T lymphocyte activation in stable angina pectoris and after percutaneous transluminal coronary angioplasty

Effects of Preoperative WBC Count on Post-CABG Surgery Clinical Outcome

OBJECTIVE

White blood cells (WBCs) play a major role in inflammation, with effects on the vascular wall, the microvascular blood flow, and endothelial cells and endothelial function. Previous studies have shown that a high WBC count may increase the risk of cardiovascular complication rate and mortality after coronary artery bypass graft (CABG) surgery. The aim of the study was to evaluate the association between preoperative WBC count and the post-CABG clinical outcome.

METHODS

A retrospective study that was based on 239 patients who underwent CABG surgery in our medical center. Statistical analysis estimated the effect of WBC count in postoperative clinical outcomes, including atrial fibrillation, length of stay, readmission rate, and death.

RESULTS

The preoperative WBC count was associated with longer hospitalization length (B = 0.392, P < 0.01). A preoperative WBC count >8150/μL predicted a longer stay (Z = 2.090, P = 0.03). A low lymphocyte count was associated with atrial fibrillation (B = -0.543, P = 0.03). Female patients were older (Z = 2.920, P < 0.01), had impaired renal function (Z = -3.340, P < 0.01), and had a higher rate of postoperative atrial fibrillation (df 2 = 3.780, P = 0.05) and readmission (df 2 = 5.320, P = 0.02).

CONCLUSIONS

Preoperative WBC count may have an effect on the postoperative clinical outcome in patients undergoing CABG. Surgeons should pay more attention to patients' WBC count and sex and plan surgery and postoperative management accordingly.

Role of cytokines and inflammation in heart function during health and disease

By virtue of their actions on NF-κB, an inflammatory nuclear transcription factor, various cytokines have been documented to play important regulatory roles in determining cardiac function under both physiological and pathophysiological conditions. Several cytokines including TNF-α, TGF-β, and different interleukins such as IL-1 IL-4, IL-6, IL-8, and IL-18 are involved in the development of various inflammatory cardiac pathologies, namely ischemic heart disease, myocardial infarction, heart failure, and cardiomyopathies. In ischemia-related pathologies, most of the cytokines are released into the circulation and serve as biological markers of inflammation. Furthermore, there is an evidence of their direct role in the pathogenesis of ischemic injury, suggesting cytokines as potential targets for the development of some anti-ischemic therapies. On the other hand, certain cytokines such as IL-2, IL-4, IL-6, IL-8, and IL-10 are involved in the post-ischemic tissue repair and thus are considered to exert beneficial effects on cardiac function. Conflicting reports regarding the role of some cytokines in inducing cardiac dysfunction in heart failure and different types of cardiomyopathies seem to be due to differences in the nature, duration, and degree of heart disease as well as the concentrations of some cytokines in the circulation. In spite of extensive research work in this field of investigation, no satisfactory anti-cytokine therapy for improving cardiac function in any type of heart disease is available in the literature.

Adrenomedullin expression in coronary circulation after stent implantation as a prognostic factor for restenosis

The authors determined the changes in adrenomedullin (AM) expression in the coronary circulation of patients with ischemic heart disease who underwent coronary stent implantation. Blood samples were drawn from the coronary sinus before, immediately after and four hours after coronary stent implantation, and plasma levels of AM were measured. AM levels in the coronary sinus blood were significantly increased four hours after stent implantation. On the other hand, in the femoral arterial blood, no significant changes in AM levels were observed. A significant positive correlation was found between AM level in the coronary sinus blood four hours after stent implantation and late loss index six months after the procedure. These results suggest that inflammation after coronary stent implantation induces AM expression, which might play an important role in restenosis after stenting.

The possible role of red blood cell microvesicles in atherosclerosis

The tendency of sickle cells to adhere to the endothelium reflects the surface features not only of the red cells but also of the endothelial cells. Sickle cell disease is a prototype of a condition where the erythrocyte is under stress, ischemic, oxidative, or shear stress, that causes changes in the erythrocyte morphology. This change leads eventually to enhanced erythrocyte-endothelial cell adhesion. Reactive oxygen species generated by cytokine-activated inflammatory cells oxidize lipoproteins such as LDL and lipoprotein(a) within the vessel wall, facilitating uptake of these particles by activated macrophages and smooth muscle cells, with conversion into lipid-laden foam cells. Notably, the membranes of sickle RBCs have undergone excessive cytoskeletal protein thiol oxidation, and sickle RBCs are abnormally prone to vesiculation during mechanical stress in vitro and apparently in vivo. This abnormality was successfully reproduced in normal RBCs by causing stress conditions using PMS-induced stimulation of intracellular superoxide generation, a process similar to that occurring in sickle RBCs. It could be that the generation of reactive oxygen species in atherosclerosis activates red blood cells, and microvesicles of red blood cells are formed, enhancing the activation of the vascular endothelium and leading to vascular inflammation and atherogenesis.

Elevated plasma levels of interleukin-2 and soluble IL-2 receptor in ischemic heart disease

BACKGROUND

T-lymphocytes are present in significant numbers in the atherosclerotic plaque, but their role in the progression and pathogenesis of coronary syndromes remains poorly understood.

HYPOTHESIS

We sought to determine the relationship between T-lymphocyte activation and ischemic heart disease by measuring plasma levels of cytokines related to T-lymphocyte function in patients with stable and unstable angina.

