Fine particulate matter (PM2.5) inhalation-induced alterations in the plasma lipidome as promoters of vascular inflammation and insulin resistance.

Fine particulate matter (PM2.5) air pollution exposure increases the risk of developing cardiovascular disease (CVD). Although the precise mechanisms by which air pollution exposure increases CVD risk remain uncertain, research indicates that PM2.5-induced endothelial dysfunction contributes to CVD risk. Previous studies demonstrate that concentrated ambient PM2.5 (CAP) exposure induces vascular inflammation and impairs insulin and vascular endothelial growth factor (VEGF) signaling dependent on pulmonary oxidative stress. To assess whether CAP exposure induces these vascular effects via plasmatic factors, we incubated aortas from naïve mice with plasma isolated from mice exposed to HEPA-filtered air or CAP (9 days) and examined vascular inflammation and insulin and VEGF signaling. We found that treatment of naïve aortas with plasma from CAP-exposed mice activates NF-κBα and induces insulin and VEGF resistance, indicating transmission by plasmatic factor(s). To identify putative factors, we exposed lung-specific ecSOD-transgenic (ecSOD-Tg) mice and wild-type (WT) littermates to CAP at concentrations of either ∼60 µg/m3 (CAP60) or ∼100 µg/m3 (CAP100) and measured the abundance of plasma metabolites by mass spectrometry. In WT mice, both CAP concentrations increased levels of fatty acids such as palmitate, myristate, and palmitoleate and decreased numerous phospholipid species; however, these CAP-induced changes in the plasma lipidome were prevented in ecSOD-Tg mice. Consistent with the literature, we found that fatty acids such as palmitate are sufficient to promote endothelial inflammation. Collectively, our findings suggest that PM2.5 exposure, by inducing pulmonary oxidative stress, promotes unique lipidomic changes characterized by high levels of circulating fatty acids, which are sufficient to trigger vascular pathology.NEW & NOTEWORTHY We found that circulating plasma constituents are responsible for air pollution-induced vascular pathologies. Inhalation of fine particulate matter (≤PM2.5) promotes a unique form of dyslipidemia that manifests in a manner dependent upon pulmonary oxidative stress. The air pollution-engendered dyslipidemic phenotype is characterized by elevated free fatty acid species and diminished phospholipid species, which could contribute to vascular inflammation and loss of insulin sensitivity.

Sustained Focal Vascular Inflammation Accelerates Atherosclerosis in Remote Arteries.

OBJECTIVE: Evidence from preclinical and clinical studies has demonstrated that myocardial infarction promotes atherosclerosis progression. The impact of focal vascular inflammation on the progression and phenotype of remote atherosclerosis remains unknown. Approach and Results: We used a novel ApoE-/- knockout mouse model of sustained arterial inflammation, initiated by mechanical injury in the abdominal aorta. Using serial in vivo molecular MRI and ex vivo histology and flow cytometry, we demonstrate that focal arterial inflammation triggered by aortic injury, accelerates atherosclerosis in the remote brachiocephalic artery. The brachiocephalic artery atheroma had distinct histological features including increased plaque size, plaque permeability, necrotic core to collagen ratio, infiltration of more inflammatory monocyte subsets, and reduced collagen content. We also found that arterial inflammation following focal vascular injury evoked a prolonged systemic inflammatory response manifested as a persistent increase in serum IL-6 (interleukin 6). Finally, we demonstrate that 2 therapeutic interventions-pravastatin and minocycline-had distinct anti-inflammatory effects at the plaque and systemic level. CONCLUSIONS: We show for the first time that focal arterial inflammation in response to vascular injury enhances systemic vascular inflammation, accelerates remote atheroma progression and induces plaques more inflamed, lipid-rich, and collagen-poor in the absence of ischemic myocardial injury. This inflammatory cascade is modulated by pravastatin and minocycline treatments, which have anti-inflammatory effects at both plaque and systemic levels that mitigate atheroma progression.

18F-FDG PET/MRI compared with clinical and serological markers for monitoring disease activity in patients with aortitis and chronic periaortitis.

