Biomedical subjects

Burton E Sobel

Publications and source records attributed to Burton E Sobel.

At least 19 recordsLinked to original sources

PubMed2006

IL-1 and IL-6 induce hepatocyte plasminogen activator inhibitor-1 expression through independent signaling pathways converging on C/EBPdelta.

To elucidate signaling pathways activated by IL-1 and IL-6 that contribute to increased expression of plasminogen activator inhibitor-1 (PAI-1), we studied human hepatoma (HepG2) cells and primary mouse hepatocytes. HepG2 cell PAI-1 mRNA increased in response to IL-1beta, IL-6, and IL-1beta plus IL-6 as shown by real-time PCR. Activity of the transiently transfected PAI-1 promoter (-829 to +36 bp) increased as well. Systematic promoter deletion assays showed that the region from -239 to -210 bp containing a putative CCAAT-enhancer binding protein (C/EBP) binding site was critical. Point mutations in this region abolished the IL-1beta and IL-6 responses. Antibody interference electrophoretic mobility shift assays showed that C/EBPdelta (but not C/EBPalpha or C/EBPbeta) binding and protein were increased by IL-1beta, IL-6, and IL-1beta plus IL-6 in HepG2 cells. IL-1beta and IL-6 increased expression of both PAI-1 mRNA and C/EBPdelta mRNA in mouse primary hepatocytes as well. Downregulation of C/EBPdelta induced with small interfering RNA (siRNA) decreased secretion of PAI-1. As judged from results obtained with inhibitors, signal transduction in all three of the mitogen-activated protein kinase pathways was involved in IL-1-inducible PAI-1 expression. By contrast, JAK signaling was responsible for the IL-6-induced inducible expression. Thus IL-1 and IL-6 exert directionally similar effects on PAI-1 expression, but the induction involves distinct signaling pathways with a final common mediator, C/EBPdelta.

Animals↗

PubMed2006

Hepatocyte growth factor regulates E box-dependent plasminogen activator inhibitor type 1 gene expression in HepG2 liver cells.

OBJECTIVE: We sought to determine the etiologic mechanism of pleiotropic growth factor, hepatocyte growth factor (HGF), as a regulator of hepatic synthesis of plasminogen activator inhibitor (PAI)-1, the physiological inhibitor of fibrinolysis and a potential inducer of atherothrombosis. METHODS AND RESULTS: HGF increased PAI-1 mRNA expression and PAI-1 protein accumulation in the conditioned media of human liver-derived HepG2 cells, and increased hepatic PAI-1 mRNA expression in vivo in mice. HGF-inducible PAI-1 mRNA was attenuated by U0126, a specific inhibitor of mitogen-activated protein kinase (MAPK) kinase, and genistein, an inhibitor of tyrosine kinase. HGF increased the human PAI-1 promoter (-829 to +36 bp) activity, and deletion and mutation analysis uncovered a functional E box (5'-CACATG-3') at positions -158 to -153 bp. Electrophoretic mobility shift assays demonstrated that this E box binds upstream stimulatory factors (USFs). HGF phosphorylated USFs through MAPK and tyrosine kinase pathways. Co-transfection of USF1 expression vector increased PAI-1 promoter activity. Sterol regulatory element-binding protein-1 attenuated HGF-inducible PAI-1 promoter activity. CONCLUSIONS: Because USFs are involved in the regulation of carbohydrates and lipid metabolism, HGF-mediated PAI-1 production may provide a novel link between atherothrombosis and metabolic derangements. Targeting HGF signaling pathway may modulate the thrombotic risk in high-risk patients.

Animals↗

PubMed2006

Insulin resistance increases PAI-1 in the heart.

