Cohort Study Examining the Association of Immunosuppressant Drug Prescription With Major Adverse Cardiovascular and Limb Events in Patients With Peripheral Artery Disease.

AIM: Immune activation is strongly implicated in atherosclerotic plaque instability, however, the effect of immunosuppressant drugs on cardiovascular events in patients with peripheral artery disease (PAD) is not known. The aim of this study was to assess whether prescription of one or more immune suppressant drugs was associated with a lower risk of major adverse cardiovascular (MACE; i.e. myocardial infarction, stroke or cardiovascular events) or limb events (MALE; i.e. major amputation or requirement for peripheral revascularization) in patients with PAD. METHODS: A total of 1506 participants with intermittent claudication (n = 872) or chronic limb threatening ischemia (CLTI; n = 634) of whom 53 (3.5%) were prescribed one or more immunosuppressant drugs (prednisolone 41; methotrexate 17; leflunomide 5; hydroxychloroquine 3; azathioprine 2; tocilizumab 2; mycophenolate 1; sulfasalazine 1; adalimumab 1) were recruited from 3 Australian hospitals. Participants were followed for a median of 3.9 (inter-quartile range 1.2, 7.3) years. The association of immunosuppressant drug prescription with MACE or MALE was examined using Cox proportional hazard analyses. RESULTS: After adjusting for other risk factors, prescription of an immunosuppressant drug was associated with a significantly greater risk of MACE (Hazard ratio, HR, 1.83, 95% confidence intervals, CI, 1.11, 3.01; P = 0.017) but not MALE (HR 1.32, 95% CI 0.90, 1.92; P = 0.153). In a sub-analysis restricted to participants with CLTI findings were similar: MACE (HR 2.44, 95% CI 1.32, 4.51; P = 0.005); MALE (HR 1.38, 95% CI 0.87, 2.19; P = 0.175); major amputation (HR 1.37, 95% CI 0.49, 3.86; P = 0.547). CONCLUSIONS: This cohort study suggested that immunosuppressant drug therapy is associated with a greater risk of MACE amongst patients with PAD.

Diet is associated with ankle-brachial index, inflammation, and ambulation in patients with intermittent claudication.

OBJECTIVE: The aims of this investigation were to determine whether the daily dietary intake of nutrients by patients with peripheral artery disease (PAD) and intermittent claudication (IC) met recommended levels for adults older than 50 years and to determine whether meeting recommended levels of nutrients was associated with ankle-brachial index (ABI), inflammation, and ambulation of patients with PAD and IC. METHODS: A total of 48 patients were assessed on their dietary intake of 20 nutrients during a 3-day period. Patients were further characterized on demographic variables, comorbid conditions, cardiovascular risk factors, ABI, 6-minute walk distance (6MWD), and high-sensitivity C-reactive protein (hsCRP) concentration. RESULTS: Few patients met the daily recommended intakes for calcium (4%), fiber (6%), vitamin E (6%), trans fatty acids (13%), vitamin A (15%), total sugars (19%), potassium (23%), sodium (29%), saturated fat (29%), and vitamin C (31%), and none of the patients met the daily recommended intake of vitamin D (0%). Overall, patients met few of the 20 dietary recommendations as the median score was seven recommendations. Only 17 of 48 patients met more than seven of the recommendations. For the ABI regression model adjusted for age, sex, race, smoking, hypertension, dyslipidemia, body mass index, and percentage body fat, the only significant predictor was total sugars (P < .001); patients who did not meet the recommendation had lower ABI values. For the hsCRP-adjusted regression model, the strongest significant predictor was omega-3 polyunsaturated fatty acids (P = .001), indicating that those who did not meet the recommendation had higher hsCRP values. Finally, for the 6MWD-adjusted regression model, folate (P = .011) and dietary score index (P = .014) were significant predictors; those who did not meet the recommendation for folate and those who met 5 or fewer of the 20 recommendations had shorter 6MWD. CONCLUSIONS: Patients with PAD and IC consume a low-nutrient-dense diet that is deficient in many vitamins, calcium, fruits, and vegetables and contains too much added sugar, saturated and trans fats, and processed foods. In addition, more severe PAD, greater inflammation, and ambulatory dysfunction are independently associated with aspects of a low-nutrient-dense diet, such as too much intake of added sugars, low intake of omega-3 polyunsaturated fatty acids and folate, and meeting the recommended intakes of only five or fewer nutrients.

