502 and 854 vasculitis patients were annually documented. GCA and AAV were the most common vasculitides. Median disease duration ranged from 2 to 16 years. Over the years, glucocorticoids decreased in proportion and dose, most markedly in GCA and TAK, while biologic therapies increased up to 27%. Physicians rated disease activity as low for the vast majority of patients, while patients-reported moderate outcomes in many dimensions. PROs remained largely unchanged. The proportion of employed patients (< 65 years) increased from 47 to 57%. In recent years, biologics are increasingly used in patients with vasculitides, while glucocorticoids decreased significantly. PRO's have not improved. Work participation increased but remains lower than that in the German population.

Surgical and endovascular cerebral revascularization for cerebral vasculitis with inflammatory vessel stenosis: a case series.

Autoimmune vasculitides affect the cerebral vasculature significantly in a considerable number of cases. When immunosuppressive treatments fail to prevent stenosis in cerebral vessels, treatment options for affected patients become limited. In this case series, we present four cases of pharmacoresistant vasculitis with recurrent transient ischemic attacks (TIAs) or stroke successfully treated with either extracranial-intracranial (EC-IC) bypass surgery or endovascular stenting. Both rescue treatments were effective and safe in the selected cases. Our experience suggests that cases of pharmacoresistant cerebral vasculitis with recurrent stroke may benefit from rescue revascularization in combination with maximum medical management.

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.

Real-World Biomarkers for Pediatric Takayasu Arteritis.

Childhood-onset Takayasu arteritis (TA) is a rare, heterogeneous disease with limited diagnostic markers. Our objective was to identify and classify all candidates for biomarkers of TA diagnosis in children reported in the literature. A systematic literature review (PRISMA) of MEDLINE, EMBASE, Wiley Cochrane Library, ClinicalTrias.gov, and WHO ICTRP for articles related to TA in the pediatric age group between January 2000 and August 2023 was performed. Data on demographics, clinical features, laboratory measurements, diagnostic imaging, and genetic analysis were extracted. We identified 2026 potential articles, of which 52 studies (81% case series) met inclusion criteria. A total of 1067 TA patients were included with a peak onset between 10 and 15 years. Childhood-onset TA predominantly presented with cardiovascular, constitutional, and neurological symptoms. Laboratory parameters exhibited a low sensitivity and specificity. Imaging predominantly revealed involvement of the abdominal aorta and renal arteries, with magnetic resonance angiography (MRA) being the preferred imaging modality. Our review confirms the heterogeneous presentation of childhood-onset TA, posing significant challenges to recognition and timely diagnosis. Collaborative, multinational efforts are essential to better understand the natural course of childhood-onset TA and to identify accurate biomarkers to enhance diagnosis and disease management, ultimately improving patient outcomes.

Anti-LAMP-2 Antibody Seropositivity in Children with Primary Systemic Vasculitis Affecting Medium- and Large-Sized Vessels.

Chronic primary systemic vasculitis (PSV) comprises a group of heterogeneous diseases that are broadly classified by affected blood vessel size, clinical traits and the presence (or absence) of anti-neutrophil cytoplasmic antibodies (ANCA) against proteinase 3 (PR3) and myeloperoxidase (MPO). In small vessel vasculitis (SVV), ANCA are not present in all patients, and they are rarely detected in patients with vasculitis involving medium (MVV) and large (LVV) blood vessels. Some studies have demonstrated that lysosome-associated membrane protein-2 (LAMP-2/CD107b) is a target of ANCA in SVV, but its presence and prognostic value in childhood MVV and LVV is not known. This study utilized retrospective sera and clinical data obtained from 90 children and adolescents with chronic PSV affecting small (SVV, n = 53), medium (MVV, n = 16), and large (LVV, n = 21) blood vessels. LAMP-2-ANCA were measured in time-of-diagnosis sera using a custom electrochemiluminescence assay. The threshold for seropositivity was established in a comparator cohort of patients with systemic autoinflammatory disease. The proportion of LAMP-2-ANCA-seropositive individuals and sera concentrations of LAMP-2-ANCA were assessed for associations with overall and organ-specific disease activity at diagnosis and one-year follow up. This study demonstrated a greater time-of-diagnosis prevalence and sera concentration of LAMP-2-ANCA in MVV (52.9% seropositive) and LVV (76.2%) compared to SVV (45.3%). Further, LAMP-2-ANCA-seropositive individuals had significantly lower overall, but not organ-specific, disease activity at diagnosis. This did not, however, result in a greater reduction in disease activity or the likelihood of achieving inactive disease one-year after diagnosis. The results of this study demonstrate particularly high prevalence and concentration of LAMP-2-ANCA in chronic PSV that affects large blood vessels and is seronegative for traditional ANCA. Our findings invite reconsideration of roles for autoantigens other than MPO and PR3 in pediatric vasculitis, particularly in medium- and large-sized blood vessels.

Recurrent Stroke as a Presenting Feature of Takayasu Arteritis in an Adolescent: A Case Report and Literature Review.

Takayasu arteritis is a large vessel vasculitis, characterized by granulomatous inflammation of arterial vessels, that typically affects the aorta, its main branches and pulmonary arteries. Disease diagnosis is a challenge and requires awareness of the condition, as clinical signs can be not specific. We report a case of an adolescent with recurrent stroke diagnosed with Takayasu arteritis. A diagnosis of Takayasu arteritis was established due to angiographic findings in the magnetic resonance angiography in conjunction with systolic blood pressure discrepancy, arterial hypertension and increased acute phase reactants. Takayasu arteritis is a rare cause of ischemic stroke in children. However, stroke may be the first manifestation of the disease. Clinical experience and multidisciplinary approach, including aggressive treatment, is essential for the favourable outcome of the disease and the reduction of the associated morbidity and mortality.