Differential phenotype and behavior in culture of CD34 positive cells from peripheral blood and adipose tissue.

The localization and quantification of endothelial progenitor cells (EPCs) are controversial. Circulating CD34 + cells in blood have been identified as EPCs and as biomarkers of cardiovascular disease. We discuss in this paper the current data describing differential phenotype and behavior in vitro of CD34 positive cells from the circulation and adipose tissue (AT). We also describe in brief our own findings from CD34 + cells isolated from leukopheresis cones derived from healthy platelet donors and from patients undergoing bariatric surgery. We conclude that CD34 + cells in blood and in AT are different in antigenic profile and behavior in culture. The findings described assert that CD34 + cells detected in blood previously identified as biomarkers of cardiovascular disease are predominantly HPCs rather than EPCs, and that true CD34 + EPCs can be readily identified and extracted from AT, supportive of the current evidence which suggests EPCs are resident in the tissue vasculature.

Simvastatin Efficiently Lowers Small LDL-IgG Immune Complex Levels: A Therapeutic Quality beyond the Lipid-Lowering Effect.

We investigated a polyethylene glycol non-precipitable low-density lipoprotein (LDL) subfraction targeted by IgG and the influence of statin therapy on plasma levels of these small LDL-IgG-immune complexes (LDL-IgG-IC). LDL-subfractions were isolated from 6 atherosclerotic subjects and 3 healthy individuals utilizing iodixanol density gradient ultracentrifugation. Cholesterol, apoB and malondialdehyde (MDA) levels were determined in each fraction by enzymatic testing, dissociation-enhanced lanthanide fluorescence immunoassay and high-performance liquid chromatography, respectively. The levels of LDL-IgG-IC were quantified densitometrically following lipid electrophoresis, particle size distribution was assessed with dynamic light scattering and size exclusion chromatography. The influence of simvastatin (40 mg/day for three months) on small LDL-IgG-IC levels and their distribution among LDL-subfractions (salt gradient separation) were investigated in 11 patients with confirmed coronary artery disease (CAD). We demonstrate that the investigated LDL-IgG-IC are small particles present in atherosclerotic patients and healthy subjects. In vitro assembly of LDL-IgG-IC resulted in particle density shifts indicating a composition of one single molecule of IgG per LDL particle. Normalization on cholesterol levels revealed MDA values twice as high for LDL-subfractions rich in small LDL-IgG-IC if compared to dominant LDL-subfractions. Reactivity of affinity purified small LDL-IgG-IC to monoclonal antibody OB/04 indicates a high degree of modified apoB and oxidative modification. Simvastatin therapy studied in the CAD patients significantly lowered LDL levels and to an even higher extent, small LDL-IgG-IC levels without affecting their distribution. In conclusion simvastatin lowers levels of small LDL-IgG-IC more effectively than LDL-cholesterol and LDL-apoB levels in atherosclerotic patients. This antiatherogenic effect may additionally contribute to the known beneficial effects of this drug in the treatment of atherosclerosis.

Endothelial dysfunction and brachial intima-media thickness: long term cardiovascular risk with claudication related to peripheral arterial disease: a prospective analysis.

