Detection of active cytomegalovirus infection in inflammatory aortic aneurysms with RNA polymerase chain reaction

Human abdominal aortic aneurysm (AAA): Evidence for an autoimmune antigen-driven disease

Abdominal aortic aneurism (AAA) is a complex immunological disease with a strong genetic component, and one of the ten leading causes of death of individuals 55-74 years old worldwide. Strong evidence has been accumulated suggesting that AAA is an autoimmune specific antigen-driven disease. Mononuclear cells infiltrating AAA lesions comprised of T and B lymphocytes and other cells expressing early-, intermediate- and late-activation antigens, and the presence of antigen-presenting cells have been documented, demonstrating an ongoing immune response. The three components of the trimolecular complex, T-cell receptor (TCR)/peptide (antigen)/HLA have been identified in AAA, and specifically: (i) clonal expansions of T-cell clones in AAA lesions; (ii) the association of AAA with particular HLA Class I and Class II; and (iii) self or nonself putative AAA-associated antigens. IgG autoantibodies recognizing proteins present in normal aortic tissue have been reported in patients with AAA. Molecular mimicry, defined as the sharing of antigenic epitopes between microorganisms (bacteria, viruses) and self antigens, maybe is responsible for T-cell responses and antibody production in AAA. Also, the frequency and the suppressor activity of CD4 + CD25 + FOXP3+ Tregs and the expression of FOXP3 transcripts and protein have been reported to be significantly impaired in AAA patients vs normal donors.

FOS gene associated immune infiltration signature in perivascular adipose tissues of abdominal aortic aneurysm

Abdominal aortic aneurysms (AAA) are pathological dilations in local aortic wall. The inflammatory infiltrates of the perivascular adipose tissue (PAT) surrounding AAAs were associated with AAAs and have been shown to contribute vascular pathology. However, the mechanism by which PAT inflammation contributes to vascular pathology in AAA remains to be clarified. This study aimed to explore the association between immune cell infiltration and key gene expression profile in PAT of AAA. For that, a gene expression dataset of human dilated perivascular adipose tissue (dPAT), non-dilated perivascular adipose tissue (ndPAT), subcutaneous abdominal fat (SAF) and omental-visceral fat (OVF) samples, as well as another microarray dataset of the abdominal perivascular adipose tissue in peripheral artery disease patients were downloaded from GEO database for analysis in this study. The CIBERSORT algorithm, weighted gene co-expression network analysis (WGCNA) and LASSO algorithm were used for the identification of immune infiltration, immune-related genes and the development of diagnostic signature. Our data discovered a significant higher proportion of activated mast cells and follicular helper T (Tfh) cells in dPAT than ndPAT, OVT and SAF samples. Moreover, AP-1 family members (FOS, FOSB, ATF3, JUN and JUNB) were found to compose the hub genes of purple module in WGCNA. Among them, FOS gene acts as a higher efficient marker to discriminate dPAT from ndPAT, OVT and SAF in AAA. Meanwhile, the expression profiles of the AP-1 family members are all significantly positive correlated with activated mast cell, plasma cell and Tfh cell infiltration in dPAT of AAA. Therefore, in the PAT surrounding AAA, the signature of inflammatory infiltration might be represented by a FOS-dominated cell network consist of activated mast cell, plasma cell and Tfh cell. Given the complicated etiology of AAA, our results are likely to shed new light on the pathophysiologic mechanism of AAA influenced by the local dPAT.

Urgent Repair of a 17.3 cm Inflammatory Abdominal Aortic Aneurysm

We describe a case of delayed presentation of a very large infra-renal inflammatory abdominal aortic aneurysm. This case highlights the importance of early detection and surveillance of aneurysms in rural communities. Definitive management of symptomatic aneurysms is time critical, and any delay such as for the transfer of patients from a rural site can impact patient survival. We present an example of a rare variant of abdominal aortic aneurysm.

Abdominal aortic aneurysm and virus infection: A potential causative role for cytomegalovirus infection?

An abdominal aortic aneurysm (AAA) is a multifactorial disease with a variety of genetic and environmental risk factors, but the exact mechanism of AAA formation and progression is still not well understood. The present study investigated the frequency of cytomegalovirus (CMV), Epstein-Barr virus (EBV), and papillomavirus types 6 and 11 (HPV6 and HPV11), their impact on clinical manifestations of cardiovascular diseases, and their possible association with inflammation in patients with AAA and healthy volunteers. Genotyping of CMV UL75, EBV LMP-1, and HPV6, and HPV11 E6 was performed by polymerase chain reaction (PCR), while the viral DNA loads were measured by quantitative real-time PCR. Cytokine levels were determined by enzyme-linked immunosorbent assays. The CMV UL75 was detected more frequently in the blood of patients with AAA than in the blood of healthy volunteers (32.7% vs. 6.3%, p < .0001). Neither EBV LMP-1 nor HPV6 E6 was found in blood and aortic wall biopsies, while the HPV11 E6 was detected in 36.4% of AAA walls. The CMV infection in patients with AAA was associated with an increased risk of hypertension and coronary artery disease (OR, 9.057; 95% CI, 1.141-71.862; p = .037; and OR, 2.575; 95% CI, 1.002-6.615; p = .049, respectively). Additionally, CMV-infected patients with AAA had higher tumor necrosis factor-α levels compared with noninfected subjects (p = .017). Our findings suggest that CMV infection can stimulate local inflammation in the aorta but is not a direct cause of most abdominal aortic aneurysms.