To determine whether insulin resistance increases expression of plasminogen activator inhibitor type-1 (PAI-1) in the heart, studies were performed in 22 mice with and 38 without myocardial infarction. Insulin resistance in transgenic animals genetically rendered insulin resistant was confirmed with the use of intraperitoneal glucose tolerance tests. Myocardial infarction was induced by coronary ligation, verified echocardiographically, and quantified by assay of depletion of creatine kinase (CK) from the left ventricle 2 weeks later. PAI-1 increased markedly in zones of infarction to 10.4+/-2.1 (SF) and significantly more to 27.3+/-3.6 in normal and insulin resistant mice compared with 0.45+/-0.04 and 0.50+/-0.03 in normal myocardium. Thus, insulin resistance induced accumulation of PAI-1 in the heart, particularly in zones of infarction. Such increases may contribute to fibrosis and diastolic dysfunction typical late after infarction in patients with insulin resistance.

Animals↗

PubMed2006

Increased plasminogen activator inhibitor type-1 (PAI-1) in the heart as a function of age.

Heart failure is associated with advanced age and insulin resistance and is thought to be exacerbated by cardiac fibrosis. Plasminogen activator inhibitor type-1 (PAI-1) has been strongly implicated as a determinant of fibrosis in diverse organs and tissues. Its concentration is increased in blood, and its expression is increased in vessel walls in association with insulin resistance. Accordingly, we sought to determine whether expression of PAI-1 in the heart increases as a function of age of 10 week old and 20 week old normal and insulin resistant transgenic mice thereby potentially predisposing to heart failure. Results obtained indicate that PAI-1 content increases significantly in the heart as a function of age by more than 60%. The increases are much greater than those that can be accounted for by the modest, and statistically insignificant increases in the concentrations of PAI-1 in plasma that were observed to occur as a function of age as well. Thus, PAI-1 increases in the heart is a function of age, occurs in insulin resistant and non-insulin resistant mice, and may contribute to fibrosis predisposing to heart failure associated with advanced age, particularly when insulin resistance is present.

Aging↗

PubMed2006

Augmentation of proliferation of vascular smooth muscle cells by plasminogen activator inhibitor type 1.

OBJECTIVE: Proliferation of vascular smooth muscle cells (VSMCs) contributes to restenosis after coronary intervention. We have shown previously that increased expression of plasminogen activator inhibitor type 1 (PAI-1) limits VSMC apoptosis. Because apoptosis and proliferation appear to be linked, we sought to determine whether increased PAI-1 would affect VSMC proliferation. METHODS AND RESULTS: VSMCs were explanted from control and transgenic mice (SM22-PAI+) in which VSMC expression of PAI-1 was increased. Increased growth of SM22-PAI+-VSMCs (2.3+/-0.4-fold) reflected, at least partially, increased proliferation. Greater expression of FLICE-like inhibitory protein (FLIP; 2.7-fold) and its cleaved active form were seen in SM22-PAI+-VSMCs. The balance between caspase-8 and FLIP favored proliferation in SM22-PAI+-VSMCs. Increased expression of NF-kappaB and activation of extracellular signal-regulated kinase (ERK) were demonstrated in SM22-PAI+-VSMCs (fold=NF-kappaB=2.2+/-0.1, fold=phosphorylated-ERK=1.6+/-0.1). Results were confirmed when expression of PAI-1 was increased by transfection. Inhibition of NF-kappaB and ERK attenuated proliferation in SM22-PAI+-VSMCs. Increased expression of PAI-1 promoted proliferation when VSMCs were exposed to tumor necrosis factor (TNF). CONCLUSIONS: Increased expression of PAI-1 is associated with greater activity of FLIP that promotes VSMC proliferation through NF-kappaB and ERK. Thus, when vascular wall expression of PAI-1 is increased, restenosis after coronary intervention is likely to be potentiated by greater proliferation of VSMC and resistance to apoptosis.