METHODS

Plasma levels of interleukin-2 (IL-2) and soluble IL-2 receptor (sIL-2R) were measured in 105 patients: 66 with stable angina, 24 with unstable angina, and 15 healthy controls. Patients who presented to the cardiac catheterization laboratory with unstable or stable anginal syndromes for coronary angiography or percutaneous coronary intervention enrolled in the study.

RESULTS

Mean levels of IL-2 were significantly higher in patients with stable angina than in those with unstable angina. The differences between stable angina and control groups, or between unstable angina and control groups, were not statistically significant. Mean levels of slL-2R were significantly higher in patients with stable angina than in either patients with unstable angina or control patients.

CONCLUSIONS

Levels of IL-2 and sIL-2 receptor are significantly elevated in patients with stable angina, but not in patients with unstable angina. The contribution of T-lymphocytes to the development of both stable and unstable angina requires further investigation.

Serum amyloid type A may be a predictor of restenosis

BACKGROUND

Elevation of acute phase proteins [C-reactive protein (CRP) and serum amyloid type A (SAA)] has been demonstrated in unstable angina with an adverse clinical prognosis.

HYPOTHESIS

The study was undertaken to determine the effect of angioplasty on the levels of SAA and the correlation with postangioplasty restenosis.

METHODS

In a university-affiliated tertiary medical center, a prospective case study was undertaken in 55 patients who underwent successful percutaneous transluminal coronary angioplasty (PTCA) of a single coronary lesion for angina pectoris. Three groups of patients were clinically characterized according to Braunwald's classification of anginal syndrome: Group A: class III; Group B: class I; Group C: stable angina. Serum amyloid type A was measured by an ELISA method before PTCA and after 24 h, 1, and 3 months. Patients were followed clinically for 12 months. A thallium stress perfusion scan was performed 3 months after PTCA and coronary angiography was repeated in patients with an abnormal thallium perfusion scan.

RESULTS

Serum amyloid type A levels > 100 micrograms/ml could identify Group A patients with a high sensitivity and specificity (r = 0.85 and 0.86, respectively). Of the patients studied, 75% increased their SAA level 24 h after angioplasty. An increase of SAA by > 100% was associated with an increased risk of restenosis, with a relative risk of 6.4 (p < 0.05).

CONCLUSION

Increased levels of SAA characterize patients with unstable angina pectoris with a high specificity and sensitivity. Levels of SAA that increase > 100% 24 h after angioplasty may serve as a marker of restenosis.

Naproxen treatment prevents periprocedural inflammatory response but not myocardial injury after percutaneous coronary intervention

BACKGROUND AND AIM

Recent studies have documented that elevation of C-reactive protein (CRP) levels after percutaneous coronary intervention (PCI) have been predictive of adverse outcome. This study was performed to test the hypothesis that preprocedural use of naproxen sodium is associated with a reduction in the extent of inflammatory response and myocardial injury after PCI.

METHODS

Ninety-seven patients who were scheduled for elective PCI were randomized either for naproxen sodium (500 mg bid) (n:39, 75% male, 59+/-10 years) or control (n:58, 76% male, 60+/-10 years). All patients were troponin negative before the procedure. Blood samples for CRP, Troponin I and CK-MB were collected at baseline and after the procedure.

RESULTS

The characteristics were similar between the two groups. After coronary stenting, the rise in CRP levels was significantly higher in controls than those treated with naproxen (DeltaCRP=6.4 mg/L in the controls and 0.43 mg/L in the naproxen group, p<0.0001). The incidence of any troponin I elevation or CK-MB elevation above upper limit of normal was not statistically different between groups. During follow up (12+/-2 months), major cardiac adverse events (death, myocardial infarction, and revascularization of target lesion) was similar between groups.

CONCLUSION

Our data show that naproxen pretreatment leads to significant suppression in PCI related CRP elevation. However this improvement in CRP levels was not associated with any significant reduction in post-PCI myonecrosis.

Effect of ischaemic preconditioning on regional release of inflammatory markers

Systemic markers of inflammation may be increased in patients after percutaneous coronary intervention. In the present study, we evaluated whether IP (ischaemic preconditioning) attenuated inflammation by activating KATP (ATP-sensitive potassium) channels in patients undergoing coronary angioplasty. Patients (n=36) undergoing angioplasty of a major left coronary artery were allocated randomly to one of four groups: a control group, a group receiving nicorandil (an agonist of KATP channels), an IP group or an IP group pretreated with glibenclamide (an antagonist of KATP channels). To measure the release of sCD40L, P-selectin and myeloperoxidase from the ischaemic region, blood samples were drawn simultaneously from the ascending aorta and the great cardiac vein before and 15 min after coronary angioplasty. At 15 min after angioplasty, a significant increase in sCD40L and P-selectin levels in the great cardiac vein in the control group was observed. IP- and nicorandil-treated patients did not show a significant change in sCD40L and P-selectin levels in response to angioplasty. However, the IP-induced attenuation of sCD40L and P-selectin release was abolished by administering glibenclamide. The change in myeloperoxidase levels mirrored those of sCD40L and P-selectin. The levels of inflammatory markers in the aorta remained stable throughout the study. Patients undergoing angioplasty had increased sCD40L and P-selectin levels in the ischaemic region. In conclusion, IP abolished angioplasty-induced myeloperoxidase release by preventing activated platelet-induced P-selectin release via a KATP-channel-initiated pathway. Therefore, in addition to its primary effect on cardioprotection, IP may also provide beneficial anti-inflammatory effects on the interaction between platelets and neutrophils.