Change of walking distance in intermittent claudication: impact on inflammation, oxidative stress and mononuclear cells: a pilot study.

BACKGROUND: Atherosclerosis is a chronic inflammatory process involving the immune system and formation of reactive oxygen species (ROS). We investigated changes of mononuclear blood cells and ROS production in relation to the walking distance of patients with intermittent claudication during home-based exercise training. METHODS: Forty patients with intermittent claudication were asked to perform a home-based exercise training for a mean time of 12 months. ROS formation was measured using the luminol analogue L-012. Peripheral blood leucocytes [monocytes, polymorphonuclear neutrophils (PMN) and dendritic cells (DC)] were analysed by flow cytometry and analysed for the expression of major inflammatory surface molecules. RESULTS: At follow-up, patients showed an increased walking distance and reduced ROS production upon stimulation with a phorbol ester derivative (PDBu) (p < 0.01). Monocytes changed their inflammatory phenotype towards an increased anti-inflammatory CD14(++)CD16(-) subpopulation (p < 0.0001). Adhesion molecules CD11b, CD11c and TREM-1 on monocytes and PMN decreased (all p < 0.01). On DC expression of HLA-DR, CD86 or CD40 decreased at follow-up. Inflammatory markers like fibrinogen, C-reactive protein or soluble TREM-1 (sTREM-1) decreased over the observation period. Finally, we found a close relation of sTREM-1 with the walking distance, fibrinogen and ROS production. CONCLUSIONS: We observed an amelioration of the proinflammatory phenotype on monocytes, DC and PMN, as well as a reduced ROS production in PAD patients under home-based exercise, paralleled by an increased walking distance. Our data suggest that a reduced inflammatory state might be achieved by regular walking exercise, possibly in a dimension proportionately to changes in walking distance.

Association of monocyte tumor necrosis factor α expression and serum inflammatory biomarkers with walking impairment in peripheral artery disease.

OBJECTIVE: Inflammation contributes to the development of peripheral artery disease (PAD) and may contribute to intermittent claudication by adversely affecting vascular and skeletal muscle function. We explored the association of inflammation to maximal walking time (MWT) in patients with claudication. METHODS: Circulating inflammatory biomarkers, including tumor necrosis factor α (TNF-α), C-reactive protein (CRP), interleukin-6 (IL-6), and soluble intercellular adhesion molecule 1 (sICAM), were measured in 75 subjects with intermittent claudication as well as in 43 healthy subjects. Real-time polymerase chain reaction was used to quantify mRNA expression of TNF-α, IL-6, interferon-γ, and CD36 from peripheral blood monocytes. Treadmill testing was performed in PAD subjects to assess MWT. RESULTS: Compared with healthy subjects, PAD subjects had higher levels of circulating TNF-α (P < .0001), CRP (P = .003), sICAM (P < .0001), and IL-6 (P < .0001). Expression of both IL-6 (P = .024) and CD36 (P = .018) was greater in PAD subjects than in healthy subjects. Among subjects with PAD, higher gene expression of TNF-α was associated inversely with MWT (P = .01). MWT was also associated inversely with greater levels of circulating TNF-α (P = .028), CRP (P = .024), IL-6 (P = .03), and sICAM (P = .018). CONCLUSIONS: Systemic inflammation, as indicated by TNF-α inflammatory gene expression in peripheral blood monocytes and by circulating biomarker levels, is associated with impairment in walking time in patients with PAD and intermittent claudication.

Phenotypic characterisation of pro-inflammatory monocytes and dendritic cells in peripheral arterial disease.