OBJECTIVE: Endothelial dysfunction plays a key role in the development, progression, and clinical manifestation of atherosclerosis, and in symptomatic peripheral arterial disease, endothelial dysfunction and enlarged intima-media thickness might be associated with increased cardiovascular risk. Flow-mediated dilatation and serologic parameters are used to evaluate individual endothelial function. Brachial intima-media thickness, a less recognized parameter of cardiovascular risk, is independently associated with coronary artery disease. The aim of this study was to evaluate the prognostic value of ultrasound and serologic parameters of endothelial function in relation to cardiovascular mortality in peripheral arterial disease. DESIGN: monocentric, prospective cohort study. METHODS: Flow mediated dilatation and brachial intima-media thickness were assessed in 184 (124 male) patients with peripheral arterial disease (Rutherford stages 2-3). Serologic parameters of endothelial function included asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and L-homoarginine. Cardiovascular events were recorded during a follow-up of 99.1±11.1 months. Subjects who died of noncardiovascular causes were excluded from further analysis. RESULTS: Eighty-two patients (44.6%) died during follow-up after a mean duration of 49.7±28.3 months. There were 49 cardiovascular deaths (59.8%) and 33 other deaths (40.2%). Flow mediated dilatation was associated with cardiovascular death [1.17% (0.0, 4.3) vs. 4.1% (1.2, 6.4), p<0.001]. Intima-media thickness was greater in patients who succumbed to cardiovascular disease [0.37 mm (0.30, 0.41)] than in survivors [0.21 mm (0.15, 0.38), p<0.001]. Brachial intima-media thickness above 0.345 mm was most predictive of cardiovascular death, with sensitivity and specificity values of 0.714 and 0.657, respectively (p<0.001). Furthermore, ADMA levels above 0.745 µmol/l and SDMA levels above 0.825 µmol/l were significantly associated with cardiovascular death (p<0.001 and 0.030). CONCLUSION: In symptomatic peripheral arterial disease, decreased flow mediated dilatation, enlarged intima-media thickness, and elevated levels of ADMA and SDMA were associated with increased cardiovascular risk.

Endothelial function and carotid intima-media thickness in giant-cell arteritis.

BACKGROUND: Vascular endothelial dysfunction and intima-media thickness are characteristic aspects of several vasculitides. We investigated retrospectively the impact of steroid treatment on endothelial dysfunction and intima-media thickness in giant-cell arteritis. METHODS: Forty-one patients with giant-cell arteritis (28 female and 13 male) underwent flow-mediated dilatation, a marker of endothelial function, and carotid intima-media thickness within 24 h after diagnosis and 6 months thereafter. Both parameters were investigated in 41 patients of an age- and gender-matched control group. RESULTS: Brachial flow-mediated dilatation response at baseline was 3.4% (0.2, 8.0) and 1.7% (0.2, 4.8) in giant-cell arteritis patients and control group, respectively. After 6 months treatment, flow-mediated dilatation response was 2.8% (0.4, 4.8) in patients with giant-cell arteritis (P = 0.066) and 1.4% (0.1, 5.5) in the control group (P = 0.741). In contrast, mean carotid intima-media thickness of giant-cell arteritis patients improved significantly between baseline [1.0 mm (0.79, 1.2)] and 6-month follow-up [0.82 mm (0.7, 1.04), P < 0.001]. Subjects with additional symptoms of polymyalgia rheumatica had a notable enlargement of carotid intima-media thickness [1.23 mm (1.14, 2.09)] compared to giant-cell arteritis patients without polymyalgia rheumatica at baseline [0.91 mm (0.76, 1.04), P = 0.001] and 6-month follow-up [1.16 mm (0.80, 1.26) vs. 0.77 mm (0.68, 0.88), P = 0.009]. CONCLUSION: Steroid therapy has no influence on endothelial function but does significantly improve carotid intima-media thickness in giant-cell arteritis. This divergence of endothelial function and intima-media thickness reflects the specifity of giant-cell arteritis for cerebrovascular arteries thereby sparing the brachial arteries.

Platelet-to-lymphocyte ratio: a novel marker for critical limb ischemia in peripheral arterial occlusive disease patients.