Altered trafficking of CD8+ memory T cells after implantation of rapamycin-eluting stents in patients with coronary artery disease

Aim of this study was to investigate the effects of implantation of different coronary drug-eluting stents on trafficking of central (T(CM)) or effector (T(EM)) memory T cells in the coronary sinus of patients with coronary artery disease (CAD) undergoing percutaneous coronary revascularization. Thirty-two patients presenting with stable coronary disease and angiographically proven stenosis of left descending coronary artery were randomly assigned to treatment with rapamycin-eluting, paclitaxel-eluting or bare metal stents. Heparinized blood samples were obtained from the coronary sinus either before or 20 min after stent implantation. Mononuclear cells were stained with mAbs specific for CD3, CD4, CD8, CD45R0, and CD27 molecules. Analysis of surface phenotype was performed by four-color flow cytometry and data on both CD4+ and CD8+ T(CM) and T(EM) cells were expressed either as absolute cell numbers/microL of blood or as percentages relative to the corresponding total memory T cell populations in the individual patients. We found that the number of CD8+ T(EM), as defined by CD3+CD45R0+CD8+CD27- phenotype, was significantly reduced in patients receiving a rapamycin-eluting stent as compared with basal values. Conversely, the number of CD8+ T(CM) (CD3+CD45R0+CD8+CD27+) was increased in the same treatment group after the revascularization procedure. No changes in the absolute number of CD4+ and CD8+ total (T(CM) plus T(EM)) memory T cells before and after the procedure were observed. These findings suggest that rapamycin eluted from medicated coronary stents rapidly induce a redistribution of memory CD8+ T lymphocyte subsets, with a significant decrease of T(EM) and a corresponding increase of T(CM) increase circulating within the coronary sinus. This anti-inflammatory effect could partially explain the reduction of coronary in-stent restenosis rate associated with the clinical use of this type of device.

Soluble CD40 ligand is an early initiator of inflammation after coronary intervention

BACKGROUND

This prospective study evaluated the early increase in markers of inflammation after coronary stenting, and the predictors of early rise. Elevation of markers of inflammation after percutaneous coronary intervention correlates with an increased risk of adverse events. The role of soluble CD40 ligand (sCD40L) as a potential initiator of inflammation after stenting has not been described.

METHODS

Seventy-five patients were treated with heparin alone (n=25), or randomized to adjuvant treatment with eptifibatide (n=26) or abciximab (n=24) during stenting. Systemic blood was obtained before coronary stenting and at 10 min after stenting. C-reactive protein (CRP), interleukin (IL)-6, IL-1 receptor antagonist and sCD40L were determined by enzyme liberated immunosorbent assay.

RESULTS

sCD40L exhibited the greatest relative rise (35%, P=0.01 compared to concentrations before intervention) in the first 10 min after stenting. In a logistic regression model, an early increase in the concentration of sCD40L was predicted by baseline laboratory values (white blood count and sCD40L level before stenting) and procedural characteristics (number of stents and glycoprotein IIb-IIIa inhibitor assignment).

CONCLUSIONS

In conclusion, a systemic inflammatory response is detectable 10 min after coronary stent placement. The early increase in sCD40L suggests a possible role for this marker in the initiation of inflammation after coronary stenting.

Expression of activation molecules in neutrophils, monocytes and lymphocytes from patients with unstable angina treated with stent implantation

Coronary angioplasty is known to mediate an inflammatory response. Recently, we have characterized the transient systemic inflammatory response after coronary stent implantation in patients with unstable angina by measuring different soluble protein markers. In the present study we have characterized the expression of various cellular activation markers in neutrophils, monocytes and lymphocytes from the same group of patients. Peripheral blood samples were taken before and 24 h, 48 h and 7 days after successful coronary stenting in 58 patients. Cell surface markers (CD11b/CD18 and CD38) were analyzed by flow cytometry to determine the activation of neutrophils, monocytes and T lymphocytes. We found that coronary angioplasty with stent implantation produces an increase in the cell surface expression of CD11b/CD18 in neutrophils and CD38 in monocytes, following a similar time-course with a peak after 24 h, returning to basal levels after 48 h and a second peak after 7 days. However, T lymphocytes were not found to be activated. These results suggest that coronary stent implantation induces a different pattern inducing soluble and cellular inflammation markers, and therefore, they should be taken into account in patients undergoing stent implantation to study clinical correlations.

The role of T-lymphocyte subpopulations in acute myocardial infarction

T lymphocytes have the potential to affect atherosclerosis at different stages of the process. They play an active role in acute myocardial infarction (AMI) and myocardial damage, and may affect the clinical outcome of patients with coronary artery disease. CD40 ligand expression on T lymphocytes promotes the expression of matrix-degrading enzymes in vascular smooth muscle cells and may thus establish a new pathway of immune-mediated destabilization of the human atheroma. The major class of T lymphocytes present in atherosclerotic lesions is CD4+. CD4+ cells differentiate into Th1 and Th2 lineage in response to the local milieu of cytokines. Much of the emphasis in atherosclerosis research is focused on the role of Th1 type responses.

