Relationship between peripheral arterial occlusive disease (PAOD) and chronic Chlamydophila (Chlamydia) pneumoniae infection

We carried out a meta-analysis of observational case-control studies published before May 2004 to assess the degree of association between Chlamydophila pneumoniae (Cp) infection and PAOD. A search of the Medline database was performed using atherosclerosis and "Chlamyd* pneumoniae" as keywords. Strict criteria were applied for the selection of case studies, which had to be studies of Cp seroprevalence or of Cp detection in patients versus controls. Forty-three published studies that met these criteria were selected. An association between PAOD and Cp was revealed by immunohistochemical analysis (OR=15.4, 95%CI=5.0–46.9) and nested PCR studies of arterial biopsies (OR=4.3, 95%CI=1.8–10), by PCR study of non-arterial samples (OR=2.9, 95%CI=1.2–7.0), by other direct-detection tests (OR=16.7, 95%CI=7.0–39.8), and by ELISA and MIF tests to detect high IgG (OR=2, 95%CI=1.1–3.5 and OR=1.7, 95%CI=1.0–2.9, respectively) and IgA (OR=1.9, 95%CI=1.1–3.4 and OR=1.5, 95%CI=1.1–2.0, respectively) titers. No significant association was found in simple PCR studies of arterial biopsies, MIF tests to detect low IgG titers or IgM, or ELISA studies to detect IgM. According to this review, the association between Cp infection and PAOD depends on the analytical method adopted. Establishing a relationship between Cp and PAOD will require a case-control study with an adequate number of cases and samples that uses a combination of direct and indirect techniques to identify the presence of the bacterium in different types of sample from the same subjects, correlating the results with the activity of the disease.

Subclavian Artery Occlusion and Pseudoaneurysm Caused by Lung Apex Mucormycosis: Successful Treatment with Transcatheter Embolization

Subclavian artery pseudoaneurysm and occlusion in young patients are usually post-traumatic. We report the case of a 33-year-old diabetic woman with subclavian artery occlusion and pseudoaneurysm formation caused by pulmonary mucormycosis infection. The patient presented with diabetic ketoacidosis, Horner's syndrome, and absent left arm pulses. A cystic lesion of the left lung apex was found by imaging, was surgically resected, and was histologically diagnosed as mucormycosis infection. Magnetic resonance angiography depicted a left subclavian artery pseudoaneurysm and occlusion adjacent to the mucormycosis lesion. To protect against thromboembolic complications and rupture, the pseudoaneurysm was embolized with coils. The patient is clinically well 1 year after the intervention with no perfusion of the pseudoaneurysm.

Investigation of Chlamydia pneumoniae DNA, chlamydial lipopolisaccharide antigens, and Helicobacter pylori DNA in atherosclerotic plaques of patients with aortoiliac occlusive disease

BACKGROUND AND INTRODUCTION

It has been suggested that chronic infections may have a role in both the initiation and progression of atherosclerosis. While the majority of available data are focused on coronary artery disease, our aim was to investigate the presence of Chlamydia pneumoniae and Helicobacter pylori in samples from aortoiliac occlusive disease.

METHODS

Aorta-iliac atherectomy specimens were collected under sterile conditions from 21 patients (19 male, 2 female) undergoing surgery for aortoiliac occlusive disease. Seventeen macroscopically healthy vessels (12 internal mammary arteries, 3 radial arteries, prepared for coronary artery bypass graft, and 2 traumatic artery specimens, one of which was a superficial femoral artery and the other was a radial artery) were used as control. Blood samples for serological assays were obtained immediately before surgery. The polymerase chain reaction (PCR) was employed to search for H. pylori and C. pneumoniae DNA in atherosclerotic plaques and healthy vessel samples. Group-specific chlamydial lipopolysaccharide (LPS) antigens in atherosclerotic plaques and in healthy vessel samples and serum IgG antibodies to chlamydial LPS were determined by using a commercially available enzyme-linked immunosorbent assay (ELISA). Antibodies to H. pylori were also tested in all cases by means of an in-house ELISA.

RESULTS

Chlamydial LPS and DNA were detected in 6 of 21 (28.57%) atherosclerotic lesions using ELISA or PCR, respectively. There was no evidence of H. pylori DNA in any plaque specimens. All cases in which C. pneumoniae DNA was positive were also seropositive for antichlamydial LPS. Neither C. pneumoniae DNA nor antigen nor H. pylori DNA was found in the macroscopically healthy samples.

