Ghrelin and adipokines as circulating markers of disease activity in patients with Takayasu arteritis

Serum leukemia inhibitory factor (LIF) levels in patients with Takayasu's and Giant cell arteritis: A cross-sectional study

INTRODUCTION AND OBJECTIVES

In this study, we aimed to evaluate LIF levels and its possible relationship with disease activity in patients with Takayasu's (TAK) and Giant cell arteritis (GCA) patients.

MATERIALS AND METHODS

23 Takayasu's arteritis, 9 Giant cell arteritis patients and 25 healthy volunteers were included in the study. Serum LIF levels were measured ELISA.

RESULTS

The mean age of Giant cell arteritis patients was statistically significantly higher than the other groups (p<0.001). The rate of women was found to be higher in Takayasu's arteritis (p=0.021). When healthy control, patients with GCA and Takayasu arteritis were compared, there was a difference in LIF values (p=0.018). In subgroup analyzes, LIF values were found to be higher in GCA patients compared to healthy controls (p<0.05). There was no statistically significant correlation between LIF and CRP (Rho=-0.038, p=0.778), ESR (Rho=0.114, p=0.399) and ITAS (Rho=-0.357, p=0.094). While CRP was statistically significantly higher in patients with disease activity (p=0.003), there was no statistically significant difference between patients in terms of ESR and LIF values. While there was a statistically significant relationship between CRP (OR=1.19 [1.03-1.37], p=0.018) and disease activity in univariate analyses, no statistically significant variable was found in multivariable analyses.

CONCLUSIONS

LIF values were significantly higher in patients with Giant cell arteritis compared to healthy controls.

Serum leptin, a potential predictor of long-term angiographic progression in Takayasu's arteritis

Aim

In patients with Takayasu's arteritis (TA), current biomarkers that properly reflect the progression of the vascular structure remain absent. We aimed to determine the serum leptin level to investigate its relationship with imaging changes and assess its value as a predictor for long‐term radiological progression.

Method

This study included 34 untreated TA patients and 40 age‐matched healthy controls. At baseline and during the 5‐year follow‐up, we assessed disease activity using Kerr's criteria and Indian Takayasu Clinical Activity Score (ITAS2010) and monitored laboratory biomarkers as well as imaging findings. Serum leptin levels were measured by enzyme‐linked immunosorbent assay.

Results

The baseline serum leptin levels were significantly higher in TA patients than in healthy controls. Leptin was significantly positively correlated with triglyceride and high‐density lipoprotein cholesterol levels and negatively correlated with fibrinogen and C‐reactive protein levels. Patients were subdivided into three groups based on their baseline leptin level. During a 5‐year follow‐up, patients in the high and medium leptin groups showed more radiological progression compared to those in the low leptin group. Cox proportional hazard regression analysis showed that a high serum leptin level was a positive predictor of radiological progression.

Conclusion

Leptin is a potential biomarker for assessing TA structural progression. Untreated patients with elevated serum leptin levels are at a higher risk of progression in the aorta. Thus, the leptin level can be a predictor of long‐term radiological progression.

Biomarkers in Vasculitides of the Nervous System

Besides being affected by the rare and severe primary angiitis of the central nervous system (PACNS) the nervous system is also affected by primary systemic vasculitides (PSV). In contrast to PACNS, PSV affect not only the central but also the peripheral nervous system, resulting in a large array of potential symptoms. Given the high burden of disease, difficulties in distinguishing between differential diagnoses, and incomplete pathophysiological insights, there is an urgent need for additional precise diagnostic tools to enable an earlier diagnosis and initiation of effective treatments. Methods available to date, such as inflammatory markers, antibodies, cerebrospinal fluid (CSF) analysis, imaging, and biopsy, turn out to be insufficient to meet all current challenges. We highlight the use of biomarkers as an approach to extend current knowledge and, ultimately, improve patient management. Biomarkers are considered to be useful for disease diagnosis and monitoring, for predicting response to treatment, and for prognosis in clinical practice, as well as for establishing outcome parameters in clinical trials. In this article, we review the recent literature on biomarkers which have been applied in the context of different types of nervous system vasculitides including PACNS, giant-cell arteritis, Takayasu's arteritis, polyarteritis nodosa, ANCA (anti-neutrophil cytoplasm antibody)-associated vasculitides, cryoglobulinemic vasculitis, IgA vasculitis, and Behçet's disease. Overall, the majority of biomarkers is not specific for vasculitides of the nervous system.

