Genome-wide methylation profiles in coronary artery ectasia.

Coronary artery ectasia (CAE) is a disease characterized by abnormally dilated coronary arteries. The mechanism of CAE remains unclear, and its treatment is limited. Previous studies have shown that risk factors for CAE were related to changes in DNA methylation. However, no systematic investigation of methylation profiles has been performed. Therefore, we compared methylation profiles between 12 CAE patients and 12 propensity-matched individuals with normal coronary arteries using microarrays. Wilcoxon's rank sum tests revealed 89 genes with significantly different methylation levels (P<0.05 and Δß > |0.1|). Functional characterization using the DAVID database and gene set enrichment analysis indicated that these genes were involved in immune and inflammatory responses. Of these genes 6 were validated in 29 CAE patients and 87 matched individuals with CAE, using pyro-sequencing. TLR6 and NOTCH4 showed significant differences in methylation between the two groups, and lower protein levels of toll-like receptor 6 (TLR6) were detected in CAE patients. In conclusion, this genome-wide analysis of methylation profiles in CAE patients showed that significant changes in both methylation and expression of TLR6 deserve further study to elucidate their roles in CAE.

Coronary artery ectasia and inflammatory cytokines: link with a predominant Th-2 immune response?

OBJECTIVE: The role of inflammation in coronary artery ectasia (CAE) remains controversial. We evaluated the hypothesis that CAE might be associated with a specific pattern of T helper (Th) lymphocyte activation by measuring the Th-1 cytokine, interleukin-2 (IL-2) and the Th-2 cytokines, interleukin-4 (IL-4) and interleukin-6 (IL-6) in patients with CAE, obstructive coronary artery disease (CAD) and controls. METHODS: Serum levels of IL-2, IL-4 and IL-6 were measured in 74 patients undergoing an elective cardiac catheterization due to angina pectoris and positive or equivocal non-invasive screening for cardiac ischaemia: 34 had CAE and non-obstructive CAD (Group A), 22 had obstructive CAD (Group B) and 18 had normal coronaries (Group C). RESULTS: Group A had significantly higher IL-4 than Group B and Group C (p<0.001 and p=0.006, respectively). In contrast, Group A had markedly lower IL-2 than Group B and Group C (p<0.001 for both comparisons). Group C had higher IL-4 and lower IL-2 than Group B (p<0.001 for both comparisons). Interleukin-6 was significantly higher in Groups A and B compared to Group C (p<0.001 for both comparisons), whilst it was comparable between Group A and Group B. Multivariate logistic regression analysis showed that higher levels of IL-4 and lower levels of IL-2 were the strongest independent predictors associated with CAE (OR: 3.846, CI: 1.677-8.822, p=0.001 and OR: 0.567, CI: 0.387-0.831, p=0.004, respectively). CONCLUSIONS: Our data demonstrates that Th-2 immune response, exhibited through increased IL-4 and low IL-2, constitutes a fundamental feature of CAE.

Inflammatory proteins and the severity of dilated Virchow-Robin Spaces in the elderly.

Recent studies suggest dilated Virchow-Robin Spaces (dVRS) could be a manifestation of cerebral small-vessel disease, but little is known about their risk factors. As inflammation has been associated with other brain MRI findings, we investigated whether interleukin-6 and C-reactive protein were associated with the severity of dVRS in the eldery. dVRS were assessed in basal ganglia and white matter and rated on a severity scale. We found that elevated interleukin-6 levels were associated with higher severity of dVRS in basal ganglia, suggesting that inflammation might be associated with the burden of dVRS in the elderly.

Relation of maternal anti-Ro/La antibodies to aortic dilation in patients with congenital complete heart block.

An association between congenital complete atrioventricular block (cCAVB) and aortic dilation during childhood has recently been reported. We sought to further explore this relation with particular emphasis on the natural history of aortic abnormalities over time. The relation of maternal anti-Ro/La antibody status to the aortic size of children affected with cCAVB was also assessed. The patients were evaluated longitudinally with serial echocardiography. During a 15-year period, 62 patients at our institution were diagnosed with cCAVB, of whom 40% were exposed to maternal autoimmune antibodies and 35% were not. The antibody status in the remaining patients was unknown. The patients underwent 9.3 ± 6.5 echocardiograms during the follow-up period. Dilation of the ascending aorta, defined as a z score >2.0, was present on the initial echocardiogram in all patients exposed to maternal antibodies and persisted during long-term follow-up in 96% of these patients. In contrast, 5% and 10% of patients without exposure to maternal autoimmune antibodies had aortic dilation on the initial and follow-up studies, respectively (p <0.001 and p <0.001, respectively). In conclusion, patients with autoimmune-mediated cCAVB merit periodic echocardiographic monitoring into adulthood to assess persistent or progressive aortic dilation and its attendant complications.

Vascular biology in sepsis: pathophysiological and therapeutic significance of vascular dysfunction.