OBJECTIVES: We compared the diagnostic value of fully integrated 18F-FDG PET/MRI to that of clinical and serological markers for monitoring disease activity in patients with aortitis/chronic periaortitis (A/CPA) during immunosuppressive therapy. METHODS: Patients positive for A/CPA at the initial and at least 2 consecutive PET/MRI studies were included for retrospective analysis. Imaging (qualitative and quantitative analysis), clinical, and serologic (C-reactive protein, erythrocyte sedimentation rate) assessments were determined at each visit, and their findings compared. Differences in various PET/MRI parameters, clinical symptoms, and serologic markers during therapy between first and second visits were tested for statistical significance. Spearman's rank correlation coefficient was calculated to relate imaging to serologic marker changes between the first 2 visits. RESULTS: Serial assessments were performed in 12 patients with A/CPA, over 34 visits. PET/MRI suggested active disease in 22/34 (64.7%) studies, whereas clinical assessment and serological analysis were positive in only 18/34 (52.9%) and 17/34 (50%) cases, respectively. Disease activity assessment differed between PET/MRI, and clinical and serological markers, in 8/34 (23.5%) and 9/34 (26.5%) cases, respectively. Imaging and serologic parameters (p < 0.009) and clinical symptoms (p = 0.063) predominantly improved at the second visit. Changes from the first to the second visit were not correlated between PET/MRI and serologic markers. CONCLUSIONS: Fully integrated 18F-FDG PET/MRI provides a comprehensive imaging approach with data on vascular/perivascular inflammation that is complementary to clinical and laboratory assessments. This highlights the potential value of imaging-based disease activity monitoring, which might have a crucial impact on clinical management in patients with A/CPA.

Mechanism and biomarkers in aortitis--a review.

Aortitis can be the manifestation of an underlying infectious or noninfectious disease process. An autoimmune cause is suggested in a large proportion of noninfectious causes. Similar to other autoimmune diseases, the pathophysiology of aortitis has been investigated in detail, but the etiology remains unknown. Most cases of aortitis often go undetected for a long time and are often identified at late stages of the disease. Recent advances in imaging techniques have significantly improved the diagnosis of aortitis. However, significant challenges associated with the imaging techniques limit their use. Several routine inflammation-based markers, such as erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and inflammatory cytokines, are nonspecific and, therefore, have limited use in the diagnosis of aortitis. The search for more specific serum biomarkers, which can facilitate detection and progression is under progress. Several autoantibodies have been identified, but assigning their role in the pathogenesis as well as their specificity remains a challenge. The current review addresses some of these issues in detail. KEY MESSAGES: • Noninfectious aortitis is an autoimmune disease. • Several biomarkers, including cytokines and autoantibodies, are increased in aortitis. • Imaging techniques, commonly used to detect aortitis, are associated with the high cost and technical challenges. • There is a need to develop low-cost biomarker-based detection tools. • The knowledge of biomarkers in aortitis detection is discussed.

Renal cystic disease in the Fbn1C1039G/+ Marfan mouse is associated with enhanced aortic aneurysm formation.

Marfan syndrome (MFS) is a connective tissue disorder caused by mutations in the fibrillin-1 gene (FBN1), resulting in aortic aneurysm formation and dissections. Interestingly, variable aortopathy is observed even within MFS families with the same mutation. Thus, additional risk factors determine disease severity. Here, we describe a case of a 2-month-old Fbn1C1039G/+ MFS mouse with extreme aortic dilatation and increased vascular inflammation, when compared to MFS siblings, which coincided with unilateral renal cystic disease. In addition, this mouse presented with increased serum levels of creatinine, angiotensin-converting enzyme, corticosterone, macrophage chemoattractant protein-1, and interleukin-6, which may have contributed to the vascular pathology. Possibly, cystic kidney disease is associated with aneurysm progression in MFS patients. Therefore, we propose that close monitoring of the presence of renal cysts in MFS patients, during regular vascular imaging of the whole aorta trajectory, may provide insight in the frequency of cystic kidney disease and its potential as a novel indicator of aneurysm progression in MFS patients.

The many faces of IgG4-related disease: report of a case with inaugural recurrent aortic aneurism ruptures and literature review.