[Late T-lymphocyte and monocyte activation in coronary restenosis. Evidence for a persistent inflammatory/immune mechanism?]

AIMS

This study was made to determine if restenosis after percutaneous coronary angioplasty is associated with acute or chronic inflammatory/immunologic activity, and explored possible relationships with latent infection.

PATIENTS AND METHOD

Forty-six consecutive patients underwent elective PTCA and 6 months of angiographic follow-up. Peripheral venous blood samples were obtained at baseline, 24-48 h, and 4-6 months post-intervention. Flow-cytometric methods were used to measure early and late circulating leukocyte activation status. Il-6 and TNF-alpha cytokines, and Il-2 soluble receptor concentrations were determined in all plasma samples. Chlamydia pneumoniae and Cytomegalovirus antibody assays were performed to detect infectious disease.

RESULTS

Angiographic coronary stenosis developed in 27 out of 46 patients. At 6 months of follow-up, these patients showed a significant increase in circulating cytotoxic T-lymphocytes CD3+/CD56+ (18.8 7.1 vs 6.12 2.7%; p = 0.005) and activated monocytes (CD11b: 1,383 624 vs 990 484 MFI, p = 0.025; CD64: 76.0 28.7 vs 56.7 21.8 MFI; p = 0.014), with no apparent relation to increased cytokines or latent infectious disease.

CONCLUSIONS

Restenosis appears to be associated to inflammatory and immunological activity that persists 6 months after coronary intervention. No relationship was found with the infections studied. The presence of inflammatory activity 4-6 months after PTCA suggess that pharmacological therapeutic interventions to prevent restenosis should be maintained for months.

Interleukins in atherosclerosis: molecular pathways and therapeutic potential

Interleukins are considered to be key players in the chronic vascular inflammatory response that is typical of atherosclerosis. Thus, the expression of proinflammatory interleukins and their receptors has been demonstrated in atheromatous tissue, and the serum levels of several of these cytokines have been found to be positively correlated with (coronary) arterial disease and its sequelae. In vitro studies have confirmed the involvement of various interleukins in pro-atherogenic processes, such as the up-regulation of adhesion molecules on endothelial cells, the activation of macrophages, and smooth muscle cell proliferation. Furthermore, studies in mice deficient or transgenic for specific interleukins have demonstrated that, whereas some interleukins are indeed intrinsically pro-atherogenic, others may have anti-atherogenic qualities. As the roles of individual interleukins in atherosclerosis are being uncovered, novel anti-atherogenic therapies, aimed at the modulation of interleukin function, are being explored. Several approaches have produced promising results in this respect, including the transfer of anti-inflammatory interleukins and the administration of decoys and antibodies directed against proinflammatory interleukins. The chronic nature of the disease and the generally pleiotropic effects of interleukins, however, will demand high specificity of action and/or effective targeting to prevent the emergence of adverse side effects with such treatments. This may prove to be the real challenge for the development of interleukin-based anti-atherosclerotic therapies, once the mediators and their targets have been delineated.

Inflammation and immune system response against unstable angina and its relationship with coronary angiographic findings

The aim of this study was to assess the relations between inflammation, immune response, and coronary angiographic findings in patients with unstable angina pectoris (UAP). Recent studies suggest a role for inflammation in the pathophysiology of UAP. Although activation of neutrophils, monocytes and lymphocytes has been shown in UAP, no studies have correlated the activation findings with clinical and angiographic features of patients with UAP. Seventy-three patients undergoing coronary angiography were classified according to their ischaemic syndrome, stable angina pectoris (SAP) (n = 25) and UAP (n = 48). Patients with UAP were classified using the Braunwald classification; UAP class I (n = 15), UAP class II (n = 15), and UAP class III (n = 18). Patients with UAP were also classified into a progression to myocardial infarction (MI (+)) group (n = 15) and a non-progression to myocardial infarction (MI(-)) group (n = 33). Venous blood samples were taken from all patients. Cell surface receptors (CD4, CD8, CD3, CD14, CD45, CD56+16, and HLA-DR) were detected by flow cytometry using monoclonal antibodies tagged with fluorescent markers and serum levels of C-reactive protein (CRP) were measured. The serum levels of CRP and the percentages of HLA-DR, CD14, and CD16+56 were higher in UAP than SAP. The serum levels of CRP and percentages of HLA-DR, CD14, and CD16+56 were higher in UAP class II than UAP class I. The serum levels of CRP and percentages of HLA-DR, CD14, and CD16+56 were higher in UAP class III than UAP class II and UAP class I. The serum levels of CRP and percentages of CD16+56 were higher in the MI(+) group than the MI(-) group. The CRP levels in serum and the percentages of cell surface antigens had no correlation with extent of coronary artery disease (no differences among one, two or three vessels) but Type C lesion had significantly higher percentages of HLA-DR, CD14, CD16+56 and the serum levels of CRP than Type A and Type B lesions. This investigation shows that inflammatory and immunologial components may be detectable in UAP and were correlated with the clinical severity, progression to myocardial infarction, and lesion morphology, but were not correlated with the extent of coronary artery disease.