Leptin in autoimmune mechanisms of systemic rheumatic diseases

In the last two decades, white adipose tissue (WAT) has been recognized as a key actor of many physiological and pathological conditions. WAT is able to produce mediators, named "adipokines", which may affect systemic homeostasis. In particular, leptin is not only involved in appetite and energy metabolism, but also in immune system. Increasing evidence established that leptin can regulate both innate and adaptive immunity mainly with pro-inflammatory effects but also, to a lesser extent, with anti-inflammatory features. In autoimmune diseases, a failure or breakdown of the mechanisms of self-tolerance is observed. Leptin, which plays an important role in the control of immune balance, has been involved in autoimmunity generation and maintenance. In this review, it has been provided an up-to-date report about the role of leptin in systemic autoimmune diseases, with particular reference to connective tissue diseases, inflammatory arthritis, and vasculitis.

Soluble-HLA-E: A follow up biomarker in Takayasu arteritis, independent of HLA-E genotype

AIM

Disease activity assessment in Takayasu arteritis (TA) is challenging. Human leukocyte antigen E (HLA-E) is shed from endothelium into serum as a soluble molecule (sHLA-E) in response to inflammation. We aimed to study: (i) utility of sHLA-E as a biomarker of disease activity; and (ii) association of HLA-E polymorphism rs1264457 with clinical disease in Asian-Indian TA patients.

MATERIALS AND METHODS

In phase-1, sHLA-E levels were estimated in sera of 50 consecutive TA patients at baseline visit and 27 healthy controls. Serial estimations were performed in 27 of them. In phase-2, DNA of 150 TA patients and 264 healthy controls were genotyped for rs1264457 polymorphism.

RESULTS

At baseline visit, disease was classified as active, stable and grumbling in 23, 18 and nine patients, respectively. sHLA-E levels were higher in active TA (43; interquartile range [IQR]: 25.3-64.6) pg/mL) than stable disease (12.9; IQR: 7.6-21.6 pg/mL) (P = 0.001). At first follow-up visit, sHLA-E levels were numerically higher in active disease than stable disease (P = 0.06) but this trend was blunted at second follow-up. sHLA-E levels increased in 54% versus 25% of patients with persistently active/relapsing and persistent stable course, respectively. rs1264457 polymorphism was not associated with susceptibility to TA and did not affect sHLA-E levels.

CONCLUSION

sHLA-E level is useful as a biomarker of disease activity and course in TA patients. rs1264457 polymorphism is neither associated with susceptibility nor did it influence sHLA-E levels in TA.

The Role of Perivascular Adipose Tissue in Non-atherosclerotic Vascular Disease

Perivascular adipose tissue (PVAT) surrounds most large blood vessels and plays an important role in vascular homeostasis. PVAT releases various chemokines and adipocytokines, functioning in an endocrine and paracrine manner to regulate vascular signaling and inflammation. Mounting evidence suggests that PVAT plays an important role in atherosclerosis and hypertension; however, the role of PVAT in non-atherosclerotic vascular diseases, including neointimal formation, aortic aneurysm, arterial stiffness and vasculitis, has received far less attention. Increasing evidence suggests that PVAT responds to mechanical endovascular injury and regulates the subsequent formation of neointima via factors that promote smooth muscle cell growth, adventitial inflammation and neovascularization. Circumstantial evidence also links PVAT to the pathogenesis of aortic aneurysms and vasculitic syndromes, such as Takayasu's arteritis, where infiltration and migration of inflammatory cells from PVAT into the vascular wall may play a contributory role. Moreover, in obesity, PVAT has been implicated to promote stiffness of elastic arteries via the production of reactive oxygen species. This review will discuss the growing body of data and mechanisms linking PVAT to the pathogenesis of non-atherosclerotic vascular diseases in experimental animal models and in humans.

Low prevalence of obesity in Behçet's disease is associated with high obestatin level

OBJECTIVE

Chronic inflammatory diseases are associated with altered body composition. Ghrelin has anti-inflammatory effects, and its level is altered in obesity and inflammatory diseases. The aim of the study was to evaluate the prevalence of obesity and ghrelin and obestatin levels in patients with Behçet's disease (BD).

MATERIAL AND METHODS

One hundred and forty-three (143) patients with BD and 112 healthy controls (HC) were enrolled. Participants were subdivided according to the body mass index (BMI) as lean (<18.5 kg/m²), normal weight (18.5-24.9 kg/m²), overweight (25-29.9 kg/m²) and obese (≥30 kg/m²). In addition to the routine evaluations (fasting blood glucose, lipid profile, and kidney and liver function tests), serum acylated-ghrelin (AG), unacylated-ghrelin (UAG), total ghrelin (TG) and obestatin levels were analyzed. Student's t-test and chi-square test were used for statistical analysis.