Vascular involvement in IgG4-related disease (IgG4-RD), is a well-recognized feature and large vessel commitment, especially the aorta, can be the only manifestation of the disease. Being a newly recognized disease, its diagnosis and workup still represents a challenge in clinical practice. A 47-year-old-man with two aortic aneurysms ruptures, one at abdominal and the other at thoracic level, was referred to our rheumatology department. The initial analysis of the surgical specimen obtained 3 years earlier revealed a nonspecific aortitis. Re-evaluation of the biopsy with immunohistology now demonstrated the presence of IgG4 deposits. Evidence-based recommendations regarding diagnosis, treatment and follow-up of IgG4-related large-vessel involvement are lacking. In this particular case, histopathology were crucial. The authors review and discuss vascular involvement in IgG4-RD and respective treatment options.

Clinical characteristics and outcomes of 61 patients with chronic periaortitis including IgG4-related and non-IgG4-related cases.

AIM: Chronic periaortitis (CP) is a disease characterized by a fibro-inflammatory periaortic cuff and adventitia-predominant fibrosis. CP encompasses idiopathic retroperitoneal fibrosis and inflammatory abdominal aortic aneurysm (AAA), and recent studies have documented overlap between CP and immunoglobulin G4-related disease (IgG4-RD). This study aimed to investigate clinical characteristics and treatment outcomes of patients with CP. METHOD: CP patients were identified by retrospective review of 1245 patients with International Classification of Diseases 10th edition code of aortitis or aortic disease. Patients were further classified into IgG4-related and non-IgG4-related CP according to the criteria proposed by a Japanese study. RESULTS: A total of 61 CP patients were identified. Patients showed a male predominance (70%) with median age of 61 at diagnosis. The abdominal aorta was most commonly involved (84%), while the thoracic aorta was affected in 46% of patients. Twenty-three (38%) patients had accompanying aortic aneurysm. Approximately 60% of patients achieved remission without further relapse during the course. Ten patients were classified as IgG4-related and 25 as non-IgG4-related. There was no significant difference in clinical features and outcomes between groups, with the exception of older age and greater pancreas involvement in IgG4-related patients. CONCLUSION: We documented 61 CP patients including 10 IgG4-related cases. CP involved the abdominal aorta in most patients and the thoracic aorta in approximately 50% of patients. IgG4-related CP patients were older and had greater pancreas involvement, but disease outcomes appeared to be similar between IgG4-related and non-IgG4-related CP.

IgG4-Aortopathy: An Underappreciated Cause of Non-Infectious Thoracic Aortitis.

IgG4 related thoracic aortitis is a recent addition to the differential diagnosis for inflammatory aortic disease - a condition which is often underappreciated until complications arise such as aneurysmal formation or aortic dissection. Currently, IgG4 aortitis remains a post-surgical diagnosis reliant on positive immunohistochemistry findings. Management is guided by the extent of disease involvement, which can be gauged by serum IgG4 levels and radiological findings. Options include surgical resection, corticosteroid therapy and steroid-sparing agents to prevent relapses.

Severity of Psoriasis Associates With Aortic Vascular Inflammation Detected by FDG PET/CT and Neutrophil Activation in a Prospective Observational Study.

OBJECTIVE: To understand whether directly measured psoriasis severity is associated with vascular inflammation assessed by (18)F-fluorodeoxyglucose positron emission tomography computed tomography. APPROACH: In-depth cardiovascular and metabolic phenotyping was performed in adult psoriasis patients (n=60) and controls (n=20). Psoriasis severity was measured using psoriasis area severity index. Vascular inflammation was measured using average aortic target-to-background ratio using (18)F-fluorodeoxyglucose positron emission tomography computed tomography. RESULTS: Both the psoriasis patients (28 men and 32 women, mean age 47 years) and controls (13 men and 7 women, mean age 41 years) were young with low cardiovascular risk. Psoriasis area severity index scores (median 5.4; interquartile range 2.8-8.3) were consistent with mild-to-moderate skin disease severity. Increasing psoriasis area severity index score was associated with an increase in aortic target-to-background ratio (ß=0.41, P=0.001), an association that changed little after adjustment for age, sex, and Framingham risk score. We observed evidence of increased neutrophil frequency (mean psoriasis, 3.7±1.2 versus 2.9±1.2; P=0.02) and activation by lower neutrophil surface CD16 and CD62L in blood. Serum levels of S100A8/A9 (745.1±53.3 versus 195.4±157.8 ng/mL; P<0.01) and neutrophil elastase-1 (43.0±2.4 versus 30.8±6.7 ng/mL; P<0.001) were elevated in psoriasis. Finally, S100A8/A9 protein was related to both psoriasis skin disease severity (ß=0.53; P=0.02) and vascular inflammation (ß=0.48; P=0.02). CONCLUSIONS: Psoriasis severity is associated with vascular inflammation beyond cardiovascular risk factors. Psoriasis increased neutrophil activation and neutrophil markers, and S100A8/A9 was related to both skin disease severity and vascular inflammation.