Carbon coating of stents has no effect on inflammatory response to primary stent deployment

The aim of this study was to investigate the effects of stent carbon coating on inflammatory response. The authors serially measured plasma concentrations of C-reactive protein (CRP), fibrinogen, and several cytokines (tumor necrosis factor, interleukin [IL]-1-beta, IL-6, and IL-8) in patients with single-vessel coronary stenosis who underwent primary stent implantation. None of the subjects had inflammatory or infectious disease at the time of the procedure. Forty-six patients (38 males; mean age 55 +/-9 years) were studied. Blood samples were collected before and at 2, 4, 6, 24, and 48 hours after stent implantation. Patients were randomly assigned 1 of 2 different stent types, an uncoated MAC (AMG Raesfeld-Erle, Germany) (UC-MAC) or a carbon-coated MAC (CC-MAC) stent. Implantations were performed without predilatation, and stents were deployed at a maximum pressure of 6 atmospheres for 90 seconds. Of the 46 patients, 14 had stable, 27 had unstable, and 5 had atypical angina. According to ACC/AHA classification, 35 lesions (76.1%) were type A, 10 (21.7%) were type B, and 1 (2.2%) was type C. Single stenosis of 28 left anterior descending, 12 circumflex, and 6 right coronary arteries were treated. Serum IL-6 increased in both the UC-MAC and CC-MAC groups, with concentrations significantly elevated above baseline at 6 hours, and then decreasing after 24 hours (baseline, 6-hour, and 24-hour values = 3.1 +/-2.3, 5.7 +/-3.8, and 6.3 +/-4.6 pg/mL, respectively, in UC-MAC; 3.7 +/-2.6, 6.2 +/-6.0, and 4.6 +/-3.7 pg/mL, respectively, in CC-MAC [p=0.002]). Plasma fibrinogen, CRP, and leukocyte concentrations also increased in both groups over the 24 hours (p < 0.05). The elevations of IL-6, CRP, and fibrinogen were similar in the 2 groups. The percent increases in IL-6, fibrinogen, and CRP were not associated with stent length, size, or clinical presentation (all p > 0.05). The results showed that stent implantation increases plasma IL-6, fibrinogen, and CRP concentrations, but carbon coating of the stent does not seem to affect this inflammatory response.

Interplay of antibody and T cell responses in acute myocardial infarction

This study sought to investigate the interplay between antibody and T cell responses triggered by an acute myocardial infarction (MI) and their possible role in the progress of this disease. Serum samples were collected from two groups of patients, group A (n = 26) within the first week of MI, and group B (n = 28) at 2 weeks and 2 months after MI. Patients in group A were older and had higher prevalence of hypertension and previous attack of MI than patients in group B. The levels of anti-myosin immunoglobulin M and immunoglobulin G antibodies in the serum samples from group A were significantly higher than those in normal control subjects. In group B, the levels of both antibodies were lower than those in group A but remained significantly higher than those in normal control subjects at both 2 weeks and 2 months. The levels of intercellular adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (sVCAM-1) in the serum samples from group A patients were significantly higher than those in normal control subjects. At 2 weeks after MI (group B), only the level of sVCAM-1, but not that of sICAM-1, was significantly higher than that in normal control subjects, and there were no significant changes in the levels of these two molecules from 2 weeks to 2 months after MI. We conclude that the higher levels of anti-myosin antibodies and adhesion molecules in group A patients as compared with group B patients may be due to higher or more frequent exposures of their immune systems to heart antigens. Furthermore, the immunoglobulin M antibody response during the first week of MI had an inverse relationship with the level of interleukin-2R (sIL-2R), which suggested a possible suppressive or regulatory role of this antibody on the cellular immune response during this time.

T lymphocyte activation and restenosis after percutaneous transluminal coronary angioplasty

We investigated the relation between the activation of T lymphocytes and the occurrence of restenosis after percutaneous transluminal coronary angioplasty (PTCA) in 10 stable angina patients. Recent studies have suggested that PTCA causes an inflammatory response, which may affect restenosis after angioplasty. Soluble interleukin-2 receptor (sIL-2R) is a useful marker to evaluate the activation of T lymphocytes. sIL-2R was measured before and 2 h after successful PTCA, and 3-month follow-up coronary angiography was done to observe restenosis. Four of 10 patients showed restenosis. The restenosis group of 4 patients had a higher level of sIL-2R after PTCA than the no-restenosis group of 6 patients (495 vs. 274 U/ml, p < 0.01). This study suggests that sIL-2R may offer prognostic information after elective PTCA and identify a subgroup of patients at high risk for clinical restenosis in a few months.

Chemokine expression in coronary circulation after coronary angioplasty as a prognostic factor for restenosis

Recent studies have clarified the significance of chemokines in cardiovascular diseases, such as development of atherosclerosis, atheromatous plaque rupture and restenosis after coronary angioplasty. We investigated changes in chemokine expression in the coronary circulation induced by percutaneous transluminal coronary angioplasty (PTCA) and their clinical significance. We examined 40 patients with angina pectoris who underwent elective PTCA for isolated stenotic lesions of the left coronary artery. Eight patients received PTCA only, 14 percutaneous transluminal rotational atherectomy and 18 stent implantation. Venous blood samples were obtained from the coronary sinus before, and immediately after as well as 4 and 24 h after PTCA. Plasma levels of interleukin (IL)-8, macrophage-colony stimulating factor (M-CSF) and monocyte chemoattractant protein-1 (MCP)-1 were measured by enzyme-linked immunosorbent assay. Plasma levels of M-CSF in the coronary sinus blood showed significant increases 4 and 24 h after PTCA. On the other hand, plasma MCP-1 levels did not change significantly during a 24-h observation period after PTCA. Immunoreactive IL-8 was not detected in any patients before or after PTCA. A significant positive correlation was found between plasma M-CSF levels 24 h after PTCA and late loss index 6 months after the procedure. Plasma levels of M-CSF 24 h after PTCA were significantly higher in patients with than in those without late restenosis. PTCA induced increases in plasma levels of M-CSF in the coronary circulation. Increased M-CSF expression may be involved in neointima formation at injured vessels through activation of mononuclear phagocytes.