Atherosclerosis is a chronic inflammatory process involving antigen-presenting cells like monocytes and dendritic cells (DC). The aim of this study was to perform a phenotypic characterisation of these cell types in patients with different degrees of peripheral arterial disease (PAD). Sixty patients with PAD [N= 30 intermittent claudication (IC), N= 30 critical limb ischemia (CLI)] and 30 controls were included. Peripheral blood leucocytes were analysed from peripheral blood by flow cytometry using different gating strategies to directly identify and analyse monocytes, myeloid DC, (mDC) and plasmacytoid DC (pDC). PAD patients showed a significantly higher proportion of proinflammatory CD14++CD16+ monocytes (p<0.0001) compared with healthy individuals. We found an increased number of mDC/ml and a reduced number of pDC/ml (both p<0.01) in PAD patients, leading to a shift in the mDC/pDC ratio (p<0.01). As compared to patients with intermittent claudication, CLI patients presented a reduced expression of HLA-DR (p<0.01), CD86 and CD40 on both mDCs and pDCs (p<0.01). Peripheral blood monocytes show a proinflammatory phenotype in PAD patients compared to controls. In contrast, CLI patients show a reduced expression of proinflammatory markers. We hypothesise that severe ischaemia and/or prolonged inflammation in CLI might lead to a paradoxical attenuation in the proinflammatory membrane pattern of circulating mononuclear cells, possibly hindering an adequate regulatory function of mDCs and pDCs and favouring the progression of disease.

C-reactive protein and the Framingham coronary risk score in patients newly diagnosed with intermittent claudication: a prospective study.

OBJECTIVE: To investigate the relationship between serum C-reactive protein (CRP) levels and the calculated 10-year Framingham risk score (FRS) in patients newly diagnosed with intermittent claudication. METHODS: Serum CRP levels were measured in 90 patients newly diagnosed with intermittent claudication over a 12-month period. In all, 76 patients (53 males [70%], mean age 63.3 ± 9.3) were included in the analysis. RESULTS: Log-transformed CRP levels significantly correlated with total FRS (r = .34, P = .002). Participants were divided into 4 groups according to log-CRP levels. Analysis of variance showed a statistically significant difference between the 4 groups in terms of mean FRS, P = .003. Post hoc comparisons indicated that group 1 was significantly different from group 4, P = .002. Analysis of covariance showed a significant difference between the 4 groups of log-CRP levels in terms of mean FRS, P = .008. CONCLUSION: There is an increased 10-year risk of coronary heart disease associated with increased plasma concentration of CRP in patients newly diagnosed with intermittent claudication.

Cardiovascular disease and serum defensin levels in systemic lupus erythematosus.

OBJECTIVES: To analyse if defensins, immunomodulatory peptides involved in angiogenesis and elevated in the sera of systemic lupus erythematosus (SLE) patients, relate to cardiovascular disease in SLE. METHODS: Serum levels of the defensins human beta defensin 2 (hBD2) and human neutrophil peptide (HNP) of 72 SLE patients were determined by ELISA at baseline. Cardiovascular risk factors and the occurrence of cardiovascular events (CVE: stroke, claudication, angina pectoris, myocardial infarction) were recorded over 6 years. Intima media thickness of the carotid arteries (CIMT) was measured by ultrasound in 42 patients at baseline and at 4 years. Normally distributed log-transformed defensin levels (log-hBD2 and log-HNP) were used for statistical analysis. RESULTS: SLE patients who experienced a CVE had significantly higher log-hBD2 values and a likelihood-ratio for CVE of 2.23 when levels increased above 3.3 log(ng/ml). Using binary logistic regression analysis, log-hBD2 significantly contributed to a model also incorporating the number of traditional cardiovascular risk factors (dyslipidemia, hypertension, positive family history, age, smoking) as explanatory variables for the incidence of cardiovascular events. Moreover, SLE patients with progressive CIMT showed increased log-hBD2 and log-HNP values. Both defensin-levels also showed some correlation to the plaque stadium at baseline (hBD2: r2 0.10; HNP r2 0.12). Neither log-hBD2 nor log-HNP were correlated to traditional cardiovascular risk factors. CONCLUSIONS: HNP and especially hBD2 may be indicators of progressive cardiovascular disease in SLE.

[Prognostic value of inflammatory markers and lipid profile in patients suffering from intermittent claudication - a pilot study]. / Valor pronóstico de marcadores inflamatorios y perfil lipídico en pacientes con claudicación intermitente. Estudio piloto.