Perfusion-based assessment of disease activity in untreated and treated patients with aortitis and chronic periaortitis: correlation with CT morphological, clinical and serological data.

OBJECTIVE: To evaluate the role of perfusion-based assessment of inflammatory activity in patients with treated and untreated aortitis and chronic periaortitis as compared with clinical and serological markers. METHODS: 35 patients (20 females; median age 66 years) with (peri) aortitis were retrospectively evaluated. All patients had clinical symptoms prompting at the time of imaging. All patients first underwent whole-body contrast-enhanced CT and subsequently segmental volume perfusion CT for assessment of the degree of vascularization of (peri) aortitis as a surrogate marker for inflammatory activity. Blood flow, blood volume, volume transfer constant (k-trans), time to peak and mean transit time were determined. The thickness of the increased connective tissue formation was measured. Perfusion data were correlated with clinical symptoms and acute-phase inflammatory parameters such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and leukocyte number. RESULTS: 21 of 35 patients were untreated and 14 of 35 had previous/ongoing immunosuppression. The interobserver agreement was good (κ = 0.78) for all perfusion parameters. Average values of perfusion parameters were higher in untreated patients but remained abnormally elevated in treated patients as well. Perfusion data and ESR and CRP correlated well both in aortitis (p < 0.05) and in periaortitis (p < 0.05). In periaortitis, perfusion parameters agreed well with ESR and CRP values (p < 0.05) only in untreated patients. CONCLUSION: Perfusion CT parameters in untreated aortitis and chronic periaortitis correlate well with serological markers with respect to disease activity assessment. However, in treated periaortitis, correlations were weak, suggesting an increased role for (perfusion-based) imaging. ADVANCES IN KNOWLEDGE: Volume perfusion CT may be used for diagnosis of aortitis/periaortitis.

Systemic Atherosclerotic Inflammation Following Acute Myocardial Infarction: Myocardial Infarction Begets Myocardial Infarction.

BACKGROUND: Preclinical data suggest that an acute inflammatory response following myocardial infarction (MI) accelerates systemic atherosclerosis. Using combined positron emission and computed tomography, we investigated whether this phenomenon occurs in humans. METHODS AND RESULTS: Overall, 40 patients with MI and 40 with stable angina underwent thoracic 18F-fluorodeoxyglucose combined positron emission and computed tomography scan. Radiotracer uptake was measured in aortic atheroma and nonvascular tissue (paraspinal muscle). In 1003 patients enrolled in the Global Registry of Acute Coronary Events, we assessed whether infarct size predicted early (≤30 days) and late (>30 days) recurrent coronary events. Compared with patients with stable angina, patients with MI had higher aortic 18F-fluorodeoxyglucose uptake (tissue-to-background ratio 2.15±0.30 versus 1.84±0.18, P<0.0001) and plasma C-reactive protein concentrations (6.50 [2.00 to 12.75] versus 2.00 [0.50 to 4.00] mg/dL, P=0.0005) despite having similar aortic (P=0.12) and less coronary (P=0.006) atherosclerotic burden and similar paraspinal muscular 18F-fluorodeoxyglucose uptake (P=0.52). Patients with ST-segment elevation MI had larger infarcts (peak plasma troponin 32 300 [10 200 to >50 000] versus 3800 [1000 to 9200] ng/L, P<0.0001) and greater aortic 18F-fluorodeoxyglucose uptake (2.24±0.32 versus 2.02±0.21, P=0.03) than those with non-ST-segment elevation MI. Peak plasma troponin concentrations correlated with aortic 18F-fluorodeoxyglucose uptake (r=0.43, P=0.01) and, on multivariate analysis, independently predicted early (tertile 3 versus tertile 1: relative risk 4.40 [95% CI 1.90 to 10.19], P=0.001), but not late, recurrent MI. CONCLUSIONS: The presence and extent of MI is associated with increased aortic atherosclerotic inflammation and early recurrent MI. This finding supports the hypothesis that acute MI exacerbates systemic atherosclerotic inflammation and remote plaque destabilization: MI begets MI. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01749254.