Adenoviridae↗

PubMed2006

wnt3a but not wnt11 supports self-renewal of embryonic stem cells.

wnt proteins (wnts) promote both differentiation of midbrain dopaminergic cells and self-renewal of haematopoietic stem cells. Mouse embryonic stem (ES) cells can be maintained and self-renew on mouse feeder cell layers or in media containing leukemia inhibitory factor (LIF). However, the effects of wnts on ES cells self-renewal and differentiation are not clearly understood. In the present study, we found that conditioned medium prepared from L cells expressing wnt3a can replace feeder cell layers and medium containing LIF in maintaining ES cells in the proliferation without differentiation (self-renewal) state. By contrast, conditioned medium from NIH3T3 cells expressing wnt11 did not. Alkaline phosphatase staining and compact colony formation were used as criteria of cells being in the undifferentiated state. ES cells maintained in medium conditioned by Wnt3a expressing cells underwent freezing and thawing while maintaining properties seen with LIF maintained ES cells. Purified wnt3a did not maintain self-renewal of ES cells for prolonged intervals. Thus, other factors in the medium conditioned by wnt3a expressing cells may have contributed to maintenance of ES cells in a self-renewal state. Pluripotency of ES cells was determined with the use of embryoid bodies in vitro. PD98059, a MEK specific inhibitor, promoted the growth of undifferentiated ES cells maintained in conditioned medium from wnt3a expressing cells. By contrast, the P38 MAPK inhibitor SB230580 did not, suggesting a role for the MEK pathway in self-renewal and differentiation of ES cells maintained in the wnt3a cell conditioned medium. Thus, our results show that conditioned medium from wnt3a but not wnt11 expressing cells can maintain ES cells in self-renewal and in a pluripotent state.

Animals↗

PubMed2006

Hypotheses, design, and methods for the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) Trial.

The Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) is a National Institutes of Health (NIH)-sponsored randomized clinical trial that evaluates treatment efficacy for patients with type 2 diabetes mellitus and angiographically documented stable coronary artery disease. Using a 2 x 2 factorial design, BARI 2D compares revascularization combined with aggressive medical treatment versus aggressive medical treatment alone; simultaneously, BARI 2D compares 2 glycemic control strategies, insulin sensitization versus insulin provision. All patients have goals of glycosylated hemoglobin values <7.0% and uniform control of hypertension, dyslipidemia, and obesity following recommended medical guidelines. The primary end point of BARI 2D is all-cause 5-year mortality analyzed by intention to treat, and the principal secondary end point is the combination of death, myocardial infarction, and stroke. A total of 2,368 patients have been enrolled at 49 clinical centers throughout North America, South America, and Europe. The study enrollment period was January 2001 through March 2005, and the patient treatment and follow-up phase is expected to extend at least through May 2007. Participants are treated at the local BARI 2D clinical sites on a monthly basis for the first 6 months and then every 3 months until the end of the study. Within BARI 2D, central management centers oversee the control of glycemia, plasma lipid levels, hypertension, and obesity. The randomized clinical trial collects data on patient symptoms, clinical measurements, medications, and clinical events as well as data from centralized evaluations of angiograms, electrocardiograms, nuclear stress tests, blood and urine specimens, and relative economic costs.

Angioplasty, Balloon, Coronary↗

PubMed2006

Ancillary studies in the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) Trial: Synergies and opportunities.

The definitive power of randomized controlled trials (RCTs) to characterize the efficacy of putative therapeutic approaches cannot be overestimated. Such trials are expensive, and their implementation requires prolonged and intensive commitments by both investigators and subjects. Accordingly, enhancing their value, in a sense increasing the "scientific return on investment," is a laudatory objective. Ancillary studies afford a great opportunity to do so. They permit acquisition of new knowledge, elucidation of cause/consequence relation, and delineation of pathogenetic mechanisms at a much lower cost than would be possible if they were performed independently of the parent RCTs. In addition, their utility is enhanced by internal consistency under the rubric of the parent trial and the presumed external validation of the parent trial. Several ancillary studies undertaken in conjunction with the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial provide cogent examples. They seek to delineate causal connections linking the accelerated coronary disease typical of diabetes with phenomena such as genetic predisposition to altered expression of cytokines and fibrinolytic system proteins, inflammation, procoagulation, insulin-induced impairment of fibrinolysis, insulin resistance, and the response to insulin-sensitizing and insulin-providing treatment strategies.