BACKGROUND AND OBJECTIVE: To analyse clinical and serological variables (lipid profile, inflammatory biomarkers) as potential risk factors for the development of short-term cardiovascular events and mortality in patients suffering from intermittent claudication. PATIENTS AND METHODS: We included all patients with a first-time diagnosis of vascular intermittent claudication in our center during 2005-2006. We analysed clinical data, serological parameters (creatinine, total cholesterol, LDL-cholesterol, HDL-cholesterol, ApolipoproteinA1, ApolipoproteinB100, lipoprotein(a), homocysteine, C-reactive protein, erythrocyte sedimentation rate [ESR], fibrinogen), cardiovascular events and mortality during 1-3 year follow-up. RESULTS: We included 162 patients: 143 (88.3%) men, mean (SD) age 66 (10.4) (41-86) years, 76 (46.9%) active smokers, 96 (59.3%) hypertensive, 56 (34.6%) diabetic, 129 (79.6%) hypercholesterolemic. We registered 16 (9.9%) coronary/cerebrovascular events, 18 (11.1%) lower limb vascular events and 9 (5.9%) late deaths during follow-up (mean [SD] 18.2 [8] months). Hypertension was the only predictor of coronary or cerebrovascular events (p=0.013); heart disease and HDL-cholesterol<45 mg/dL were independent risk factors for lower limb vascular events (p=0.021 and 0.049), and ESR>20 mm/h was associated with all-cause death (p=0.008). CONCLUSIONS: Reduced HDL-cholesterol and elevated ESR have emerged as independent risk factors for short-term lower limb vascular events and death.

High MAPK p38 activity and low level of IL-10 in intermittent claudication as opposed to stable angina.

AIM: The aim of the present pilot study was to relate the activity of MAPK p38 with the levels of pro- and anti-inflammatory cytokines in a small cohort of patients with either stable angina (N=5) or intermittent claudication (N=5) compared to healthy controls (N=10). METHODS: The activity of MAPK p38 was determined in peripheral blood mononuclear cells, isolated from whole blood by western blot using phospho-specific anti-MAPK p38 antibodies. Cytokine levels of 11 pro- and anti-inflammatory cytokines were determined from the serum using flow cytometry. RESULTS: We found a significant elevation of the MAPK p38 activity in the intermittent claudication group (P=0.0027) compared with the healthy control group whereas the stable angina group showed similar MAPK p38 activity as the healthy control group. The IL-10 level in serum found in the stable angina group was significantly higher compared with both the healthy control group (P=0.0116) and the intermittent claudication group (P=0.0317). CONCLUSION: Our results imply that there is a casual relationship between increased levels of the anti-inflammatory cytokines IL-10 and IL-4 and the activity of the MAPK p38. Possibly has IL-10 a protective role that down-regulates the activity of MAPK p38 and thereby further inflammatory processes in stable angina patients.

Inflammatory profiling of peripheral arterial disease.

The progression of peripheral arterial disease (PAD) is poorly understood but may be caused by an underlying inflammatory dysfunction. This study therefore profiled interleukin (IL)-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, IL-13, anticardiolipin, and anti-beta2-glycoprotein 1 antibody concentrations and characterized patients' inflammatory response in vitro. Patients were classified according to World Health Organization criteria and ankle-brachial pressure index into critical ischemics (n=20), stable claudicants (n=20), and controls (n=20). In vitro studies involved culturing whole blood with RPMI-1640 for 24hr with and without 1 microg/mL lipopolysaccharide and profiling cytokine production. Autoantibody levels were measured using enzyme-linked immunosorbent assays, while cytokine profiles were determined by multiplex immunoassay. Serum IL-6, IL-10, IL-13, and anti-beta2-glycoprotein 1 antibody levels were higher in PAD (p<0.05). In the case of IL-6 and anti-beta2-glycoprotein 1 antibody, levels reflected increasing disease severity (p<0.05). In vitro studies revealed that IL-8 and IL-13 secretory capacities were significantly higher in PAD after 6 hr. However, when these were standardized against patient leukocyte count, cytokine production profiles did not differ. PAD features an increased inflammatory burden irrespective of Th1:Th2 cytokine type; this is more pronounced with increasing disease severity. However, the inflammatory hyperresponsiveness of cultured whole blood from PAD patients probably relates to associated leukocytosis, rather than being attributable to an inherent inflammatory dysfunction.