Interleukin 6 expression in coronary circulation after coronary angioplasty as a risk factor for restenosis

OBJECTIVE

To investigate changes in cytokine expression in the coronary circulation induced by percutaneous transluminal coronary angioplasty (PTCA).

METHODS

The study involved 32 patients with ischaemic heart disease who underwent elective PTCA for isolated stenotic lesions of the left coronary artery. Ten patients had plain old balloon angioplasty, 10 had percutaneous transluminal rotational atherectomy, and 12 had stent implantation. Blood samples were drawn from the coronary sinus before and immediately after PTCA. Plasma concentrations of interleukin 6 (IL-6), platelet derived growth factor (PDGF), monocyte chemoattractant protein 1 (MCP-1), and macrophage coronary stimulating factor (M-CSF) were measured. The patients were scheduled for follow up angiography six months after PTCA. Late loss index was calculated using quantitative coronary angiography.

RESULTS

IL-6 concentrations in coronary sinus blood increased immediately after PTCA (p < 0.001), but there was no change in PDGF, MCP-1, or M-CSF. There was a positive correlation between changes in IL-6 concentrations immediately after PTCA and late loss index six months after PTCA (r = 0.73, p < 0.001). IL-6 concentrations in coronary sinus blood were higher in patients with late restenosis than in those without restenosis (p < 0.001).

CONCLUSIONS

PTCA induces IL-6 production in the coronary circulation. This may induce subsequent inflammatory responses in injured vessels and play an important role in late restenosis after PTCA.

Circulating levels of IL-1beta, a prothrombotic cytokine, are elevated in unstable angina versus stable angina

BACKGROUND

Multiple studies support a role for inflammation in the pathogenesis of coronary atherosclerosis and unstable cardiac syndromes. However, of the known proinflammatory cytokines, only elevated plasma levels of interleukin-6 have been linked to unstable angina. We sought to examine the plasma levels of other major proinflammatory cytokines in similar clinical settings and to determine the extent of the relationship between inflammation and unstable coronary syndromes by measuring the levels of various proinflammatory cytokines in patients with stable and unstable angina.

METHODS

We measured plasma levels of interleukin-1 beta (IL-1beta), tumor necrosis factor alpha (TNF-alpha), and interleukin 6 (IL-6) in 97 patients: 67 with stable angina, 24 with unstable angina, and 15 healthy controls.

RESULTS

Mean levels of IL-1beta were significantly higher in patients with unstable angina as compared to patients with stable angina (p =.009). Levels of IL-6 were significantly higher than control patients for both stable angina and unstable angina patients (p =.031 and.006, respectively). No significant differences were found in the levels of TNF-alpha.

CONCLUSIONS

Our results suggest that both IL-1beta and IL-6 contribute to the pathogenesis of unstable angina, and that the profile of circulating plasma levels of proinflammatory cytokines differs in unstable angina from that in stable angina. Abbreviated Abstract. Multiple studies support a role for inflammation in the pathogenesis of coronary atherosclerosis and unstable cardiac syndromes. We measured plasma levels of interleukin-1 beta (IL-1beta), tumor necrosis factor alpha (TNF-alpha), and interleukin 6 (IL-6) in patients with stable and unstable coronary syndromes. Levels of IL-1beta and IL-6 were found to be elevated in patients with unstable coronary syndromes. No significant differences were found in the levels of TNF-alpha. Our results suggest that both IL-1beta and IL-6 contribute to the pathogenesis of unstable angina.

Plasma Markers of Procoagulant Activity Among Individuals with Coronary Artery Disease

Background: There is compelling evidence that coronary atherosclerosis represents a chronic active process characterized by inflammation, impaired fibrinolysis, intermittent plaque rupture, and luminal thrombosis. Identifying readily measurable plasma markers of procoagulant activity may have an important role in both tracking and understanding the natural history, as well as in defining the ideal treatment, of patients with coronary artery disease. Methods/Results: A total of 30 men and women with suspected coronary artery disease who underwent outpatient cardiac catheterization were sampled for evidence of thrombin generation and fibrin formation in plasma. Compared with healthy controls, patients had significantly increased concentrations of fibrinopeptide A (18.8 +/- 10.8 ng/ml vs. 2.5 +/- 2.3, p < 0.001), thrombin-antithrombin complexes (8.13 +/- 4.56 ng/ml vs. 3.4 +/- 3.0, p < 0.001), and prothrombin activation fragment 1.2 (0.15 +/- 0.09 ng/ml vs. 0.12 +/- 0.19, p = 0.01). There was a statistically insignificant trend toward increased thrombin-antithrombin complex concentrations in patients with hypercholesterolemia (p = 0.10). Patients with angiographically defined coronary artery disease involving two or more vessels were found to have heightened thrombin generation and fibrin formation compared with those with single vessel disease. Conclusions: Patients with atherosclerotic coronary artery disease exhibit evidence of heightened procoagulant activity, including thrombin generation and fibrin formation. This observation, coupled with those derived from other recent studies, support the hypothesis that coronary atherosclerosis represents a chronic active process typified by vessel wall inflammation and recurrent thrombosis. Future efforts in disease prevention and treatment must consider these fundamental pathobiologic properties.