BACKGROUND: Platelet-to-Lymphocyte Ratio (PLR) is an easily applicable blood test. An elevated PLR has been associated with poor prognosis in patients with different oncologic disorder. As platelets play a key role in atherosclerosis and atherothrombosis, we investigated PLR and its association with critical limb ischemia (CLI) and other vascular endpoints in peripheral arterial occlusive disease (PAOD) patients. METHODS AND FINDINGS: We evaluated 2121 PAOD patients treated at our institution from 2005 to 2010. PLR was calculated and the cohort was categorized into tertiles according to the PLR. An optimal cut-off value for the continuous PLR was calculated by applying a receiver operating curve analysis to discriminate between CLI and non-CLI. In our cohort occurrence of CLI significantly increased with an increase in PLR. As an optimal cut-off value, a PLR of 150 was identified. Two groups were categorized, one containing 1228 patients (PLR≤150) and a second group with 893 patients (PLR>150). CLI was more frequent in PLR>150 patients (410(45.9%)) compared to PLR≤150 patients (270(22.0%)) (p<0.001), as was prior myocardial infarction (51(5.7%) vs. 42(3.5%), p = 0.02). Regarding inflammatory parameters, C-reactive protein (median 7.0 mg/l (3.0-24.25) vs. median 5.0 mg/l (2.0-10.0)) and fibrinogen (median 457 mg/dl (359.0-583.0) vs. 372 mg/dl (317.25-455.75)) also significantly differed in the two patient groups (both p<0.001). Finally, a PLR>150 was associated with an OR of 1.9 (95%CI 1.7-2.1) for CLI even after adjustment for other well-established vascular risk factors. CONCLUSIONS: An increased PLR is significantly associated with patients at high risk for CLI and other cardiovascular endpoints. The PLR is a broadly available and cheap marker, which could be used to highlight patients at high risk for vascular endpoints.

Primary antiphospholipid antibody syndrome-one further aspect of thrombophilia in overweight and obese patients with venous thromboembolism.

OBJECTIVE: Overweight and obesity are established risk factors for venous thromboembolism (VTE). We examined the difference in the frequency of primary antiphospholipid antibody syndrome (PAPS) in VTE patients according to their BMI. DESIGN AND METHODS: We included 998 VTE patients treated at our institution between 2009 and 2011 in a retrospective data analysis. Thrombophilia screening including evaluation for APS (lupus anticoagulant, anti-cardiolipin, and anti-B2-glycoprotein-I IgG and IgM antibodies) was performed in all patients. RESULTS: PAPS was diagnosed in 6.8% (24/355) of normal weight (BMI < 24 kg/m2) VTE patients, in 11.1% (50/452) of overweight (BMI 25-30 kg/m2) VTE patients, and in 15.7% (30/191) of obese (BMI > 31 kg/m2) VTE patients. The difference of PAPS occurrence between these groups was statistically significant (P = 0.001). PAPS patients demonstrated higher fibrinogen levels as compared to non-PAPS patients (median 416.0 md/dl vs. 352.0 mg/dl, P = 0.001). Furthermore, fibrinogen levels increased significantly according to the body weight of patients (median normal weight patients 330.0 mg/dl vs. overweight patients 359.0 mg/dl vs. obese patients 415.0 mg/dl, P = 0.001). CONCLUSION: PAPS seems to be more frequent in overweight and obese patients. As PAPS patients showed significantly higher fibrinogen levels and as fibrinogen levels increased significantly according to the body weight of patients, an elevated inflammatory state in overweight and obese patients as a reason for the increased PAPS occurrence can be assumed.

Neutrophil-to-lymphocyte ratio and its association with critical limb ischemia in PAOD patients.

BACKGROUND: The Neutrophil-to-Lymphocyte ratio (NLR) is an easy to perform test from the white blood cell count. An increase in NLR has been associated with vascular endpoints reflecting inflammation in atherosclerotic lesions. Atherosclerosis is a global threat and vascular endpoints, like myocardial infarction or critical limb ischemia (CLI), are a leading cause of death in industrialized countries. We therefore investigated NLR and its association with CLI and other vascular endpoints in peripheral arterial occlusive disease (PAOD) patients. METHODS AND FINDINGS: We evaluated 2121 PAOD patients treated at our institution from 2005 to 2010. NLR was calculated and the cohort was divided into tertiles according to the NLR. An optimal cut-off value for the continuous NLR was calculated by applying a receiver operating curve analysis to discriminate between CLI and non-CLI. In our cohort occurrence of CLI significantly increased with an increase in NLR. As an optimal cut-off a NLR of 3.95 was identified. Two groups were categorized, one containing 1441 patients (NLR≤3.95) and a second group with 680 patients (NLR>3.95). CLI was more frequent in NLR>3.95 patients (330(48.5%)) compared to NLR≤3.95 patients (350(24.3%)) (p<0.001), as were prior myocardial infarction (48(7.0%) vs. 47(3.3%), p<0.001) and stroke (73(10.7) vs. 98(6.8%), p<0.001). Regarding other inflammatory parameters, C-reactive protein (median 5.6 mg/l (2.3-19.1) vs. median 3 mg/l (1.5-5.5)) and fibrinogen (median 412 mg/dl (345.5-507.5) vs. 344 mg/dl (308-403.5)) also significantly differed in the two patient groups (both p<0.001). A NLR>3.95 was associated with an OR of 2.5 (95%CI 2.3-2.7) for CLI even after adjustment for other vascular risk factors. CONCLUSIONS: An increased NLR is significantly associated with patients at high risk for CLI and other vascular endpoints. The NLR is an easy to perform test, which could be used to highlight patients at high risk for vascular endpoints.