Sepsis is the leading cause of mortality in critically ill patients. In this pathological syndrome, septic shock and sequential multiple organ failure correlate with poor outcome. The pathophysiology of sepsis with acute organ dysfunction involves a highly complex, integrated response that includes activation of number of cell types, inflammatory mediators, and the hemostatic system. Central to this process may be alterations in vascular functions. This review article provides a growing body of evidence for the potential impact of vascular dysfunction on sepsis pathophysiology with a major emphasis on the endothelium. Furthermore, the role of apoptotic signaling molecules in the mechanisms underlying endothelial cell injury and death during sepsis and its potential value as a target for sepsis therapy will be discussed, which may help in the assessment of ongoing therapeutic strategies.

Plasma interleukin-6 levels are increased in coronary artery ectasia.

OBJECTIVE: Recent studies have suggested a cytokine-induced tissue inflammation in the pathogenesis of abdominal aortic aneurysms and it has been documented that circulating interleukin-6 (IL-6) levels in these patients are increased. The aim of this study was to investigate whether a similar association also exists for patients with coronary ectasia, which may also be regarded as an abnormal dilatation of the arterial system. METHODS AND RESULTS: The study group was composed of 43 patients with coronary ectasia and 48 patients with normal coronary arteries constituted the control group. Coronary diameters were measured by quantitative angiography. A coronary diameter index was defined for each segment as the coronary diameter divided by the body surface area (BSA). A coronary segment with a diameter index of more than 1.5 fold of the control group was defined as ectatic. Baseline characteristics of the two groups were similar. Serum IL-6 levels were significantly higher in patients with coronary ectasia (5.18 +/- 2.04 pg/ml vs. 4.13 +/- 0.5 pg/ml, p = 0.002). There was no significant correlation with the maximal diameter of the most dilated coronary segment and IL-6 levels in patients with coronary ectasia (r = 0.10, p = 0.50). CONCLUSIONS: Results of this study have demonstrated increased levels of circulating IL-6 in patients with coronary ectasia which might indicate a possible role of inflammatory processes. Absence of a significant correlation between the dimensions of the ectatic segments and IL-6 levels might be due to the narrower range of the diameters of the coronary arteries compared with the abdominal aorta.

Association of idiopathic hepatic sinusoidal dilatation with the immunological features of the antiphospholipid syndrome.

BACKGROUND: Isolated sinusoidal dilatation is an uncommon hepatic lesion and the cause is largely unknown. OBJECTIVE: To investigate whether prothrombotic disorders or perisinusoidal cell changes could be involved in pure idiopathic hepatic sinusoidal dilatation (HSD). METHODS: Evaluation for associated conditions, prothrombotic disorders, and studies of hepatic perisinusoidal cell activation in consecutive patients, seen between 1993 and 2002, with isolated sinusoidal dilatation unrelated to outflow block, sinusoidal infiltration, or hepatic granulomas. RESULTS: Among 11 patients, associated conditions were prothrombotic disorders (n = 5) and oral contraceptive use (n = 3). Prothrombotic disorders were polycythemia vera (n = 1) and anticardiolipin antibodies combined with lupus anticoagulant (n = 4). No genetic thrombophilia factor was found. Of four patients with lupus anticoagulant, three had antinuclear factors and high serum levels of anticardiolipin antibodies at repeated testing. There was no evidence of intrahepatic or extrahepatic thrombosis in any of the patients. Sinusoidal dilatation was marked in six of 11 patients (54%), including two patients with antiphospholipid antibodies. Activated perisinusoidal cells were only found around markedly dilated sinusoids. CONCLUSION: Idiopathic pure HSD is frequently associated with the immunological features of the antiphospholipid syndrome. Therefore, finding pure HSD in a liver biopsy specimen should prompt the search for antiphospholipid antibodies.

Ectasias of the subcapsular sinus in lymph nodes of athymic and euthymic rats: a relation to immunodeficiency.

This paper describes a morphologically unusual feature occurring in lymph nodes of some aged euthymic animals but mostly athymic animals. It initially consists of small alveole-like excrescences of the cortical wall of the subcapsular sinus. With dilatation, an excrescence becomes an ectasia which expands into the cortex. Observations suggest that ectasias enlarge under the influence of an increased pressure of the afferent lymph of a node. Such condition conceivably results from a greater lymph formation due to inflammation of the drained tissue site, combined with an impairment to the flow of lymph from the subcapsular sinus into medullary sinuses. A probable relation of ectasia formation to immunodeficiency is discussed. This formation results in the atrophy of the affected lymphoid cell populations of a node which likely contributes to aggravate the deficiency of the immune system.

[Mechanisms of bronchial hyperreactivity. Bronchial edema, mechanical and vascular factors]. / Mécanismes de l'hyperréactivité bronchique. L'oedème bronchique, les facteurs mécaniques et vasculaires.