Lymphocyte activation in angina pectoris

To determine the role of immune responses in the etiology of coronary angioplasty, the distribution of blood lymphocytes and levels of soluble immune factors in sera of patients with primary unstable angina were determined at pre and post coronary angioplasty. Our data showed (1) an increase in the numbers of lymphocytes bearing lymphocyte activating gene-3 (LAG-3) and CD40 in the blood and (2) an increase in levels of sIL2-R and sVCAM-1 in the sera of patients with unstable angina, compared with normal subjects. In contrast, there were no changes in these values in blood or sera of patients shortly after coronary angioplasty. However, levels of sCD8 in the sera of patients, which were similar to those of normal subjects, significantly increased post coronary angioplasty. These results indicate that peripheral blood lymphocytes of patients with unstable angina are immunologically activated and are producing soluble factors which may allow their interaction with endothelial cells in areas of inflammation. This may play a role in antigen presentation and T-B cell interactions which can lead to potentiation of heart disease.

Plasma levels of interleukin 2, 6, 10 and phenotypic characterization of circulating T lymphocytes in ischemic heart disease

The purpose of this study was to assess lymphocyte receptors expression in patients with ischemic heart diseases, as well as to measure the plasma levels of interleukin (IL) 2, 6 and 10. T Lymphocytes are found in large numbers in human atherosclerotic plaques, indicating that immune and inflammatory mechanisms are important factors in the pathogenesis of atherosclerosis. Recent data have also implicated T lymphocytes in the pathogenetic mechanism of unstable angina and ischemic heart disease. Three groups of patients were studied: 42 with an acute ischemic syndrome (AIS), 36 with stable angina (SA) and 39 healthy controls. To characterize lymphocyte phenotype, flow cytometry was performed in whole-blood samples. IL-2, IL-6 and IL-10 were measured using the ELISA method. Double fluorescence evaluation showed an increase in CD8+/CD11b+ cells (cytotoxic T lymphocytes) and in CD11b+/CD16+CD56+ cells (NK lymphocytes) in the AIS group and in SA group as compared to the control group (P < 0.05 and P < 0.001, respectively). IL-2 was increased in the AIS and SA groups compared to the control group (AIS 4.5 +/- 0.5 pg/ml; SA 6.3 +/- 0.6 pg/ml; controls 2.4 +/- 0.8 pg/ml, P < 0.05), whereas IL-6 was higher in the AIS group than in the other two groups (AIS 10.8 +/- 1.8 pg/ml; SA 1.8 +/- 0.8 pg/ml; controls 1.2 +/- 0.6 pg/ml, P < 0.0001). These data show that patients with ischemic heart disease have an increase in circulating cytotoxic T lymphocytes and in IL-2 plasma levels, irrespective of their clinical presentation, compared to normal control subjects, whereas IL-6 is elevated only in patients with AIS.

Immune system activation follows inflammation in unstable angina: pathogenetic implications

OBJECTIVES

The aim of this study was to assess the relations between inflammation, specific immune response and clinical course in unstable angina (UA).

BACKGROUND

Several studies suggest that either inflammation and/or T-cell activation might have a pathogenetic role in UA, but neither their potential reciprocal connection nor their relation to the clinical course is known.

METHODS

Serum levels of C-reactive protein (CRP) (inflammation), IgG, IgA, IgM, C3, C4 (humoral immunity), IL-2 and the percentage of CD4+, CD8+ and CD3+/DR+ T-cells (cell-mediated immunity) were measured in 35 patients with UA and 35 patients with chronic stable angina (CSA) during a period of 6 months.

RESULTS

The CRP levels and the main specific immune markers (CD4+ and CD3+/DR+ cells, IL-2 and IgM) were higher in unstable than in stable angina. In UA, the serum levels of IgM and IL-2 and the percentage of double positive CD3+/DR+ significantly increased at 7 to 15 days, and returned to baseline at 6 months. The increment of circulating activated T cells (CD3+/ DR+) in UA was inversely related to the admission levels of CRP (r=-0.63, p=0.003) and associated with a better outcome.

CONCLUSIONS

Our data suggest that the inflammatory component systemically detectable in UA may be antigen-related and that the magnitude of the immune response correlates with the clinical outcome of instability.

Autoimmune and inflammatory responses may have an additive effect in postpercutaneous transluminal coronary angioplasty restenosis

Patients who had an increase in their serum amyloid type A level of > 100% in the first 24 hours after percutaneous transluminal coronary angioplasty (PTCA) and also developed a positive antibody result (antinuclear factor or anticardiolipin), had a relative risk of 10.6 for developing restenosis in the first year after PTCA.

Systemic inflammatory responses in acute coronary syndrome: increased activity observed in polymorphonuclear leukocytes but not T lymphocytes

BACKGROUND

Local inflammation within the coronary arteries is involved in the pathogenesis of acute coronary syndrome. However, the contribution of a systemic inflammatory response to the pathogenesis of this syndrome has not been well characterized. Accordingly, we investigated systemic inflammatory responses in patients with acute coronary syndrome.