CONCLUSION

Our results suggest that C. pneumoniae but not, as proposed, H. pylori may be involved in the pathogenesis of aortoiliac atherosclerosis.

Detection and localization of periodontopathic bacteria in abdominal aortic aneurysms

OBJECTIVES

We examined a possible link between periodontal disease and abdominal aortic aneurysm (AAA) by studying resected aneurysmal specimens from AAA patients for the presence of periodontopathic bacteria.

DESIGN

Prospective case control study.

MATERIAL AND METHODS

Thirty-two AAA patients were enrolled in the study. Periodontitis was classified according to the probing depth of periodontal pocket. Thirty-two aneurysmal walls, 16 mural thrombi, 5 atherosclerotic occlusive aorta and 5 control arterial tissue, were examined for 7 periodontal bacteria using polymerase chain reaction (PCR) method. The localization of the bacteria in the aneurysmal/atherosclerotic wall was determined by thromboendarterectomy.

RESULTS

All patients had periodontal disease, and most cases were severe. PCR examination of the aneurysmal specimens showed that 86% were positive for periodontal bacterial DNA. No bacteria were detected in the control specimens. The bacteria were found in both the intimal/medial layer and the adventitial layer of the aneurysmal wall but only in intimal/medial layer of the atherosclerotic occlusive aorta.

CONCLUSION

Periodontopathic bacteria were present in a high percentage of specimens of diseased arteries from AAA patients and were found throughout the whole aneurysmal wall. These bacteria may play a role in the development of AAAs and/or contribute to weakening the aneurysmal wall.

Progression of peripheral arterial occlusive disease is associated with Chlamydia pneumoniae seropositivity and can be inhibited by antibiotic treatment

A possible influence of Chlamydia pneumoniae seropositivity on the clinical course of peripheral arterial occlusive disease (PAOD) has not been investigated previously. Though roxithromycin therapy was found to inhibit progression of PAOD, the nature of this effect (antibiotic or anti-inflammatory) has remained elusive. The course of PAOD was prospectively assessed in elderly men during 4 years, comparing 51 C. pneumoniae seropositive (IgG>/=1:128) with 46 seronegative patients (IgG<1:64 and IgA<1:32). Twenty of the seropositive patients were treated with roxithromycin (400 mg daily) for 4 weeks. Limitation of the walking distance to 200 m or less was observed in 55% of the seropositive untreated patients as compared to 30% of both, seronegative and macrolide-treated patients. The number of invasive revascularizations per patient was 1.7 in the seropositive untreated group as compared to 0.5 in the seronegative and the macrolide-treated group. Considering possible confounding variables, such as classical vascular risk factors, ordinal regression analyses showed a significant association of C. pneumoniae seropositivity with limitation of the walking distance (p=0.027) and need for invasive revascularization (p=0.037). The effect of macrolide treatment on these outcome measures was marked (p<0.001 and p=0.040, respectively) during 2.7 years but decreased in the second part of the observation period. This study provides good evidence that C. pneumoniae are involved in the progression of PAOD and that antibiotic treatment directed against C. pneumoniae is effective in inhibiting this process.

Determinants of lumbar artery occlusion among patients with sciatica: a three-year follow-up with magnetic resonance angiography

