Interactive role of infection, inflammation and traditional risk factors in atherosclerosis and coronary artery disease

Detection of Chlamydia pneumoniae but not cytomegalovirus in occluded saphenous vein coronary artery bypass grafts

BACKGROUND

A causal relation between atherosclerosis and chronic infection with Chlamydia pneumoniae and/or cytomegalovirus (CMV) has been suggested. Whether the unresolved problem of venous coronary artery bypass graft occlusion is related to infection with C pneumoniae and/or CMV has not been addressed.

METHODS AND RESULTS

Thirty-eight occluded coronary artery vein grafts and 20 native saphenous veins were examined. Detection of C pneumoniae DNA was performed by use of nested polymerase chain reaction (PCR). Homogenisates from the specimen were cultured for identification of viable C pneumoniae. Both conventional PCR and quantitative PCR for detection of CMV DNA were applied. Differential pathological changes (degree of inflammation, smooth muscle cell proliferation [MIB-1]) were determined and correlated to the detection of both microorganisms. C pneumoniae DNA could be detected in 25% of occluded vein grafts. Viable C pneumoniae was recovered from 16% of occluded vein grafts. Except for 1 native saphenous vein, all control vessels were negative for both C pneumoniae detection and culture. All pathological and control specimens were negative for CMV DNA detection. Pathological changes did not correlate with C pneumoniae detection.

CONCLUSIONS

Occluded aorto-coronary venous grafts harbor C pneumoniae but not CMV. The detection of C pneumoniae in occluded vein grafts warrants further investigation.

Aging and cardiovascular disease. Use of subclinical measurements

This article examines the use of subclinical measurements in cardiovascular disease in the elderly. In the past 10 years, the development of new technology to measure subclinical disease has provided the opportunity to evaluate the prevalence of subclinical disease, the risk factors for subclinical disease, and the risk for clinical disease given the presence or absence of subclinical disease.

Intense acute phase response in ischemic patients

The aim of this study was to estimate the qualitative and quantitative changes of acute phase proteins in patients suffering from coronary heart disease. The study was carried out on 74 patients and 12 healthy volunteers. The patients were divided into three groups as follows: patients with myocardial infarction (n=37), Group I--without heart failure, Group II--with heart failure (II-III NYHA), Group III--patients with unstable angina pectoris (n=35); controls-healthy volunteers (n=12). The immunological measurements were performed at the beginning of hospitalisation (point 0), after 4, 8, 12 and 72 h, and after 6, 9 and 12 days of hospitalisation. The concentrations of C-reactive protein (CRP), alpha1-acid glycoprotein (AGP) and alpha1-antichymotrypsin (ACT) were measured using rocket immunoelectrophoresis according to Laurell. Glycosylation profiles of AGP and ACT were determined using crossed affinity immunoelectrophoresis with Con A as ligand according to Bøg-Hansen. Between Groups I and II statistically significant differences were observed for all investigated parameters. Highest concentration values were observed for Groups II and III; for Group II they appeared earlier than for Group III. The maximal values for reactivity coefficients (AGP-RC and ACT-RC) were observed earlier than the respective maximal values of concentrations. Continuous activation occurring in unstable angina leads to a more rapid increase in the concentrations of acute phase proteins and more marked alterations in their glycosylation profiles. In a way these patients seem to be 'primed' with constant stimulation, so that they respond dramatically to the stimulus of ischemia.

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.