Hindrance to gas flow in the bronchi is affected not only by airway smooth muscle tone but also by airway circulation. Congestion and oedema increase airway wall thickness and act in series with airway smooth muscle contraction to reduce airway calibre, an effect which is more marked in small and intermediate bronchi. Many mediators, neuromediators, paracrine mediators produced by resident (epithelium) or migrant (inflammatory cells) cells share bronchomotor and vascular effects. In addition, contraction of airway smooth muscle and vascular phenomena are mechanically coupled. Contraction of airway smooth muscle facilitates vascular congestion and oedema because the diameter of the muscle ring is more reduced than the external diameter of the airways. In addition, a negative intrathoracic pressure, e.g. in asthma, increases the mechanical loading of both ventricles, thereby facilitating pulmonary and bronchial oedema. The effects of this mechanical coupling are enhanced by airway inflammation that facilitates both vascular congestion and leakage. Stimuli such as exercise and hyperventilation cause airway vasodilatation which, in turn, facilitates and, possibly, triggers the post-exercise asthma attack. Conversely, congestion and vasodilatation may have a protective effect through an increase in the clearance of bronchoconstrictor substances, or in reducing the amplitude of airway cooling and water loss in exercise-induced asthma. The relative role in bronchial hyperresponsiveness of airway smooth muscle contraction and vascular phenomena probably depends upon individual factors such as, for instance, both intensity and nature of inflammation of the airway walls.

Neurogenic inflammation, vascular permeability, and mast cells.

Electrical stimulation (ES) of sensory nerves causes increased vascular permeability and vasodilatation, a process known as neurogenic inflammation. The purpose of this study was to assess the role of mast cells in neurogenic inflammation induced by ES of sensory nerves. ES of the rat saphenous nerve for 1, 3, 5, 15, or 30 min induced a 166 to 436% increase in the amount of 125I-albumin deposited in the skin. Through the initial 15 min of ES, the histamine content of the skin remained unchanged. However, 30 min of ES caused a 22.1% decrease in skin histamine (p less than 0.05). ES for 5 min followed by measurement of vascular permeability from 0 to 30 min thereafter resulted in maximal increases in 125I-albumin in the skin immediately after cessation of the pulse of ES. When skin histamine was measured at various intervals after a 5-min pulse of ES, no change in the histamine content was observed through the subsequent 30 min. When mast cell degranulation was assessed histologically, 5 min of ES failed to stimulate mast cell degranulation. However, 30 min of ES caused a significant increase in the proportion of degranulating mast cells. When draining venous plasma histamine was monitored before, during and after ES, no change in plasma histamine was observed. In contrast, the intradermal injection of 5 micrograms of compound 48/80 produced a significant increase in plasma histamine. In order to examine the possibility that histamine might be released but remain in the skin after ES, skin "blisters" were developed by intradermal injections of saline. There was a significant increase in the amount of 125I-albumin extravasated into blister fluid measured after 3, 5, and 10 min of ES and a significant increase in histamine after 5 or 10 min. Therefore, prolonged ES of sensory nerves can cause mast cell degranulation. However, ES causes increased vascular permeability at times when no mast cell activation can be observed. These data suggest that the initial phases of neurogenic inflammation are independent of mast cell activation.

Exercise induced augmentation of cellular and humoral autoimmunity associated with increased cardiac dilatation in experimental autoimmune myocarditis.

To determine the effects of exercise in experimental autoimmune myocarditis, guinea pigs immunised with heterologous heart protein (rat heart), Freund's complete adjuvant, and pertussis vaccine (treated group) were exercised on a treadmill for a total of 11 weeks and compared with non-exercise treated animals. In vivo heart rates and pressures, in vitro left ventricular pressure-volume relations, myocardial histology, circulating antiheart antibody, and in vitro lymphocyte stimulation were determined. Exercise resulted in increased cardiac dilatation in treated animals as assessed by in vitro left ventricular pressure-volume relations compared with non-exercise treated animals (at 8 mmHg 1.41(0.17) ml.kg-1 vs 1.20(0.17) ml.kg-1 respectively, p less than 0.005). Exercise also resulted in increased concentrations of circulating antiheart antibody as assessed by radioimmunoassay (0.14(0.04) microgram vs 0.10(0.03) microgram respectively, p = 0.01), and increased lymphocyte activation to specific antigen (stimulation index 3.7(0.07) vs 2.4(1.0) respectively, p less than 0.001). Despite the associated augmentation of autoimmunity with cardiac dilatation, there were no differences in the histopathological findings between the exercised treated and the non-exercised treated animals either qualitatively or quantitatively (number of inflammatory cell microaggregates). This finding suggests that, although the immune system is important in experimental autoimmune myocarditis, the amount of inflammation and necrosis does not appear to correlate with the degree of left ventricular dilatation and presumed dysfunction.