We showed previously that chronic Chlamydia pneumoniae infection increases the risk of lumbar artery occlusion. We did not evaluate, however, the effect of other risk factors for cardiovascular diseases in combination with this chronic infection. The purpose of this study was to investigate the combined effect of chronic C. pneumoniae infection and other known determinants of artery occlusion in a population of sciatica patients. Two-dimensional time-of-flight magnetic resonance angiography (MRA) was used to evaluate lumbar arteries at baseline and three years. The arteries on both sides (L1-L4) were evaluated visually and scored as normal, narrowed or occluded. Logistic regression analysis was performed separately for baseline total arterial stenosis and each L1-L4 segmental artery pair, and for incident new stenosis during the follow-up period. The determinants analyzed included age, body mass index (BMI, kg/m(2)), education, gender, and smoking, in addition to presence of chronic C. pneumoniae infection. MRA was obtained at baseline for 147 patients and at 3 years for 134 patients. Sixty-four (47.8%) of 134 patients had new arterial stenosis. Total incidence of new arterial stenosis was distributed quite evenly between the individual segmental levels, varying from 12.7 to 18.6%. BMI was the only predictor of new arterial stenosis (odds ratio (OR) 1.13). A reasonable logistic model could be established only for baseline L4 and total arterial scores. At L4, education was a protective factor (OR 0.07), whereas age (OR for the oldest age group 6.7) and BMI (OR 1.17) were associated with increased risk of occlusion. For total arterial score, chronic C. pneumoniae infection was an independent determinant of arterial occlusion, increasing the risk to almost eightfold. Additionally, BMI (OR 1.16), and age (for the oldest age group OR 11.4) were significant determinants for stenosis. Smoking was not statistically significant. As chronic C. pneumoniae infection was an independent determinant of lumbar artery occlusion, treatments of this chronic infection may have an impact on lumbar diseases. The importance of BMI for new arterial stenosis suggests that weight reduction may also have a beneficial effect in lumbar artery disease.

Genomic, serologic, and clinical case-control study of Chlamydia pneumoniae and peripheral artery occlusive disease

OBJECTIVES

Chlamydia pneumoniae has been related to atherosclerotic disease in both seroepidemiologic and genomic studies. We performed a case-control study to determine seropositivity and DNA detection in arteries of patients with peripheral artery occlusive disease and of healthy subjects.

METHODS

The study included 64 patients with peripheral artery occlusive disease, and 50 control subjects who underwent varicose vein surgery, matched to the patient group for age, sex, and tobacco use. The fibrinogen level in all study subjects was measured as a marker of inflammation. Blood samples were taken from all subjects for determination of immunoglobulin (Ig) G elementary bodies (EB) against C pneumoniae with microimmunofluorescence (MIF) and enzyme-linked immunosorbent assay (ELISA), and of IgA EB with ELISA. The cutoff titers were 1:32 for MIF and 1.1 for ELISA. Biopsy specimens of arterial atheromatous plaque were obtained from patients, and of pudendal artery and saphenous vein from control subjects, and were studied with hemi-nested polymerase chain reaction.

RESULTS

There were no differences in fibrinogen level between patients and controls. The prevalence of IgG anti-EB with MIF was 78% in patients and 24% in control subjects (P =.0001; odds ratio [OR], 11.3; 95% confidence interval [CI], 4.7-27.2). Prevalence of IgG anti-EB with ELISA was 75% in patients and 16% in control subjects (P =.0001; OR, 15.7; 95% CI, 6.1-40). There were no differences in IgA anti-EB titers. Bacterial DNA was detected in 67% of atheromatous plaques versus 12% of pudendal arteries (P =.0001) and 4% of saphenous veins. A weak correlation was found between seropositivity and the presence of intravascular DNA.

CONCLUSIONS

Our results support the hypothesis that C pneumoniae is related to the pathogenesis of atherosclerotic peripheral artery occlusive disease.

CLINICAL RELEVANCE

This study explored the infectious hypothesis in the context of the pathogenesis of atherosclerosis. This hypothesis has been supported by findings that certain infectious agents can cause or accelerate the course of diseases in which the possibility of a microbial cause was not previously proposed, as in the case of peptic ulcer and spongiform encephalopathy. The present study demonstrated the presence of Chlamydia pneumoniae and seropositivity in atheromatous plaques in patients with peripheral artery occlusive disease. These results contribute to a body of research that is opening up the possibility of treating atherosclerotic disease with antibiotic agents, and preventing it with immunization.

Myelopathy due to spinal epidural abscess without cord compression: a diagnostic pitfall

Spinal epidural abscess (SEA) is a neurological emergency that requires urgent diagnosis and treatment. We report 2 patients with SEA, in whom, on neuropathological examination, the neurological signs were found to be caused by spinal cord ischemia due to thrombosis of leptomeningeal vessels and compression of spinal arteries, respectively, while evidence of spinal cord compression was absent. Clinicians and neuropathologists should be aware of the variable mechanisms underlying the neurological involvement in SEA. Absence of spinal cord compression by the abscess may hamper early diagnosis and treatment.