Clonally expanded alpha-chain T-cell receptor (TCR) transcripts are present in aneurysmal lesions of patients with Abdominal Aortic Aneurysm (AAA)

Abdominal aortic aneurysm (AAA) is a life-threatening immunological disease responsible for 1 to 2% of all deaths in 65 year old or older individuals. Although mononuclear cell infiltrates have been demonstrated in AAA lesions and autoimmunity may be responsible for the initiation and account for the propagation of the disease, the information available about the pathogenesis of AAA is limited. To examine whether AAA lesions from patients with AAA contain clonally expanded α-chain TCR transcripts, we amplified by the non-palindromic adaptor-PCR (NPA-PCR)/Vα-specific PCR and/or the Vα-specific PCR these α-chain TCR transcripts. The amplified transcripts were cloned and sequenced. Substantial proportions of identical α-chain TCR transcripts were identified in AAA lesions of 4 of 5 patients, demonstrating that clonally expanded T cells are present in these AAA lesions. These results were statistically significant by the bimodal distribution. Three of 5 of these patients were typed by DNA-based HLA-typing and all three expressed DRB1 alleles containing the DRβGln70 amino acid residue that has been demonstrated to be associated with AAA. All three patients exhibited clonally expanded T cells in AAA lesions. Four of the 5 patients with AAA who exhibited clonal expansions of α-chain TCR transcripts, also exhibited clonal expansions of β-chain TCR transcripts in AAA lesions, as we have demonstrated previously (J Immunol 192:4897, 2014). αβ TCR-expressing T cells infiltrating AAA lesions contain T-cell clones which have undergone proliferation and clonal expansion in vivo in response to as yet unidentified specific antigens that may be self or nonself. These results provide additional evidence supporting the hypothesis that AAA is a specific antigen-driven T-cell autoimmune disease.

Analysis of host Toll-like receptor 3 and RIG-I-like receptor gene expression in patients with abdominal aortic aneurysm

OBJECTIVE

Abdominal aortic aneurysm (AAA) is a vascular disease relatively common in the elderly population. Although some events that contribute to the development and progression of AAA are known, there are limited data examining the association of Toll-like receptor 3 (TLR3) and RIG-I-like receptor expression with the pathogenesis of AAAs. In this study, we investigated the gene and protein expression of TLR3 and RIG-I-like receptors (RIG-I and MDA5) in aortic wall and blood of AAA patients and examined the relationship between their expression and immune response.

METHODS

Total RNA was extracted from aortic wall tissues and blood samples collected from 20 patients with AAA and blood samples of 17 healthy volunteers without aortic aneurysm. To evaluate the DDX58 (RIG-I), IFIH1 (MDA5), and TLR3 gene expression level, quantitative real-time polymerase chain reaction was used. Extracellular cytokine and pattern recognition receptor levels were quantified by enzyme-linked immunosorbent assays.

RESULTS

TLR3, RIG-I, and MDA5 were constitutively expressed in both aortic tissues and blood samples from AAA patients and healthy volunteers. In patients with AAA, higher TLR3 expression in aortic tissues than in blood was found (P = .004). The DDX58 messenger RNA expression was higher in blood of patients with AAA compared with healthy subjects (P = .021). A significantly higher level of plasma interleukin 4 was noticed in patients with AAA than in healthy individuals (P = .008).

CONCLUSIONS

This study suggests that RIG-I and TLR3 seem to be important factors in the pathogenesis of AAA.

Double-locus lymphoplasmacytic aortitis

Thoracic aortic aneurysm is an indication for major cardiovascular operative procedures. The etiology is usually hypertension and/or atherosclerotic disease; reaching a certain diameter often results in acute aortic syndrome. Immunoglobulin G4-related aortitis, characterized by lymphoplasmacytic vascular tunica media induration without well-defined underlying infectious or autoimmune systemic causes, is uncommon. Histological similarity to immunoglobulin G4 disease in other organs suggests that this aortitis might be a manifestation of systemic pathology. We describe a case of double-locus lymphoplasmacytic aortitis in a 72-year-old man who had the incidental finding of intramural hematoma on elective thoracic computed tomography as part of a respiratory work-up.

Inflammatory diseases of the aorta: Part 1: Non-infectious aortitis

Aortitis is a term which encompasses inflammatory changes to the aortic wall from various pathogenic etiologies. Large vessel vasculitis, such as Takayasu arteritis and giant cell arteritis represent the most common entities; however, there is also an association with other rheumatological diseases. Chronic idiopathic periaortitis represents a distinct disease entity and infectious aortitis is a rare but life-threatening disease. Due to the diverse clinical pictures vascular surgeons often face a significant challenge in terms of making an accurate initial diagnosis. Treatment requires an interdisciplinary approach. This article describes the pathogenesis of the various forms of aortitis as well as the diagnostic methods and treatment approaches.

Vasculitis related to viral and other microbial agents

Vasculitis due to infection may occur as a consequence of the inflammation of vessel walls due to direct or contiguous infection, type II or immune complex-mediated reaction, cell-mediated hypersensitivity, or inflammation due to immune dysregulation triggered by bacterial toxin and/or superantigen production. As immunosuppressive therapy administered in the absence of antimicrobial therapy may increase morbidity and fail to effect the resolution of infection-associated vascular inflammation, it is important to consider infectious entities as potential inciting factors in vasculitis syndromes. The causality between infection and vasculitis has been established in hepatitis B-associated polyarteritis nodosa (HBV-PAN) and hepatitis C-associated (cryoglobulinemic) vasculitis (HCV-CV). The review summarizes the recent literature on the pathophysiological mechanisms and the approaches to the management of HBV-PAN and HCV-CV. Roles of other viral and microbial infections, which either manifest as vasculitic syndromes or are implicated in the pathogenesis of primary vasculitides, are also discussed.

Endovascular repair versus open repair for inflammatory abdominal aortic aneurysms

BACKGROUND

Inflammatory abdominal aortic aneurysm (IAAA) is a rare but potentially life-threatening condition characterised by marked thickening of the aortic wall, peri-aneurysmal and retroperitoneal fibrosis, and dense adhesions of adjacent abdominal organs. The pathogenesis of IAAA remains an enigma. The main aim of invasive or surgical therapy of AAAs is prevention or correction of aortic rupture. Prevention or treatment of AAA rupture by open or endovascular repair is proven by numerous studies published in the literature. Treatment of IAAA poses a different challenge to surgeons compared with traditional atherosclerotic AAA because of the potential for iatrogenic injury in open repair or, alternatively, potential increased inflammatory response to endoprosthesis implantation.