Angioplasty, Balloon, Coronary↗

PubMed2006

Quantitative analysis of atherosclerotic lesion composition in mice.

Comparative quantitation has become an increasingly desirable tool in determining compositional differences of aortic plaque lesion in transgenically altered mice. To this end, methodology has been developed to identify lipid, cellularity, collagen, and elastin components using traditional bright-field microscopy, fluorescence, and polarized light microscopy, employing both confocal and wide-field imaging systems. Subsequent imaging processing and analysis on the digitally captured images reveals differences in compositional components as influenced by diet, age and gender. This method can be expanded to employ a rich variety of histochemical and immunohistochemical staining protocols.

Animals↗

PubMed2006

Osteoprotegerin is not associated with angiographic coronary calcification.

UNLABELLED: Coronary artery calcification may play a significant role in the pathophysiology of plaque progression and healing. We hypothesized that osteoprotegerin, an inhibitor of osteoclastogenesis, may participate in the calcification of coronary plaques or the response to injury after coronary stenting. A prospective registry was performed in 2004. Blood samples from 100 patients undergoing percutaneous coronary intervention (PCI) were obtained before PCI and 24 h after PCI. The concentrations of osteoprotegerin (OPG), C-reactive protein, interleukin-6, and soluble CD40 ligand (sCD40L) were determined by ELISA. Quantitative coronary angiography was performed to define the presence of culprit lesion calcification (CLC). Comparisons among markers of inflammation and tertiles of OPG were stratified with respect to CLC. Patients with CLC (n = 28) compared with no CLC (n = 71) were older (P < 0.01), had lower creatinine clearance (P < 0.01), lower hemoglobin (P = 0.02), and were less likely to smoke (P = 0.04). Patients without CLC were over twice as likely to present with a marker-positive acute coronary syndrome. CLC was associated with less pre-PCI platelet-mediated inflammation as measured by sCD40L (4.65 vs. 7.15 pg/ml, P = 0.05), but not with lower levels of OPG. Inflammatory cytokines increased significantly after PCI for patients with and without CLC. For patients in the highest tertile of OPG at baseline, there was a reduction in OPG after PCI. Systemic osteoprotegerin levels are not associated with angiographic calcification of culprit plaques. For patients with elevated levels of OPG prior to PCI, there is a significant reduction after PCI consistent with a counterregulatory role for OPG. CONDENSED ABSTRACT: Both calcified and non-calcified culprit plaques exhibited a similar inflammatory response to stent-mediated injury. After PCI, osteoprotegerin decreased while proinflammatory cytokines increased, which may be consistent with a counterregulatory role for osteoprotegerin.

Aged↗

PubMed2006

Increased plasma concentrations of N-terminal pro-brain natriuretic peptide reflect the presence of mildly reduced left ventricular diastolic function in hypertension.

