Congruency of the development of peripheral nerves and blood vessels has been well described and usually nerves and blood vessels follow each other during development. While little is known about the existence of a substantial neural component in vascular malformations we investigate the presence of an intralesional component of nerve bundles in congenital vascular malformations of soft tissues. Resection specimens of 130 congenital vascular malformations of soft tissue were retrospectively screened for the presence and extent of intralesional mature nerves bundles. Lesions were histopathologically categorized in arteriovenous malformations (AVM, n=83), pure venous malformations (VM, n=33) and lymphaticvenous malformations (LVM, n=14). For identification of nerves, all sections were immunostained with anti-S100. GLUT1 immunostaining excluded the presence of infantile hemangiomas in these series. Ninety six (96) of 130 cases (74%) showed a substantial increase of intralesional nerves in close apposition to the vessels. The nervous component appeared to be more extensive in the head and neck region and upper extremities than in malformations of other topographic sites. Most cases of arteriovenous malformations (AVMs) showed an increase in nerve elements (87% of all AVMs), which was more than in pure venous malformations (VM, 55%). In cases of lymphatic-venous malformations the areas composed of lymphatic vessels showed an almost complete absence of nerves. Prior surgery in the malformation gave no different nerve pattern compared to cases which were surgically treated for the first time. The abundant presence of intralesional mature nerves in the majority of congenital vascular malformations suggests that, at least in a large subset of lesions, neural components are an integral part of the developmental disorder. This is particularly evident in the arteriovenous type of malformations, and lesions that arise in the head and neck region of the body. LorineMeyerJorna27-3-12.indd 144 27-3-2012 10:40:58 145 11 A neural component in congenital vascular malformations

Atherosclerotic vascular disease is the consequence of a chronic inflammatory process, and prolactin has been shown to be a component of the inflammatory response. Additionally, recent studies indicate that prolactin contributes to an atherogenic phenotype. We hypothesized that this may be the result of a direct effect of prolactin on atherogenesis through activation of the prolactin receptor. Human carotid atherosclerotic plaques were obtained from patients by endarteriectomies. The mRNA of prolactin receptor, but not of prolactin, was detected in these atherosclerotic plaques by quantitative real-time PCR. In situ hybridization confirmed the expression of the prolactin receptor in mononuclear cells. Analysis at the protein level using immunohistochemistry and immunoelectron microscopy revealed that the prolactin receptor was abundantly present in macrophages near the lipid core and shoulder regions of the plaques. Our findings demonstrate that the prolactin receptor is present in macrophages of the atherosclerotic plaque at sites of most prominent inflammation. We therefore propose that prolactin receptor signaling contributes to the local inflammatory response within the atherosclerotic plaque and thus to atherogenesis.

Interleukin (IL)-25, also known as IL-17E, belongs to the IL-17 family of cytokines. Unlike other IL-17 family members, IL-25 promotes Th2-type immune responses, stimulating IL-4, IL-5, and IL-13 production. Here, we employed murine models of skin graft to explore the role of IL-25 in suppression of graft rejection. We found that IL-25 expression is increased during allograft rejection, and allograft rejection was enhanced in IL-25 KO mice. IL-25 KO was associated with down-regulation of Foxp3 expression in CD4+ T cells. Further, while adoptive transfer of WT regulatory T cells (Tregs) protected against allograft rejection, adoptive transfer of IL-25 deficient Tregs failed to protect against allograft rejection. Exogenous IL-25 restored Foxp3 expression and Treg function in vitro. Moreover, IL-25 promoted phosphorylation of NFAT2. Thus, IL-25 may enhance Treg function by up-regulating NFAT2 phosphorylation. Our findings suggest that IL-25 can sustain Foxp3 expression, enhance the suppressive function of Tregs, and prolong skin-graft survival.