Neointimal hyperplasia after silverhawk atherectomy versus percutaneous transluminal angioplasty (PTA) in femoropopliteal stent reobstructions: a controlled, randomized pilot trial.

BACKGROUND: Due to intimal hyperplasia instent reobstruction in the femoropopliteal arterial segment is still an unsolved problem. Different techniques have been discussed in case of reintervention to guarantee longlasting patency rate. METHODS: We conducted a randomized, controlled, pilot trial comparing Silverhawk atherectomy with percutaneous transluminal angioplasty (PTA) in patients with a first instent reobstruction in the femoropopliteal arterial segment, to evaluate intima media thickness (IMT) within the treated segment, as a parameter of recurrence of intimal hyperplasia. RESULTS: In a total 19 patients were included: 9 patients in the atherectomy device and 10 patients in the PTA arm. IMT within the treated segment was statistically significantly elevated in all patients treated with the Silverhawk device versus the patients treated with PTA. The obvious differentiation in elevation of IMT in nonfavor for patients treated with the Silverhawk device started at month 2 (max IMT SH 0.178 mm vs. IMT PTA 0.1 mm, p = 0.001) with a spike at month 5 (max IMT SH 0.206 mm vs. IMT PTA 0.145 mm, p = 0.003) and a decline once again at month 6 (max IMT SH 0.177 mm vs. IMT PTA 0.121 mm, p = 0.02). The values for mean IMT performed the same way. CONCLUSIONS: Although Silverhawk atherectomy provides good results at first sight, in the midterm follow-up of treatment of first instent restenosis it did not perform better than PTA as it showed elevated reoccurrence of intimal media hyperplasia.

Blood pressure measurements in patients with Takayasu arteritis: a work of caution.

Takayasu arteritis is a large vessel vasculitis among young women that affects the aorta and its branches. Disease-related subclavian or brachial obstructions can lead to hypotensive brachial blood pressure values. By contrast, arterial hypertension is also frequent in this disease, possibly unrecognized in case of solitary brachial blood pressure measurement. We present the case of a 28-year-old woman with cerebral hypoperfusion related to Takayasu arteritis. Despite "pseudo-hypotensive" brachial blood pressure values of 70 mm Hg, Doppler measurement of the ankle revealed a systolic pressure of 220 mm Hg. In Takayasu vasculitis, additional ankle pressure measurement may represent the true cardiac load and blood pressure.

Lipoproteins and the development of restenosis after stent implantation in the superficial femoral artery in patients with peripheral artery disease.