METHODS

A total of 83 patients with ischemic heart disease (15 with stable exertional angina and 68 with acute coronary syndrome) were studied. The luminol-dependent chemiluminescence (CL) response of polymorphonuclear leukocytes (PMNs), which reflects their ability to generate oxygen species, was used as a marker for PMN activation. Soluble interleukin-2 receptor (sIL-2R) levels were measured to assess T-lymphocyte activation.

RESULTS

CL counts of whole blood from patients with acute coronary syndrome were twice those of patients with stable angina (2.38 +/- 0.22 vs 1.10 +/- 0.17 x 10(6) counts, P < 0.05). A comparison of CL counts between patients with unstable angina and those with acute myocardial infarction revealed no significant differences. T-lymphocyte activity, measured by serum sIL-2R, was significantly lower in patients with acute coronary syndrome than those with stable angina (214.3 +/- 11.5 vs. 358.3 +/- 115.7 U/ml, P < 0.05).

CONCLUSIONS

This investigation shows that there is a systemic increase in PMN activity and a decrease in T-lymphocyte activity in patients with acute coronary syndrome. This contrasts with the pattern of cellular activation seen at sites of local inflammation within atherosclerotic plaques, suggesting that two independent inflammatory processes (local and systemic) may be involved in the pathogenesis of this syndrome.

Interleukin-2 modulates the responsiveness to angiotensin II in cultured vascular smooth muscle cells

Preincubation with interleukin-2 (IL-2), a T cell-derived cytokine, enhanced the increase in intracellular Ca2+ ([Ca2+]i) induced by angiotensin II (AII) in vascular smooth muscle cells (VSMC). IL-2 itself did not affect the basal [Ca2+]i level or the maximal response of [Ca2+]i increase induced by AII. Furthermore, IL-2-induced enhancement was not observed in the absence of extracellular Ca2+, suggesting that IL-2 enhances Ca2+ influx induced by AII. IL-2 also enhanced the stimulation of DNA synthesis induced by AII, although IL-2 alone did not stimulate DNA synthesis. Genistein, an inhibitor of protein tyrosine kinases, significantly inhibited IL-2-induced enhancement of both Ca2+ influx and DNA synthesis induced by AII. A neutralizing antibody against heparin-binding epidermal growth factor-like growth factor (HB-EGF) partially inhibited IL-2-induced enhancement of DNA synthesis induced by AII. These findings suggest that autocrine HB-EGF is partially involved in the mechanism of IL-2-induced enhancement of DNA synthesis. On the other hand IL-2 stimulated both glycosaminoglycan (GAG) and prostacyclin syntheses and enhanced the stimulation of both GAG and prostacyclin syntheses induced by AII. Therefore, IL-2 may play important roles in the pathogenesis of atherosclerosis and vascular disease by modulating the responsiveness to AII in VSMC.

Effects of ultraviolet light in vascular cells in vitro and in intact atherosclerotic explants: potential role of apoptosis in vascular biology

Complex cell-to-cell interactions are known to participate during vascular injury and remodeling, resulting in smooth muscle cell proliferation. Mechanical interventions have yielded little benefit in limiting this process and several site-specific genetic therapies are not yet clinically available. The aim of this study was to delineate the effect of very short wavelength ultraviolet (UVC) light therapy on the viability of macrophage and smooth muscle cells. Vascular cells were both treated in vitro and in intact explanted atherosclerotic aortic segments ex vivo with UVC light. Brief exposure to short wavelength UVC light in the absence of photosensitizers elicited a differential temporal and functional response among treated cells. However, dramatic reduction in both cellular viability and proliferative capacity with eventual cell demise was observed in all UVC-treated cells. Flow cytometry and immunohistochemical analyses revealed the presence of extensive DNA fragmentation, suggestive of apoptosis as a predominant pathway of cell death in these cells exposed to UVC light. We hypothesize that selective induction of apoptosis, in contrast to necrosis, with UVC light may represent a beneficial approach to interdict the complex biologic cascade of messengers that participate in the restenotic response to vascular injury.

The effect of cytotoxic lymphocytes on contraction, action potential and calcium handling in cultured myocardial cells

Cytotoxic T lymphocytes are important in the pathogenesis of several disease states, yet the pathophysiology of the lymphocyte-myocyte interaction is not well known. We have developed in vitro viral and autoimmune models to study the physiological phenomena associated with this interaction. To produce these models, lymphocytes were obtained from adult rats injected either with mengo virus or autologous cardiac myocytes. Cardiac myocytes from neonatal rats were then exposed to these lymphocytes. In both models, reversible physiologic changes in myocytes preceded irreversible cell damage. The physiologic changes included reduced amplitude of myocyte contraction, impairment of relaxation and prolongation of the duration of contraction and action potential. In addition, oscillations were noted in the plateau phase of the action potentials. These physiologic changes were accompanied by an early elevation in the cytosolic free calcium concentration, a late elevation in the total exchangeable calcium pool, and attenuation of the [Ca2+]i transient signals. Verapamil inhibited the late elevation in the total exchangeable calcium pool, but failed to inhibit the early elevation in the cytosolic free calcium concentration. These phenomena may explain transient cardiac functional abnormalities that may appear during myocarditis prior to cell destruction.