OBJECTIVES

To assess the effects of elective endovascular versus open repair for inflammatory abdominal aortic aneurysms.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator (TSC) searched the Specialised Register (April 2015) and the Cochrane Register of Studies (CRS) (2015, Issue 3). The TSC searched trial databases for details of ongoing and unpublished studies.

SELECTION CRITERIA

We sought all published and unpublished randomised controlled trials (RCTs), quasi-RCTs and controlled clinical trials comparing results of elective endovascular or open repair of IAAAs without language restriction.

DATA COLLECTION AND ANALYSIS

Both review authors independently assessed studies identified for potential inclusion in the review. We planned to conduct data collection and analysis in accordance with the Cochrane Handbook for Systematic Review of Interventions.

MAIN RESULTS

We identified no studies that met the inclusion criteria.

AUTHORS' CONCLUSIONS

We found no published RCTs, quasi RCTs or controlled clinical trials comparing open repair and elective endovascular repair for IAAA, assessing immediate (30-day), intermediate (up to one-year follow-up) and long-term (more than one-year follow-up) mortality or complications rates. High-quality studies evaluating the best treatment for inflammatory abdominal aneurysm repair are required.

Idiopathic and secondary forms of retroperitoneal fibrosis: a diagnostic approach

Retroperitoneal fibrosis (RPF) is an uncommon disease characterized by a fibrous reaction that takes place in the peri-aortic retroperitoneum and often entraps the ureters causing obstructive uropathy. RPF is idiopathic in the majority of cases, but can also be secondary to malignancies, infections, drugs, radiotherapy, and rare histiocytic disorders such as Erdheim-Chester disease. Idiopathic RPF is an immune-mediated disease, which can either be isolated, associated with other autoimmune diseases, or arise in the context of a multifocal fibro-inflammatory disorder recently renamed as IgG4-related disease. The differential diagnosis between idiopathic, IgG4-related and secondary RPF is crucial, essentially because the therapeutic approaches - especially of idiopathic vs. secondary RPF - can be dramatically different. This review focuses on the clinical, laboratory and imaging features of the different RPF forms, and also provides an overview of the available treatment options.

Aneurysmal lesions of patients with abdominal aortic aneurysm contain clonally expanded T cells

Abdominal aortic aneurysm (AAA) is a common disease with often life-threatening consequences. This vascular disorder is responsible for 1-2% of all deaths in men aged 65 years or older. Autoimmunity may be responsible for the pathogenesis of AAA. Although it is well documented that infiltrating T cells are essentially always present in AAA lesions, little is known about their role in the initiation and/or progression of the disease. To determine whether T cells infiltrating AAA lesions contain clonally expanded populations of T cells, we amplified β-chain TCR transcripts by the nonpalindromic adaptor-PCR/Vβ-specific PCR and/or Vβ-specific PCR, followed by cloning and sequencing. We report in this article that aortic abdominal aneurysmal lesions from 8 of 10 patients with AAA contained oligoclonal populations of T cells. Multiple identical copies of β-chain TCR transcripts were identified in these patients. These clonal expansions are statistically significant. These results demonstrate that αβ TCR(+) T lymphocytes infiltrating aneurysmal lesions of patients with AAA have undergone proliferation and clonal expansion in vivo at the site of the aneurysmal lesion, in response to unidentified self- or nonself Ags. This evidence supports the hypothesis that AAA is a specific Ag-driven T cell disease.

Inflammatory Abdominal Aortic Aneurysm

We report a case of an abdominal aortic aneurysm (AAA) that underwent inflammatory transformation which we treated medically with corticosteroids. Medical therapy resulted in resolution of presenting symptoms and observed inflammatory changes. We review the clinical features, associated pathology, diagnostic, and therapeutic options in the management of inflammatory AAA.

Autoantigenicity of carbonic anhydrase 1 in patients with abdominal aortic aneurysm, revealed by proteomic surveillance

Abdominal aortic aneurysm (AAA) is sometimes detected in patients with atherosclerosis. One of the histological characteristics of AAA walls is infiltration of inflammatory cells, in which autoimmunity may be involved. Thereby, we here surveyed autoantigens in AAA walls by proteomics. Specifically, we separated proteins extracted from AAA wall samples by 2-dimensional electrophoresis and detected candidate autoantigens by western blotting. One of the detected candidates was carbonic anhydrase 1 (CA1). ELISA confirmed that the autoantibodies to CA1 were detected more frequently in AAA patients (n=13) than in healthy donors (n=25) (p=0.03). Interestingly, some serum samples from the AAA patients reacted to CA1 of the AAA walls stronger than to CA1 of peripheral blood mononuclear cells from healthy donors. Our data indicate that CA1 in the AAA walls would be modified to express neo-epitope(s) and that the autoimmunity to CA1 may be involved in the pathogenesis of AAA.

Inflammatory aneurysms of the ascending aorta: diagnosis and surgical treatment

Inflammatory aortic aneurysms (IAAs) are rare and located mainly in the infra-renal abdominal aorta. The ascending aorta has been typically spared from this process. We report on two cases of ascending aortic inflammatory aneurysms and describe the available literature on this rare entity. 

Significance of cytomegalovirus infection in the failure of native arteriovenous fistula

High cytomegalovirus (CMV) IgG levels have been identified as a risk factor for arteriovenous fistula (AVF) failure. None of the 68 patents in our study were CMV IgM positive, although 96% were CMV IgG positive. CMV antigens were detected in the radial artery or cephalic vein of 46% of patients who received an AVF. The presence of CMV antigens or high serum CMV IgG levels had no prognostic value for AVF failure.

Predictors for pathologically confirmed aortitis after resection of the ascending aorta: a 12-year Danish nationwide population-based cross-sectional study

Introduction

Assessing the prevalence of, and predictors for, pathologically-confirmed inflammation of the aorta in Denmark, using a nationwide population-based study design.