En el origen de la enfermedad arterial periférica: papel de la endotelina en la disfunción endotelial / At the origin of peripheral arterial disease: the role of endothelin in endothelial dysfunction

Introducción. La etiopatogenia de la arterioesclerosis reúne una serie de factores condicionantes y procesosinflamatorios crónicos que originan un estado permanente de disfunción endotelial. La endotelina (ET) es una proteínarelacionada con la función de las células endoteliales, y que parece tener un papel en la enfermedad arterial periférica(EAP), como manifestación de la arterioesclerosis. Objetivo. Investigar el papel de la ET en la EAP, y su relación con lossíntomas, la función endotelial y los procesos inflamatorios. Sujetos y métodos. Realizamos un estudio transversal con141 sujetos: 66 pacientes con claudicación intermitente, 37 pacientes con isquemia crítica y 38 controles sanos. Medimoslos niveles de ET y proteína C reactiva (hsPCR) plasmática y la dilatación de la arteria braquial mediada por flujo(DABMF) en estos tres grupos. Resultados. Las concentraciones de ET son significativamente más altas en pacientescomparados con los controles sanos (8,76 ± 7,1 frente a 6,45 ± 0,89 pM/L; p = 0,002). Los pacientes con claudicaciónpresentan concentraciones de ET significativamente más altas que los pacientes con isquemia crítica (10,97 ± 7,9 frentea 4,82 ± 2,57 pM/L; p < 0,001). Los valores de hsPCR fueron mayores en los pacientes con isquemia crítica que en losclaudicantes (16,94 frente a 4,73 mg/L; p = 0,001). En la DABMF no obtuvimos diferencias significativas entre los dosgrupos (5,4 ± 3,7% en claudicantes, 5,85 ± 4,35% en críticos; p = 0,58). Las concentraciones de ET presentan una modestacorrelación negativa con los valores de hsPCR (–0,165; p = 0,095). Conclusión. Las concentraciones plasmáticasde ET en los pacientes con EAP son mayores en etapas iniciales de la enfermedad. Con la progresión de la enfermedad,se observa una disminución de los valores de ET, mientras que existe un incremento del marcador inflamatorio hsPCR

Introduction. The aetiopathogenesis of arteriosclerosis includes a series of conditioning factors and chronicinflammatory processes that give rise to a permanent state of endothelial dysfunction. Endothelin (ET) is a protein thatis involved in the functioning of endothelial cells and which seems to play a role in peripheral arterial disease (PAD), asa manifestation of arteriosclerosis. Aim. To examine the role of ET in PAD and its relation with the symptoms,endothelial functioning and inflammatory processes. Subjects and methods. We conducted a cross-sectional study with141 subjects: 66 patients with intermittent claudication, 37 patients with critical ischaemia and 38 healthy controls. Wemeasured the levels of ET and C-reactive protein (hsCRP) in plasma and the brachial artery flow-mediated dilation(BAFMD) in these three groups. Results. ET concentrations are significantly higher in patients than in healthy controls(8.76 ± 7.1 vs. 6.45 ± 0.89 pM/L; p = 0.002). Patients with claudication show significantly higher ET concentrationsthan patients with critical ischaemia (10.97 ± 7.9 vs. 4.82 ± 2.57 pM/L; p < 0.001). Patients with critical ischaemia hadhigher hsCRP values than those with claudication (16.94 vs. 4.73 mg/L; p = 0.001). No significant differences were observedin the BAFMD in the two groups (5.4 ± 3.7% in those with claudication, 5.85 ± 4.35%; p = 0.58). ET concentrationsshow a slight negative correlation with the hsCRP values (–0.165; p = 0.095). Conclusions. Plasma concentrations ofET in patients with PAD are higher in the early stages of the disease. As the disease progresses, the ET values diminishwhile the inflammatory marker hsCRP increases

Platelet membrane CD154 and sCD154 in progressive peripheral arterial disease: a pilot study.

