Assessment of IgG antibodies to oxidized LDL in patients with acute coronary syndrome.

OBJECTIVES: Circulating IgG antibodies to oxidized low-density lipoprotein (anti-oxLDL) have been implicated in the development of atherosclerotic plaques. In this study, we investigated the prognostic value of IgG anti-oxLDL antibodies in patients with acute coronary syndrome (ACS). METHODS: In total 54 patients with ACS and 41 matched healthy controls were involved in this prospective study. Serum IgG anti-oxLDL levels were assessed by ELISA. RESULTS: Higher IgG anti-oxLDL levels were found in patients with ACS versus controls (22.8 ± 23.3 vs. 7.5 ± 5.27 EU/ml, p < 0.0001). IgG anti-oxLDL concentrations were significantly higher in ACS patients with unstable clinical complications (circulatory insufficiency, malignant arrhythmias, recurring ischaemic pain, positive stress-test, need for urgent coronary intervention or sudden cardiac death) versus those without such complications (30.0 vs. 11.7 EU/ml, p < 0.001). Twelve patients (22%) were taking statins. Patients on statins had a significant reduction in clinical complications (33%) versus patients not receiving statin therapy (61%). IgG anti-oxLDL levels were also different in these two groups (11.4 vs. 25.8 EU/ml, respectively; p = 0.03). Serum IgG anti-oxLDL levels correlated with the subsequent development of unstable coronary events. Levels of anti-oxLDL significantly decreased in response to statin therapy, independently of its lipid-lowering effect. CONCLUSIONS: Anti-oxLDL antibodies are involved in ACS. The association of anti-oxLDL with unstable clinical complications may indicate the role of this antibody in plaque destabilization.

Immunological parameters, including CXCL8 (IL-8) characterize cerebro- and cardiovascular events in patients with peripheral artery diseases.

The most commonly occurring atherosclerotic manifestations are peripheral artery diseases (PAD). Immune-mediated processes contribute to the development of atherosclerosis, and affect the diseases outcome. The aim of the present study was to assess various immune-competent cells, cytokines and chemokines in patients with PAD and to evaluate whether the base immunological values reflect the subsequent development of cardio/cerebrovascular symptoms. One hundred sixty patients with PAD were followed-up for 42 months. At the time of enrolment, we determined blood lymphocyte subpopulations, both T-helper (Th)1/Th2-type intracytoplasmic cytokines and soluble cytokines, chemokines. Intracellular cytokines were measured on phorbol-myristate-acetate- and ionomycine- stimulated cells. Lymphocyte subgroups were quantified by flow cytometry, soluble cytokines by ELISA and intracellular cytokine levels were measured by flow cytometry. The ankle-brachial index (ABI), indicator of atherosclerosis, was also evaluated. The clinical results were correlated with the immune-parameters to assess the input of immune-inflammatory events in the propagation of vascular manifestation. CD4(+) T-cell proportions in patients with PAD with cerebro- cardio-vascular manifestations were decreased, which further reduced in patients with fatal outcome. Of circulating chemokines, IL-8 (CXCL-8) was increased in patients with subsequent cerebro- cardio-vascular manifestations, compared to those without the symptoms, and further raised in patients with fatal outcome. The percentage of interferon (IFN)-gamma positive cells showed clear negative correlation with ABI. We conclude that altered peripheral lymphocyte subsets and cytokine/chemokine imbalance play important roles in the proinflammatory cascade and reflect disease severity in patients with PAD.

TH1/TH2 imbalance, measured by circulating and intracytoplasmic inflammatory cytokines--immunological alterations in acute coronary syndrome and stable coronary artery disease.

To describe how peripheral immune-parameters reflect the inflammatory alterations of the atherosclerotic plaques in coronary atherosclerosis. We measured general inflammatory markers C-reactive protein (CRP) and granulocyte activity, lymphocyte subpopulations and their state of activation, evaluated circulating Th1/Th2-type cytokines, and specific intracytoplasmic cytokines. We investigated the association of immune-parameters with disease outcome and mortality. Thirty-three patients with acute coronary syndrome (ACS), 62 with stable coronary artery disease (CAD) and 58 healthy controls were studied. Peripheral blood lymphocyte subgroups were quantified by flow cytometry, soluble cytokines and autoantibodies were assessed using enzyme-linked immunosorbent assay (ELISA), while intracellular cytokine levels were measured by flow cytometry after intracellular staining. We found elevated levels of CRP and granulocyte activity in ACS versus CAD (P < 0.001, P = 0.017, respectively). Natural killer (NK) cell percentages were elevated, while percentage of T cells to the total lymphocyte count was slightly decreased in ACS compared to controls (P < 0.0001, P = 0.012, respectively). Both forms of coronary atherosclerosis showed significantly higher percentages of activated T cells than controls when stained for the activation markers HLA-DR3 and CD69(+) (ACS: P < 0.0001, P = 0.002, CAD: P < 0.0001, P = 0.018, respectively). IL-1, IL-4 and IL-10 proved significantly higher in ACS versus controls (P = 0.036, P = 0.01, P < 0.0001 respectively). Th1 to Th2 ratio shifted towards a Th1 dominance in both diseases. Both general proinflammatory markers and activated T cells signify CAD. The orchestrated proinflammatory cascade eventually leads to the development of the disease.

Quantitative assessment of blood flow reserve using 99mTc-HMPAO in carotid stenosis.

Dynamic imaging of the inflow of technetium-99m hexamethylpropylene amine oxime (HMPAO) to the brain has been proved to allow estimation of the hemispherical cerebral blood flow (CBF) using the Patlak plot. In this study, we compared the hemispherical CBF (in ml/min/100 g) of different patient groups. A total of 25 patients (comprising 13 with migraine and 12 scheduled for endarterectomy owing to angiographically confirmed severe stenosis of the internal carotid artery on at least one side) underwent baseline and acetazolamide 99mTc-HMPAO brain perfusion studies. In addition, acetazolamide 99mTc-HMPAO studies were performed in 12 healthy subjects (no baseline study was performed for ethical reasons.) Dynamic studies were acquired by means of a dual-detector gamma camera with a large field of view (HELIX, Elscint). Special difference images were created to make definition of the aortic arch and hemispherical brain regions easier and more reproducible. A semi-automatic method was developed to determine the transit time from the aorta to the brain, making the generation of the Patlak plot even more robust. The baseline CBF values did not significantly depend on the disease (P>0.1), whereas the CBF values obtained after acetazolamide provocation did do so (ANOVA, P<0.001). Patients suffering from migraine showed a significant increase in global CBF values after acetazolamide provocation (paired t test, P<0.05), but we could not find any effect of the provocation in patients awaiting carotid endarterectomy, indicating a lack of cerebrovascular reserve capacity. Comparison of the results of the acetazolamide study in patients and the control group revealed the CBF values to be significantly lower in patients with carotid stenosis (two-sample t-test, P<0.001), but not in those with migraine (P>0.1). In summary, using quantitative analysis of 99mTc-HMPAO brain studies we could objectively compare the CBF of patients suffering from different diseases. Especially the CBF values obtained after acetazolamide provocation permitted effective differentiation of disease states. The quantitative results may be of assistance in therapy planning, e.g. in selection of the correct operative technique.