BACKGROUND: The potential use of assays of N-terminal pro-brain natriuretic peptide for detection of diastolic abnormalities associated with alterations in blood pressure has not been elucidated. This study was designed to determine whether increased plasma concentrations of N-terminal pro-brain natriuretic peptide sensitively reflect abnormal diastolic function associated with hypertension. METHODS: Concentrations of N-terminal pro-brain natriuretic peptide in plasma were assayed in 40 previously untreated hypertensive patients without overt congestive heart failure and in 20 age and sex-matched controls. Hypertensive patients were studied with the use of pulsed Doppler and color M-mode Doppler echocardiography for the evaluation of left ventricular diastolic function. RESULTS: Concentrations of N-terminal pro-brain natriuretic peptide were elevated in hypertensive patients [75.1+/-75.2 (SD) pg/ml compared with 37.9+/-38.5 in controls, P<0.05]. In hypertensive patients, concentrations of N-terminal pro-brain natriuretic peptide were negatively correlated with the ratio of color M-mode flow propagation velocity to transmitral E velocity consistent with the view that increased concentrations of N-terminal pro-brain natriuretic peptide are indicative of alterations in diastolic function. Hypertensive patients with N-terminal pro-brain natriuretic peptide values above the mean value in the control group exhibited significantly increased brachial intimal-medial thickness and reduced wall stress, consistent with the view that increased N-terminal pro-brain natriuretic peptide was associated with favorable peripheral arterial remodeling. CONCLUSIONS: Elevated concentrations of N-terminal pro-brain natriuretic peptide in plasma reflect the presence of left ventricular diastolic abnormalities and peripheral arterial remodeling in asymptomatic patients with hypertension.

Biomarkers↗

PubMed2006

Increased ability of tirofiban to maintain its inhibitory effects on the binding of fibrinogen to platelets in blood from patients with and without diabetes mellitus.

OBJECTIVES: Both tirofiban and eptifibatide release rapidly from glycoprotein IIb-IIIa but have different dissociation constants (KD of tirofiban=15 nmol/l, of eptifibatide=120 nmol/l). Binding of fibrinogen to glycoprotein IIb-IIIa is biphasic, forming an initial reversible complex (KD=155-180 nmol/l) and a second more stable complex (KD=20-70 nmol/l). Diabetes is known to alter platelet function. To determine the influence of affinity on inhibitory effects in blood from patients with (n=20) and without (n=20) diabetes mellitus, we characterized the extent of inhibition as a function of time. METHODS: Blood was added to reaction tubes containing tirofiban 100 ng/ml or eptifibatide 1.7 microg/ml (concentrations previously defined to be optimal) plus a platelet agonist (1 micromol/l adenosine diphosphate or 25 micromol/l thrombin receptor agonist peptide), and fluorochrome-labeled fibrinogen before analysis by flow cytometry. RESULTS: The extent of inhibition early on (30 s to 3 min) was similar (>85%) with either agent in blood from those with and without diabetes mellitus, whereas the extent of inhibition 10-15 min later was maintained more effectively with tirofiban than with eptifibatide (difference in slope P<0.01). After 15 min, the extent of inhibition in response to adenosine diphosphate in those with diabetes mellitus was 95+/-6% for tirofiban and 70+/-15% for eptifibatide (P<0.001); in those without diabetes mellitus, it was 91+/-9% for tirofiban and 73+/-19% for eptifibatide (P<0.001). CONCLUSION: For glycoprotein IIb-IIIa antagonists with a rapid rate of release, the biphasic binding of fibrinogen influences to a similar extent their ability to maintain inhibitory effects in blood from patients with and without diabetes mellitus.

Aged↗

PubMed2006

The metabolic syndrome: a call to action.

Metabolic syndrome, a cluster of risk factors that enhances the risk for atherosclerotic cardiovascular disease, has received increasing attention in recent years, especially as the worldwide prevalence of obesity has become better defined. Recent controversy has questioned the scientific basis for metabolic syndrome, but does not negate its value as a description of a common phenotype of patients encountered in clinical practice. Revised and refined diagnostic criteria may be useful for physicians. While more research is needed to understand the pathology of the metabolic syndrome, there is no ambiguity that physicians should treat cardiovascular risk factors in individuals with metabolic syndrome.

Cardiovascular Diseases↗

PubMed2006

Greater inhibitory effects of bivalirudin compared with unfractionated heparin plus eptifibitide on thrombin-induced platelet activation.