OBJECTIVE: The expression and potential role of platelet membrane CD154 and sCD154 in atherosclerosis was investigated in patients with peripheral arterial disease. METHODS: This prospective observational study measured the expression of platelet-bound CD154 and soluble CD154 (sCD154) in 39 patients with critical limb ischaemia (CLI, n=15), stable intermittent claudication (SIC, n=12) and age-matched controls (AMC, n=12). Basal and agonist-stimulated CD154, P-selectin expression and fibrinogen binding was measured by whole blood flow cytometry, while sCD154 was measured in paired plasma samples by ELISA. RESULTS: Basal expression of CD154 on the platelet surface was enhanced in both groups of patients with peripheral arterial disease. However, the critical limb ischaemics showed the highest level of basal expression 0.7+/-0.3 [median+/-IQR] and was significantly increased compared to both stable intermittent claudicants and age-matched controls (P<0.001). On agonist stimulation with either ADP or thrombin critical limb ischaemics demonstrated greater platelet reactivity and propensity to express CD154 compared to age-matched controls (P<0.05). Confirmation of the cellular expression of CD154 results was obtained by measuring sCD154 concentrations in autologous plasma samples. Here plasma levels of sCD154 in critical limb ischaemics were significantly greater than both stable intermittent claudicants and age-matched controls (P<0.005). CONCLUSIONS: Enhanced basal platelet expression and increased propensity to express CD154 and sCD154 in critical limb ischaemics compared to both controls and patients with stable intermittent claudication support evidence for the role of CD154 in atherogenesis and suggest a novel function in progressive and acute peripheral arterial disease.

Statins and biomarkers in claudicants with peripheral arterial disease: cross-sectional study.

This exploratory substudy of The Iron (Fe) and Atherosclerosis Study (FeAST) compared baseline inflammatory markers, including cytokines, C-reactive protein (CRP), and ferritin, in subjects with peripheral arterial disease (PAD) taking statins with subjects with PAD who were not taking statins. Inflammatory markers in the serum of 47 subjects with PAD not taking statins and a healthy cohort of 21 medication-free men were compared with 53 PAD subjects taking statins at entry to the FeAST. Healthy subjects demonstrated lower levels of tumor necrosis factor (TNF)-R1, interleukin-6 (IL-6), and CRP. TNF-alpha R1 averaged 2.28 ng/mL versus 3.52 ng/mL, p = .0025; IL-6 averaged 4.24 pg/mL versus 16.61 pg/mL, p = .0008; and CRP averaged 0.58 mg/dL versus 0.92 mg/dL, p = .0192. A higher level of IL-6 was observed in PAD statin takers versus PAD subjects not taking statins: 19.47 pg/mL versus 13.24 pg/mL, p = .0455. As expected, total cholesterol and low-density lipoprotein levels were lower in the statin-treated group, p = .0006 and p = .0001, respectively. No significant differences in inflammatory cytokines were detected for varying doses of simvastatin. Additionally, no significant differences in inflammatory biomedical markers were found in subjects with PAD alone compared with those with concomitant coronary artery disease (CAD). Unexpectedly, serum inflammatory cytokine IL-6 levels were significantly higher in PAD subjects receiving statins. There was no difference in measured inflammatory markers in PAD subjects with concomitant CAD.

The role of endothelial cell reactive antibodies in peripheral arterial disease.

OBJECTIVES: It is hypothesised that endothelial cell reactive antibodies (ECRA) play a role in the progression of PAD through activation of endothelial cells and the release of inflammatory cytokines. We aimed to test this hypothesis by assessing levels of ECRA, E-selectin and IL-6 in patients with PAD of varying severity in a case controlled study. DESIGN, MATERIALS, METHODS: Patients were assessed clinically and with ankle-brachial pressure indices. Patients with critical ischaemia (CI, n=30), stable claudicants (SC, n=30), and age-matched controls (AMC, n=20) were studied. Antibody, E-selectin and IL-6 levels were measured using ELISA. RESULTS: ECRA levels were significantly raised in the CI group over AMC. IL-6 levels were significantly elevated in both SC and CI over the control group and in CI over SC. There were no significant differences in E-selectin levels between the AMC, SC and CI. CONCLUSION: Our findings support the hypothesis that autoantibodies play a role in promoting PAD by elevating IL-6. The absence of an elevation in E-selectin in this study may be due to its short half-life, and casts doubt on its value as a marker of inflammation in atherosclerosis.