Methods

We identified all adults with first-time surgery on the ascending aorta between January 1, 1997 and March 1, 2009 in Denmark. Presence of aortic inflammation was ascertained through linkage to a nationwide pathology registry. We used logistic regression to compute prevalence odds ratios (ORs) for sex, age at surgery, cardiovascular risk factors, cancer, connective tissue disease, and infectious diseases associated with the presence of aortitis.

Results

A total of 1,210 adults underwent resection of the ascending aorta, of who 610 (50.4%) had tissue submitted for pathological examination. Aortitis was found in 37 (6.1%) patients whose tissue was examined. Ten of the 37 patients were diagnosed with conditions known to be associated with aortitis or aortic aneurysm: five patients with temporal arteritis, one with Crohn's disease, one with rheumatoid arthritis, one with systemic lupus erythematosus, one with infectious aortitis, and one with Marfan's disease. Twenty-seven patients had idiopathic aortitis. Predictors of aortitis included history of connective tissue disease (adjusted OR 4.7, 95% confidence interval (CI) 1.6, 13.6), diabetes (OR 5.2, 95% CI 0.9, 29.7), advanced age (> 67 years OR 2.5, 95% CI 0.8, 7.6), and aortic valve pathology (OR 2.3, 95% CI 1.1, 4.9).

Conclusions

Aortitis was present in 6.1% of adults in Denmark who had pathological examination after resection of the ascending aorta. Predictors of inflammation included connective tissue disease, diabetes, advanced age, and aortic valve pathology.

A new clinicopathological entity of IgG4-related inflammatory abdominal aortic aneurysm

OBJECTIVE

Recently, the relationship between immunoglobulin (Ig)G4 and idiopathic sclerosing lesions has attracted much attention. IgG4-related disease was first described with regard to the pancreas (autoimmune pancreatitis), and has been expanded to various organ systems. We previously reported that inflammatory abdominal aortic aneurysm (IAAA) could be one of the manifestations of IgG4-related disease. In this study, we tried to elucidate the clinical characteristics of IgG4-related IAAA.

METHODS

This study consisted of 23 cases of IAAA and 40 cases of atherosclerotic abdominal aortic aneurysm (AAA). Clinical presentation, laboratory findings, and pathological features were examined. Aneurysms of 13 cases histologically corresponded to IgG4-related IAAA.

RESULTS

Those cases accounted for 5% of all surgical AAAs, and 57% of IAAAs. Compared to non-IgG4-related IAAA, IgG4-related cases were characterized by less frequent association with abdominal or back pain. Serum IgG4 concentrations were significantly elevated in IgG4-related cases. Interestingly, patients with IgG4-related IAAA frequently showed an allergic constitution, such as drug allergy, autoimmune diseases, high serum IgE concentrations, and a high titer of antinuclear antibody. Pathologically, IgG4-related cases were characterized by more significant thickening of the adventitia and more numerous IgG4-positive plasma cell infiltrations. Three non-IgG4-related cases showed aneurysmal rupture at the time of first presentation, whereas no IgG4-related cases showed rupture.

CONCLUSION

Recognizing a new disease entity of IgG4-related IAAA seems important because this was clinically and pathologically different from conventional aAAA and non-IgG4-related IAAA.

Inflammatory abdominal aortic aneurysm: close relationship to IgG4-related periaortitis

Inflammatory abdominal aortic aneurysm (AAA) is a member of a family of disorders referred to as "chronic periaortitis" together with retroperitoneal fibrosis. Retroperitoneal fibrosis is included in IgG4-related disease, which is characterized by numerous infiltrating IgG4-positive plasma cells and high serum IgG4 concentrations. However, the relationship between IgG4-related disease and inflammatory AAA has not been documented. In this study, we examined the clinicopathologic characteristics of inflammatory (10 cases) and atherosclerotic (22 cases) AAAs, based on the hypothesis that inflammatory AAA might be related to IgG4-related disease. Cases of inflammatory AAA could be classified into 2 groups based on immunostaining of IgG4. Four patients showed diffuse infiltration of abundant IgG4-positive plasma cells (IgG4-related cases), whereas the remaining 6 cases of inflammatory AAA and all cases of atherosclerotic AAA had only a few IgG4-positive plasma cells (non-IgG4-related cases). IgG4-related inflammatory AAA was pathologically characterized by the frequent infiltration of eosinophils, lymph follicle formation, perineural inflammatory extension, and inconspicuous infiltration of neutrophils compared with non-IgG4-related inflammatory AAA. Obliterative phlebitis, which is venous occlusion with inflammatory cell infiltration, is observed in all IgG4-related cases. In addition, serum IgG4 concentrations were significantly higher in IgG4-related inflammatory AAA (109 to 559 mg/dL, normal range: 4 to 110 mg/dL) than non-IgG4-related inflammatory AAA (32 to 59 mg/dL) and all atherosclerotic AAA (12 to 83 mg/dL). In conclusion, inflammatory AAAs might be classified into 2 groups: IgG4-related or nonrelated. The former might be one of the IgG4-related diseases, and could be included in IgG4-related periaortitis together with retroperitoneal fibrosis.

In vivo reduction of the nuclear factor-kappaB activity using synthetic cis-element decoy oligonucleotides suppresses intimal hyperplasia in the injured carotid arteries in rabbits

PURPOSE

Nuclear factor-kappaB (NF-kappaB) plays a critical role in inflammation-related reactions, and is also found in the injured arterial wall. The purpose of this study was to introduce synthetic double-stranded cis-element "decoy" oligonucleotides (ODNs) into the arterial wall using the hemagglutinating virus of Japan (HVJ) liposome, and to investigate the inhibitory potential of decoy ODN against balloon injury-induced intimal hyperplasia by reducing NF-kappaB activity.

METHODS

Fluorescein isothiocyanate (FITC)-labeled decoy ODNs using the HVJ-liposome method were tranfected in balloon-injured rabbit carotid arteries. We then performed electrophoretic mobility shift assay to examine NF-kappaB activity using balloon-injured arteries, and we introduced NF-kappaB decoy into balloon-injured arteries.