PURPOSE: High levels of apolipoprotein B (apo B) are a risk factor for the development of major vascular events. We evaluated the association between plasma lipoproteins and the development of superficial femoral artery (SFA) in-stent restenosis and reocclusion in patients with peripheral artery disease. MATERIALS AND METHODS: We included 139 patients with SFA stenting. Plasma lipoproteins were measured after stent implantation. Stent restenosis was assessed with duplex scan after 3, 6, and 12 months. A stenosis grade was considered relevant if >50%. RESULTS: Seventy-two patients experienced recurrence of their atherosclerotic disease, meaning restenosis of >50% within 1 year of follow-up. Ten of these patients had a stent occlusion. In the patients who experienced recurrence, the mean apo B level was 105.8 versus 94.9 mg/dl in patients without recurrence (P < 0.05). Patients without recurrence had higher high-density lipoprotein cholesterol levels than patients with recurrence (39.7 vs. 34.7 mg/dl, P < 0.05). Comparing patients with a stent occlusion (n = 10) and those with a restenosis of 75-99% (n = 28), the patients with a stent occlusion had higher levels of plasma cholesterol (234.1 vs. 185.9 mg/dl, P < 0.05), apo B (135.3 vs. 99.8 mg/dl, P < 0.05), low-density lipoprotein cholesterol (160.3 vs. 113.6 mg/dl, P < 0.05), and low-density lipoprotein apo B (115.5 vs. 82.4 mg/dl, P < 0.001) than the patients with restenosis of 75-99% (n = 28). CONCLUSION: Changes in the lipid profile could be one reason for the development of restenosis and for the development of reocclusion after SFA stenting.

Regulation of circulating progenitor cells in left ventricular dysfunction.

BACKGROUND: Reductions in numbers of circulating progenitor cells (CD34+ cell subsets) have been demonstrated in patients at risk for, or in the presence of, cardiovascular disease. The mediators of these reductions remain undefined. To determine whether neurohumoral factors might regulate circulating CD34+ cell subsets in vivo, we studied complementary canine models of left ventricular (LV) dysfunction. METHODS AND RESULTS: A pacing model of severe LV dysfunction and a hypertensive renal wrap model in which dogs were randomized to receive deoxycorticosterone acetate (DOCA) were studied. Circulating CD34+ cell subsets including hematopoietic precursor cells (HPCs: CD34+/CD45(dim)/VEGFR2-) and endothelial progenitor cells (EPCs: CD34+/CD45-/VEGFR2+) were quantified. Additionally, the effect of mineralocorticoid excess on circulating progenitor cells in normal dogs was studied. The majority of circulating CD34+ cells expressed CD45dimly and did not express VEGFR2, consistent with an HPC phenotype. HPCs were decreased in response to pacing, and this decrease correlated with plasma aldosterone levels (Spearman rank correlation=-0.67, P=0.03). In the hypertensive renal wrap model, administration of DOCA resulted in decreased HPCs. No changes were seen in EPCs in either model. Normal dogs treated with DOCA exhibited a decrease in HPCs in peripheral blood but not bone marrow associated with decreased telomerase activity. CONCLUSIONS: This is the first study to demonstrate that mineralocorticoid excess, either endogenous or exogenous, results in reduction in HPCs. These data suggest that mineralocorticoids may induce accelerated senescence of progenitor cells, leading to their reduced survival and decline in numbers.

Carotid repair using autologous adipose-derived endothelial cells.

BACKGROUND AND PURPOSE: Adipose tissue is an abundant source of endothelial cells as well as stem and progenitor cells which can develop an endothelial phenotype. It has been demonstrated that these cells have distinct angiogenic properties in vitro and in vivo. However, whether these cells have the capacity to directly improve large vessel form and function after vascular injury remains unknown. To define whether delivery of adipose-derived endothelial cells (ADECs) would improve healing of injured carotid arteries, a rabbit model of acute arterial injury was used. METHODS: Autologous rabbit ADECs were generated using defined culture conditions. To test the ability of ADECs to enhance carotid artery repair, cells were delivered intraarterially after acute balloon injury. Additional delivery studies were performed after functional selection of cells before delivery. RESULTS: After rabbit omental fat harvest and digestion, a proliferative, homogenous, and distinctly endothelial population of ADECs was identified. Direct delivery of autologous ADECs resulted in marked reendothelialization 48 hours after acute vascular injury as compared to saline controls (82.2+/-26.9% versus 4.2+/-3.0% P<0.001). Delivery of ADECs that were selected for their ability to take up acetylated LDL significantly improved vasoreactivity and decreased intimal formation after vascular injury. CONCLUSIONS: Taken together, these data suggest that ADECs represent an autologous source of proliferative endothelial cells, which demonstrate the capacity to rapidly improve reendothelialization, improve vascular reactivity, and decrease intimal formation in a carotid artery injury model.