OBJECTIVES: The effects of antithrombotic agents on the activation of platelets by thrombin were determined in blood from patients (n=12) with symptomatic coronary artery disease. METHODS: Blood obtained immediately before cardiac catheterization was incubated in vitro with therapeutic concentrations of unfractionated heparin (1.2 and 2.0 U/ml) alone and in combination with eptifibatide (unfractionated heparin 1.2 U/ml+eptifibatide, 1.7 microg/ml) or bivalirudin (8 and 14 microg/ml). An activated clotting time was determined. Platelet activation was induced with thrombin (0, 5, 15, and 40 U/ml) and assessed with the use of flow cytometry. Fibrin polymerization was prevented by the peptide Gly-Pro-Arg-Pro. The activation of glycoprotein IIb-IIIa and surface expression of P-selectin were identified with antibodies (PAC-1 and anti-CD62). RESULTS: The activated clotting time was 258+/-13 s with 1.2 U/ml unfractionated heparin alone, 396+/-8 s with unfractionated heparin+eptifibatide, and 348+/-9 s with 8 microg/ml bivalirudin. The binding of PAC-1 (reflecting the potential to aggregate) was decreased most effectively by bivalirudin (percentage of platelets binding PAC-1 in response to 15 U/ml thrombin-unfractionated heparin=54+/-7%, unfractionated heparin+eptifibatide=12+/-4%, bivalirudin=1+/-0.3% of platelets, P<0.05 for bivalirudin compared with unfractionated heparin or unfractionated heparin+eptifibatide and unfractionated heparin+eptifibatide compared with unfractionated heparin). Bivalirudin prevented thrombin-induced surface expression of P-selectin more effectively than unfractionated heparin alone or unfractionated heparin+eptifibatide (percentage of platelets expressing P-selectin in response to 15 U/ml thrombin-unfractionated heparin alone=74+/-5%, unfractionated heparin+eptifibatide=53+/-7%, bivalirudin=1+/-0.3%, P<0.05 for bivalirudin compared with unfractionated heparin or unfractionated heparin+eptifibatide). CONCLUSION: Comparison between pharmacologic concentrations shown to be therapeutic demonstrated that bivalirudin inhibited thrombin-induced activation of platelets to a greater extent than unfractionated heparin alone or in combination with eptifibatide.

Drug Therapy, Combination↗

PubMed2006

The role of modern biology and medicine in drug development in academia and industry.

This symposium addresses careers in drug development in industry; the performance of translational research by academia, industry, and both; and numerous factors pertinent to alliances essential to drug discovery and development. Drug development is a complex process that regularly involves effective collaborations between academic and physician scientists and industry. There are specific occupational factors affecting recruitment of scientists and physicians in drug development programs in industry; ideal backgrounds for successful applicants for positions in industry in drug development; ethical and regulatory considerations particularly germane to the performance of scientists and physicians in drug development programs in industry and at universities; and particular gratifications available to scientists in industry working on drug development. Both similarities and differences characterize the performance of translational research in industry compared with academia. In industry, logistic, operational, and scientific oversight is complex, especially because it often involves relationships with clinical enterprises outside of the corporation. The process is long and arduous from formulation of a good idea in discovery to acceptance of a novel drug in the marketplace. Collaborations and partnerships by industry often involving academia and confrontation of multiple issues are pivotal.

Academic Medical Centers↗

PubMed2005

Enhancement by growth factors of cardiac myocyte differentiation from embryonic stem cells: a promising foundation for cardiac regeneration.

Cell transplantation is a promising, still novel, potentially therapeutic approach for the treatment of heart diseases. Clinical applications require generation of large number of donor cells. Embryonic stem (ES) cells are capable of self-renewal apparently in an unlimited fashion, in vitro. Theoretically, they can differentiate into any cell type required for cell transplantation, including cardiac myocytes. Diverse growth factors have been implicated in programming diverse cellular processes, including development of the embryonic heart, ES cell self-renewal, and cardiac myocyte differentiation from ES cells. This review addresses the current understanding of the role of growth factors in the differentiation of cardiac myocytes from ES-embryoid body cell systems in vitro as well as cardiac regeneration in vivo.