RESULTS

Transfection of FITC-labeled decoy ODNs by using the HVJ-liposome method demonstrated highly efficient protein expression with diffuse, frequent, and widespread nuclear signals over the entire medial layer, while the same amount of naked ODNs showed much less efficiency with scattered distribution of fluorescence in balloon-injured carotid arteries. Electrophoretic mobility shift assay showed activation of NF-kappaB in balloon-injured arteries. In vivo transfection of decoy ODNs mediated by HVJ liposome abolished the NF-kappaB activity in injured arteries with specific binding affinity to NF-kappaB protein. Intimal hyperplasia of carotid artery after balloon injury was reduced by approximately 50% by NF-kappaB decoy transfection compared with buffer treatment or scrambled decoy transfection.

CONCLUSION

Our results demonstrated involvement of NF-kappaB in intimal formation after arterial injury, and indicated that NF-kappaB can be an appropriate molecular target for anti-restenosis therapy.

[Abdominal aortic aneurysm and renovascular disease]

Recent technological advances in the diagnosis and therapy of abdominal aortic aneurysm and renovascular disease are continuing to bring about changes in the way patients suffering from these conditions are treated. The prevalence of both these conditions is increasing. This is due to greater life-expectancy in patients with arteriosclerosis, a pathogenetic factor underlying both conditions. The application of diagnostic imaging techniques to non-vascular conditions has led to the early diagnosis of abdominal aortic aneurysm. Clinical suspicion of reno-vascular disease can be confirmed easily using high-resolution diagnostic imaging modalities such as CT angiography and magnetic resonance angiography. Endovascular intervention is successfully replacing conventional surgical repair techniques, with the result that it may be possible to improve outcome in both conditions using effective and minimally invasive approaches. Future technological developments will enable these endovascular techniques to be applied in the large majority of patients with abdominal aortic aneurysm or renovascular disease.

Abdominal aortic aneurysm is a specific antigen-driven T cell disease

To determine whether monoclonal/oligoclonal T cells are present in abdominal aortic aneurysm (AAA) lesions, we amplified beta-chain T cell receptor (TCR) transcripts from these lesions by the nonpalindromic adaptor (NPA)-polymerase chain reaction (PCR)/V-beta-specific PCR followed by cloning and sequencing. Sequence analysis revealed the presence of substantial proportions of identical beta-chain TCR transcripts in AAA lesions in 9 of 10 patients examined, strongly suggesting the presence of oligoclonal populations of alphabeta TCR+ T cells. We have also shown the presence of oligoclonal populations of gammadelta TCR+ T cells in AAA lesions. Sequence analysis after appropriate PCR amplification and cloning revealed the presence of substantial proportions of identical VgammaI and VgammaII TCR transcripts in 15 of 15 patients examined, and of Vdelta1 and Vdelta2 TCR transcripts in 12 of 12 patients. These clonal expansions were very strong. All these clonal expansions were statistically significant by the binomial distribution. In other studies, we determined that mononuclear cells infiltrating AAA lesions express early- (CD69), intermediate- (CD25, CD38), and late- (CD45RO, HLA class II) activation antigens. These findings suggest that active ongoing inflammation is present in the aortic wall of patients with AAA. These results demonstrate that oligoclonal alphabeta TCR+ and gammadelta TCR+T cells are present in AAA lesions. These oligoclonal T cells have been clonally expanded in vivo in response to yet unidentified antigens. Although the antigenic specificity of these T cells remains to be determined, these T cells may play a significant role in the initiation and/or the propagation of the AAA. It appears that AAA is a specific antigen-driven T cell disease.

Inflammatory abdominal aortic aneurysm: Predictors of long-term outcome in a case-control study

BACKGROUND

Inflammatory abdominal aortic aneurysms (AAAs) are relatively rare clinical entities. The aim of this study is to ascertain the risk factors in patients with inflammatory AAAs and clarify which feature plays a role in determining the long-term outcome in these patients.

METHODS

Between 1990 and 1997, 238 patients underwent surgery for an AAA at our institution, 17 (7.1%) of whom had the diagnosis of inflammatory type AAA. This group was matched in a case-control fashion to a group of 35 patients with similar characteristics of age, gender, and preoperative risk factors who were operated on for a noninflammatory AAA. All available clinical, pathologic, and postoperative variables were retrospectively reviewed, and the 2 groups were compared. In the inflammatory group, risk factor analysis was performed for poor outcome.

RESULTS

All operations were performed through a standard transperitoneal median laparotomy. The 2 groups did not differ significantly in terms of clinical characteristics and preoperative risk factors Patients with inflammatory AAAs were significantly more symptomatic (100% vs 31%, P = .03) and had larger aneurysm size on admission (8.2 +/- 1.2 cm vs 6.1 +/- 0.4 cm, P = .04). In inflammatory AAAs, preoperative erythrocyte sedimentation rate was found to be significantly elevated (mean, 48 +/- 14 mm/h vs 8 +/- 3 mm/h, P = .01). Surgical morbidity and mortality rates did not differ between 2 groups. The intensive care unit and hospital stay periods were similar in both groups (2.2 days vs 1.8 days, P = .25, and 9.2 days vs 8.1 days, P = .35). Eight-year survival rates of inflammatory and noninflammatory groups were 60% and 74%, respectively (P = .01). Results from Cox proportional hazards model analysis showed that a high sedimentation rate after surgical intervention (P = .02), cardiovascular disease (P = .01), postoperative persisting fibrosis with ureteral entrapment (P = .01), and postoperative chronic renal failure (P = .02) were independent risk factors for death. Other surgical variables did not prove to be risk factors for long-term mortality.

CONCLUSIONS

Although the preoperative characteristics may differ in patients with inflammatory type AAAs, they can be treated today with low morbidity and mortality rates. However, inflammatory process may continue postoperatively because of unknown reasons, and the study documented that persisting, postoperative inflammatory process with or without retroperitoneal fibrosis may place a patient at high risk for poor outcome. This is important information for the long-term management of these patients, and we believe that their follow-up protocols should be more comprehensive to further improve their long-term survival rates.