Risk of treatment of peripheral arterial disease is related to inflammation-sensitive plasma proteins: a prospective cohort study.

BACKGROUND: Studies in patients with peripheral arterial disease (PAD) have reported an association between inflammatory markers and severity of disease or worsening of symptoms. However, few have studied the prognostic significance of inflammatory markers in asymptomatic subjects, measured many years before the onset of symptomatic PAD requiring treatment (trPAD). MATERIAL AND METHODS: Five inflammation-sensitive plasma proteins (ISPs), including fibrinogen, alpha 1-antitrypsin, haptoglobin, ceruloplasmin, and orosomucoid, were determined in 5619 healthy men (mean age, 46.8 +/- 3.7 years) without walking-induced calf pain. Data for men who subsequently underwent a revascularization procedure because of trPAD (intermittent claudication or critical ischemia) were retrieved from hospital-based registers. Future trPAD was studied in relation to the number of ISPs in the top quartile at the baseline examination. RESULTS: Seventy men (1.2%) underwent revascularization because of trPAD at a mean of 16.5 years after the baseline examination. The proportion with future trPAD was 0.4%, 1.0%, 1.5%, and 3.2%, respectively, for men with 0, 1, 2, and 3 or more ISPs in the top quartile (trend, P < .0001). After adjustment for age, screening year, systolic blood pressure, blood pressure medication, cholesterol concentration, diabetes, smoking, and tobacco consumption the corresponding odds ratios (95% confidence interval [CI]) were 1.00 (reference), 1.5 (CI, 0.7-3.6), 1.9 (CI, 0.8-4.6), and 2.9 (CI, 1.3-6.4), respectively, in these groups (trend, P = .003). CONCLUSION: Elevated ISPs, measured 16 years earlier in apparently healthy men without walking-induced calf pain, were associated with increased risk for development of PAD requiring revascularization.

Anticardiolipin antibodies as a risk factor of atherosclerosis in intermittent claudication.

Anticardiolipin antibodies have been associated as a risk factor of atherosclerosis. The aim of this study was to evaluate the association between anticardiolipin antibodies and intermittent claudication. Forty consecutive patients (33 men, 7 women; age range: 45-84 years, mean 65.5) who were seen in the angiology and vascular surgery department with intermittent claudication were evaluated. Exclusion criteria included prior revascularization, angioplasty, or a history of thrombosis of a lower limb. Forty individuals (23 men, 17 women; age range: 58-82 years, mean 67.1) who attended a support group for senior citizens and who were apparently healthy formed the control group. Anticardiolipin antibodies were evaluated by means of enzyme-linked immunosorbent assay (ELISA) for quantitative measurement of immunoglobulin G (IgG) and IgM antibodies against cardiolipins in serum. IgG levels were considered normal when < 7, borderline from 7 to 10, and elevated at > 10 GPL units/mL; IgM levels were normal when < 4, borderline from 4 to 7, and elevated at > 7 MPL, as recommended by the test manufacturers. Statistical analysis used the relative risk test with a confidence interval of 95%. Twenty-three patients from the study group and 6 individuals from the control group were found to have elevated levels of anticardiolipin antibodies giving a relative risk of 3.833 (ranging from 1.749 to 8.4; p value < 0.0001). In conclusion, patients who have elevated levels of anticardiolipin antibodies present a 3.8 times greater risk of developing intermittent claudication.

Helicobacter pylori seropositivity is associated with enhanced platelet activation in patients with intermittent claudication.