[Role of extra-anatomical bypasses in the treatment of aorto-iliac occlusion]

In the last six years we have performed 468 operations because of aortoiliac occlusion or septic complications of these arteries. 410 (87.6%) of these operations were anatomical reconstructions, in 58 (12.4%) patients we performed extra anatomical bypasses. The distribution of the operations was the following; 12 obturator, 23 femoro-femoral crossover, 13 axillofemoral and 10 axillobifemoral bypasses. The indication for extra-anatomical reconstruction in 24 (41.4%) patients was septic complication (EABS), and in 34 cases (58.6%) poor general condition or difficulties during surgery. The average age of the patients with non-septic indication (EABNS) was significantly higher than the average age of the patients treated with anatomical reconstruction (AR) (66.3 vs. 60.9 year, p < 0.01). There were more REDO operations in the group EABNS then in the AR group (35.3%/11.7% p < 0.02). Despite of the high operative risk, the rate of early complications (EABNS 13.8%, AR 10%) and postoperative mortality (EABNS 3.7%, AR 4.0%) was not statistically different between the two groups. If the indication was aorto-duodenal fistula (6 patients) or acute limb ischaemia (7 patients), the mortality was significantly higher compared to other extra-anatomical operations (46.2% vs. 4.4%, p < 0.01). The postoperative mortality after EABNS and EABS operations was similar (11.7% vs. 16.6%), but we performed more reoperations after EABS operations (10/24 vs. 2/34, p < 0.05). According to our early postoperative results elective extra-anatomical bypasses are suitable for the treatment of aortoiliac occlusion in high risk patients, with poor life expectancy. Extra-anatomical bypasses are performed because of acute ischemia or septic complications which are life or limb threatening complications, so early results must be validated concerning this fact.

A case of pulmonary arteritis with stenosis of the main pulmonary arteries with positive myeloperoxidase-antineutrophil cytoplasmic autoantibodies

A 53-year-old woman was referred to our hospital with the main symptoms of productive cough, fever and exertional dyspnoea. Chest X-ray revealed enlargement of the left hilar shadow and cavitary infiltration in the right upper lobe. 99mTechnetium-macroaggregated albumin (99mTc-MAA) perfusion scintigram showed complete hypoperfusion through the entire right lung. A pulmonary angiogram revealed stenotic lesions in the right and left main pulmonary arteries. Right cardiac catheterization showed an elevated right ventricular systolic pressure. There was no evidence of systemic arterial lesions nor vasculitis. The patient was positive for myeloperoxidase (MPO)-antineutrophil cytoplasmic autoantibodies (ANCA) (168 EU). The Mycobacterium avium complex sputum culture was positive. The pulmonary stenotic lesions were surgically resected. The resected pulmonary arterial lesions were pathologically diagnosed as non-specific vasculitis. The cavitary lesion disappeared 6 months after the surgery. Two years after the surgery, although the MPO-ANCA level had decreased to 12 EU, stenosis of the pulmonary arteries reappeared. It is suggested that the patient became positive for MPO-ANCA in association with the Mycobacterium avium complex infection, and that the presence of MPO-ANCA may not be related to the development of pulmonary stenosis of the main pulmonary arteries.

Large artery vasculopathy in HIV-positive patients: another vasculitic enigma

Human immunodeficiency virus (HIV) infection has impacted on all the systems of the body, and the cardiovascular system is no exception, with small to medium-sized vessel vasculitis being most frequently described. We present 16 HIV-positive patients with large vessel disease consisting of either aneurysms (often multiple) or occlusive disease. Nine men and 7 women ranging in age from 18 to 38 years presented with rupture of aneurysm, transient ischemic attacks, hypertension, ischemia to the lower extremity, or a mass at the site of the aneurysm. Eight patients had 1 aneurysm, 2 had 2 lesions, and the remaining 6 cases had from 3 to 7 aneurysms. Arteries affected included the common carotid, abdominal aorta, common iliac, femoral, and popliteal. Three patients had intercurrent infections, but none had any obvious infective vascular lesion. Only 1 patient had a positive TPHA test for syphilis. Microbiologic culture of both blood and thrombus contents was positive for Staphylococcus aureus in 1 case; no other organisms were cultured. The key histological features were within the adventitia: leukocytoclastic vasculitis of the vasa vasora and periadventitial vessels, proliferation of slit-like vascular channels, chronic inflammation, and fibrosis. There was associated medial fibrosis with loss and fragmentation of muscle and elastic tissue. Intimal changes consisted of duplication and fragmentation of the internal elastic lamina with calcification. Atheroma and marked intimal thickening were not evident We believe that the occurrence of this large vessel vasculopathy (mainly aneurysmal) often with multiple lesions in young HIV-positive patients, is characteristic of possible infective or immune complex origin, with leukocytoclastic vasculitis of vasa vasora and periadventitial vessels being pivotal in many cases.