Cytomegalovirus-associated cutaneous vasculopathy and scleroderma sans inclusion body change

Viruses have long been held to be of pathogenetic importance in the evolution of autoimmune connective tissue disease. We describe 7 adults who developed cutaneous connective tissue disease stigmata in temporal association with recent cytomegalovirus (CMV) infection but without the classic cytopathic changes of CMV infection. We examined 7 adults with clinical presentations encompassing cutaneous vasculitis in 4 and scleroderma in 3. In all 7 patients, there was either IgM seropositivity for CMV and/or CMV DNA isolation from peripheral blood. Although no CMV inclusions were seen, in situ hybridization studies revealed very focal CMV RNA transcript expression with localization mainly to the endothelium. The patients with vasculitis treated with ganciclovir had improvement or resolution of symptoms, whereas only 1 patient with scleroderma received antiviral therapy, without benefit. Another scleroderma patient responded to infliximab therapy. Abortive/partial CMV reactivation can be associated with a syndrome complex mimicking and/or triggering a primary immune-based cutaneous microvascular injury syndrome. Antiviral therapy appears to be of therapeutic value in those cases associated with active necrotizing vasculitic changes. The role of tumor necrosis factor alpha blockers in scleroderma cases temporally associated with CMV infection requires further evaluation.

Chronic Inflammation, Immune Response, and Infection in Abdominal Aortic Aneurysms

Abdominal aortic aneurysms (AAA) are associated with atherosclerosis, transmural degenerative processes, neovascularization, decrease in content of vascular smooth muscle cells, and a chronic infiltration, mainly located in the outer aortic wall. The chronic infiltration consists mainly of macrophages, lymphocytes, and plasma cells. The dominant cells are Th2 restricted CD3+ lymphocytes expressing interleukine 4, 5, 8, and 10, and tumor necrosis factor-alpha for regulation of the local immune response. They also produce interferon-gamma and CD40 ligand to stimulate surrounding cells to produce matrix metalloproteases and cysteine proteases for aortic matrix remodeling. The lymphocyte activation may be mediated by microorganisms as well as autoantigens generated from vascular structural proteins, perhaps through molecular mimicry. As in autoimmune diseases, the risk of AAA is increased by certain genotypes concerning human leucocyte antigen class II. These types are also associated with increased aneurysmal inflammation indicating a genetic susceptibility to aortic inflammation. Chlamydia pneumoniae is often detected in AAA but the validity of the methods can be questioned, and two small antibiotic trials have been disappointing. However, serum antibodies against C. pneumoniae have been associated with AAA growth and cross-react with AAA wall proteins. Thus, immune responses mediated by microorganisms and autoantigens may play a pivotal role in AAA pathogenesis.

Inflammation and cellular immune responses in abdominal aortic aneurysms

Expansion and rupture of abdominal aortic aneurysms (AAA) result in high morbidity and mortality rates. Like stenotic atherosclerotic lesions, AAA accumulate inflammatory cells, but usually exhibit much more extensive medial damage. Leukocyte recruitment and expression of pro-inflammatory Th1 cytokines typically characterize early atherogenesis of any kind, and modulation of inflammatory mediators mutes atheroma formation in mice. However, the mechanistic differences between stenotic and aneurysmal manifestations of atherosclerosis remain unexplained. We recently showed that aortic allografts deficient in interferon-gamma (IFN-gamma) signaling developed AAA correlating with skewed Th2 cytokine environments, suggesting important regulatory roles for Th1/Th2 cytokine balance in modulating matrix remodeling and important implications for the pathophysiology of aortic aneurysm and atherosclerosis. Further probing of their distinct aspects of immune and inflammatory responses in vascular diseases should continue to shed new light on the pathophysiologic mechanisms that give rise to aneurysmal versus occlusive manifestations and atherosclerosis.

Idiopathic Inflammatory Aneurysm of the Ascending Aorta

Inflammatory aneurysms of the ascending aorta are exceedingly rare. The principal cause of ascending aortic aneurysms remains arteriosclerosis. We present a patient with an ascending aortic aneurysm caused by active inflammatory disease superimposed on complex atherosclerotic disease of the aorta.

Endovascular Therapy of Inflammatory Aortic Aneurysms:A Meta-Analysis

PURPOSE

To report a meta-analysis of results from endovascular aneurysm repair (EVAR) of inflammatory aortic aneurysms (IAA).

METHODS

A comprehensive literature review was performed to identify all studies reporting the results of EVAR in patients with IAA. To be included in the analysis, an article had to provide a minimum follow-up of 6 months, information about primary technical success, details of immediate and long-term complications, and evaluation of at least one of the basic outcome criteria: changes in aneurysm sac diameter, periaortic fibrosis (PAF), and/ or renal impairment. All studies were reviewed by 2 independent observers for the inclusion criteria. Data were retrieved on the technical and clinical success, outcome criteria, mortality in follow-up, and reinterventions from 14 articles selected from among 701 initially identified.

RESULTS

The 14 articles encompassed 46 patients (45 men [97.8%]; mean age 65 years, range 59-75) with a mean follow-up of 18 months after endovascular repair of IAAs located in the abdominal aorta. The primary technical success rate was 95.6% (44/46) and the 30-day clinical success rate was 93.4% (43/46). The median aneurysm sac diameter regression was 11 mm. Of 43 patients with PAF prior to the intervention, 22 (51.2%) patients showed complete regression, 18 (41.8%) remained unchanged, and 3 (7.0%) showed progression after EVAR. Renal impairment disappeared in 11 (45.8%) of 24 patients. Reinterventions were reported in 8 patients. The procedure-related and follow-up mortality rates were 0% and 13.0%, respectively.

CONCLUSIONS

EVAR of IAA is feasible, excludes the aneurysm effectively, and reduces PAF and renal impairment in most patients with very low periprocedural and midterm mortality and an acceptable reintervention rate.