[IgG4-related disease, the new "great mimicker": report of one case]. / Enfermedad relacionada a IgG4, el nuevo "gran simulador": caso clínico.

Due to its multisystem involvement, IgG4 -related disease should be considered in the differential diagnosis of medical conditions such as lymphadenopathies, aortitis, serositis and retroperitoneal fibrosis. It shares features with other entities historically described as "great mimickers" such as syphilis, tuberculosis, sarcoidosis, and systemic lupus erythematosus. We report a 40 year-old male with recurrent effusive - constrictive pericarditis, lymphadenopathy and aortitis. The study revealed an inactive tuberculosis with negative cultures for acid fast bacilli. The patient had high serum levels of IgG4 and a mediastinal lymph node biopsy was consistent with IgG4 -related disease. The patient was treated with prednisone 40 mg/day with an excellent response.

Enfermedad relacionada a IgG4, el nuevo "gran simulador": caso clínico / IgG4-related disease, the new "great mimicker": Report of one case

Due to its multisystem involvement, IgG4 -related disease should be considered in the differential diagnosis of medical conditions such as lymphadenopathies, aortitis, serositis and retroperitoneal fibrosis. It shares features with other entities historically described as "great mimickers" such as syphilis, tuberculosis, sarcoidosis, and systemic lupus erythematosus. We report a 40 year-old male with recurrent effusive - constrictive pericarditis, lymphadenopathy and aortitis. The study revealed an inactive tuberculosis with negative cultures for acid fast bacilli. The patient had high serum levels of IgG4 and a mediastinal lymph node biopsy was consistent with IgG4 -related disease. The patient was treated with prednisone 40 mg/day with an excellent response.

Peroxisome proliferator-activated receptor δ agonist GW1516 attenuates diet-induced aortic inflammation, insulin resistance, and atherosclerosis in low-density lipoprotein receptor knockout mice.

OBJECTIVE: The peroxisome proliferator-activated receptor (PPAR) δ regulates systemic lipid homeostasis and inflammation. However, the ability of PPARδ agonists to improve the pathology of pre-established lesions and whether PPARδ activation is atheroprotective in the setting of insulin resistance have not been reported. Here, we examine whether intervention with a selective PPARδ agonist corrects metabolic dysregulation and attenuates aortic inflammation and atherosclerosis. APPROACH AND RESULTS: Low-density lipoprotein receptor knockout mice were fed a chow or a high-fat, high-cholesterol (HFHC) diet (42% fat, 0.2% cholesterol) for 4 weeks. For a further 8 weeks, the HFHC group was fed either HFHC or HFHC plus GW1516 (3 mg/kg per day). GW1516 significantly attenuated pre-established fasting hyperlipidemia, hyperglycemia, and hyperinsulinemia, as well as glucose and insulin intolerance. GW1516 intervention markedly reduced aortic sinus lesions and lesion macrophages, whereas smooth muscle α-actin was unchanged and collagen deposition enhanced. In aortae, GW1516 increased the expression of the PPARδ-specific gene Adfp but not PPARα- or γ-specific genes. GW1516 intervention decreased the expression of aortic proinflammatory M1 cytokines, increased the expression of the anti-inflammatory M2 cytokine Arg1, and attenuated the iNos/Arg1 ratio. Enhanced mitogen-activated protein kinase signaling, known to induce inflammatory cytokine expression in vitro, was enhanced in aortae of HFHC-fed mice. Furthermore, the HFHC diet impaired aortic insulin signaling through Akt and forkhead box O1, which was associated with elevated endoplasmic reticulum stress markers CCAAT-enhancer-binding protein homologous protein and 78kDa glucose regulated protein. GW1516 intervention normalized mitogen-activated protein kinase activation, insulin signaling, and endoplasmic reticulum stress. CONCLUSIONS: Intervention with a PPARδ agonist inhibits aortic inflammation and attenuates the progression of pre-established atherosclerosis.