The increased mortality in patients with rheumathoid arthritis (RA) is mainly due to high incidence of cardiovascular (CV) disease. CV morbidity and mortality in RA can be explained by several mechanisms: (1) chronic inflammation, (2) enhanced prevalence of traditional CV risk factors including atherogenic dyslipoproteinemia, (3) a lower use of evidence-based therapy such as statins and (4) chronic treatment for RA such as glucocorticoids. It is difficult to distinguish between the role of pharmacological treatment per se and the severity or duration of the disease since these two parameters are closely interrelated. RA likely influences lipoprotein metabolism leading to quantitative and qualitative alteration of low-density lipoproteins (LDL) and of high-density lipoproteins. Glucocorticoids alter carbohydrate and lipid metabolism. However, by reducing the inflammation level, the net effect on lipid parameters and on the CV risk may be favorable. Data from open follow-up studies would suggest that methotrexate use is associated with a beneficial effect on lipid parameters and with a reduction in the incidence of CV disease. Anti-TNF agents increase LDL-cholesterol in some but not all studies; however the use of anti-TNF agents likely reduce CV risk in patients with RA. The influence of recently developed compounds, anti-CD20, CTLA-4 Ig or anti-IL6 is not well documented. Anti-IL6 seem to increase total and LDL-cholesterol; however these changes are associated with an improvement in the TC/HDL-C ratio.L’augmentation de la mortalité chez les patients atteints de polyarthrite rhumatoïde (PR) est essentiellement liée à une incidence élevée des maladies cardiovasculaires (CV). Il existe plusieurs explications à l’augmentation de la morbidité et de la mortalité CV : (1) inflammation liée à l’évolutivité de la maladie, (2) prévalence élevée de certains facteurs de risque cardiovasculaire et notamment des dyslipoprotéinémies athérogènes, (3) moindre utilisation des médicaments ayant fait la preuve de leur efficacité en prévention CV, notamment les statines, (4) utilisation de certains médicaments comme les glucocorticoïdes. Le rôle des traitements médicamenteux utilisés contre la PR est difficile à isoler de celui de l’évolution (amélioration ou aggravation) de la maladie rhumatismale. La PR elle-même entraîne des modifications du métabolisme lipidique responsables d’anomalies quantitatives et qualitatives des low-density lipoproteins (LDL) et des high-density lipoproteins (HDL). Les glucocorticoïdes perturbent le métabolisme glucido-lipidique, mais en réduisant l’inflammation, ils exercent également des effets favorables sur le risque athérogène. Des études en ouvert sont en faveur d’un rôle neutre ou bénéfique du méthotrexate sur les paramètres lipidiques. L’emploi de ce médicament semble réduire le risque CV des patients atteints de PR. L’effet des anti-TNF est variable selon les études : certaines d’entre elles montrent qu’ils augmentent le LDL-C. Toutefois, l’emploi des anti-TNF semble associé à une réduction de l’incidence des maladies CV. Les effets des molécules récentes, anti-CD20 ou CTLA-4 Ig ou anti-IL6, sont mal documentés. Les anti-IL6 semblent augmenter le cholestérol total et le LDL-C mais en améliorant parallèlement le rapport cholestérol total/HDL-C.

BACKGROUND:Infection with microorganisms is considered a pathogenic factor in atherogenesis. Several studies have shown the presence of a broad spectrum of bacterial species in atherosclerotic plaques, which could trigger local inflammation. Because T cells contribute to atherosclerotic plaque inflammation, we studied the responsiveness of human plaque derived T-cell cultures to bacteria of different species.MATERIALS AND METHODS:Primary polyclonal T-cell cultures were generated from both carotid endarterectomy tissue and peripheral blood of nine patients, and the peripheral blood of eight matched controls. The in vitro proliferative responses of the T-cell cultures against H. pylori, N. meningitidis, N. lactamica, S. aureus, S. pneumoniae, S. epidermidis and E. coli were analysed. T-cell proliferation was measured by (3)H-thymidine incorporation and expressed as a stimulation index. Selective outgrowth of intraplaque microbial specific T cells was studied by calculating the ratio of plaque T-cell SI and peripheral blood T-cell SI in each patient.RESULTS:All patients showed T-cell responsiveness to multiple bacteria in their plaque tissue. Stimulation indices were in the range of 0.3-30, and this degree of reactivity with the different species was heterogeneous among patients. Selective outgrowth (plaque/peripheral blood ratio) of T cells against multiple bacteria was observed in six out of nine patients.CONCLUSIONS:T cells in atherosclerotic plaques have the capacity to selectively respond to antigens of a wide variety of microbial antigens. This supports the view that such mechanisms could contribute to the atherosclerotic inflammatory response.