Inflammatory Abdominal Aortic Aneurysms

BACKGROUND

Inflammatory abdominal aortic aneurysms (IAAA) are a variant of aortic aneurysm characterised by extensive peri-aneurysmal fibrosis, thickened walls and dense adhesions and represent between 3 and 10% of all abdominal aortic aneurysms (AAA). Surgery is technically challenging and is still associated with an increased morbidity and mortality. Controversy exists about aetiology and pathogenesis.

METHODS

We review the literature on the current theories, the available imaging modalities and the current thinking on management of IAAA. A Medline database search was performed. Articles were cross-referenced.

RESULTS AND CONCLUSIONS

Aneurysm development is multifactorial with important genetic and environmental factors. The literature supports the theory that IAAA arise from the same antigenic stimulus that is responsible for the non-IAAA, representing one extreme of an inflammatory spectrum. The results after open repair have improved and there is now little difference in the mortality between non-IAAA and IAAA repair. However, there is likely to be a role for endovascular stenting in IAAA management and this requires further study. It is clear that closer follow-up of patients after IAAA repair with either technique is necessary to monitor the inflammatory process. No evidence-based follow-up protocol exists but three to six-monthly monitoring of renal function and erythrocyte sedimentation rate (ESR) for 24 months post-repair would seem a reasonable regime.

Detection of herpes simplex virus, cytomegalovirus and Epstein-Barr virus DNA in atherosclerotic plaques and in unaffected bypass grafts

BACKGROUND

Herpes virus infections are suspected to be involved in the pathogenesis of atherosclerosis.

OBJECTIVE AND METHOD

Viral DNA of herpes simplex virus (HSV), Epstein-Barr virus (EBV) and cytomegalovirus (CMV) was analyzed by real-time PCR on 48 biopsies from atherosclerotic plaques extracted by end-arterectomy (46 coronary arteries, 2 carotid arteries), and in tissue from non-atherosclerosis vessels from the same patient as controls (23 internal mammary arteries, 43 saphenous veins).

RESULTS

HSV-1 DNA was detected significantly more frequently in plaques (35%) than in control veins (9%, P = 0.006). However, the frequency of HSV-1 DNA detection in the internal mammary artery grafts was as high as in plaques (22%, P = 0.28). CMV and EBV DNA were exclusively found in plaques but not in controls, with 10% for CMV (P = 0.06 versus veins, P = 0.17 versus graft arteries) and 2% for EBV (P = 1.0), respectively. HSV-2 was neither detected in plaques nor in controls. Herpes viral DNA was significantly associated only with arterial hypertension but not with other classical risk factors (P = 0.02), in accordance with the hypothesis that herpes viral infection may alter the vessel wall.

CONCLUSION

We conclude that herpes viral infections may have a role in atherosclerosis and that the presence of herpes viral DNA in the grafts used for bypass surgery might constitute a potential risk for atherosclerosis or restenosis.

Identification of candidate microbial sequences from inflammatory lesion of giant cell arteritis

Giant cell arteritis (GCA) is a granulomatous inflammatory disease of medium and large arteries which is prevalent in the elderly population. The etiology of GCA is unknown, although the immunologic features suggest the possible presence of a microorganism. Our group has examined whether microbial DNA fragments were present at GCA lesions and whether such microbial fragments could be associated with disease pathogenesis. Initial identification of microbial sequences was performed using genomic representational difference analysis (RDA). Laser dissecting microscopy was used to isolate cells from GCA lesions and adjacent uninvolved temporal artery. Using genomic RDA, we isolated 10 gene fragments; three of these sequences had high homology with prokaryotic genes and were considered high-priority candidates for further study. An examination of serum from GCA(+) individuals (in contrast to healthy age-matched controls) showed the presence of IgG which recognized in vitro translated proteins from these clones.

Aortic emergencies

Prompt recognition of actual or impending aortic emergencies is essential to the effective practice of emergency medicine. Understanding the pathophysiologic principles and awareness of the potential subtleties in the clinical presentations of aortic dissection, aneurysm, and occlusive disease are prerequisites to this task. Knowledge of current diagnostic modalities is also important if these entities are to be identified rapidly and managed efficiently to maximize the potential for a good patient outcome. Awareness of the potential complications of these conditions and the necessary interventional and resuscitative measures that might be called for in the appropriate clinical setting are likewise essential requirements for the EP. Appropriate surgical consultation and mobilization of operative resources form the backbone of appropriate management in the patient who has an aortic emergency.

Inflammatory aortic aneurysm is associated with increased incidence of autoimmune disease

OBJECTIVE

It has been suggested that certain genetic risk factors indicative of an autoimmune mechanism can be identified in patients with inflammatory aortic aneurysm (IAA). We therefore investigated whether there was a higher incidence of autoimmune diseases in patients with IAA. Further, we explored risk factors, need for in-hospital resources, and early results of treatment, in a case-control study in a university hospital setting. Material and methods From 1983 to 1994, 520 patients were operated because of abdominal aortic aneurysm (AAA). Thirty-one patients had IAA. Control subjects were matched for aneurysm rupture, emergency or elective hospital admission, and date of operation. Two noninflammatory AAA were included for every IAA.

RESULTS

Of the 31 patients with IAA, 6 patients (19%) had autoimmune disease, compared with none of the control subjects (P =.0017). Two patients had rheumatoid arthritis, 2 patients had systemic lupus erythematosus, 1 had giant cell arteritis, and 1 patient had an undifferentiated seronegative polyarthritis diagnosed as rheumatoid arthritis. Nineteen patients (61%) with IAA had involvement of the duodenum, and 8 patients (26%) had hydronephrosis with ureteral involvement. Operating time was longer in the IAA group, which also had a higher need for blood transfusion. Hospital stay, intensive care unit stay, and 30-day mortality were similar in the two groups.

CONCLUSION

Except for longer operating time and more need for blood transfusions in the IAA group, use of hospital resources was similar after operations to treat IAA or noninflammatory AAA. The study findings indicate an association between IAA and autoimmune disease. This is in accordance with other reports that showed a genetic risk determinant mapped to the human leukocyte antigen (HLA) molecule in these patients. Further research is necessary to explore whether IAA might be a separate entity with a role of antigen binding in the origin of the disease.