Animals↗

PubMed2005

Increased expression of platelet P-selectin and formation of platelet-leukocyte aggregates in blood from patients treated with unfractionated heparin plus eptifibatide compared with bivalirudin.

INTRODUCTION: Platelet-leukocyte aggregates have been implicated in atherogenesis. This study was designed to determine the influence in vivo of a direct thrombin inhibitor, bivalirudin, compared with unfractionated heparin (UFH) plus the GP IIb-IIIa inhibitor eptifibatide (E) on platelet reactivity, the formation of platelet-leukocyte aggregates, and leukocyte activation. MATERIALS AND METHODS: Blood was taken before and after percutaneous coronary intervention (PCI) from 60 patients randomized to UFH+E (n=26) or bivalirudin (n=34). Platelet function and the formation in vivo of platelet-monocyte aggregates (PMA) and platelet-neutrophil aggregates (PNA) were assessed with the use of flow cytometry. Myeloperoxidase (MPO) elaborated during leukocyte activation was measured by ELISA. RESULTS: Compared with those treated with bivalirudin, patients treated with UFH+E exhibited a 45% decrease in the capacity of platelets to bind fibrinogen (p=0.006) but a 2-fold increase in platelet surface expression of P-selectin (p=0.04) in samples taken from the coronary ostium before PCI. Platelet-leukocyte aggregation in vivo was greater (PMA=2-fold, p=0.04; PNA=3-fold, p=0.006) with UFH+E as was the concentration in blood of MPO (1.5-fold, p=0.007). CONCLUSIONS: Increased platelet surface expression of P-selectin, augmented platelet-leukocyte aggregation in vivo, and consequent activation of leukocytes was seen before PCI in blood from patients treated with UFH+E compared with bivalirudin. Benefits associated with decreased platelet aggregation when PCI is performed with UFH plus GP IIb-IIIa inhibition may be partially offset by increased platelet-leukocyte aggregation.

Anticoagulants↗

PubMed2005

Relation of leukocytosis to C-reactive protein and interleukin-6 among patients undergoing percutaneous coronary intervention.

An elevated white blood cell (WBC) count and elevated C-reactive protein (CRP) have been associated with an increased risk of adverse cardiac events. The relation between these 2 parameters of heightened systemic inflammation was characterized in patients who underwent percutaneous coronary intervention (PCI). Femoral arterial blood samples from a prospective registry of 100 patients who underwent PCI were obtained immediately before the procedure. The concentrations of CRP and interleukin-6 were determined by an enzyme-linked immunosorbent assay. Patients were stratified according to tertiles of ascending WBC counts before PCI. Univariate analysis compared patients in the highest WBC count tertile with the lower tertiles for clinical, angiographic, and procedural characteristics, as well as pre-PCI cytokine concentrations. Multiple logistic regression analysis was performed to examine the association between the elevated WBC count and baseline elevations in either CRP or interleukin-6, accounting for the simultaneous effect of confounding characteristics. Approximately 75% of patients had stable or unstable angina pectoris versus a marker-positive acute coronary syndrome. Patients in the highest WBC count tertile were more likely to be smokers, have received unfractionated heparin, have a marker-positive acute coronary syndrome, and have a CRP >3.0 mg/L. Multivariate analysis showed that only elevated troponin-I before PCI was independently associated with the highest WBC count tertile (odds ratio 10.9, 95% confidence interval 3.7 to 32.4, p < 0.01). In patients with negative troponin I findings, CRP >3.0 mg/L was a powerful independent predictor of an elevated pre-PCI WBC count (odds ratio 3.78, 95% confidence interval 1.07 to 13.3, p = 0.04). In conclusion, in patients with troponin I negative coronary syndromes, a pre-PCI elevation in the WBC count reflected cytokine-mediated inflammation.

Acute Disease↗