Increased serum levels and expression of S100A8/A9 complex in infiltrated neutrophils in atherosclerotic plaque of unstable angina.
BACKGROUND
The S100A8/A9 complex is expressed in a subset of activated neutrophils and macrophages in acute inflammatory lesions associated with various diseases.


OBJECTIVE
To investigate (a) whether serum S100A8/A9 levels are increased in patients with unstable angina (UA); and (b) whether S100A8/A9 expression is upregulated in coronary atherosclerotic plaques of patients with UA.


METHODS
Serum S100A8/A9 levels in 39 patients with stable angina (SA) and 53 patients with UA were measured. In addition, the presence of the S100A8/A9 complex in directional coronary atherectomy specimens was studied immunohistochemically. Cell types which stain positive for S100A8/A9 were identified by immunodouble staining with neutrophils and macrophages.


RESULTS
Mean (SD) serum S100A8/A9 levels were significantly higher in patients with UA than in those with SA (3.25 (3.08) microg/ml vs 0.77 (0.31) microg/ml, p<0.05). In patients with UA, immunodouble staining clearly showed that the S100A8/A9 complex was expressed in infiltrated neutrophils and occasional macrophages. The S100A8/A9-positive area was significantly higher in UA than in SA (mean (SD) 18.3 (14.2)% vs 1.3 (2.4)%, respectively, p<0.001).


CONCLUSIONS
The S100A8/A9 complex may be involved in the inflammatory process of coronary atherosclerotic plaques in patients with UA.
Miyamoto
S
S
Division of Cardiology, Kitano Hospital, Tadukekofukai Medical Research Institute, Osaka, Japan.
Ueda
M
M
Ikemoto
M
M
Naruko
T
T
Itoh
A
A
Tamaki
S
S
Nohara
R
R
Terasaki
F
F
Sasayama
S
S
Fujita
M
M
D000368:Aged; D000787:Angina Pectoris / Q000175:diagnosis; D000789:Angina, Unstable / Q000175:diagnosis / Q000209:etiology / Q000378:metabolism*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D040501:Calgranulin A / Q000097:blood / Q000378:metabolism*; D040502:Calgranulin B / Q000097:blood / Q000378:metabolism*; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000150:complications / Q000175:diagnosis / Q000378:metabolism*; D003937:Diagnosis, Differential; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D020556:Neutrophil Infiltration; D009504:Neutrophils / Q000378:metabolism*
D015415:Biomarkers; D040501:Calgranulin A; D040502:Calgranulin B; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D; D002097:C-Reactive Protein