Coma in fulminant pneumococcal meningitis: new MRI observations

We report a 45-year-old man with fulminant pneumococcal meningitis. Fluid attenuated inverse ratio MR images showed the ravaging consequences of occlusive vasculopathy and a transient purulent basal exudate. Bilateral thalamic lesions may have explained the failure to awaken despite appropriate antibiotic therapy.

Chlamydia pneumoniae and occlusive vascular disease: identification and characterization

Chlamydia pneumoniae, a respiratory pathogen, has been associated with occlusive vascular disease, including atherosclerosis and intimal hyperplasia, through seroepidemiologic studies. Furthermore, using immunohistochemistry (IHC), polymerase chain reaction (PCR), transmission electron microscopy (TEM), and in situ hybridization, this association has been reconfirmed by detecting this organism in atherosclerotic vascular tissue. This review summarizes and critically analyzes these findings and also discusses various mechanisms of how Chlamydia pneumoniae could be involved in the pathogenesis of occlusive vascular disease. Although more studies are needed to reproduce these results and, possibly, uncover a mechanism, the current literature fails to include detailed methodologies for studying Chlamydia pneumoniae. Therefore, to provide a general standard, we have also outlined specific protocols for IHC, PCR, and TEM. These protocols incorporate essential components from various studies and are presented in a concise and easily adaptable format.

Arterial occlusion and progressive gangrene caused by mucormycosis in a patient with burns

Ischemic necrosis of the upper extremities caused by invasive mucormycosis developed in a patient with soil contamination of severe burn wounds. An arteriogram of the arm showed complete obstruction of blood flow in the forearm. Histologic specimens showed nonseptate branching hyphae obliterating the arterial lumens. Cutaneous mucormycosis affects patients who are immunocompromised, including victims of multiple trauma and burns. This case represents a previously undescribed clinical presentation in a patient with major burns. Because of its lethal nature, mucormycosis in a patient with burns must be treated with aggressive surgical debridement, including amputation, and with parentral amphotericin B at the earliest sign of cutaneous presence.

Aspergillar myocarditis and acute coronary artery occlusion in an immunocompromised patient

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Artery, periarterial adipose tissue, and blood microbiology during vascular reconstructive surgery: perioperative and early postoperative observations

The presence and clinical significance of bacteria in the arterial wall, periarterial adipose tissue, and blood samples acquired during elective vascular operations were assessed in this study. Specimens were obtained from a random series of 84 patients (56 men, 28 women) undergoing 75 primary and 9 secondary arterial reconstructions. Operations performed most frequently included abdominal aortic aneurysmectomy (42), aortofemoral bypass reconstruction (15), and lower extremity bypass surgery for occlusive disease (7). Perioperative antibiotics were administered to all but one patient. A sample of artery, adjacent adipose tissue, and blood were obtained for microbial analysis during the vascular anastomosis or arteriotomy. This yielded a total of 152 artery, 139 adipose tissue, and 129 blood samples for study. Each specimen was divided and placed in blood agar plates, thioglycolate broth, and brain-heart infusion broth. Tissues yielding growth of the same organism(s) in two or more different media were considered positive for the presence of bacteria. Bacteria were present in at least one of the three tissues studied in 32/84 patients (38%). The frequency of positive cultures in primary (29/75, 39%) and secondary procedures (3/9, 33%) were similar. One positive culture site occurred in 26/32 (81%) patients, two positive culture sites existed in 5/32 (16%) patients, and three positive sites were found in 1/22 (3%) patients. Eighteen individual artery (18/152, 12%) and 19 adipose tissue samples (19/139, 14%) harbored bacteria, whereas only two blood cultures were positive (2/129, 2%). Organisms identified included coagulase-negative staphylococci (71%), gamma-streptococci (7%), diphtheroids (7%), Micrococcus (5%), alpha-streptococci (5%), Staphylococcus aureus (2%), and Pseudomonas picketti (2%).(ABSTRACT TRUNCATED AT 250 WORDS)