Gamma glutamyl transferase activity: relationship with thoracic aortic intima media thickness and inflammation.

OBJECTIVE: Increased serum gamma-glutamyl transferase (GGT) activity is known to be associated with atherosclerotic diseases. Thoracic aortic intima-media thickness (IMT) was reported as a marker of preclinical atherosclerosis. However, there is a lack of research directly examining the relationship between serum GGT activity and thoracic aortic IMT. Therefore, we aimed to investigate the association between serum GGT activity and thoracic aortic IMT. PATIENTS AND METHODS: The study population consisted of 329 patients without coronary artery disease, who underwent transesophageal echocardiography (TEE) examination for various indications from January 2011 to April 2013. GGT, high-sensitivity C-reactive protein (hs-CRP) and other biochemical markers were measured in all patients. The patients were classified into tertiles according to their GGT activities (GGTlow < 19 U/l, GGTmid ≥ 19 U/l < 29 U/l, and GGThigh ≥ 29). RESULTS: The highest aortic IMT values were observed in the GGThigh group compared with the GGTmid and GGTlow groups (p < 0.05, for all). Also, aortic IMT values in the GGTmid group were higher than in the GGTlow group (p < 0.05). Multivariate regression analysis showed that GGT activity was independently associated with aortic IMT (ß = 0.487, p < 0.001) hs-CRP (ß = 0.282, p < 0.001), and triglyceride level (ß = 0.161, p = 0.007). CONCLUSION: The higher serum GGT concentrations within the "normal" range were associated with a greater IMT of the thoracic aorta. GGT activity may be a predictor of the extent of subclinical aortic atherosclerosis assessed with thoracic aortic IMT.

Inflammatory thoracic aortic aneurysm (lymphoplasmacytic thoracic aortitis): a 13-year-experience at a German Heart Center with emphasis on possible role of IgG4.

BACKGROUND & AIM: Aortic aneurysms represent one of the major causes of cardiovascular surgery. Their etiology varies greatly based on patient's age and other clinicopathologic determinants. In addition to common atherosclerotic vascular diseases, an inflammatory etiology, in particular IgG4-related disease (IgG4-RD) has increasingly emerged as a cause of dissecting inflammatory aortic aneurysms (IAA). METHODS: To assess the frequency and types of IAA, we reviewed all cases of aortic aneurysms resected at our Erlangen Heart Center during 2000-2013. RESULTS: 376 patients underwent resection of aortic aneurysms in the study period. These are further categorized as ascending aortic aneurysms (45%), aortic arch aneurysm (2%), descending aortic aneurysm (3%), type A dissection (46%) and type B dissection (4%). Fifteen cases (4%) showed variable lymphoplasmacytic inflammation thus qualifying as IAA. Affected were 9 females and 6 males (female to male ratio = 1.5:1; age range: 52-80 yrs; mean: 70 yrs; median: 72 yrs). None was known to have IgG4-RD and serum IgG4 and/or IgG levels (known in 6 cases) were normal. Variable sclerosing lymphoplasmacytic inflammation was seen either confined to the adventitia (periaortitis; mainly in males) or extending through all layers (mainly in females). A wide range of IgG4 plasma cells (range: 3-182/HPF; mean: 51/HPF) and IgG4: IgG ratios (range: 0.02 to 0.91; mean: 0.37) were detected. All but one of the cases with at least focally transmural inflammation showed a higher IgG4: IgG ratios in excess of 0.3 (range, 0.32-0.91; median, 0.62). Lymphoid follicle and variable fibrosis were common but obliterative phlebitis was not seen. CONCLUSION: IgG4-rich sclerosing lymphoplasmacytic thoracic aortitis is a constant histological feature of thoracic IAA. Normal serum IgG4 in most patients, predilection for women and absence of other features of IgG4-RD all suggest a tissue-specific localized autoimmunological process and argue against a systemic disorder. The relationship (if any) of IgG4-rich lymphoplasmacytic thoracic aortitis in those patients with IAA lacking other organ manifestations or an elevated serum IgG4 level to systemic IgG4-RD remains unclear and merit further studies.