RESULTS

The prevalence of obesity was relatively lower in the BD group than in the HC group (12.6% vs. 20.5%, p=0.089). Serum ghrelin levels were similar in the BD and HC groups (p>0.05 for all) although the obestatin level was higher in the BD group compared to the HC group (p<0.001). Serum UAG, TG and obestatin levels were lower in obese BD patients (n=18) than non-obese BD patients (p=0.027, p=0.014 and p=0.001, respectively).

CONCLUSION

The obestatin level was high and the prevalence of obesity was low in the BD group. Moreover, obese BD patients had low obestatin levels. These results suggest that obestatin may protect BD patients from obesity.

Outcome assessment in Takayasu arteritis

Takayasu arteritis (TAK) is a systemic granulomatous large-vessel vasculitis with a phenotype that overlaps with GCA and defined by the 1993 and 2012 Chapel Hill Consensus Conference statements. However, the diagnosis of TAK is often delayed since TAK patients may be asymptomatic or have non-specific symptoms. Once a diagnosis is made, it is difficult to judge remission or recurrence since there are no reliable assessment tools. With the availability of newer agents, such as cytokine blockade, which are being evaluated in GCA, there is the potential for real advances in TAK patient management. Without reliable assessment tools it will be difficult to introduce newer agents in an organized way or to optimally benefit patients in the future. In this article we review the use and performance of disease indicators in TAK clinical trials as a basis for the further development of assessment tools for this disease.

Outcome measures for Takayasu's arteritis

PURPOSE OF REVIEW

Takayasu's arteritis (TAK) is a large-vessel vasculitis with a chronic, indolent course affecting the aorta and its main branches. This review will describe the recent studies to develop validated outcome measures to assess TAK.

RECENT FINDINGS

TAK is traditionally assessed with a physician's global assessment including symptoms and signs of inflammation and vascular insufficiency, acute-phase reactants (APRs), and imaging including conventional digital subtraction angiography, computerized tomographic, and magnetic resonance angiography, and recently 18-FDG-PET. Recent attempts to develop a validated tool for disease assessment include the Indian Takayasu Clinical Activity Score (ITAS2010), which incorporates clinical signs and symptoms with APRs in a simplified and weighted adoption of the Birmingham Vasculitis Activity Score. Among biomarkers to assess clinical activity, pentraxin-3 is perhaps the most promising, but its validity and superiority against APRs in clinical practice need to be demonstrated. Patient-reported outcomes (PROs) are increasingly recognized as of substantial importance to measure in clinical trials; in addition to so-called 'generic' tools such as the SF-36 or measures of fatigue, disease-specific instruments would likely help capture aspects of TAK not measured by generic quality-of-life assessments or physician-based tools.

SUMMARY

Although outcome measures for TAK are not sufficiently validated, progress in the assessment of TAK is reflected in recent studies with new tools such as ITAS2010, new biomarkers, and a variety of PROs.

Role of inflammatory markers in Takayasu arteritis disease monitoring

Background

Takayasu arteritis (TA) is an idiopathic large-vessel vasculitis that can result in significant morbidity and mortality secondary to progressive stenosis and occlusion. Monitoring disease progression is crucial to preventing relapse, but is often complicated by the lack of clinical symptoms in the setting of active disease. Although acute phase reactants such as ESR and CRP are generally used as an indicator of inflammation and disease activity, mounting evidence suggests that these markers cannot reliably distinguish active from inactive TA.

Case presentation

We report a 24-year-old Hispanic female with a 5-year history of TA who presented with stroke-like symptoms and evidence of left MCA occlusion on imaging, despite a history of decreasing inflammatory markers. CTA revealed complete occlusion of the left common carotid artery, left subclavian, and left MCA from their origins. It also revealed a striking compensatory circulation supplying the left anterior circulation as well as the left subclavian as a response to progressive stenosis.

Conclusion

Monitoring ESR and CRP levels alone may not be a reliable method to evaluate disease progression in patients with TA, and should be taken in context with both patient’s clinical picture and the imaging. We recommend that serial imaging be performed regularly in the setting of active disease to monitor progression and allow for immediate therapy in response to evidence of disease advancement, with a relaxation of the imaging interval once the disease is presumed inactive.