OBJECTIVE: Patients with intermittent claudication have a significantly increased risk of mortality from cardiovascular and cerebrovascular causes. Helicobacter pylori infection and abnormal platelet function have been shown to be associated with atherosclerosis as well as with acute ischemic events. The aim of this study was to assess for the first time the relation between H pylori serology status, platelet activation, and endothelial injury in patients with intermittent claudication. Design of study : A prospective observational study of 125 patients with intermittent claudication suitable for angioplasty was conducted at the Vascular Unit of the Aberdeen Royal Infirmary. Main outcome measures Main outcome measures were (1) H pylori serology using ELISA kit for immunoglobulin G antibody to H pylori and (2) whole blood flow cytometric analysis of resting platelet P-selectin expression and fibrinogen binding as measures of platelet activation. Results are presented as platelet percentage. von Wildebrand factor levels were measured using ELISA as a marker of endothelial injury. Carstair deprivation scores were calculated for all patients. RESULTS: H pylori serology was positive in 62 patients (49.6%), negative in 56 (44.8%) and equivocal in 7 (5.6%). Median P-selectin expression was significantly increased in H pylori-positive patients compared with seronegative patients (0.815 vs 0.65; P =.039). Median platelet fibrinogen binding was higher in seropositive patients, but this failed to reach statistical significance (2.135 vs 1.85%; P =.11). There was no difference in von Wildebrand factor levels between the two groups (P =.51). There was no difference in socioeconomic status between the two groups. CONCLUSION: Patients with intermittent claudication who are H pylori positive show enhanced platelet activation that does not appear to be mediated by means of endothelial cell injury.

Platelet activation is increased in peripheral arterial disease.

OBJECTIVE: Platelet activation was assessed in patients with peripheral arterial disease compared with healthy control subjects. METHODS: This prospective comparative study included 100 subjects: 40 consecutive patients with intermittent claudication, 20 consecutive patients with critical ischemia and tissue loss, and 40 healthy control subjects. Whole blood flow cytometric analysis was performed to determine resting and stimulated platelet P-selectin expression and resting and stimulated platelet fibrinogen binding. Results are presented as platelet percentage and also as mean fluorescence intensity. RESULTS: P-selectin expression was significantly increased in patients with intermittent claudication (median, 0.85%; range, 0.31%-4.77%; P =.023) and critical ischemia (median, 1.11%; range, 0.2%-3.26%; P =.028) compared with control subjects (median, 0.59%; range, 0.16%-4.58%). The percentage of platelets binding fibrinogen was also significantly higher in patients with intermittent claudication (median, 2.89%; range, 1.08%-9.59%; P <.001) compared with control subjects (median, 1.57%; range, 0.17%-10.7%). There was no significant difference in percentage of platelet fibrinogen binding between control subjects and patients with critical ischemia. Fibrinogen binding by stimulated platelets was significantly diminished in patients with critical limb ischemia compared with control subjects (67.2% vs 77.9%; P =.006). CONCLUSIONS: Platelet activation is increased in patients with peripheral arterial disease, suggesting an underlying prothrombotic state. Platelets from patients with critical limb ischemia are less responsive to in vitro stimulation.

A randomised, double blind, placebo-controlled study to determine the efficacy of immune modulation therapy in the treatment of patients suffering from peripheral arterial occlusive disease with intermittent claudication.

OBJECTIVES: this study examined the effect of immune modulation therapy (IMT) on claudication distances. MATERIALS AND METHODS: a double-blind placebo controlled trial was performed on patients with disabling intermittent claudication with randomisation stratified for short and long distance IC. For IMT, following exposure to UV light, oxidisation and 42.5 degrees C, 10 ml of citrated autologous blood was administered by intra-muscular injection. One course consisted of 6 injections in 3-weeks followed by 3-weeks rest. Patients received 2, 3 or 4 courses depending on response. The primary end-point was the number of responders (>50% increase in initial claudication distance (ICD)) in each group. Secondary end-points included percentage changes in ICD and change in quality of life. RESULTS: at week 24, there were more responders in the IMT group (20/31, 65%) compared to placebo (16/39, 41%) (p=0.06). In the subgroup of short distance claudicants this difference reached significance (IMT 17/26, 65%) (Placebo 12/33, 36%) (p=0.04). The median increase in ICD was significantly greater in the IMT group (81%) compared to placebo (44%, p=0.04). These results were supported by quality of life measurements. CONCLUSIONS; IMT is a safe and apparently effective treatment for patients with short distance claudication.