Despite the discovery in 1990 that mutations in the fibrillin-1 gene cause the Marfan syndrome, the pathogenesis of the life-threatening dissections associated with this disease is far from elucidated. Both the massive number of known fibrillin-1 mutations that result in a heterogeneous patient population and the strongly heterogeneous histology of patients' aortae presumably contribute to this lack of knowledge. We performed a detailed ultrastructural immunoelectron microscopic and histochemical analysis of the dissected media of ascending aortae of 10 patients with Marfan syndrome and compared them with those of 6 patients without Marfan syndrome and 77 individuals without known aortic disease. Relatively similar abnormalities were found in both patient groups, although they were more numerous and more diffusely spread in the patients with Marfan syndrome than in the patients without Marfan syndrome. The most conspicuous ultrastructural defects were the formation of abrupt transverse tears in thick and compact elastic lamellae and the local breaking up of smooth muscle cell-elastic lamella connections (that largely consist of microfibrils and elastic extensions, protruding from the elastic lamellae). This breaking up was characterized by a strongly reduced number of microfibrils and a severe shortening of the elastic extensions. Finally, the elastic extensions detached from the lamellae to ultimately degenerate and disappear. These changes were found mainly in the oldest group of patients with Marfan syndrome, indicating that they represented a loss of previously normally developed structures. We also compared our findings with those from a recently developed murine Marfan model (Pereira L, Lee SY, Gayraud B, Andrilopoulos K, Shapiro SD, Bunton T, Biery NJ, Dietz HC, Sakai LY, Ramirez F. Pathogenetic sequence for aneurysm revealed in mice underexpressing fibrillin-1. Proc Natl Acad Sci. U. S. A. 1999: 96: 3819-3823). Next to similarities, several striking differences existed, demonstrating that this model is not fully representative of the human Marfan syndrome.

Objective: T-cell activation is an essential feature of atherosclerotic plaque inflammation, which eventually may lead to plaque rupture. In this study, we investigated if EBV, a common herpes virus, is capable of stimulating atherosclerotic plaque derived T-cells and thus could contribute to atherosclerotic plaque inflammation.Methods: Plaque derived T-cell cultures were established from symptomatic carotid atherosclerotic plaques of 19 patients. B-cells from the same patients were transformed with EBV to form lymphoblastoid cell lines (B-LCL) that served as antigen presenting cells. The proliferation of T-cells in the presence of autologous B-LCL was analyzed using 3H-thymidine incorporation. The presence of EBV in atherosclerotic material was analyzed by PCR.Results: Of the 19 cell obtained T-cell cultures, I I responded to EBV (58%, mean stimulation index: 10.1 +/- 3.1). PCR analysis showed that EBV DNA was present in 15 of the tissue samples (79%). All the specimens that contained EBV responding T-cells also contained EBV. EBV specific T-cells secreted granzymes, as indication of functional cytotoxic potential.Conclusions: EBV-specific cytotoxic T-cells and EBV DNA can be frequently observed in human atherosclerotic plaques. This suggests that a T-cell response against EBV could contribute to plaque inflammation, and thus to the onset of acute clinical symptoms. (c) 2005 Elsevier Ireland Ltd. All rights reserved.

Inflammation plays an important role in the initiation, development, progression and complications of atherosclerotic vascular disease. Our present knowledge of the elementary role of inflammation for the onset of plaque rupture in atherosclerotic coronary lesions primarily stems from autopsy studies. However, the introduction of directional coronary atherectomy catheters has provided a unique opportunity to directly investigate the role of inflammation in coronary syndromes. In this report we describe the role of coronary plaque inflammation, as determined by immunohistochemistry, on the presentation of coronary syndromes and on the clinical outcome following percutaneous interventions.

Atherosclerotic plaques contain a chronic immune mediated inflammation in which T cells play an important role. A previous study revealed that the numbers of interleukin-2 receptor-positive T cells is increased in culprit lesions of patients with acute coronary syndromes; a finding of considerable interest since it indicates a recent change in the intraplaque T cell mediated immune response. Confirmation of this observation is important, because it could provide insight into the onset of the acute event. We have, therefore, expanded our earlier work by using a panel of different T cell activation markers (CD25, CD26, CD40L, CD69). The study is based on 58 culprit lesions from patients who underwent coronary atherectomy. There were four groups of patients: chronic stable angina (n=13), stabilized unstable angina (n=16), refractory unstable angina (n=15), and acute myocardial infarction (AMI; n=14). Activated T cells were expressed as a percentage of the total of CD3-positive cells. CD25, CD26, CD40L, and CD69/CD3 percentages increased with the severity of the coronary syndrome. In patients with AMI all percentages were significantly higher than in patients with chronic stable angina. CD25, CD26, CD40L, and CD69/CD3 percentages in patients with an unstable condition (refractory unstable angina and AMI) were significantly higher than those in patients with a stable condition (chronic stable or stabilized unstable angina) The finding that the percentage of T cells with recent onset activation is significantly increased in the culprit lesions of patients with acute coronary syndromes suggests strongly that a recent change in pathogenic stimulation has occurred leading to local T cell activation.