Herpesvirus (HSV-1, EBV and CMV) infections in atherosclerotic compared with non-atherosclerotic aortic tissue

The viral nucleic acid of herpes simplex virus type 1 (HSV-1), Epstein-Barr virus (EBV) and cytomegalovirus (CMV) was studied by polymerase chain reaction (PCR), Southern blotting and in situ hybridization (ISH) in aortic tissues from 33 autopsies. In 23 cases involving persons who ranged from 23 weeks to 75 years of age at the time of death, the tissue was histologically non-atherosclerotic. Of these 23, aortic tissues tested positive for HSV-1 in 13%, for EBV in 13% and for CMV in 4%. In the other 10 cases involving persons who were 53-75 years old at death, atherosclerotic aortic tissue tested positive for HSV-1 in 80%, for EBV in 80% and for CMV in 40%. Neither double nor triple infections occurred in the non-atherosclerotic group, whereas six of 10 were positive for two viruses, and two of 10 were positive for three viruses in the atherosclerotic group. By in situ hybridization, the viruses were localized in cells morphologically consistent with endothelial cells and smooth muscle cells. We detected HSV-1, EBV and CMV DNA in cells in the upper portion of the non-atherosclerotic aortic wall, whereas viral DNA was detected more extensively in atherosclerotic lesions than in non-atherosclerotic tissue. We also are the first to show the existence of EBV DNA in the human aortic wall. In conclusion, we suggest that the high incidence and kinds of herpesviruses are related to the high incidence of atherosclerosis.

MCMV induces neointima in IFN-gammaR-/- mice: intimal cell apoptosis and persistent proliferation of myofibroblasts

BACKGROUND

CMV infections have been linked to vasculopathies like atherosclerosis and Scleroderma. CMV infects vascular endothelium with intermittent shedding of the virus and the development of latency.

METHODS

We adopted a model of arteritis, developed by Presti et al. (1998), triggered by murine cytomegalovirus (MCMV) infection. Our studies focused on neointima formation. Groups of mice include: 1) immunocompetent 129S, 2) immunocompetent 129S receiving whole body irradiation and MCMV, 3) IFN-gammaR-/- receiving MCMV, and 4) IFN-gammaR-/- receiving MCMV and whole body irradiation.

RESULTS

Mice were inoculated with MCMV (5 x 10(4) or 1 x 10(5) PFU's) by i.p. injection; hearts and abdominal aortas were collected and histopathology evaluated. Infected immunocompetent animals exhibited widespread perivascular inflammation, which subsided by 8 weeks. Intimal pathology was not observed in any control group. Immunocompetent animals receiving MCMV and irradiation developed mild to moderate intimal lesions associated with medial and adventitial inflammation. IFN-gammaR-/- mice infected for 4 months and receiving whole body irradiation 2 months after infection developed pathology characterized by extensive adventitial and medial infiltrate and significant neointima, suggesting that infection and immunosuppression were co-requisites of neointima formation. Immunohistochemical analysis revealed myofibroblasts as a major component of neointima. The disease is characterized by up-regulation of growth factors (TGF-beta1, PDGF-A and B). Apoptosis was detected in the intimal layer of affected aortas. Active proliferation of myofibroblasts and infiltrating cells was also detected.

CONCLUSION

These results indicate that CMV infections may lead to intimal injury that results in the formation of neointima characteristic of autoimmune vasculopathies.

Polymyalgia rheumatica and giant cell arteritis

PMR and GCA are related conditions that seem to represent a continuum of disease. These conditions are relatively common and seem to be mediated by a cellular inflammatory response. Increasing evidence suggests an infectious cause (or causes) precipitating this immune response in genetically susceptible individuals. Whereas previously thought to affect primarily branch vessels of the aortic arch, GCA is now thought of as a disease in which proximal aortic involvement is frequent. Despite the potential for serious, even fatal complications, overall prognosis for patients with GCA or PMR is excellent. Corticosteroids remain the standard treatment, although not curative. Whereas the ESR is a useful indicator of disease activity, other markers which may be more precise such as creative protein and Il-6 seem to offer added information about disease activity.

Chlamydia pneumoniae in abdominal aortic aneurysms: abundance of membrane components in the absence of heat shock protein 60 and DNA

In this article, we describe the results of a comparative study for the detection of Chlamydia pneumoniae in abdominal aortic aneurysm specimens of 19 patients through the use of immunocytochemistry (ICC), in situ hybridization (ISH), and polymerase chain reaction (PCR), along with the detection of cytomegalovirus (CMV) and herpes simplex virus (HSV) by ICC and PCR. C pneumoniae-specific membrane protein was detected in specimens of all 19 (100%; 95% confidence interval [CI] 82% to 100%) and of 15 (79%; 95% CI 54% to 94%) patients with monoclonal antibodies RR-402 and TT-401, respectively. Chlamydial lipopolysaccharide was detected in specimens of 15 (79%; 95% CI 54% to 94%) patients when the results of 4 different monoclonal antibodies were combined. Surprisingly, chlamydial heat shock protein 60 was not detected in any of the specimens by ICC. Furthermore, C pneumoniae DNA was not detected by ISH when a C pneumoniae major outer membrane protein gene fragment was used as probe, nor was it reproducibly detected by PCR on extracted DNA. These results may be explained either by different kinetics of degradation of the different components of C pneumoniae after infection of the vessel wall or by the involvement of other Chlamydia-like microorganisms. Coexistence of C pneumoniae antigens and HSV antigens but not CMV antigens was observed in specimens from 10 of 18 (56%; 95% CI 31% to 78%) patients by ICC. CMV and HSV DNAs were not detected by PCR. In conclusion, we have demonstrated the presence of antigens of C pneumoniae in the absence of specific DNA in abdominal aortic aneurysms, suggesting persistence of the antigens rather than a persistent infection.