A key event in neointima formation and atherogenesis is the migration of vascular smooth muscle cells (VSMCs) into the intima. This is controlled by cytokines and extracellular matix (ECM) components within the microenvironment of the diseased vessel wall. At present, these signals have only been partially identified. In this study, we demonstrate that Met, the receptor tyrosine kinase for hepatocyte growth factor (HGF), is expressed on VSMCs isolated from the intima of atherosclerotic plaques of carotid arteries. Stimulation with HGF led to activation of Met as well as to activation of PI3-K, PKB/Akt, MEK, and the MAP kinases Erk1 and -2. Moreover, HGF induced lamellipodia formation, a characteristic feature of motile cells, and promoted VSMC migration across fibronectin-coated filters. The HGF-induced cell migration was mediated by beta1 integrins and required PI3-K activation. Our results suggest a role for the HGF-Met signaling pathway in the pathogenesis of atherosclerosis and restenosis.

OBJECTIVES This study was performed to evaluate the relationship between plaque inflammation of the initial culprit lesion and the incidence of recurrent angina for one year after directional coronary atherectomy (DCA).BACKGROUND A positive correlation between coronary plaque inflammation and angiographic restenosis has been reported.METHODS A total of 110 patients underwent DCA. Cryostat sections were immunohistochemically stained with monoclonal antibodies CD68 (macrophages), CD-3 (T lymphocytes) and alpha-actin (smooth muscle cells [SMCs]). The SMC and macrophage contents were planimetrically quantified as a percentage of the total tissue area. T lymphocytes were counted as the number of cells/mm(2). The patients were followed for one year to document recurrent unstable angina pectoris (UAP) or stable angina pectoris (SAP).RESULTS Recurrent UAP developed in 16 patients, whereas recurrent SAP developed in 17 patients. The percent macrophage areas were larger in patients with recurrent UAP (27 +/- 12%) than in patients with recurrent SAP (8 +/- 4%; p = 0.0001) and those without recurrent angina (18 +/- 14%; p = 0.03). The number of T lymphocytes was also greater in patients with recurrent UAP (25 +/- 14 cells/mm(2)) than in patients with recurrent SAP (14 +/- 8 cells/mm(2) p = 0.02) and those without recurrent angina (14 +/- 12 cells/mm(2); p = 0.002). Multiple stepwise logistic regression analysis identified macrophage areas and T lymphocytes as independent predictors for recurrent UAP.CONCLUSIONS There is a positive association between the extent of initial coronary plaque inflammation and the recurrence of unstable angina during long-term follow-up after DCA. These results underline the role of ongoing smoldering plaque inflammation in the recurrence of unstable angina after coronary interventions. (J Am Cell Cardiol 2001;37:1271-6) (C) 2001 by the American College of Cardiology.

Immunohistochemistry is a widely accepted tool to investigate the presence and immunolocalization of cytokines in tissue sections at the protein level. We have tested the specificity and reproducibility of IFNgamma immunohistochemistry on tissue sections with a large panel of anti-IFNgamma antibodies. Thirteen different commercially available anti-IFNgamma antibodies, including seven advertised and/or regularly applied for immunohistochemistry/-cytochemistry, were tested using a three-step streptavidin-biotin-peroxidase technique and a two-step immunofluorescence (FACS) analysis. Immunoenzyme double staining was used to identify the IFNgamma-positive cells. Serial cryostat sections were used of human reactive hyperplastic tonsils, rheumatoid synovium, and inflammatory abdominal aortic aneurysms, known to possess a prominent Th1-type immune response. In vitro phorbol myristate acetate/ionomycin-stimulated T-cells served as positive control; unstimulated cells served as negative control. Cultured T-cells were used adhered to glass slides (immunocytochemistry), in suspension (FACS), or snap-frozen and sectioned (immunohistochemistry). Immunocytochemistry and FACS analysis on stimulated cultured T-cells showed positive staining results with 12 of 13 anti-IFNgamma antibodies. However, immunohistochemistry of sectioned stimulated T-cells was negative with all. Unstimulated cells were consistently negative. IFNgamma immunohistochemical single- and double staining analysis of the tissue sections showed huge variations in staining patterns, including positivity for smooth muscle cells (n = 8), endothelial cells (n = 4), extracellular matrix (n = 4), and CD138+ plasma cells (n = 12). Specific staining of T-cells, as the sole positive staining, was not achieved with any of the 13 antibodies. IFNgamma-immunohistochemistry appears unreliable because of lack of specificity to stain T-cells in situ. In fact, depending on the type of anti-IFNgamma antibody used, a variety of different cell constituents were nonspecifically stained. Consequently, data based on IFNgamma-immunohistochemistry must be interpreted with great caution.